Environmental Management Unit 1
- 2. Now a days the word environment is often being used by almost all people around us, on television and in newspapers. Everyone is speaking about the protection and pre-serration of environment. Global summits are being held regularly to discuss environmental issues. During the last hundred years, the mutual relationship among environment, social organization and culture has been discussed in sociology, anthropology and geography. All this shows the increasing importance of environment.
- 3. Introduction The word Environment is derived from the French word ‘environ’ which means to encompass or encircle. It is believed to have been introduced in the subject by biologist Jacob Van Erkul in the early 1990’s In the Hindu mythology we come across with the word ‘Pancha Mahabhute’ which are the basic elements of our natural environment. Those are naturally present right from the origin of the earth. These includes 5 basic units – Earth (Land) Water Wind (Air) Sky Energy
- 4. However, the man on the earth is surrounded also by the man-made or artificial features. Environment is the mixture of the components of both natural and man-made environments. The proportion of these two parts may be variable from place to place. In short, Environment encompasses the interaction between the living & non-living world within a particular geographical area. OR Environment is the sum total of all living & non-living factors that compose the surrounding of man.
- 5. In other words environment refers to those surroundings that surrounds living beings from all sides and affect their lives in toto. It consists of atmosphere, hydrosphere, lithosphere and biosphere. It’s chief components are soil, water, air, organisms and solar energy. It has provided us all the resources for leading a comfortable life. Definitions According to P. Gisbert “Environment is anything immediately surrounding an object and exerting a direct influence on it.” According to E. J. Ross “Environment is an external force which influences us.”
- 6. CHARACTERTICS OF ENVIRONMENTAL MANAGEMENT Environmental management supports sustainable development. Environmental management demands the multi-disciplinary approach. It deals with a world affected by humans. Environmental management has to integrate different development viewpoints. Environmental management seeks to integrate natural and social science. Environmental management can extend from short-term to long-term and from local to global level.
- 7. COMPONENTS OF ENVIRONMENT The environment consists of various segments such as atmosphere, hydrosphere, lithosphere and biosphere. 1. Atmosphere: The following points highlight the vital role played by atmosphere in the survival of life in this planet: The atmosphere is the protective blanket of gases which is surrounding the earth. It protects the earth from the hostile environment of outer space. It absorbs 1R radiations emitted by the sun and reemitted from the earth and thus controls the temperature of the earth. It allows transmission of significant amounts of radiation only in the regions of 300 – 2500 nm (near UV, Visible, and near IR) and 0.01 – 40 meters (radio waves), i.e. it filters tissue damaging UV radiation below 300 nm. It acts as a source for C02 for plant photosynthesis and 02 for respiration It acts as a source for nitrogen for nitrogen fixing bacteria and ammonia producing plants. The atmosphere transports water from ocean to land.
- 8. HYDROSPHERE The hydrosphere is a collective term given to all different forms of water. It includes all types of water resources such as oceans, seas, rivers, lakes, streams, reservoirs, glaciers and ground waters. The distribution of earth’s water supply As can be seen, only 1 % of the total water supply is available as fresh water in the form of rivers, lakes, streams and ground water for human consumption and other uses. The extent of the use of available fresh water for various purposes. The major problem with global water supply is its non-uniform distribution, since people in areas with low precipitation often consume more than people in regions with more rainfall.
- 9. LITHOSPHERE The earth is divided into layers The lithosphere consists of upper mantle and the crust. The crust is the earth’s outer skin that is accessible to human. The crust consists of rocks and soil of which the latter is the important part of lithosphere.
- 10. BIOSPHERE • The biosphere refers to the realm of living organisms and their interactions with the environment (VIZ: atmosphere, hydrosphere and lithosphere) • The biosphere is very large and complex and is divided into smaller units called ecosystems. • Plants, animals and microorganisms which live in a definite zone along with physical factors such as soil, water and air constitute an ecosystem. • Within each ecosystems there are dynamic inter relationships between living forms and their physical environment. The natural cycles operate in a balanced manner providing a continuous circulation of essential constituents necessary for life and this stabilizes and sustains the life processes on earth. • These inter relationships manifest as natural cycles, (hydrologic cycle, oxygen cycle, nitrogen cycle, phosphorous cycle and Sulphur cycle).The shape of the Earth is very close to that of an oblate spheroid, a sphere flattened along the axis from pole to pole.
- 11. Bio-geo-chemical Cycle Though the energy flow in an ecosystem is one way, the flow of nutrient is cyclical. All organisms need nutrients for their growth. The cyclical flow of nutrients within an ecosystem is called the Bio-geo-chemical cycle
- 12. Nutrients, necessary for the growth of organisms are continuously transferred from abiotic to biotic factors & from biotic to abiotic factors within an ecosystem. This cycle operates continuously through the medium of biosphere formed by lithosphere, hydrosphere & atmosphere. The recycling of biological, geological & chemical sources of nutrients in this process is a complex process and depends upon the level of energy transfer in the ecosystem. Bio-geo-chemical cycle Gaseous cycle Sedimentary cycle
- 13. NITROGEN CYCLE Atmospheric nitrogen cannot be used directly by plants and animals. Nitrogen needs to get converted to nitrogenous compounds. This process is called Nitrogen fixation. Nitrogen forms 78% i.e. the maximum portion of the atmosphere. It is necessary for the maintenance of the cycle of nature. The circulation & recycling of nitrogen gas into the form of different compounds through various biotic & abiotic processes in nature is called the Nitrogen Cycle. All organism participate in the Nitrogen Cycle. It is an important component of proteins & nucleic acid as compared to other elements it is inactive & does not easily combine with other elements. Most organisms cannot use free form of nitrogen
- 14. IMPORTANT PROCESS OF NITROGEN CYCLE Nitrogen fixation Conversion of nitrogen into nitrates & nitrites through atmospheric, industrial & biological processes. Ammonification Release of ammonia through decomposition of dead bodies & excretory wastes of organisms. Nitrification Conversion of ammonia into a nitrite & then nitrate. Denitrification Conversion of nitrogen compounds into gaseous nitrogen.
