ENVIRONMENTAL CONCEPTS AND MANAGMENT
Environment is not a single subject. It is an integration of several subjects that include both Science and Social Studies. To understand all the different aspects of our environment we need to understand biology, chemistry, physics, geography, resource management, economics and population issues. Thus the scope of environmental studies is extremely wide and covers some aspects of nearly every major discipline. We live in a world in which natural resources are limited. Water, air, soil, minerals, oil, the products we get from forests, grasslands, oceans and from agriculture and livestock, are all a part of our life support systems. Without them, life itself would be impossible. As we keep increasing in numbers and the quantity of resources each of us uses also increases, the earth's resource base must inevitably shrink.
The earth cannot be expected to sustain this expanding level of utilization of resources. Added to this is misuse of resources. We waste or pollute large amounts of nature's clean water; we create more and more material like plastic that we discard after a single use; and we waste colossal amounts of food, which is discarded as garbage. Manufacturing processes create solid waste byproducts that are discarded, as well as chemicals that flow out as liquid waste and pollute
water, and gases that pollute the air. Increasing amounts of waste cannot be managed by natural processes. These accumulate in our environment, leading to a variety of diseases and other adverse environmental impacts now seriously affecting all our lives. Air pollution leads to
Respiratory diseases, water pollution to gastro-intestinal diseases, and many pollutants are known to cause cancer. Improving this situation will only happen if each of us begins to take actions in our daily lives that will help preserve our environmental resources. We cannot expect Governments alone to manage the safeguarding of the environment, nor can we expect other people to prevent environmental damage. We need to do it ourselves. It is a responsibility that each of us must take on as ones own.
Definition An integrated system of living and non living things interacting with each other and creating a unique biological, chemical and physical environment is known as ecosystem.
An 'Ecosystem' is a region with a specific and recognizable landscape hence we can have different forms of ecosystems like Forest Ecosystem, Grassland Ecosystem, Desert Ecosystem, Wetland or Coastal Ecosystem The nature of ecosystem is based on various factors like Geographical features such as hills, mountains, plains, rivers, lakes, coastal areas or islands. Climatic conditions such as the amount of sunlight, the temperature and the rainfall in the region.
Compositions of soil characteristics form its non-living (abiotic) component. These three features create conditions that support a community of plants and animals that evolution has produced to live in these specific conditions. The living part of the ecosystem is referred to as its biotic component.
Ecosystems are divided into terrestrial or land based ecosystems, and aquatic ecosystems in water. These form the two major habitat condition for the Earth's living organisms. All the living organisms in an area live in communities of plants and animals. They interact with their non-living environment and with each other at different points in time for a large number of reasons. Life can exist only in a small proportion of the earth's land, water and its atmosphere.
Some definitions pertaining to the ecosystem
Population:- The total number or group of organisms of the same species living in a given area.
Food chain: - The transfer of food ( nutrition and energy) from one source to another through a series of different organisms is known as food chain.e.g the plant synthesize the energy from sun, herbivores animals consume the plant and grass for their energy requirements, these animals are then eaten by carnivores or omnivores animals. Finally when all these animals die they are eaten by the scavengers.
Herbivores animals: - All living organism which are dependent only on plants or grass for their energy/food requirements. E.g. deer, sheep, etc.
Carnivores: - Organism like tiger and lion which are dependent only on other animals for their energy/ food requirements.
Omnivores:- Organisms like bear, monkey and human which can fulfill their requirements of energy/ food from any the source i.e plants or animals is known as omnivores.
Scavenger:- Organisms like jackal, which fulfill their energy requirement from the decaying flesh of the other animal.
Habitat: A place where living organisms live in their natural surroundings. E.g marine, terrestrial, forest etc.
Carrying capacity:- The maximum number of a given species of any organisms which the habitat can sustain, beyond which the ecosystem will not be able to maintain the equilibrium.
Community:- the integration of all the species living in a given area or habitat.
Ecosystem structure and major ecosystems of the world,
Based on the structure of the ecosystem and its functions we can divide the earth in an integration of different ecosystems, which is done on the basis of similar structure and nature with the consideration of the biodiversity of that place. Ecology is distinguishable according to the geographical, climatic and biological factors, Based on the above we can divide the world ecosystem in following manner
Mountains ecosystem: - Mountain ecosystems are found throughout the world, from the equator almost to the poles, occupying approximately one-fifth of its land surface. Common characteristics include high relative relief and steep slopes, each mountain ecology is remarkably diverse found on every continent, and at every altitude, from close to sea level to the highest place on the earth - the summit of Mount Everest on the border between Nepal and the Tibet Autonomous Region of China.
An estimated one-tenth of the human population derives their life-support directly from mountains. Mountains are important not only for their inhabitants, but for millions of people living in lowlands. From the mountains many rivers originiate which are the essential requirements for our development. Mountains play a critical role in the water cycle by capturing moisture from air masses; when this precipitation falls as snow, it is stored until it melts in the spring and summer, providing essential water for settlements, agriculture and industries downstream - often during the period of lowest rainfall. Even in dry regions, over 90 percent of river flow comes from the mountains. Even in temperate Europe, the Alps that occupy only 11 percent of the area of the Rhine river basin supplies 31 percent of the annual flow - and in summer more than 50 percent.
Mountain water can also be used as a source of hydroelectric power, by constructing a dam the potential energy of water can be used to move the turbines to generate electricity.
Even In rural Nepal there are an estimated 25 000 water wheels and over 900 micro-hydropower turbines - a more recent technology - that provide a critical source of energy, mainly for agro processing . river water flowing from the mountains act as sources of renewable energy which is a vital catalyst for economic development in areas that are at the far ends of the distribution networks for the fossil fuels on which most urban dwellers depend.
In developing countries, wood fuel is the predominant energy source in mountain settlements, but it is also essential - whether as wood or charcoal - to many people living in urban centers in the lowlands and on the plains. For example, any visitor to Marrakech can observe the large piles of fuel wood stacked outside communal bakeries, to which every household brings its daily bread to be baked; the wood comes from the forests in the Atlas Mountains.
CENTRES OF BIODIVERSITY
Mountain ecosystems are globally important as centres of biological diversity. The greatest diversity of vascular plant species occurs in mountains: Costa Rica, the tropical eastern Andes, the Atlantic forest of Brazil, the eastern Himalaya-Yunnan region, northern Borneo and Papua New Guinea. Other important centers are found in arid subtropical mountains. Many of these areas with the greatest biological diversity are designated as national parks or other types of protected area. Mountains also a wide variety of animals like the bears, large cats, sheep, etc
Tundra grass lands: tundra is found in extreme high elevations in the Southwest. This type is often only the small summit area above timberline. Tundra is characterized by diverse herbaceous plants, lichens and mosses, and low-growing woody shrubs, all adapted to a brief and often interrupted growing season. tundra grass land can also be found on peaks above 3,500 m. These communities are extensions of the larger and more extensive tundra of the rocky Mountains.
Relatively contiguous alpine communities extend into the Southwest through
the San Juan and Sangre de Cristo Mountains of southern Colorado and
Northern New Mexico. Disjunction patches occur in Arizona, San Francisco and
White Mountains and small marginal alpine grassland on the 3,659 m summit
of Sierra Blanca on the Mescalero Apache Reservation in central New Mexico is
the southernmost alpine community in the US
Climate
The climate of the tundra is characterized by severe subfreezing temperatures, severe physiological drought, and intense isolation. Rain fall is vary but it occurs mostly as winter snow. Growing season is short (60-150 days) and occasionally interrupted by nights of below freezing temperatures. Direct solar radiation and high exposure to winds can cause conditions of severe drought for plants. Snow accumulations can exceed 365.7 cm and may persist year long.
Biodiversity of Tundra
A great variety of plant and animal species are supported by tundra some of the plant varieties include fir, spruce, few shrubs occur in this type although a number of root perennial forbs may have woody or semi-woody bases. Species of willow mingle with sedges to form mat-like communities that hug the ground. Carex, an important component of almost every vascular community above timberline, usually dominates and often forms a grass-like cover; sometimes enough to qualify as an alpine grassland, with tufted hair grass alpine fescue, some bluegrasses and rushes often intermingled with the sedges. Low mat and cushion forbs are common..
Wildlife and habitats
Few mammals live and breed in the tundra. The climate is too severe but still many birds and animal species are supported by it like the Pika, yellow-bellied marmots, and shrews can be found along the border with the sub-alpine zone.
Bighorn sheep, Mountain elk .Birds include White-tailed ptarmigan, water pipit, white-crowned sparrow, and hummingbird. Tundra also provide habitat for the migratory birds like bluebird and killdeer.
Marine and island Islands ecosystem
Marine ecosystems constitute over 70% of earth's surface and forms the largest aquatic system on the planet. The marine ecosystem varies from the productive near shore regions to the barren ocean floor resulting in to a vast system, which is dynamic, magnanimous and diverse. We can classify the marine ecosystem in to :
oceans
estuaries and Salt Marshes
coral reefs and Other Tropical Communities (Mangrove Forests)
coastal areas like Lagoons, Kelp and Seasgrass Beds and Intertidal systems (rocky, sandy, and muddy shores)
Marine ecosystems are home to a host of different species ranging from tiny planktons that comprise the base of the marine food web (i.e., phytoplankton and zooplankton) to large marine mammals like the whales, manatees, and seals. In addition, many fish species reside in marine ecosystems including flounder, scup, sea bass, monkfish, squid, mackerel, butterfish, and spiny dogfish. Birds are also plentiful including shorebirds, gulls, wading birds, and terns. Some marine animals are also endangered including whales, turtles, etc. In summary, many animal species rely on marine ecosystems for both food and shelter from predators.
Marine ecosystems contain several unique qualities that set them apart from other aquatic ecosystems, the key factor being the presence of dissolved compounds in seawater, particularly salts. This total gram weight of dissolved substances (salts) in one kg of seawater is referred to as salinity. In general 85% of the dissolved substances are Sodium (Na) and Chlorine (Cl) in seawater. On average seawater has a salinity of 35 parts per thousand grams (ppt) of water. These dissolved compounds give seawater its distinctive "salty" taste, affect species composition of particular marine habitats, and prevent oceans from freezing during the winter.
Regular changes in factors such as weather, currents, and seasons as well as variations in climate and location will cause salinity levels to vary among different marine ecosystems. In areas such as estauries, tidal marshes, and mangrove forests, tidal and freshwater influences from river and streams makes it necessary for marine organisms to adapt to a wide range of salinity levels. These organisms such as mussels, clams, and barnacles, are called euryhaline (salt tolerant) organisms. Other organisms, in particular finfish, are unable to tolerate such changes in salinity. These organisms are considered to be stenohaline (salt intolerant). These species require more constant levels of salinity, forcing them to either migrate to new areas when fluctuations in salinity levels occur or to seek out areas where salinity change is minimal (e.g., the deep ocean).
Like other aquatic ecosystems, marine ecosystems require nutrients and light to produce food and energy. However, both nutrients and light are limiting factors in marine ecosystem productivity. Like many other aquatic plants, photosynthetic marine organisms (i.e., phytoplankton) rely upon sunlight and chlorophyll a to absorb visible light from the sun as well as nitrogen (N), phosphorus (P), and silicon (Si) to generate food and promote growth and reproduction. However, the amount of light penetrating the ocean surface tends to decrease with increasing water depth, therefore photosynthesis can only take place within a small band near the surface of the water (called the photic zone). In addition, nutrient availability often varies significantly from place to place. For example, in the open ocean, nutrient levels are often very poor causing primary production to be very low. In contrast, near shore waters such as estuaries and marshes are often rich in nutrients, allowing primary production to be very high. In some instances, near shore ecosystems have an excess of nutrients due to runoff and other terrestrial sources. Excess nutrients can cause an over-stimulation of primary production, depleting oxygen levels and causing eutrophic conditions to occur in coastal habitats.
Marine ecosystems are very important in to the overall health of both marine and terrestrial environments. According to the World Resources Center, coastal habitats alone account for approximately 1/3 of all marine biological productivity, and estuarine ecosystems (i.e., salt marshes, sea grasses, mangrove forests) are among the most productive regions on the planet. In addition, other marine ecosystems such as coral reefs, provide food and shelter to the highest levels of marine diversity in the world.
The diversity and productivity of marine ecosystems are also important to human survival and well-being. These habitats provide us with a rich source of food and income, and support species that serve as animal feed, fertilizers for crops, additives in foods (i.e., ice-cream) and cosmetics (i.e., creams and lotions). Areas such as mangroves, reefs, and sea grass beds also provide protection to coastlines by reducing wave action, and helping to prevent erosion, while areas such as salt marshes and estuaries have acted as sediment sinks, filtering runoff from the land. Despite the importance of marine ecosystems, increased human activities such as overfishing, coastal development, pollution, and the introduction of exotic species have caused significant damage and pose a serious threat to marine biodiversity.
A place of land surrounded with water from all side is termed as island. They vary tremendously when it comes to shapes, sizes and climates. Some are tropical and lush, while others are jagged and arid. They also support thousands of unique and unparalleled types of animals, such as the giant tortoises of Galapagos, Madagascar's lemurs, and the humongous Komodo dragons, the largest lizards in the world. Oceanic and continental are two broad categories of islands, regardless of the islands' shape, size or the type of animals that dwell on their surfaces.
Oceanic islands were created from the lava of giant underwater volcanoes. An example of this would be the Hawaiian Islands. Normally these islands are located far from major land masses. Continental islands once were part of a larger land mass and in recent geologic history, have become separated from the mainland because of rising sea levels after massive glaciers melted thousands of years ago or by earthquakes which separated them from the original land mass. An example of a continental island would be California's Channel Islands. These types of islands have an older and more complicated geological history than the oceanic islands.
Tropical rain forests
Area under tropical rainforest covers 10 degrees north or south of the equator. Tropical rainforest are present in different parts of world like asia, australia, africa, south america, central america, mexico and pacific islands.
Also known as, lowland equatorial evergreen rainforest. Minimum normal annual rainfall between 1,750 millimeters (69 in) and 2,000 millimeters (79 in) occurs in this climate region. Mean monthly temperatures exceed 18 °C (64 °F) during all months of the year. Rainforests are home to half of all the living animal and plant species on the planet. Tropical rain forests are called the "world's largest pharmacy" because over one-quarter of modern medicines originate from its plants. The undergrowth in a rainforest is restricted in many areas by the lack of sunlight at ground level.
The rainforests are home to more species or populations than all other biomes added together. 80% of the world's biodiversity are found in tropical rainforests. The leafy tops of tall trees - extending from 50 to 85 meters above the forest floor forms an understory. Organic matter that falls to the forest floor quickly decomposes, and the nutrients are recycled. Rainforests are characterized by high rainfall. This often results in poor soils due to leaching of soluble nutrients. Oxisols, as are the soils of many seasonally flooded forests, which are annually replenished with fertile silt.
Tropical rain forests have been subjected to heavy logging and agricultural clearance throughout the 20th century, and the area covered by rainforests around the world is rapidly shrinking. Rainforests are also often called the "Earth's lungs," however there is no scientific basis for such a claim as tropical rainforests are known to be essentially oxygen neutral, with little or no net oxygen production.
Tall, broad-leaved evergreen trees are the dominant plants, forming a leafy canopy over the forest floor. Taller trees, called emergent, may rise above the canopy. The upper portion of the canopy often supports a rich flora of epiphytes, including orchids, bromeliads, mosses, and lichens, who live attached to the branches of trees. The undergrowth or understory in a rain forest is often restricted by the lack of sunlight at ground level, and generally consists of shade-tolerant shrubs, herbs, ferns, small trees, and large woody vines which climb into the trees to capture sunlight. The relatively sparse under story vegetation makes it possible for people and other animals to walk through the forest. In deciduous and semi-deciduous forests, or forests where the canopy is disturbed for some reason, the ground beneath is soon colonized by a dense tangled growth of vines, shrubs and small trees called jungle.
The temperature ranges from 15 to 50 °C and 125 to 660 cm of rainfall yearly.
The rainforest is divided into five different layers, each with different plants and animals, adapted for life in the particular area. These are: the ground layer, the shrub layer, the under storey layer, the canopy layer and the emergent layer. Only the emergent layer is unique to tropical rainforests, while the others are also found in temperate rainforests.
The emergent layer contains a small number of very large trees which grow above the canopy layer, reaching heights of 45-55 m, although on occasion a few species will grow up to 70 m or 80 m tall. They need to be able to withstand the hot temperatures and strong winds. Eagles, butterflies, bats and certain monkeys inhabit this layer.
Canopy - This is the primary layer of the forest and forms a roof over the two remaining layers. Most canopy trees have smooth, oval leaves that come to a point. It's a maze of leaves and branches. Many animals live in this area since food is abundant. Those animals include: snakes, toucans and tree frogs.
Under canopy - Little sunshine reaches this area so the plants have to grow larger leaves to reach the sunlight. The plants in this area seldom grow to 12 feet. Many animals live here including jaguars, red-eyed tree frogs and leopards. There is a large concentration of insects here.
Shrub layer/forest floor - This layer is very dark. Almost no plants grow in this area, as a result. Since hardly any sun reaches the forest floor things begin to decay quickly. A leaf that might take one year to decompose in a regular climate will disappear in 6 weeks. Giant anteaters live in this layer.
Tropical dry forests
The tropical and subtropical dry broadleaf forest biome, also known as tropical dry forest, is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive several hundred centimeters of rain per year, they have long dry seasons which last several months and vary with geographic location. These seasonal droughts have great impact on all living things in the forest.
Deciduous trees predominate in most of these forests, and during the drought a leafless period occurs, which varies with species type. Because trees lose moisture through their leaves, the shedding of leaves allows trees such as teak and mountain ebony to conserve water during dry periods. The newly bare trees open up the canopy layer, enabling sunlight to reach ground level and facilitate the growth of thick underbrush. Trees on moist sites and those with access to ground water tend to be evergreen. Infertile sites also tend to support evergreen trees. Three tropical dry broadleaf forest eco regions, the East Deccan dry evergreen forests, the Sri Lanka dry-zone dry evergreen forests, and the Southeastern Indochina dry evergreen forests, are characterized by evergreen trees.
Though less biologically diverse than rainforests, tropical dry forests are home to a wide variety of wildlife including monkeys, deer, large cats, parrots, various rodents, and ground dwelling birds. Mammalian biomass tends to be higher in dry forests than in rain forests, especially in Asian and African dry forests. Many of these species display extraordinary adaptations to the difficult climate.
This biome is alternately known as the tropical and subtropical dry forest biome or the tropical and subtropical deciduous forest biome. Locally some of these forests are also called monsoon forests, and they tend to merge into savannas.
Dry forests tend to exist north and south of the equatorial rainforest belt, south or north of the subtropical deserts, generally in two bands, one between 10° and 20°N latitude and the other between 10° and 20°S latitude. The most diverse dry forests in the world occur in southern Mexico and in the Bolivian lowlands. The dry forests of the Pacific Coast of northwestern South America support a wealth of unique species due to their dry climate. The subtropical forests of Maputo land and pondo land in southeastern Africa are diverse and support many endemic species. The dry forests of central India and Indo china are notable for their diverse large vertebrate faunas. Madagascar dry deciduous forests and New Caledonia dry forests are also highly distinctive for a wide range of taxa and at higher taxonomic levels. Trees use underground water during the dry seasons.
Species tend to have wider ranges than moist forest species, although in some regions many species do display highly restricted ranges; most dry forest species are restricted to tropical dry forests, particularly in plants.
Effective conservation of dry broadleaf forests requires the preservation of large and continuous areas of forest. Large natural areas are required to maintain larger predators and other vertebrates, and to buffer sensitive species from hunting pressure. The persistence of riparian forests and water sources is critical for many dry forest species. Large swathes of intact forest are required to allow species to recover from occasional large events, like forest fires.
Dry forests are highly sensitive to excessive burning and deforestation; overgrazing and exotic species can also quickly alter natural communities; restoration is possible but challenging, particularly if degradation has been intense and persistent. Degrading dry broadleaf forests often leaves thorny shrub lands, thickets, or dry grasslands in their place.
Desserts
Dessert ecology is identified by their dry climates resulting from rain-blocking mountain ranges and remoteness from oceanic moisture. Deserts occupy one-fifth of the Earth's land surface and occur in two belts: between 15° and 35° latitude in both the southern and northern hemispheres, the dessert of Sahara is the best example for the dessert ecology. Desert ecology is characterized by dry, alkaline soils, low net production and opportunistic feeding patterns by herbivores and carnivores. Lichens and blue-green algae are significant primary producers in the desert. The detrital food chain is less important in desert ecology than in the ecology of other regions. The rainfall in dessert is less than even few mm in a year, resulting in to harsh climatic conditions. But deserts support diverse communities of plant and animals that have evolved resistance to and methods of circumventing the extreme temperatures and arid conditions. Under the challenging conditions various varieties of cactuses which has the capability to store water in them for long dry season, the trees like date and other palms grow.
The dessert is also a habitat for camels, wide variety of scorpions, snakes and lizards.
Cold climate forests
Canada, and some parts of Asia and Europe are cold forest areas that have short summers and long cold winters. Temperatures range in the winter from -65 to 30F (-54 to -1C) and in the summer from 20 to 70F (-7 to 21C).The vegetation there is made of many coniferous trees (with needles) such as pine trees (like Christmas trees). This type of vegetation is called the Taiga.
Life in the Taiga is cold and snowy; food is hard to find especially in the winter.
The Canadian goose, ermine, weasel, howl, moose, red fox and wolverine are typical animals that live in these areas. Summers are rainy, warm and humid.
Yearly precipitations are between 12 and 33 inches (30-85 cm).
Animals and plants have adapted to the four seasons of the temperate forests: winter, spring, summer, and This cold climate that supports coniferous trees (which means that they carry cones) is found at very high latitudes extending across Eurasia and North America. Rainfall in this climate is moderately high but is spread throughout the course of the year, with snow covering the ground in winter. Very little water is evaporated by the sun, thus ponds, lakes and bogs also known as "muskegs" are found everywhere, especially in glacially carved areas. Trees in the taiga use a lot of energy to grow their leaves, thus they have found a way to keep their needles all year round. This way, when the sun comes out again in the spring these trees are already gathering much needed sunlight instead of wasting more energy to grow new leaves. In addition they have adapted their needles to be filled with a chemical that repels grazing animals, and their thick bark resists the loss of moisture in the cold winters. Trees of this biome are also known as boreal or the Northern coniferous forests usually have shrubs underneath them with blueberries (which is a favorite food of many animals) which act as heath plants. The days in the Taiga are very short in the winter, as short as six hours. In the summer the days lengthen and plants grow rapidly in the 70°F weather. Along the river banks throughout the taiga, willows and many other well known trees can be found. Leaves cover the ground for the relatively low temperature and the acidic soil slows down the process of decay.
Many animals migrate to the taiga in the summer months. However, those who do not have learned to adapt to the cold. Moose, wolves, woodland caribou, wood bison, black bear, marten, lynx, and the arctic ground squirrel are common, although they are not as abundant as the mammals living in the grasslands and the savanna biomes. Most of the animal activity in the taiga is seasonal, with large quantities of birds, such as the redpoll, raven, gray jay, red-throated loon, northern shrike, sharp-tailed grouse, and fox sparrow, present only in summer. Also the bald eagle, peregrine falcon, and osprey which are fish eaters, live in this biome.
For the animals that stay in the taiga during the winter months, conserving heat is one of the most important steps of survival. Most animals go into long-term hibernation and other animals such as the Canadian Lynx grow an insulating layer of fur or in other cases feathers. In order to conserve heat some animals have a rounded body structure, with shortened limbs to create less heat loss from long limbs and skin surfaces. Also other animals grow fur or plumage that camouflage with the snowy white background
Savannah grass lands Although the term savanna is believed to have originally come from an arawak word describing "land which is without trees but with much grass either tall or short" , by the late 1800s it was used to mean "land with both grass and trees". It now refers to land with grass and either scattered trees or an open canopy of trees.
Spanish explorers familiar with the term "sabana" called the grasslands they found around the Orinoco River "llanos", as well as calling Venezuelan and Colombian grasslands by that term. "cerrado" was used on the higher savannas of the Brazilian Central Plateau. Many grassy landscapes and mixed communities of trees, shrubs, and grasses were described as savanna before the middle of the 19th century, when the concept of a tropical savanna climate became established. The Köppen climate classification system was strongly influenced by effects of temperature and precipitation upon tree growth, and his over-simplified assumptions resulted in a tropical savanna classification concept which resulted in it being considered as a "climatic climax" formation. The common usage meaning to describe vegetation now conflicts with a simplified yet widespread climatic concept meaning. The divergence has sometimes caused areas such as extensive savannas north and south of the Congo and Amazon Rivers to be excluded from mapped savanna categories. "Barrens" has been used almost interchangeably with savanna in different parts of North America; ecologically related are rock outcrop plant communities although fires are often not important to outcrop communities. Sometimes Midwestern savannas were described as "grassland with trees". Different authors have defined the lower limits of savanna tree coverage as 5-10% and upper limits range from 25-80% of an area.
Two factors common to all savanna environments are rainfall variations from year to year, and dry season wildfires. Savannas around the world are also dominated by tropical grasses which use the C4 type of photosynthesis. In the Americas, savanna vegetation is similar from Mexico to South America and to the Caribbean.[ In North America nearby trees are of subtropical types, ranging from southwestern Pinyon pine to southeastern Long leaf Pine and northern chestnut oak.
Functional aspects of ecosystems and concept of Industrial ecosystem
Characteristics of ecosystem
The ecosystem is the fundamental system of living and non living elements interacting with each other.
Ecosystem is dynamic system; any ecosystem is dynamic which means it keeps on changing, these changes takes place in its structure, its elements and its characteristics.
Ecosystem has the ability to maintain equilibrium or balance, every ecosystem is able to regulate itself as all the elements present in the ecosystem are interdependent on each other and this interdependence helps in regulation e.g the plants growth in any area is dependent on the amount of rainfall and sunlight it receives, the flora of any ecosystem support a population of herbivores, the number of herbivores living in an ecosystem depends on the number of trees and plants available and carnivores present, the ecosystem also have mechanism to regulate the final disposal of the organic matter which remains after the end of life of these plants and animals. So whenever there is an increase or decrease in the numbers or characteristics of these element the ecology brings the impact on the other constituents resulting in to balancing e.g. if plants population increase it will help in increasing in the population of herbivores which will regulate the increase of plant by consuming them.
Ecosystem also regulates itself by cycles of creation, destruction and degeneration and regeneration e.g. the plant synthesize carbon dioxide from atmosphere and water and nutrients from soil. With help of solar radiation to convert it in to carbohydrates, when animals and insect eat these plant as food they consume the carbohydrates and degenerate it into carbon oxide and water to release energy for their body, so the water and carbon dioxide again goes back in the ecosystem which can again be utilized by the plants.
Human being is a crucial part of any ecosystem, human being is a social animal with very distinctive feature and ecosystem also support life of human beings but when we keep on exploiting the ecosystem for economical development or modernization, it can not replenish or regenerate itself or maintain the balance or equilibrium. Such human intervention brings changes which has long lasting effects on our planet earth. We are doing economic development at the cost of environment.
Services and benefits of ecosystem
Ecosystem provides a variety of services and benefits to us, Ecosystem provides us with natural resources like
Food (vegetables, fruits, grain, cereals etc)
Water (from River, Ponds, Springs, Ground water, Rain, Sea, Glacier etc)
Oxygen (for breathing, oxidation for release of energy)
Ecosystem also provides material like rubber, medicinal plants, wood etc.
Ecosystem also provides food sources to us from oceans and forests.
Ecosystem provides us with deposits of metal and minerals.
Ecosystem provides with deposits of fossil fuel like coal mines and crude oil.