- 16. The atmospheric nitrogen cannot be taken directly by plants and animals. Certain bacteria and blue green algae present in the soil fix nitrogen from the atmosphere and convert into compounds of nitrogen. Once nitrogen is converted into these usable compounds, it can be utilized by plants from the soil through their root system. Nitrogen is then used for the synthesis of plant proteins and other compounds. Animals feeding on plants get these proteins and other nitrogen compounds. When plants and animals die, bacteria and fungi present in the soil convert the nitrogenous wastes into nitrogenous compounds to be used by plants again. Certain other bacteria convert some part of them to nitrogen gas which goes back into the atmosphere. As a result, the percentage of nitrogen in the atmosphere remains more or less constant.
- 17. WATER CYCLE INTRODUCTION The vast majority of Earth's water is saltwater found in oceans. Only a tiny fraction is readily accessible freshwater, which is what humans need. Water found at the Earth's surface can cycle rapidly, but much of Earth's water lies in ice, oceans, and underground reservoirs; this water cycles slowly. The water cycle is complex and involves state changes in water as well as the physical movement of water through and between ecosystems. Groundwater is found underground between soil particles and in cracks of rocks. Aquifers are groundwater reservoirs often tapped by wells.
- 18. • Of the water on Earth, 97.5% is salt water. • Of the remaining water, over 99% is in the form of underground water or ice. • All told, less than 1% of fresh water is found in lakes, rivers, and other available surface forms.
- 19. • The water cycle is driven by the Sun’s energy. The sun warms the ocean surface and other surface water, causing liquid water to evaporate and ice to sublime—turn directly from a solid to a gas. These sun-driven processes move water into the atmosphere in the form of water vapor. • Over time, water vapor in the atmosphere condenses into clouds and eventually falls as precipitation, rain or snow. When precipitation reaches Earth's surface, it has a few options: it may evaporate again, flow over the surface, or percolate—sink down—into the ground. • In land-based, or terrestrial, ecosystems in their natural state, rain usually hits the leaves and other surfaces of plants before it reaches the soil. Some water evaporates quickly from the surfaces of the plants. The water that's left reaches the soil and, in most cases, will begin to move down into it.
- 21. Water in the upper levels of the soil can be taken up by plant roots. Plants use some of the water for their own metabolism, and water that's in plant tissues can find its way into animals’ bodies when the plants get eaten. However, most of the water that enters a plant's body will be lost back to the atmosphere in a process called transpiration. In transpiration, water enters through the roots, travels upwards through vascular tubes made out of dead cells, and evaporates through pores called stomata found in the leaves.
- 22. CARBON CYCLE The circulation & recycling of carbon from the atmosphere to living organisms & after their death back to the atmosphere is called the carbon cycle. Abiotic carbon atoms are circulated & recycled into biotic form mainly through photosynthesis & respiration. Hence the carbon cycle is one of the important bio-geo-chemical cycle.
- 23. Plants convert carbon dioxide into carbohydrates by the process of photosynthesis. Similarly, they produce carbon compounds like proteins & fats etc. Herbivores feed upon plants . Carnivores feed upon herbivores. In this way, biotic carbon is transported from plants to herbivores, from herbivores to carnivores and from carnivores to apex consumers. Eventually, after death, all types of consumer, are decomposed by decomposer like bacteria & fungi & carbon dioxide is released again into the atmosphere and is used again by living organism. In this way, carbon is continuously passed from one living organism to another. After the death of living organisms, carbon goes to the atmosphere & is again taken up by living organisms. Carbon dioxide is released into the atmosphere through abiotic processes like burning of fossil fuels & wood, forest fires & volcanic activity.
- 24. OXYGEN CYCLE Oxygen forms 21% of the atmosphere. It is also present in the hydrosphere & lithosphere. Circulation & recycling of oxygen within the biosphere is called the Oxygen Cycle.
- 25. • Oxygen is continuously produced & used up in the atmosphere. The oxygen cycle includes both biotic & abiotic components. • During photosynthesis plants use carbon dioxide & release oxygen in the atmosphere. Animals utilize this oxygen for respiration & release carbon dioxide. The released carbon dioxide is again used up by plants for photosynthesis. • Oxygen is also utilized in various other processes such as- combustion, decomposition, corrosion, rusting etc. • As, oxygen is highly reactive, it readily reacts with other elements & compounds. • Equilibrium of oxygen & carbon dioxide gaseous is maintained in the atmosphere by the plants.