Ecosystem also provide cyclic mechanisms like
Water Cycle, Carbon Cycle, Nitrogen Cycle, Nutrient Cycle.
Ecosystem also controls regulatory functions like Movement of water currents, in sea. Movement of winds across the globe. Climate control and seasonal changes.
Control of rain, storms, floods and cyclones
The Water Cycle
When it rains, the water runs along the ground and flows into rivers or falls directly into the sea. A part of the rainwater that falls on land percolates into the ground.
This is stored underground throughout the rest of the year. Water is drawn up from the ground by plants along with the nutrients from the soil. The water is transpired
from the leaves as water vapor and returned of a wide variety of species. In the species-rich tropical ecosystems (such as in our country), only a few species are very common, while most species have relatively few individuals. Some species of plants and animals are extremely rare and may occur only at a few locations. These are said to be 'endemic' to these areas. When human activities alter the balance in these ecosystems, the "perturbation" leads to the disappearance of these uncommon species. When this happens to an endemic species that Detrivores to the atmosphere. As it is lighter than air, water vapour rises and forms clouds. Winds blow the clouds for long distances and when the clouds rise higher, the vapor condenses and changes into droplets, which fall on the land as rain. Though this is an endless cycle on which life depends, man's activities are making drastic changes in the atmosphere through pollution which is altering rainfall patterns. This is leading to prolonged drought periods extending over years in countries such as Africa, while causing floods in countries such as the US. El Nino storms due to these effects have devastated many places in the last few years.
The Carbon cycle .
carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphsere, geosphere, Hydrosphere, and atmosphere of the Earth. It is one of the most important cycles of the earth and allows for the most abundant element to be recycled and reused throughout the biosphere and all of its organisms.
The carbon cycle is usually thought of as five major reservoirs of carbon interconnected by pathways of exchange. These reservoirs are:
The atmosphere the terrestrial biosphere, which is usually defined to include fresh water systems and non-living organic material, such as soil carbon.
The oceans, including dissolved inorganic carbon and living and non-living marine biota,
The sediments including fossil fuel the earth's interior, carbon from the earth's mantle and crust is released to the atmosphere and hydrosphere by volcanoes and geothermal systems.
The annual movements of carbon, the carbon exchanges between reservoirs, occur because of various chemical, physical, geological, and biological processes. The ocean contains the largest active pool of carbon near the surface of the Earth, but the deep ocean part of this pool does not rapidly exchange with the atmosphere.
The global carbon budget is the balance of the exchanges (incomes and losses) of carbon between the carbon reservoirs or between one specific loop (e.g., atmosphere ↔ biosphere) of the carbon cycle. An examination of the carbon budget of a pool or reservoir can provide information about whether the pool or reservoir is functioning as a source or sink for carbon dioxide.
In the atmosphere
Carbon exists in the Earth's atmosphere primarily as the gas carbon dioxide (CO2). Although it is a small percentage of the atmosphere (approximately 0.04% on a molar basis), it plays a vital role in supporting life. Other gases containing carbon in the atmosphere are methane and chlorofluorocarbons (the latter is entirely anthropogenic. Trees convert carbon dioxide into carbohydrates during photosynthesis, releasing oxygen in the process. This process is most prolific in relatively new forests where tree growth is still rapid. The effect is strongest in deciduous forests during spring leafing out. This is visible as an annual signal in the Keeling curve of measured CO2 concentration. Northern hemisphere spring predominates, as there is far more land in temperate latitudes in that hemisphere than in the southern.Forests store 86% of the planet's above-ground carbon and 73% of the planet's soil carbon. At the surface of the oceans towards the poles, seawater becomes cooler and more carbonic acic is formed as CO2 becomes more soluble. This is coupled to the ocean's thermohaline circulation which transports dense surface water into the ocean's interior (see the entry on the solubility pump.)
In upper ocean areas of high biological productivity, organisms convert reduced carbon to tissues, or carbonates to hard body parts such as shells and tests. These are, respectively, oxidized soft tissue pump and redissolved (carbonate pump) at lower average levels of the ocean than those at which they formed, resulting in a downward flow of carbon (see entry on the biological pump).
The weathering of silicate rock (see Carbonate-Silicate Cycle). Carbonic acid reacts with weathered rock to produce bicarbonate ions. The bicarbonate ions produced are carried to the ocean, where they are used to make marine carbonates. Unlike dissolved CO2 in equilibrium or tissues which decay, weathering does not move the carbon into a reservoir from which it can readily return to the atmosphere. In 1850, atmospheric carbon dioxide was about 280 parts per million (ppm), and today it is about 385ppm. Future CO2 emission can be calculated by the kaya identity Carbon is released into the atmosphere in several ways:Through the respiration performed by plants and animals. This is an exothermic reaction and it involves the breaking down of glucose (or other organic molecules) into carbon dioxide and water. Through the decay of animal and plant matter. Fungi and bacteria break down the carbon compounds in dead animals and plants and convert the carbon to carbon dioxide if oxygen is present, or methane if not. Through combustion of organic material which oxidizes the carbon it contains, producing carbon dioxide (and other things, like water vapor). Burning fossil fuels such as coal, petroleum products, and natural gas releases carbon that has been stored in the geo sphere for millions of years. Burning agro fuels also releases carbon dioxide which has been stored for only a few years or less.
Production of cement. Carbon dioxide is released when limestone (calcium carbonate) is heated to produce lime (calcium oxide), a component of cement.
At the surface of the oceans where the water becomes warmer, dissolved carbon dioxide is released back into the atmosphere.
Volcanic eruptions and metamorphism release gases into the atmosphere. Volcanic gases are primarily water vapor, carbon dioxide and sulfur dioxide. The carbon dioxide released is roughly equal to the amount removed by silicate weathering so the two processes, which are the chemical reverse of each other, sum to roughly zero, and do not affect the level of atmospheric carbon dioxide on time scales of less than about 100,000 years.
In the biosphere
Around 42,000 gigatons of carbon are present in the biosphere Carbon is an essential part of life on Earth. It plays an important role in the structure, biochemistry, and nutrition of all living things.
Autotrophs are organisms that produce their own organic compounds using carbon dioxide from the air or water in which they live. To do this they require an external source of energy. Almost all autotrophs use solar radiation to provide this, and their production process is called photosynthesis. A small number of autotrophs exploit chemical energy sources in a process called chemosynthesis. The most important autotrophs for the carbon cycle are plants in forests on land and phytoplankton in the Earth's oceans. Photosynthesis follows the reaction 6CO2 + 6H2O → C6H12O6 + 6O2
Carbon is transferred within the biosphere as heterotrophs feed on other organisms or their parts (e.g., fruits). This includes the uptake of dead organic material (detritus) by fungi and bacteria for fermentation or decomposition.
Most carbon leaves the biosphere through respiration. When oxygen is present, aerobic respiration occurs, which releases carbon dioxide into the surrounding air or water, following the reaction C6H12O6 + 6O2 → 6CO2 + 6H2O. Otherwise, anaerobic respiration occurs and releases methane into the surrounding environment, which eventually makes its way into the atmosphere or hydrosphere (e.g., as marsh gas or flatulence).
Burning of biomass (e.g. forest fires, wood used for heating, anything else organic) can also transfer substantial amounts of carbon to the atmosphere
Carbon may also be circulated within the biosphere when dead organic matter (such as peat) becomes incorporated in the geosphere. Animal shells of calcium carbonate, in particular, may eventually become limestone through the process of sedimentation.
Much remains to be learned about the cycling of carbon in the deep ocean. For example, a recent discovery is that larvacean mucus houses (commonly known as "sinkers") are created in such large numbers that they can deliver as much carbon to the deep ocean as has been previously detected by sediment traps. Because of their size and composition, these houses are rarely collected in such traps, so most biogeochemical analyses have erroneously ignored them.
Carbon storage in the biosphere is influenced by a number of processes on different time-scales: while net primary productivity follows a diurnal and seasonal cycle, carbon can be stored up to several hundreds of years in trees and up to thousands of years in soils. Changes in those long term carbon pools (e.g. through de- or afforestation or through temperature-related changes in soil respiration) may thus affect global climate change.
The oceans contain around 36,000 giga tonnes of carbon, mostly in the form of bicarbonate ion (over 90%, with most of the remainder being carbonate). Extreme storms such as hurricanes and typhoons bury a lot of carbon, because they wash away so much sediment. For instance, a team reported in the July 2008 issue of the journal Geology that a single typhoon in Taiwan buries as much carbon in the ocean—in the form of sediment—as all the other rains in that country all year long combined. Inorganic carbon, that is carbon compounds with no carbon-carbon or carbon-hydrogen bonds, is important in its reactions within water. This carbon exchange becomes important in controlling pH in the ocean and can also vary as a source or sink for carbon. Carbon is readily exchanged between the atmosphere and ocean. In regions of oceanic upwelling, carbon is released to the atmosphere. Conversely, regions of down welling transfer carbon (CO2) from the atmosphere to the ocean. When CO2 enters the ocean, it participates in a series of reactions which are locally in equilibrium:
Solution:
CO2(atmospheric) ⇌ CO2(dissolved)
Conversion to carbonic acid:
CO2(dissolved) + H2O ⇌ H2CO3
First ionization:
H2CO3
⇌ H+ + HCO3− (bicarbonate ion)
Second ionization:
HCO3−
⇌ H+ + CO3−− (carbonate ion)
This set of reactions, each of which has its own equilibrium coefficient, determines the form that inorganic carbon takes in the ocean. The coefficients, which have been determined empirically for ocean water, are themselves functions of temperature, pressure, and the presence of other ions (especially borate). In the ocean the equilibrium strongly favor bicarbonate. Since this ion is three steps removed from atmospheric CO2, the level of inorganic carbon storage in the ocean does not have a proportion of unity to the atmospheric partial pressure of CO2. The factor for the ocean is about ten: that is, for a 10% increase in atmospheric CO2, oceanic storage (in equilibrium) increases by about 1%, with the exact factor dependent on local conditions. This buffer factor is often called the "Revelle Factor", after Roger Revelle.
In the oceans, carbonate can combine with calcium to form limestone (calcium carbonate, CaCO3, with silica), which precipitates to the ocean floor. Limestone is the largest reservoir of carbon in the carbon cycle. The calcium comes from the weathering of calcium-silicate rocks, which causes the silicon in the rocks to combine with oxygen to form sand or quartz (silicon dioxide), leaving calcium ions available to form limestone
The Nitrogen Cycle
Carnivorous animals feed on herbivorous animals that live on plants. When animals defecate, this waste material is broken down by worms and insects mostly beetles and ants. These small 'soil animals' break the waste material into smaller bits on which microscopic bacteria and fungi can act. This material is thus broken down further into nutrients that plants can absorb and use for their growth. Thus nutrients are recycled back from animals to plants. Similarly the bodies of dead animals are also broken down into nutrients that are used by the plants for their growth. Thus the nitrogen cycle on which life is dependent is completed.
Nitrogen fixing bacteria and fungi in soil gives this important element to plants, which absorb it as nitrates. The nitrates are a part of the plant's metabolism, which help in forming new plant proteins. This is used by animals that feed on the plants. The nitrogen is then transferred to carnivorous animals when they feed on the herbivores. Various plants known as leguminous plants have nitrogen fixing bacteria such as Rhizobium, convert the free nitrogen from air into nitrogenous compound which is required by the plant for its growth. The nitrogen from the air also converts in to nitrogen compounds when lighting strikes the nitrogen reacts with the oxygen to form oxides which dissolves in rain water and falls on earth.
Oxygen cycle
Oxygen is taken up by plants and animals from the air during respiration. The plants return oxygen to the atmosphere during photosynthesis. This links the Oxygen Cycle to the Carbon Cycle. Similarly when ever we burn any fuel it is known as combustion where and substance burn in the presence of oxygen to release energy, combustion is basically oxidation where substance reacts with the oxygen forming oxides. Deforestation is likely to gradually reduce the oxygen levels in our atmosphere. Thus plant life plays an important role in our lives which we frequently do not appreciate. The oxygen is the most important gas required by all living beings although its percentage is around 21 % in the atmosphere but continuous burning of fuel and depletion of forest covers is reducing the levels of oxygen on earth
The Energy Cycle
The energy cycle is based on the flow of energy through the ecosystem. Energy from sunlight is converted by plants themselves into growing new plant material which includes leaves, flowers, fruit, branches, trunks and roots of plants.
Since plants can grow by converting the sun's energy directly into their tissues, they are known as producers in the ecosystem. The plants are used by herbivorous animals as food, which gives them energy. A large part of this energy is used up for day to day functions of these animals such as breathing, digesting food, supporting growth of tissues, maintaining blood flow and body temperature. Energy is also used for activities such as looking for food, finding shelter, breeding and bringing up young ones. The carnivores in turn depend on herbivorous animals on which they feed. Thus the different plant and animal species are linked to one another through food chains. Each food chain has three or four links. However as each plant or animal can be linked to several other plants or animals through many different linkages, these inter-linked chains can be depicted as a complex food web web. This is thus called the 'web of life' that shows that there are thousands of interrelationships in nature.
The energy in the ecosystem can be depicted in the form of a food pyramid or energy pyramid. The food pyramid has a large base of plants called 'produc- producers. The pyramid has a narrower middle section that depicts the number and biomass of herbivorous animals, which are called 'first order consumers'. The apex depicts the small biomass of carnivorous animals called 'second order consumers '. Man is one of the animals at the apex of the pyramid. Thus to support mankind, there must be a large base of herbivorous animals and an even greater quantity of plant material.
When plants and animals die, this material is returned to the soil after being broken down into simpler substances by decomposers such as insects, worms, bacteria and fungi so that plants can absorb the nutrients through their roots. Animals excrete waste products after digesting food, which goes back to the soil. This links the energy cycle to the Nitrogen cycle. Integration of cycles in Nature these cycles are a part of global life processes. These biogeochemical cycles have specific features in each of the ecosystems. These cycles are however linked to those of adjacent ecosystems. Their characteristics are specific to the plant and animal communities in the region. This is related to the geographical features of the area, the climate and the chemical composition of the soil. Together the cycles are responsible for maintaining life on earth. If mankind disturbs these cycles beyond the limits that nature can sustain, they will eventually break down and lead to a degraded earth on which man will not be able to survive.
INDUSTRIAL ECOLOGY
Concept of industrial ecology was developed by two experts Frosch and Gallopoulas the concept is multidisciplinary study of industrial and economic systems and their linkages with fundamental natural systems. Industrial ecology try to convert the industrial system as an analogues to the natural ecological system which is based on cyclical flow of material and energy instead of a linear flow.
It advocates bringing out changes in the system of production and consumption practice of product and services. It emphasize on integrating all the activities or processes run by an organization as a never ending cycle, which starts from identifying and acquiring the raw material, transportation of the material in to the industry processing it to convert in to finished goods, delivering it to the end user, its use and disposal by the consumer after the use.
Once the organization has identified all such steps the organization should do research and analysis of all its activities the company try to find out the impact of each such activity on the environment, neighborhood, and social and culture aspects
Principles of industrial ecology
Creation of economic systems, where material flows are managed in a manner so that they can be reused rather than becoming waste and creating a linear flow of the materials.
It emphasizes to integrate all components of industry to relate with the biosphere.
It considers long term evolution of key technologies as a crucial element for the transition from the actual unsustainable industrial system to a viable industrial ecosystem.
Industrial ecology is concerned not just with static analyses of systems but with their responses over time, and particularly with their resilience.
Industrial ecosystem can be defined as application of natural ecosystem concepts to industry, which means linking the all the activities to each other in an interdependent system, which is of cyclic nature.
Following aspects are noted in industrial ecology concept
Reduction of material requirements, Reduction in wastage at all level, Recycling of the material, reduction of use of energy and its conservation,
Bringing safe and secure products with multiple features and long life, so that requirements of such products are moderated.
Establishing ways to use scrape or wasted products as raw material.
Environmental issues in natural resource management
INTRODUCTION
Environment has given the mankind with so many material, substance and service which is being utilized for a variety of purposes necessary for our existence and maintenance of lifestyle. The substances and services which we use for our requirements from the environment are called natural resources which include, air, water, soil, minerals, along with the climate and solar energy,
The nonliving components are called 'abiotic' part of nature. The living components which include flora and fauna are called 'biotic' parts of nature. In the ecosystem the abiotic and biotic components are linked with each other in interdependent network
History
Thousands of years ago, mankind changed from a hunter-gatherer, living in wilderness areas such as forests and grasslands, into an agriculturalist and pastoralist, man began to change his lifestyle and in the phase of its development his needs has gone a considerable change, due to his changed requirement and increasing demand he looked towards the environment to fulfill his needs.
With the increase in mental ability and knowledge man started to grow more variety of food and need of housing and agricultural the natural ecosystem were manipulated to develop land to grow food, make houses and domesticate animals. The demands of mankind increased with an enormous rate and we started using the natural resources for fulfilling our various needs, these needs kept on increasing and man maintained its rate of modernization and development with out ever thinking of the environment. The over exploitation of natural resources like the water reservoirs, forests, mines, fossil fuel deposit etc and the emergence of degrading anthropogenic activities had caused imbalance in the ecosystem which is now a threat for our sustainable growth and existence .So we had realized that all this has led to several undesirable changes in our environment. Mankind has been overusing and depleting natural resources. The over-intensive use of land has been found to exhaust the capability of the ecosystem to support the growing demands of more and more people, all requiring more intensive use of resources. Increased Industrial growth, urbanization, burst in population growth and the enormous increase in the use of commodities and consumer goods have all put further stresses on the environment. They create great quantities of solid waste. Pollution of air, water and soil has begun to seriously affect human health.
Various sources of natural resources
The earth is surrounded by a thick cover of various gases which is termed as the atmosphere. The various benefits of atmosphere as follows
The lowest layer, the troposphere, helps in maintaining a suitable temperature for our life it is the only part warm enough for us to survive in, it is only 12 kilometers thick and has following composition.
It provides oxygen to breath and also helps in oxidation of various substances for combustion and release the energy locked in it.
Carbon dioxide helps in photosyntehsis process where the plants synthesis the solar energy and convert water and carbon dioxide into glucose which is required to support all life forms on earth in direct or indirect relation.
Atmosphere
Nitrogen - 78.084%
Oxygen - 20.95%
Argon - 0.934%
CarbonDioxide - 0.036%
Neon - 0.0018%
Helium - 0.0005%
Methane - 0.00017%
Hydrogen - 0.00005%
Nitrous Oxide - 0.00003%
Ozone - 0.000004%
. The second level of atmosphere is stratosphere which is 50 kilometers thick and contains a layer of sulphates which is important for the formation of rain. It also contains a layer of ozone, which absorbs ultra-violet light known to cause cancer and without which, no life could exist on earth.
The atmosphere maintains air flows and variations in climate, temperature and rainfall in different parts of the earth. It is a complex dynamic system. But due to anthropocentric activities the air is polluted and its basic characterstics were changed leading to problems of global scale like global warming and ozone holes etc.
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2) Hydrosphere
The earth surface is covered up to three fourth with one substance water known as universal solvent, water is a colorless, odorless and tasteless liquid which is very essential for living creature's existence. Our human body is composed of 75% water and we need clean water for drinking (a metabolic requirement for living processes) and other uses of water are as follows
- water for irrigation of fields, water for cooking and washing, water is also required for industrial processes.
- Water reservoir like oceans and sea support large amount of food sources for us including fish, shellfish, weeds etc
- The potential energy of water flowing down from mountain ranges harnessed to generate electricity in hydroelectric projects.
- The portable water or clean drinking water in rivers, lakes and glaciers, is perpetually being renewed by a process of evaporation and rainfall. Some of this fresh water lies in underground aquifers.
- Human activities such as deforestation create serious changes in the hydrosphere. Due excessive use of water resources and affluent added in to these resources are creating problems of gigantic nature.
3) Lithosphere
The hard rocky crust which surround the earth divided into tectonic plates including the peaks of Himalayas to the shore bed of deep seas the lithosphere is the outer most crust of earth's mantle and provide following resources to mankind like soil for agriculture. stone, sand and gravel, for building infrastructures, micronutrients in soil are required for plant growth. Lithosphere provide us land as habitat of humans, it also support microscopic flora, small soil fauna and fungi in soil, important living organisms of the lithosphere, which break down plant litter as well as animal wastes to provide nutrients for plants in a cyclic manner.
Lithosphere also holds large deposits of variety of minerals like iron, aluminum, zinc, copper etc. it also store deposits of Crude oil, Gas, coal etc which are required to fulfill our energy needs for transportation and production etc It also provides power for vehicles, agricultural machinery, industry, and for our homes. The crust of the earth is 6 or 7 kilometers thick and lies under the continents. Of the 92 elements in the lithosphere only eight are common constituents of crustal rocks. Of these constituents, 47% is oxygen, 28% is silicon, 8% is aluminum, 5% is iron, while sodium, magnesium, potassium and calcium constitute 4% each. Together, these elements form about 200 common mineral compounds. Rocks, when broken down, form soil on which man is dependent for his agriculture. Their minerals are also the raw material used in various industries.
4) Biosphere
Biosphere include the living world, an integration of all ecosystem on earth on which life can exist e.g ocean and sea, forest etc
The biosphere give food in form of fruit vegetable and other crops, it also give food in the form of domesticated animals.
The biosphere also support various forms of lives of flora and fauna where nutrition and energy is transformed in a network of food chains.
Bioshpere also fulfill energy needs through biomass and wood collected from forests and plantations, along with other forms of organic matter, used as a source of energy.
Materials like timber and other construction materials. Various other substances like rubber, medicinal plants, flowers, spices and herbs also comes from the biosphere.This is the relatively thin layer on the earth in which life can exist. Within it the air, water, rocks and soil and the living creatures, form structural
and functional ecological units, which together can be considered as one giant global living system, that of our Earth itself.
RENEWABLE AND NON-RENEWABLE RESOURCES
Resources which can regenerate/ replenish itself after reasonable amount of time is known as renewable resources, similarly resources which can not regenerate or replenish itself and become exhausted after its use is known as non renewable resources our ecosystems act as resource producers and processors.
On planet earth sunlight or solar energy is the main resource provider.
It is the solar energy which is being converted in to one form or the other and is stored on earth, the plants synthesis Solar energy with the help of photosynthesis and this energy is consumed by all the animal world directly or directly.
A forest recycles its plant material slowly by continuously returning its dead material, leaves, branches, etc. to the soil.
Grasslands recycle material much faster than forests as the grass dries up after the rains are over every year.
All the aquatic ecosystems are also solar energy dependent and have cycles of growth when plant life spreads and aquatic animals breed.
The sun also drives the water cycle. Water, a natural resources can also be reused as the water cycle rotates the same water all across the earth
Our food comes from both natural and agricultural ecosystems which also follow the patterns of regeneration we can plant the seeds and will be able to grow the same crops again and again.
Similarly the oxygen we need for breathing is generated as a byproduct of photosynthesis from plants.
Apart from all the above renewable resources the earth has deposits of minerals these are minerals that have been formed in the lithosphere over millions of years and constitute a closed system. These non-renewable resources, once used, remain on earth in a different form and, unless recycled, become waste material. Fossil fuels like crude oil and coal, which has formed by long process of sedimentation of microorganisms since a long time is also a non renewable resource and if it is extracted at the current rate, it will soon be consumed, according to some estimates the total deposits of crude oil will only last long for less than 100 years only.
The renewable resources are considered to regenerate itself but it is renewable to certain extent e.g. water is renewable resources but overexploitation of water resources and over use of water will cause changes which will be irreplaceable,
By the sun's energy, forms water vapors and is reformed in clouds and falls to earth as rain. However, water sources can be overused or wasted to such an extent that they locally run dry. Water sources can be so heavily polluted by sewage and toxic substances that it becomes impossible to use the water.
• Forests, once destroyed take thousands of years to re grow into fully developed natural ecosystems with their full complement of species. Forests thus can be said to behave like non-renewable resources if overused.
• Fish are today being over-harvested until the catch has become a fraction of the original resource and the fish are incapable of breeding successfully to replenish the population.
• The output of agricultural land if mismanaged drops drastically.
• When the population of a species of plant or animal is reduced by human activities, until it cannot reproduce fast enough to maintain a viable number, the species becomes extinct.
• Many species are probably becoming extinct without us even knowing, and other linked species are affected by their loss.
Human development is entirely dependent on the natural resources, developed countries had exploited the natural resources for their use and now due to increasing population and increasing demand of an individual the depletion of the natural resources had reached critical level, the major issue today is to find out ways to maintain sustainable development at the same time maintaining the quality of the environment.
Natural resources and associated problems
For our development we need to use natural resources, we are consuming the natural resources with an enormous rate out of which the developed nations are consuming these resources at a much greater speed than the developing nation and due to their excessive exploitation of natural resources the overall world is facing problems, according to statistical data, the consumption of resources per capita (per individual) of the developed countries is up to 50 times greater than in most developing countries.
Advanced countries produce over 75% of global industrial waste and greenhouse gases. Energy from fossil fuels is consumed in relatively much greater quantities in developed countries. Their per capita consumption of food too is much greater as well as their waste of enormous quantities of food and other products, such as packaging material, used in the food industry.
The USA for example with just 4% of Natural Resources the world's population consumes about 25% of the world's resources. For instance rearing animal food for human consumption requires more land than growing crops. Thus countries that are highly dependent on non-vegetarian diets need much larger areas for pastureland than those where the people are mainly vegetarian.
Land Use : the 25% area of earth comprises of Land which is a major resource for us, mankind require land for the following purpose For agriculture to produce food, animal husbandry. Land is also required for making houses for living. We also use land for industry, Land is required for infrastructure development e.g. roads, bridges and buildings etc. Due to increase in population and growing demands due to changes lifestyle the demand for land is increasing, but the irony is that the area of earth under land is same, so we have started deforestation so as to convert the land under forestry to agricultural or urban lands causing in to various environmental problems like floods, extinction of species of flora and fauna, increase in the amount of green house gases etc. if we want sustainable development then we should do land use planning to find out what should be the areas under different land use e.g agricultural land, land under forestry, land under urbanization.
Earlier the major land resources were under forest cover but due to requirement of more land for agriculture, habitation and for infrastructural growth the land under forest cover is receding today the area under forestry in India is les than 12% so we need not only to protect existing forests but also to increase our forest cover. Forest provides us means of livelihood and we are directly or indirectly dependent on the forest e.g. The water we use depends on the existence of forests on the watersheds around river valleys. Our requirements of furniture and other wooden substance are fulfilled from the forests. Our industries like the paper and pulp industry depends on the forest. Many medicines are based on forest produce. Forest also contribute in creating biomass and generating oxygen. Forest also support a wide variety of animals which are used by us for many reasons like food, leather, wool etc
The major concern which is effecting the forest ecosystem is Deforestation which is increasing due to various reason like urbanization, mining, infrastructure growth, requirements of raw materials etc. today there is are requirement of conserving our existing forests but we have to increase the area under forestry because due to overutilsation and degradation of forests we are facing problems of global nature. One of the major concern in protection and preservation of the forest ecosystem is the need and importance of the local people, without their contribution the targets to conserve and improve the quality of forest will not be achieved.
Water resources
Our water resources are extensively used for different purposes to fulfill our daily needs such as drinking water,washing, cooking, watering animals, and irrigating
fields. There is a limited supply of water on earth, only 3% of the total water is portable water. Of this, 2% is in polar ice caps and only 1% is usable water in rivers, lakes and subsoil. We can use only a fraction of this. We can divide the total water consumption in following manner
70% of water is used for agriculture
25% for industry
5% for domestic use.
This may vary from country to country; apart from the above statistics we can understand why water resources are very important. Secondly as the population of the world is increasing the requirement for water is also increasing tremendously. Hence we have to conduct thorough management of our water resources. Studies indicate that a person needs a minimum of 20 to 40 liters of water per day for drinking and sanitation. More than one billion people worldwide
have no access to clean water, and to many more, supplies are unreliable.
The other environmental problem related to our water resources is that due to overutilization of water the levels of ground water is receding and its replenishment is reduced as due to extensive urbanization, infrastructure growth and deforestation the rain water is not able to seep in to the ground, the rainwater is drained in to the sewage system and wash away with the river and finally into the sea where it can't be utilized today we have to find out ways to collect and store the rain water so that we can use rain water for our increasing demands. The best method is the rain water harvesting where with the help of a basic system the rain water is collected and instead of draining into the sewer or drainage system it is directed towards increasing ground water levels. Rain water harvesting can be done for residential buildings, industries etc the rain water falling on the roofs are directed towards the small inlet made in the ground the water is filtered by natural manner i.e passing the water through layers of stones, sand and charcoal and then water is allowed to seep in to ground. This water helps in increasing the level of the ground water. Such mechanism is very useful in the cities like dehli where the population had grown to magnanimous levels and the water level has gone down to around 100 MTs
Mineral Resources
For our development activities mineral and metal is very crucial and critical and all our requirements of it is fulfilled by the deposits of these minerals present in our environment but extraction of these minerals have an intense impact on the ecology due to extreme monetary vale of these deposit mankind tend to forget the damages brought by the mining or extraction activities. mineral is a naturally occurring substance of definite chemical composition and identifiable physical properties. An ore is a mineral or combination of minerals from which a useful substance can be extracted with a commercial value, such as a metal, can be extracted and used to manufacture a useful product. Deposits of minerals are formed over a period of millions of years in the earth's crust. Iron, aluminum, zinc, manganese and copper are important raw materials for industrial use. Apart from metal we also use the non-metal resources which include coal, salt, clay, cement and silica. Stone used for building material, such as granite, marble, limestone, constitute another category of minerals. Minerals with special properties that humans value for their aesthetic and ornamental value are gems such as diamonds, emeralds, rubies. The luster of gold, silver and platinum is used for ornaments. Minerals in the form of oil, gas and coal were formed when ancient plants and animals were converted into underground fossil fuels. Minerals and their ores need to be extracted from the earth's interior so that they can be used. This process is known as mining.
Mining has extensive damages for the environment it is also hazardous for the professional working for this. Mining also require lot of energy and the process of extracting metal from ore require huge amount of water and fuel to melt the ore for extraction of metal. Mining also involves various hazards like fire or explosions in mines due to presence of methane gas in the underground mines, many lung diseases are also associated with the mining activities. Increase in the flash floods, soil erosion and extensive damage to the forest ecosystem are some of the other impacts of mining. The huge amount of waste in the form of sludge also adds in to the environmental problems.
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Energy resources and environmental concerns
The major factor in our growth is the energy we need energy to carryout any work, on earth we different sources of energy some are renewable and other are non renewable, the major source of energy is sun, as per the physical law of nature energy can nor be created nor be destroyed, it can be changed from one form to another. Our earth receives the solar energy which is synthesized be plants to create biomass which is used as source of energy. Our earth is heated with solar energy and with the help of various natural processes that provide us with food, water, fuel and shelter. The deposit of fossil fuel is also the solar energy synthesized by the micro organism since thousand of year before.
We can convert various forms of energy like the heat energy or potential energy in to electrical energy which is one of the most significant form of energy required for our development. We can generate the electricity with various methods like hydroelectric generation, nuclear power generation etc the power can be used for mass transport system like railways etc, artificial lighting for highways and industries
The need of power is growing at an exorbitant rate with the rapid growth the requirement of energy is increased many folds resulting in to changes in environment and its degradation
The energy is required in the following areas
Industries :- around 50% of the total energy is produced is required in the industrial sector for producing different product and services for the market. Industries like cement, metal, fertilizer, textile etc are energy intensive industries i.e the energy requirement in these industries are very high. And need lot of energy. Industries fulfill their energy requirement from different sources, the major sources include coal, lignite and bituminous, oil and gas, electricity, the minor sources include nuclear power, solar energy , wind energy etc.
Second largest consumer of energy is the transport sector which include the private transport (like cars etc ) the commercial transport ( taxis and buses) the mass transit or transport systems like railways, metro, monorail, trams etc. the commercial transport like the trucks and tankers transporting the materials and products etc. Airplane and ships are also the part of transport systems, the energy requirement in this sector is growing due to increase in the new users, increase in overall population etc.
The next sector is the agriculture sector where there is huge requirement of energy, agriculture is now adopting new methods of cultivation and require more mechanization e,g tractors and harvesting and winnowing machines similarly today agriculture require formal irrigation systems like the tube well and sprinklers etc which had also increased the requirement in this sector. The agriculture sector fulfill their energy requirements from sources like diesel, electricity etc today initiatives are taken to use even the biogas and biomass to fulfill the requirements of the agriculture sector.
Lastly the energy requirements are in the domestic sector, domestic energy requirements are because of cooking, hot water and lightning and other purposes like TV, Fridge AC etc. in countries like india the domestic energy requirements for cooking are fulfilled through the biomass like the wood, cow dung cake, kerosene. But today the trends are changing to cleaner fuels like the biogas, LPG etc the requirement in this sector is also increasing due to changes in the lifestyle and more demands of the mankind. Secondly the domestic energy requirement are fulfilled by the electricity, this requirement is increasing at a tremendous rate because of increase in the demand of the white good or consumer durable goods like the Fridge AC and washing machines etc, the energy requirements in india will grow for some more decades to go as still a huge area in india are still doesn't have electricity connections.
Growing energy needs: The growth of mankind is directly related to energy but the power generation all across the globe is bringing out tremendous environmental changes. The energy can be classified according to the kind of its resources like the renewable, non renewable and nuclear energy. The energy sources, which can be used repeatedly without getting depleted or they can regenerate themselves within a reasonable time is known as renewable resources of energy.
Renewable resources of energy include
Hydro power the energy from flowing water is known as hydro energy, it is because of water cycle we have a continuous flow of water in our rivers, rivers originates from mountains and flows downwards, when the water is at high altitude it has potential energy which can be converted to mechanical energy. We can generate electric power with help of the hydro energy, the water is stored in dams when the water flows out from the reservoir (the potential energy of water flowing from heights of water) which can be converted in to electric energy.
Solar energy the solar energy is the primary source of energy on earth and we can also use this for many of our anthropocentric activities like power generation, heating water for industrial purpose etc.
The various uses and methods of using solar energy
Solar heating for homes: in this method the solar energy is collected through the changes in architecture of the house where building is so designed to collect the sun's heat through large, south-facing glass windows. sunspaces are built on the south side of the structure which act as large heat absorbers. The floorings of the sunspaces are usually made of heat absorbing materials like the tiles or bricks the heat absorbed throughout the day is released at night when its cold.
We can also use the architecture of the building so as to use the sun; water and wind are used to regulate the temperatures of building depending on the season or weather. Building the house with thick walls of stone or mud helps in regulating the temperature as these materials act as insulator. Small doors and windows kept direct sunlight and heat out. Deeply set glass windows in colonial homes, on which direct sunlight could not reach, permitted the glass from creating a green house effect. Verandahs also served a similar purpose. High roofs and ventilators helps the removal of heated air from the inside of the houses. Having good cross ventilation where wind can drive the air in and out of a room keeps it cool. Large overhangs over windows prevent the glass from heating the room inside. Double walls are used to prevent heating. Shady trees around the house help reduce temperature.
Solar water heating: A method to heat the water with solar energy in this method a solar water heating plant is set up on the roofs of houses where the exposure to sun is high. Solar water heating plant has two main parts: the solar collector and the storage tank. The solar energy collector heats the water, which then flows to a well insulated storage tank. A common type of collector is the flat-plate collector, a rectangular box with a transparent cover that faces the sun, usually mounted on the roof. Small tubes run through the box, carrying the water or other fluid, such as antifreeze, to be heated. The tubes are mounted on a metal absorber plate, which is painted black to absorb the sun's heat. The back and sides of the box are insulated to hold in the heat. Heat builds up in the collector, and as the fluid passes through the tubes, it too heats up. The only draw back of Solar water-heating systems is that it cannot heat water when the sun is not shining. Secondly the capital investment is high but with maintenance cost is very low and the cost is recovered with the long durations of its use.
Solar cookers: it is a device which use the solar enrgy to cook the food in this method a metal box which is black on the inside to absorb and retain heat. The lid has a reflective surface to reflect the heat from the sun into the box. The box contains black vessels in which the food to be cooked is placed. With help of solar cooker one can boil rice, vegetables etc but it is not fit for frying as the temperature doesn't reach to the level of frying . there is no chance of food getting overcooked or burnt. But the working on solar cooker depends on sun shine.
Solar desalination systems :- basically a water filtering system which works on uses the solar energy to convert saline water to convert in to steam which can be condensed and collected to get pure or distilled water , suitable for areas like gulf countries where the sources of portable water is scarce but at the same time the sea shore and excessive heat of sun is available.
Photovoltaic energy:
Photovoltaic energy is system where the solar energy is converted into electric energy with the help of photovoltaic cells. photovoltaic (PV) or solar cells trap the sun's light, not its heat, to make electricity. PV cells have silicon panels, when a photon of light strikes the silicon panel a small wave of current is generated which is very minimal but with multiple panels we can produce sufficient amount of electricity, which can be used to charge the batteries from which we can transfer energy even when we do not have sunlight, PV cells are expensive but require little maintenance, have no moving parts, and essentially no environmental impact. They work cleanly, safely and silently. They can be installed quickly in small modules, anywhere there is sunlight. PV cells are wired together to form a module. A module of about 40 cells is enough to power a light bulb. For more power, PV modules are wired together into an array. PV arrays can produce enough power to meet the electrical needs of a home. Over the past few years, extensive work has been done in decreasing PV technology costs, increasing efficiency, and extending cell lifetimes. Many new materials, such as amorphous silicon, are being tested to reduce costs and automate manufacturing. PV cells are commonly used today in calculators and watches. They also provide power to satellites, electric lights, and small electrical appliances such as radios and for water pumping, highway lighting, weather stations, and other electrical systems located away from power lines. Some electric utility companies are building PV systems into their power supply networks. PV cells are environmentally benign, ie. they do not release pollutants or toxic material to the air or water, there is no radioactive substance, and no catastrophic accidents. Some PV cells, however, do contain small quantities of toxic substances such as cadmium and these can be released to the environment in the event of a fire. Solar cells are made of silicon which, al-Photovoltaic Cells
Solar thermal electric power: Solar radiation can produce high temperatures this heat can be stored and used for generation of electricity this process of generating electricity with the help of solar thermal energy. is known as solar thermal electric power. Solar thermal electric power plant generates heat by using lenses and reflectors to concentrate the sun's energy. Because the heat can be stored, these plants are unique because they can generate power when it is needed, day or night, rain or shine.
There are three technologies to generate solar thermal electric power; they are solar tower, parabolic dish and parabolic trough.
Biomass energy: the solar energy which is stored in the plant in the form of organic material like wood, grass, fiber etc
When a firewood is burned we are using biomass energy. Biomass energy is one of the oldest resource of energy and we are using it ever since, but today we use following kind of organic material as biomass; they are agricultural waste, sugarcane wastes, and other farm byproducts to make energy.
We can use biomass by different methods like we can burn biomass to produce heat, we can use this heat to generate electricity, biomass can also be changed to a gas-like fuel such as methane, or changed to a liquid fuel.
Liquid fuels, also called biofuels, include two forms of alcohol: ethanol and methanol. Because biomass can be changed directly into liquid fuel, it could someday supply much of our transportation fuel needs for cars, trucks, buses, airplanes and trains with diesel fuel replaced by ' biodiesel' made from vegetable oils. In the United States, this fuel is now being produced from soybean oil.
Researchers are also developing algae that produce oils, which can be converted to biodiesel and new ways have been found to produce ethanol from grasses, trees, bark, sawdust, paper, and farming wastes. Organic municipal solid waste includes paper, food wastes, and other organic non-fossil-fuel derived materials such as textiles, natural rubber, and leather that are found in the waste of urban areas. Currently, in the US, approximately 31% of organic waste is recovered from municipal solid waste via recycling and composting programs, 62% is deposited in landfills, and 7% is incinerated. Waste material can be converted into electricity by combustion boilers or steam turbines. Note that like any fuel, biomass creates some pollutants, including carbon dioxide, when burned or converted into energy. In terms of air pollutants, biomass generate less relative to fossil fuels. Biomass is naturally low in sulphur and therefore, when burned, generates low sulphur dioxide emissions. However, if burned in the open air, some biomass feedstock would emit relatively high levels of nitrous oxides.
The fibrous waste of the sugar industry is the world's largest potential source of biomass energy. Ethanol produced from sugarcane molasses is a good automobile fuel and is now used in a third of the vehicles in Brazil.
Wind energy, due to temperature variations across the globe, wind flow is continuous this energy of wind can be converted into other sources of energies like mechanical energy or electric energy with the help of wind mills. It is considererd that around 2000 years ago, windmills were developed in China, Afghanistan and Persia to draw water for irrigation and grinding grain. Denmark, is the first country to use the wind mills for generation of electricity. Today, Denmark and California have large wind turbine cooperatives which sell electricity to the government grid.
India is also the third largest wind energy producer in the word even various private firms are generating wind power to generate electricity e.g Siemens, suzlon, indowind energy. In Tamil Nadu, there are large wind farms producing more than 850 megawatts of electricity. The speed of the wind is very critical along with the altitude of the place for establishing a wind energy plant we have to find an area where average speed of wind is more secondly we have to determine the altitude of the wind mill so as to increase its efficiency, the ideal height will be some where 30 meters or so. Over the past two decades, a great deal of technical progress has been made in the design, siting, installation, operation, and maintenance of power-producing wind mills (turbines). These improvements have led to higher wind conversion efficiencies and lower electricity production costs.
The major advantages of wind energy are that apart from the initial capital cost it doesn't have any air or water emissions, nor radiation, zero solid waste production. It has a little maintenance and practically no operational cost apart from general maintenance. The only drawbacks are that it can't be established everywhere and also involves problems like bird kills, noise, effect on TV reception, and aesthetic objections to the sheer number of wind turbines that are required to meet electricity needs. Wind farms can be set up in agricultural or grazing grass fields, secondly various countries are trying to establish wind farms in the ocean hence zero land use.
Biogas: an organic gas formed due to decomposition of organic material or waste in the absence of oxygen with the help of anaerobic bacteria ( bacteria which doesn't require oxygen ). The biogas can be produced from organic waste in the form of cow or animal dung, house hold garbage, plant material, animal waste, and some types of industrial wastes, such as fish processing, dairies, and sewage treatment plants.
The major constituent of biogas is methane it also has some percentage of other gases which includes methane, carbon dioxide, hydrogen sulphide and water vapor. With a ton of food waste, one can produce 85 Cu. M of biogas.
The biogas has following benefits it is a clean fuel as the combustion results into carbon dioxide and water, doesn't produce smoke or odors, the raw material required is easily available.
Denmark produces a large quantity of biogas from waste and produces 15,000 megawatts of electricity from 15 farmers' cooperatives. London has a plant which makes 30 megawatts of electricity a year from 420,000 tons of municipal waste which gives power to 50,000 families. In Germany, 25% of landfills for garbage produce power from biogas. Japan uses 85% of its waste and France about 50%. Biogas plants have become increasingly popular in India in the rural sector. The biogas plants use cow dung, which is converted into a gas which is used as a fuel. It is also used for running dual fuel engines. The reduction in kitchen smoke by using biogas has reduced lung conditions in thousands of homes.
Geothermal energy:
Geothermal energy originates from the core of the earth which is hot, molten rock (called magma) which due to some reason comes out from surfaces of earth's crust. Some times this heat is released form the bottoms of the pool or springs of water and when this comes out from an opening it forms hot springs, or it may boil to form geysers, these wells are drilled deep below the surface of the earth to tap into geothermal reservoirs. These hot water springs can be used as source of energy. We can pump this hot water and convert the heat energy to other sources of energy. E.g. the heat energy can be used for heating the surrounding and buildings in winters or generation of power.
In 1998, the World Resources Institute found that the average American uses 24 times the energy used by an Indian. Between 1950 and 1990, the world's energy needs increased four fold. The world's demand for electricity has doubled over the last 22 years! The world's total primary energy consumption in 2000 was 9096 million tons of oil. A global average per capita that works out to be 1.5 tons of oil. Electricity is at present the fastest growing form of end-use energy worldwide. By 2005 the Asia-Pacific region is expected to surpass North America in energy consumption and by 2020 is expected to consume some 40% more energy than North America. For almost 200 years, coal was the primary energy source fuelling the industrial revolution in the 19th century. At the close of the 20th century, oil accounted for 39% of the world's commercial energy consumption, followed by coal (24%) and natural gas (24%), while nuclear (7%) and hydro/renewables (6%) accounted for the rest. Among the commercial energy sources used in India, coal is a predominant source accounting for 55% of energy consumption estimated in 2001, followed by oil (31%), natural gas (8%), hydro (5%) and nuclear (1%). In India, biomass (mainly wood and dung) accounts for almost 40% of primary energy supply. While coal continues to remain the dominant fuel for electricity generation, nuclear power has been increasingly used since the 1970s and 1980s and the use of natural gas has increased rapidly in the 80s and 90s.
Tidal and Wave Power
The power of the rise and fall of the sea level or tidal power, can be harnessed to generate electricity.
The earth's surface is 70% water. By warming the water, the sun, creates ocean currents and wind that produces waves. It is estimated that the solar energy absorbed by the tropical oceans in a week could equal the entire oil reserves of the world – 1 trillion barrels of oil The energy of waves in the sea that crash on the land of all the continents is estimated at 2 to 3 million megawatts of energy
Tidal power traditionally involves erecting a dam across the opening to a tidal basin. The dam includes a sluice that is opened to allow the tide to flow into the basin; the sluice is then closed, and as the sea level drops, traditional hydropower technologies can be used to generate electricity from the elevated water in the basin. Some researchers are also trying to extract energy directly from tidal flow streams.
The energy potential of tidal basins is large — the largest facility, the La Rance station in France, generates 240 megawatts of power. Currently, France is the only country that successfully uses this power source. French engineers have noted that if the use of tidal power on a global level was brought to high enough levels, the Earth would slow its rotation by 24 hours every 2,000 years.
Tidal energy systems can have environmental impacts on tidal basins because of reduced tidal flow and silt buildup.
Ways of Using the Tidal Power of the Ocean
There are three basic ways to tap the ocean for its energy. We can use the ocean's waves, we can use the ocean's high and low tides, or we can use temperature differences in the water.
Wave Energy
Kinetic energy (movement) exists in the moving waves of the ocean. That energy can be used to power a turbine. In this simple example, (illustrated to the right) the wave rises into a chamber. The rising water forces the air out of the chamber. The moving air spins a turbine which can turn a generator.
When the wave goes down, air flows through the turbine and back into the chamber through doors that are normally closed.
This is only one type of wave-energy system. Others actually use the up and down motion of the wave to power a piston that moves up and down inside a cylinder. That piston can also turn a generator.
Most wave-energy systems are very small. But, they can be used to power a warning buoy or a small light house.
Tidal Energy
Another form of ocean energy is called tidal energy. When tides comes into the shore, they can be trapped in reservoirs behind dams. Then when the tide drops, the water behind the dam can be let out just like in a regular hydroelectric power plant.
In order for this to work well, you need large increases in tides. An increase of at least 16 feet of low tide to high tide is needed. There are only a few places where this tide change occurs around the earth. Some power plants are already operating using this idea. One plant in France makes enough energy from tides to power 240,000 homes.
Ocean Thermal Energy
The final ocean energy idea uses temperature differences in the ocean. If you ever went swimming in the ocean and dove deep below the surface, you would have noticed that the water gets colder the deeper you go. It's warmer on the surface because sunlight warms the water. But below the surface, the ocean gets very cold. That's why scuba divers wear wet suits when they dive down deep. Their wet suits trapped their body heat to keep them warm.
Power plants can be built that use this difference in temperature to make energy. A difference of at least 38 degrees Fahrenheit is needed between the warmer surface water and the colder deep ocean water.
Using this type of energy source is called Ocean Thermal Energy Conversion or OTEC. It is being used in both Japan and in Hawaii in some demonstration projects.
Non renewable energy.
Fossil fuels.
Fossil fuels are the fuels derived from fossils, which were formed millions of years ago during the time of the dinosaurs. They are fossilized organic remains that over millions of years have been converted to oil, gas, and coal. As these fossil fuels take millions of years to form and their deposit are scarce they are called non renewable source of energy. When plants, animals and other living organisms died, they decomposed and were buried, layer upon layer under the ground. Their decomposed remains gradually changed over the years. It took millions of years to form these layers into a hard, black rock-like substance called coal, a thick liquid called oil or petroleum, and natural gas—the three major forms of fossil fuels. The fossil fuels are actually the decomposed organic matter of animals and plant origin.
After the industrial revolution of Europe the industries grew up and the need of energy increase tremendously, and mankind has started using these fossil fuel to fulfill their requirements of energy,
Previously we neglected the value of these fossil fuels as our demands were less and we do not have any mechanism to find out the total content of the deposit but today the demands is ever increasing, the economic growth is touching newer heights, population is increasing and lastly we have technologies to assess the total quantity of these fossil fuels available in a particular place hence we can make a judge the fact, that for how much time the deposits of our fossil fuels will last.
Coal
Coal is by far the most abundant fossil fuel on earth. It is essentially carbon and is mainly used as a combustion fuel. The large-scale use of coal began with the Industrial Revolution in the 19th century. As the number of industries increased, demand for more sources of energy grew.
Coal is the product of plants, mainly trees that died tens or hundreds of millions of years ago. Due to water logging in low-lying swampy areas or in slowly sinking lagoons, dead trees and plants did not decompose as they normally would. The dead plant matter was covered with water and protected from the oxidizing effect of air. The action of certain bacteria released the oxygen and hydrogen, making the residue richer and richer in carbon. Thick layers of this carbon-rich substance, called peat, built up over thousands of years. As more material accumulated above the peat, the water was squeezed out leaving just carbon-rich plant remains. Pressure and temperature further compressed the material. This aided the process of producing coal as more gases were forced out and the proportion of carbon continued to increase. The carbon slowly metamorphosed into coal over millions of years. Coal is either mined or dug out while oil and natural gas are pumped out. Coal is widely distributed and is easier to locate than oil and gas.
Every year, millions of tonnes of coal is consumed as energy. This has led to global warming (greenhouse effect) and the depletion of resources.
At present, the worldwide burning of coal releases billions of tonnes of carbon dioxide (measured as carbon) into the atmosphere every year. Burning any fossil fuel means pollution of some sort. Even if the fuel is low in sulphur, the atmosphere contains nitrogen, which combines with oxygen at the high burning temperatures found in boilers, jet, or car engines. This yields nitrogen oxides, which like sulphur dioxide, dissolves in rain to form nitric acid. Both gases are poisonous to humans.Mining and exploration for coal can cause disturbance to the surrounding ecosystem.
There are three main types of coal: lignite, bituminous, and anthracite.
Anthracite has about 98% carbon, burns slowly and releases much less smoke. Lignite and bituminous have a lesser percentage of carbon in them and therefore burn faster but release a great deal of pollutants into the atmosphere.
Coal of all types contains sulphur to some degree. Sulphur is the worst of the pollutants and causes damage to human health and to vegetation. Though petroleum gained importance over the 20th century and continues to do so, coal remains essential for the industrial sector. It is the principal heat source for electricity generation in most countries and is used directly in such heavy industries as iron and steel making.
Especially in the US for many decades the government to curtail the dependency on Middle East countries for oil and gas had encouraged the use of coal for power generation.
Until recently, most coal came from underground mines. But now there are a large number of opencast mines. Underground coal mines are notorious killers due to roof falls and explosions. Accidents have resulted in the deaths of hundreds of miners. Almost 80% of today's coal comes from surface strip mines (opencast mines), which is much safer. Huge earth-moving equipment strips off the soils and rocks covering the buried coal seams. The land is backfilled and returned to normal after the coal has been removed, thereby repairing the landscape. But most companies do not refill the excavated area and leave it damaged. Most countries have now enforced backfilling by law.
Coal mining in India.
India has about seven per cent of the world's proven coal reserves. Coal supplies more than 50% of the country's total energy requirements. By current estimates, the reserves are enough to meet India's needs for at least another 100 years.
Coal mining in India dates back to the 18th century. The regulation of its use in the industrial sector was conceived in 1923. In 1972-73, the Indian government nationalized the coal industry, primarily to develop the sector, since it was considered to be of strategic importance for rapid industrial development.
India's coal demand is expected to increase several fold within the next 5–10 years due to the completion of ongoing coal-based power projects, and demand from metallurgical and other industries.
Coal is the dominant source of fuel in the industrial sector, with a share of nearly 72.5% in the total energy consumption. The industrial sector is the largest consumer of electricity, with a share of 41% of the total consumption. The transport sector is the largest consumer of petroleum products, and accounts for nearly 50% of the total consumption.
The small amount of coal presently consumed adds atmospheric pollutants, some of which precipitate into the ground and water. This assault on the environment has been the cause of heavy pollution in many areas of the world.
Oil and Gas.
Almost all oil and natural gas are found deep underground in tiny holes in rocks. Millions of years ago a sea covered much of what is now dry land. In prehistoric times, tiny plants and animals lived in the sea. When these creatures died, they sank to the bottom of the sea, and got buried in layers of mud and sand. As the ages passed, this organic material sank deeper and deeper. The earth's crust changed its shape, and put intense pressure and heat on what was once only plants and tiny animals. Heat from the earth's interior and the weight of the overlying rocks gradually changed the energy-containing substances in the accumulated plants into hydrocarbon liquids and gases. As millions of years passed, these deposits turned into chemicals that are now called 'hydrocarbons'.
Hydrocarbons are simple molecules made up of carbon and hydrogen atoms joined together in chains or in rings. These molecules, being light and mobile, migrated upwards through the rocks but eventually became trapped beneath impermeable rock structures in the earth's crust. That is where oil and natural gas come from. Some were created millions of years ago, some were created thousands of years ago, and some are being created right now!
Much of the oil and gas production now comes from underneath the sea-bed. As the technology for extraction continues to advance, production becomes possible from deeper and deeper waters. But the supplies are limited. Every drop of oil burnt adds to the monumental environment problems already created by pumping gases like carbon dioxide into the atmosphere. Many scientists worry that this continual release of carbon dioxide is an important cause of global warming.
Natural gas is usually found underground near an oil source. It is a mixture of light hydrocarbons including methane, ethane, propane, butane, and pentane. Other compounds found in natural gas include carbon dioxide, helium, hydrogen sulphide, and nitrogen. It is found around the world, but the largest reserves are in the former Soviet Union and the Middle East. This gas is lighter than air and is highly flammable, made up mainly of a gas called methane. Methane is a simple chemical compound that is made up of carbon and hydrogen atoms. Natural gas usually has no odour and cannot be seen. Before it is sent to the pipelines and storage tanks, it is mixed with a chemical that gives it a strong odour, almost like rotten eggs. The odour makes it easy to detect a leak.
Natural gas is the cleanest burning fossil fuel. When it is burned, it gives off less carbon dioxide than oil or coal, virtually no sulphur dioxide, and only small amounts of nitrous oxides. Natural gas is mostly composed of methane and other light hydrocarbons. Both the carbon and the hydrogen in methane combine with oxygen when natural gas is burned, giving off heat. Coal and oil contain proportionally more carbon than natural gas, therefore giving off more carbon dioxide per unit of energy produced. Natural gas gives off 50% of the carbon dioxide released by coal and 25% less carbon dioxide than oil, for the same amount of energy produced. Carbon dioxide is the most important greenhouse gas contributing to global warming.
To find oil and natural gas, companies drill through the earth to the deposits deep below the surface. The oil and natural gas are then pumped from below the ground by oil rigs. They then usually travel through pipelines.
At oil refineries, crude oil is split into various types of products by heating the thick black oil. The crude oil is refined by the process known as fractional distillation due to different melting points of each constituents the fractional distillation separate the different product like gasoline, diesel fuel, aviation fuel, home heating oil, oil for ships, and oil to burn in power plants to make electricity. Oil is used for transportation cars, airplanes, trucks, buses, and motorcycles.
Oil is stored in large tanks until it is sent to various places to be used. Oil is also made into many different products fertilizers for farms, clothes, toothbrush, plastic bottle, and plastic pen. There are thousands of other products that come from oil. Almost all plastic comes originally from oil. Oil is transported in huge pipelines and tanker ships to places where it is made into other products.
The origin of the oil industry in India can be traced back to the last part of the 19th century when petroleum was discovered in Digboi in north-east India. Thereafter large numbers of oil fields have been discovered both inland and off-shore. This has led to the setting up of refineries to process the oil and gas for use in various sectors. Today oil and gas is extracted from area like Mumbai sea high, Krishna Godavari basins etc.
As per the estimates the Oil and gas resources however are likely to be used up within the next 50 years. along with it when these fuels are burnt, they produce waste products that are released into the atmosphere as gases such as carbon dioxide, oxides of sulphur, nitrogen, and carbon monoxide, all causes of air pollution. These have led to lung problems in an enormous number of people all over the world, and have also affected buildings like the Taj Mahal and killed many forests and lakes due to acid rain. Many of these gases also act like a green house gases which traps the heat from sun and add into the average temperature of the earth causing the problems of global warming
Nuclear Power
The energy which is released by splitting a heavy atom in to two smaller atoms resulting into release of energy this atomic reaction is known as fission reaction, similarly when two smaller atoms are fused together to form one heavy atom accompanied with release of high amount of energy is known as fusion reaction. This energy which is released during this atomic reaction is known as nuclear energy or power, It was in 1938 two German scientists Otto Hahn and Fritz Strassman demonstrated nuclear fission. They discovered that when a slow speed neutron strikes the nucleus of an uranium atom it splits in to two smaller atoms and huge amount of energy is released. This huge amount of energy being released can be utilized to convert the water in to steam which can run a turbine and electric power can be generated. Nuclear fusion requires enormously high temperature and pressure to start the reaction secondly controlling this reaction is also very difficult. Hence still under experimentation stage
It was after the 1950s the nuclear power has come up as energy resource. The first large-scale nuclear power plant in the world became operational in 1957 in Pennsylvania, US. Dr. Homi Bhabha was the father of Nuclear Power development in India. The Bhabha Atomic Geo-Thermal Research Center in Mumbai studies and develops modern nuclear technology. India has 10 nuclear reactors at 5 nuclear power stations that produce 2% of India's electricity. These are located in Maharashtra (Tarapur), Rajasthan, Tamil Nadu, Uttar Pradesh and Gujrat. India has uranium from mines in Bihar. There are deposits of thorium in Kerala and Tamil Nadu. The nuclear reactors use Uranium 235 to produce electricity. Energy released from 1kg of Uranium 235 is equivalent to that produced by burning 3,000 tons of coal. After enriching the uranium to convert it in to U235 it is made into rods which are fitted into a nuclear reactor. When the reaction is carried out the controlling of reaction is very critical as if the reaction goes uncontrolled then it will result in to chain reaction resulting in to nuclear bomb which will be catastrophic. To control the speed of nuclear reaction control rods usually made of boron is used which, absorb neutrons and thus adjust the fission which releases energy due to the chain reaction in a reactor unit. The heat energy produced in the reaction is used to heat water and produce steam, which drives turbines that produce electricity. The drawback is that the rods need to be changed periodically. This has impacts on the environment due to disposal of nuclear waste. The reaction releases very hot waste water that damages aquatic ecosystems, even though it is cooled by a water system before it is released. The disposal of nuclear waste is becoming an increasingly serious issue. The cost of Nuclear Power generation must include the high cost of disposal of its waste and the decommissioning of old plants. These have high economic as well as ecological costs that are not taken into account when developing new nuclear installations. Although the nuclear energy has negligible conventional environmental impacts but even one accident can be devastating and the effects last for long periods of time. While it does not pollute air or water routinely like oil or biomass, a single accident can kill thousands of people, make many others seriously ill, and destroy an area for decades by its radioactivity which leads to death, cancer and genetic deformities. Land, water, vegetation are destroyed for long periods of time. Management, storage and disposal of radioactive wastes resulting from nuclear power generation are the biggest expenses of the nuclear power industry. There have been nuclear accidents at Chernobyl in USSR and at the Three Mile Island in USA. The radioactivity unleashed by such an accident can affect mankind for generations.
Introduction to key concepts of environmental management
Ecology is self regulated and cyclic in nature and try to maintain balance of its different elements, the anthropogenic activities ( activities and substances created by man) for the rapid development along with exploitation of natural resources for increasing demand is causing stress on the ecosystem,
Human beings are important part of the ecosystem but with rapid increase of human population and changes in life style, the ecosystem is not able to maintain the thin balance, resulting in to drastic changes like elimination of various species of flora and fauna, changes in climates and cycles of seasons, global warming, ozone hole and increase in the natural disasters like floods, hurricane, draught and earthquake etc all these changes not only hamper sustainable development on larger scale it will create devastating conditions for human existence.
Environmental management is a process to improve the harmonious relationship between man and nature so that the condition of both can be maintained and improved. Environmental management is a process to bring out balance between the human activities and environmental concerns by controlling the destructive anthropogenic activities and conserving, protecting and fostering regeneration capacities of nature.
Environmental management helps us understand that economic development should not be done at the cost of environment and we have to give the due importance to environment. Environmental management is a two prong strategy which involves socio economic development of society and maintenance of environment quality at the same time.
Due to increase in the human population which is because of following reasons
Decrease in infant mortality rate, improved health facilities, better standard of living and increase in average life span, along with increased demand of commodities a person demand, there is unscrupulous demand on ecosystem, hence environmental management helps to balance out increase in demand and control and maintenance of environment and its basic nature.
Environmental management involves following things
Conservation of natural resources, Preservation of environment for future generation, creating awareness in society about the importance of environment and its protection, protecting the various components of environment which are at verge of destruction, regulating and eliminating anthropogenic substances and activities which are creating havoc in our ecosystems. Protecting biosphere diversity of ecosystems.
Objectives of environmental management
To plan a judicious utilization and regulate exploitation of natural resources, mainly non renewable resources like fossil fuel, deposits of metal and minerals etc.
To protect the environment from further degradation and help it regenerate itself.
To reduce and restrict pollution and aftermaths related to it.
To curtail the effects of natural disaster which are caused by anthropocentric activities.
To improve the efficiency of utilization of resources and reduce wastage.
Conservation of environment and encouragement of reduce, recycle and reuse for all kind of resources like water, raw material etc.
To bring newer technologies to improve means of production and to mitigate the adverse impacts on environment cause earlier by us.
To help bring stringent laws and regulation to avoid further degradation of environment by human activities.
Paul Erlich equation
From the previous section it is evident that due to increased utilization of the natural resources the ecosystem is getting stressed out and the environment is changing drastically. We had also seen that the major factor is the increase in the population which is resulting into such catastrophe. Paul Erlich has given an equation to find out the impact on environment due to different factors
Paul Ehrlich Equation can be presented as:
I = P x A x T.
I is the impact on the environment.
P is the population.
A is the consumption per capita (affluence)
T is the technology factor.
According to Paul Ehrlich equation the impact on environment is directly related to number of population i.e with the increase in population the impact on environment will increase as the demand for different resources will increase.
Secondly the average consumption of an individual is also directly related to the environmental impact i.e if the demands for the different product and services increases the environmental impact will also increase.
Lastly the technological factor according to Ehrlich if we can develop efficient and more effective technologies then even if there is an increase in the population or affluence we can sustain, and there will be no increase in the in environmental impact. Ehrlich equation was also mentioned in the UNEP report of April 2002, "Sustainable consumption: it was termed as 'The Consumption Equation':
The relationship between population, consumption and environmental impact can be described in approximate terms by an equation first proposed by Ehrlich and Holdren in 1971:
TEI = P x UC/hp x EE -1
where TEI is total environmental impact is population, UC/hp is (average) units of consumption of products and services per head of population and EE is the environmental efficiency of the production, use and disposal of those units.
This equation makes it easy to visualize the importance of considering levels of consumption of goods and services (per head) and the resources used (and waste generated) to produce those goods and services. Patterns of consumption are a term that intends to capture both these variables. Consumption pressure per head describes the (aggregated) product of the two terms UC/hd and the inverse of EE. It is from such an equation that the concept of factor 4 (etc) emerges – being the level of change in EE that can be achieved through technical and organizational improvements (cleaner production; product re-design etc). If the intent is to reach some specific level of TEI (say for CO2 production) in a given period, then estimates of the likely population growth over that period, as well as the likely rise in the average level of consumption per head (from development, GDP growth etc), will define the factor of improvement in EE necessary to compensate for this rise.
Arguments that arise over the role of population growth in environmental degradation can also be clarified with reference to this equation, since it is clear that the issue is the product of population numbers times the average consumption pressure per head. Rebound effects arise from a relationship between UC/hd and EE, where improvements in EE generate increased consumption per head.
Tools of environmental management and environmental decision making
We had already discussed the definition and objectives of the environmental management, for implementation of environmental management and make decision related to environment and to make any decision where we have to consider the environmental impact we need to follow a formal approach of decision making, being a manager one has to keep in mind the effect of his decision on environment similarly the government while doing planning for development activities at macro level also rely on certain tools which they can use for making right decision and asses the impact on environment and achieve the target of environmental management.
Decision making process starts when there is a compelling situation and there is a need to select an alternative from various alternatives available to us , we need to asses those alternatives and find out which alternatives suitable for us which will give us the desired outcomes, the quality of decision depends on the information we have and its rational analysis.
When we are taking decision pertaining to environmental management we have to ensure that the decisions taken at micro or macro level should be rational and based on thorough information gathering and rational interpretations because the aftermaths of wrong decisions are long lasting, irrevocable and damaging hence we need sound and reliable mechanism to gather and interpret the data for decision making.
In environmental management we can use following tools to collect data from different sources to make better decisions.
Interviews: - it can be structured or unstructured and this method is suitable when one to one interactions from the experts are required.
Group Discussions:- a group usually comprising experts from different fields and representatives of different pressure groups do brainstorming sessions e.g group discussions can be in the form of focus discussion, fish bowling etc here an ideas generated are tested by others and the view from different parties are collected and judged in the background of the facts collected by other methods. The finalized
Questionnaires:- A quantitative method of data collection, and data is analyzed with statistical method to come to any conclusion.
Observations: observations in terms remote sensing GIS etc, sample testing can also yield a good quality of data for making decisions for environmental management
Scientific testing (It has been proven that communities can undertake effective testing without sophisticated training) provides scientific proofs and facts which can be used in making decisions.
Maps, drawings or any other visual techniques that can accurately depict changes is also beneficial for making decisions.
Before-and-after images captured by audio-visual equipment
Other methods devised by the community.
Environmental impact assessments are also a detailed method which helps in taking rational and logical decisions which has environmental concerns.
Introduction to natural resource accounting and auditing
With increasing development activities the exploitation of natural resources grew up and reached such level when the growth of human development come under threat, due to extinction of resources and irreversible damages caused by the anthropogenic activities. Earlier we talk about economical development whether it is in terms of micro or macro level e.g. the growth of the company is discussed in terms of profits and country's development is rated according to GDP but at no point of time the impact on environment due to development activities were considered. But after increasing impacts of environmental change and improving technology man become conscious about the environmental concerns today company or nation not only talk about economic growth they talk about economic growth , social growth and environmental growth.
Due to increased awareness towards environmental concerns concepts of natural resource accounting and auditing came in to the existence.
Natural resource accounting is process to record, classify, analyze and interpret all activities which are directly or indirectly related to natural resource available, natural resource accounting involves gathering and storing data pertaining to natural resources available in a given areas and record any changes in them at periodic basis.
Natural resource accounting involves following
- To classify different resources available in an area.
- To collect data from different sources, about different resources e.g. inventories about water resources, mineral and metal resources, fossil fuel deposits etc.
- To collect the data at regular interval and find out changes in them e.g. with the help of remote sensing technology we can find changes in land under forest.
- To asses the total deposits of resources available and its life before extinction e,g the assessing the total amount of ore or crude oil deposit in a mine or oil field and make an estimate up to how much time it will last.
- To find out requirements of natural resources for achievement of economical targets.
- To relate the economic growth targets with the depletion of natural resources.
- Natural resource auditing is a process to verify the facts and data pertaining to natural resource management of any area or country, under natural resource accounting we had seen that we have to give due importance to the environmental concern and its role in economic development, we have to find out what is intended and what is achieved in term of natural resource planning for conservation, prevention and regeneration of our natural resources along with changes in them brought by economical development activities. Natural resource auditing also assist in identifying natural resource management priorities, and allowing analyzing the progress in natural resource management of any area due to initiatives or projects undertaken by the government or the industry in this regard. Under natural resource accounting we calculate the changes in the natural resources after a give period of time.
Natural resource accounting helps in assessing natural resource management through the development and maintenance of accurate, cost-effective, accessible and timely data and information on the nation's natural resources. To help assess: health of land, water, vegetation and biological resources performance of government programs, strategies and policies. Auditing only verify that up to what degree the planning and implementation is matching.
Following are the benefits of natural resource auditing
- Helps in identifying information needs for management of natural resource available in a given area, its conservation, preservation and growth.
- Helps in generating and storing information, which can be made available for any comparative analysis in this regard.
- Conducting different analysis and reporting through assessments.
- Building capabilities through partnerships of public with governments etc
- Helps in providing strategic advice on natural resource information to any user
Role of Remote Sensing and Geographical Information System (GIS)
Introduction
Remote sensing can be defined as the collection of data about an object from a distance or collection of data remotely. Man and many other types of animals accomplish this task with help of eyes or by the sense of smell or hearing. Certain other animals like bees use the uv rays and bats use electromagnetic waves. Environmentalists and Geographers use the technique of remote sensing to monitor or measure phenomena found in the Earth's lithosphere, bioshperhe, hydrosphere, and atmosphere. Remote sensers are the devices which are used to conduct remote sensing of the environment. These gadgets have a greatly improved ability to receive and record information about an object without any physical contact. Often, these sensors are positioned away from the object of interest by using helicopters, planes, and satellites. Most sensing devices record information about an object by measuring an object's transmission of electromagnetic energy from reflecting and radiating surfaces.
Use of remote sensing in environmental management
Mapping land-use which provide details and helps to do analysis and planning about the land being used for agriculture, forestry, urbanization etc. Remote sensing is also useful in soils mapping, conducting assessments for mineral and fossil fuel deposits under the earth. Remote sensing can also be used for predicting and forecasting climate changes and predicting natural disasters like cyclones, storms and hurricanes etc, forecast of rains etc can be done by remote sensing devices. Remote sensing also helps in geomorphologic surveying, among other uses. For example, foresters use aerial photographs for preparing forest cover maps, locating possible access roads, and measuring quantities of trees harvested. Specialized photography using color infrared film has also been used to detect disease and insect damage in forest trees.
Methods
The simplest form of remote sensing uses photographic cameras to record information from visible or near infrared wavelengths (Table 2e-1). Under this method cameras are projected above the area and photographs are taken based on the analysis of the reflected waves information is collected about the area.
In the beginning in late 1800s, cameras were positioned above the Earth's surface in balloons or kites to take oblique aerial photographs of the landscape. these photographs were taken during World War I, to collect data about the position and movements of enemy troops. These photographs were often taken from airplanes. Later on this method is used in other areas and specially for environmental management e.g for developing maps etc.
Remote sensing can be done with the help of recording the waves reflected by the objects underneath and remote sensing use following types of waves of the collection and interpretation of data which has following attributes.
Major regions of the electromagnetic spectrum.
Region Name | Wavelength | Comments |
Gamma Ray | < 0.03 nanometers | Entirely absorbed by the Earth's atmosphere and not available for remote sensing. |
X-ray | 0.03 to 30 nanometers | Entirely absorbed by the Earth's atmosphere and not available for remote sensing. |
Ultraviolet | 0.03 to 0.4 micrometers | Wavelengths from 0.03 to 0.3 micrometers absorbed by ozone in the Earth's atmosphere. |
Photographic Ultraviolet | 0.3 to 0.4 micrometers | Available for remote sensing the Earth. Can be imaged with photographic film. |
Visible | 0.4 to 0.7 micrometers | Available for remote sensing the Earth. Can be imaged with photographic film. |
Infrared | 0.7 to 100 micrometers | Available for remote sensing the Earth. Can be imaged with photographic film. |
Reflected Infrared | 0.7 to 3.0 micrometers | Available for remote sensing the Earth. Near Infrared 0.7 to 0.9 micrometers. Can be imaged with photographic film. |
Thermal Infrared | 3.0 to 14 micrometers | Available for remote sensing the Earth. This wavelength cannot be captured with photographic film. Instead, mechanical sensors are used to image this wavelength band. |
Microwave or Radar | 0.1 to 100 centimeters | Longer wavelengths of this band can pass through clouds, fog, and rain. Images using this band can be made with sensors that actively emit microwaves. |
Radio | > 100 centimeters | Not normally used for remote sensing the Earth. |
Initially the black and white images were used for remote sensing which was not very accurate, later on with the development of color photography the colored pictures gave a more natural depiction of surface objects more accurate information can be gathered .the difference the color patterns can be better understood by the human eye and we can differentiate many more shades of color than tones of gray and whites. After the development, done by Kodak in color infrared film, which recorded wavelengths in the near-infrared part of the electromagnetic spectrum. This film type had good haze penetration and the ability to determine the type and health of vegetation.
Remote Sensing by satellites
Later on mankind was able to place satellite in the earth's orbit and high resolution cameras were fitted on it and era of satellite remote sensing commenced. The basic advantage of satellite based remote sensing is that they are placed at greater height which helps to take a view of larger areas and secondly they have better resolution cameras which helps us take better pictures. The first meteorological satellite, TIROS-1 , was launched by the United States using an Atlas rocket on April 1, 1960. This early weather satellite used vidicon cameras to scan wide areas of the Earth's surface. Early satellite remote sensors did not use conventional film to produce their images. Instead, the sensors digitally capture the images using a device similar to a television camera. Once captured, this data is then transmitted electronically to receiving stations found on the Earth's surface. The image below is from TIROS-7 of a mid-latitude cyclone off the coast of New Zealand.
Remote sensing with the help of GOES (Geostationary Operational Environmental Satellite) system of satellites provides most of the remotely sensed weather information. A geostationary satellite is placed in earth's orbit it remains stationary relative to its location in the orbit and is suitable to gather data from a particular site. For collection of data we can use two or more than two geostationary satellites which can act in close network to collect data for the planet. The advanced sensors aboard the GOES satellite produce a continuous data stream so images can be viewed at any instance. The imaging sensor produces visible and infrared images of the Earth's terrestrial surface and oceans. Infrared images can depict weather conditions even during the night. Another sensor aboard the satellite can determine vertical temperature profiles, vertical moisture profiles, total perceptible water, and atmospheric stability.
By the year 1970s, the second revolution in remote sensing technology began with the deployment of the Landsat satellites. Since this 1972, several generations of Landsat satellites with their Multispectral Scanners (MSS) have been providing continuous coverage of the Earth for almost 30 years. Current, Landsat satellites orbit the Earth's surface at an altitude of approximately 700 kilometers. Spatial resolution of objects on the ground surface is 79 x 56 meters. Complete coverage of the globe requires 233 orbits and occurs every 16 days. The Multispectral Scanner records a zone of the Earth's surface that is 185 kilometers wide in four wavelength bands: band 4 at 0.5 to 0.6 micrometers, band 5 at 0.6 to 0.7 micrometers, band 6 at 0.7 to 0.8 micrometers, and band 7 at 0.8 to 1.1 micrometers. Bands 4 and 5 receive the green and red wavelengths in the visible light range of the electromagnetic spectrum. The last two bands image near-infrared wavelengths. A second sensing system was added to Landsat satellites launched after 1982. This imaging system, known as the Thematic Mapper, records seven wavelength bands from the visible to far-infrared portions of the electromagnetic spectrum. In addition, the ground resolution of this sensor was enhanced to 30 x 20 meters. This modification allows for greatly improved clarity of imaged objects.
Radarsat-1 was launched by the Canadian Space Agency in November, 1995. As a remote sensing device, Radarsat is quite different from the Landsat and SPOT satellites. Radarsat is an active remote sensing system that transmits and receives microwave radiation. Landsat and SPOT sensors passively measure reflected radiation at wavelengths roughly equivalent to those detected by our eyes. Radarsat's microwave energy penetrates clouds, rain, dust, or haze and produces images regardless of the Sun's illumination allowing it to image in darkness. Radarsat images have a resolution between 8 to 100 meters. This sensor has found important applications in crop monitoring, defense surveillance, disaster monitoring, geologic resource mapping, sea-ice mapping and monitoring, oil slick detection, and digital elevation modeling.
Object Identification in remote sensing
One can easily identify objects from photographs taken from an oblique angle. Such views are natural to the human eye and are part of our everyday experience. However, most remotely sensed images are taken from an overhead or vertical perspective and from distances quite removed from ground level. Under these circumstances interpretation of natural and human-made objects is somewhat difficult. In addition, images obtained from devices that receive and capture electromagnetic wavelengths outside human vision can present views that are quite unfamiliar.
To overcome the potential difficulties involved in image recognition, professional image interpreters use a number of characteristics to help them identify remotely sensed objects. Some of these characteristics include:
Shape: this characteristic alone may serve to identify many objects. Examples include the long linear lines of highways, the intersecting runways of an airfield, the perfectly rectangular shape of buildings, or the recognizable shape of park etc
Size: noting the relative and absolute sizes of objects is important in their identification. The scale of the image determines the absolute size of an object. As a result, it is very important to recognize the scale of the image to be analyzed.
Image Tone or Color: all objects reflect or emit specific signatures of electromagnetic radiation. In most cases, related types of objects emit or reflect similar wavelengths of radiation. Also, the types of recording device and recording media produce images that are reflective of their sensitivity to particular range of radiation. As a result, the interpreter must be aware of how the object being viewed will appear on the image examined. For example, on color infrared images vegetation has a color that ranges from pink to red rather than the usual tones of green.
Pattern: many objects arrange themselves in typical patterns. This is especially true of human-made phenomena. For example, orchards have a systematic arrangement imposed by a farmer, while natural vegetation usually has a random or chaotic pattern.
Shadow: shadows can sometimes be used to get a different view of an object. For example, an overhead photograph of a towering smokestack or a radio transmission tower normally presents an identification problem. This difficulty can be over come by photographing these objects at Sun angles that cast shadows. These shadows then display the shape of the object on the ground. Shadows can also be a problem to interpreters because they often conceal things found on the Earth's surface.
Texture: imaged objects display some degree of coarseness or smoothness. This characteristic can sometimes be useful in object interpretation. For example, we would normally expect to see textural differences when comparing an area of grass with a field corn. Texture, just like object size, is directly related to the scale of the image.
Geographic Information Systems (GIS).
Introduction and History
After growth in the computerized technologies and advent of super computers the development of innovative software applications for the storage, analysis, and display of geographic data is increased. Such softwares were also developed for the purpose of Many of these applications belong to a group of software known as Geographic Information Systems (GIS). We can define GIS as integration of processes, procedures, equipments and machinery to carry out activities to gather analyze and interpret data which can be used for the purpose of gathering, storing, sharing and interpreting information pertaining to geographic information, it includes the measurement of natural and human made phenomena and processes from a spatial perspective. These measurements emphasize three types of properties commonly associated with these types of systems: elements, attributes, and relationships.
The storage of measurements in digital form in a computer database. These measurements are often linked to features on a digital map. The features can be of three types: points, lines, or areas (polygons).
The analysis of collected measurements to produce more data and to discover new relationships by numerically manipulating and modeling different pieces of data.
The depiction of the measured or analyzed data in some type of display - maps, graphs, lists, or summary statistics.
The first computerized GIS began its life in 1964 as a project of the Rehabilitation and Development Agency Program within the government of Canada. The Canada Geographic Information System (CGIS) was designed to analyze Canada's national land inventory data to aid in the development of land for agriculture. The CGIS project was completed in 1971 and the software is still in use today. The CGIS project also involved a number of key innovations that have found their way into the feature set of many subsequent software developments.
From the mid-1960s to 1970s, developments in GIS were mainly occurring at government agencies and at universities. In 1964, Howard Fisher established the Harvard Lab for Computer Graphics where many of the industries early leaders studied. The Harvard Lab produced a number of mainframe GIS applications
including: SYMAP (Synagraphic Mapping System),CALFORM, SYMVU, GRID, POLYVRT, and ODYSSEY. ODYSSEY was first modern vector GIS and many of its features would form the basis for future commercial applications. Automatic Mapping System was developed by the United States Central Intelligence Agency (CIA) in the late 1960s. This project then spawned the CIA's World Data Bank, a collection of coastlines, rivers, and political boundaries, and the CAM software package that created maps at different scales from this data. This development was one of the first systematic map databases. In 1969, Jack Dangermond, who studied at the Harvard Lab for Computer Graphics, co-founded Environmental Systems Research Institute (ESRI) with his wife Laura. ESRI would become in a few years the dominate force in the GIS marketplace and create Arc Info and Arc View software. The first conference dealing with GIS took place in 1970 and was organized by Roger Tomlinson (key individual in the development of CGIS) and Duane Marble (professor at Northwestern University and early GIS innovator). Today, numerous conferences dealing with GIS run every year attracting thousands of attendants.
In the 1980s and 1990s, many GIS applications underwent substantial evolution in terms of features and analysis power. Many of these packages were being refined by private companies who could see the future commercial potential of this software. Some of the popular commercial applications launched during this period include: ArcInfo, ArcView, MapInfo, SPANS GIS, PAMAP GIS, INTERGRAPH, and SMALLWORLD. It was also during this period that many GIS applications moved from expensive minicomputer workstations to personal computer hardware.
Components of a GIS
A Geographic Information System combines computer cartography with a database management system. The following Figure describes some of the major components common to a GIS. This diagram suggests that a GIS consists of three
subsystems: (1) an input system that allows for the collection of data to be used and analyzed for some purpose; (2) computer hardware and software systems that store the data, allow for data management and analysis, and can be used to display data manipulations on a computer monitor; (3) an output system that generates hard copy maps, images, and other types of output.
Three major components of a Geographic Information System. These components consist of input, computer hardware and software, and output subsystems. |
Two basic types of data are normally entered into a GIS. The first type of data consists of real world phenomena and features that have some kind of spatial dimension. Usually, these data elements are depicted mathematically in the GIS as points, lines, or polygons that are referenced geographically (or geocoded) to some type of coordinate system. This type data is entered into the GIS by devices like scanners, digitizers, GPS, air photos, and satellite imagery. The other type of data is sometimes referred to as an attribute. Attributes are pieces of data that are connected or related to the points, lines, or polygons mapped in the GIS. This attribute data can be analyzed to determine patterns of importance. Attribute data is entered directly into a database where it is associated with element data.
Within the GIS database a user can enter, analyze, and manipulate data that is associated with some spatial element in the real world. The cartographic software of the GIS enables one to display the geographic information at any scale or projection and as a variety of layers which can be turned on or off. Each layer would show some different aspect of a place on the Earth. These layers could show things like a road network, topography, vegetation cover, streams and water bodies, or the distribution of annual precipitation received.
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