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BEVAE-181: Environmental Studies

BEVAE-181: Environmental Studies

IGNOU Solved Assignment Solution for 2022-23

If you are looking for BEVAE-181 IGNOU Solved Assignment solution for the subject Environmental Studies, you have come to the right place. BEVAE-181 solution on this page applies to 2022-23 session students studying in BAG, BSCG, BAVTM, BAECH, BAHIH, BAPSH, BAPAH, BAPCH, BASOH, BAEGH, BSCANH, BSCBCH, BAPFHMH, BBARIL, BAVMSME, BCOMG, BAHDH, BAFSM, ADIR, BAGS courses of IGNOU.

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Assignment Code: BEVAE-181/TMA/2022-23

Course Code: BEVAE-181

Assignment Name: Environment Studies

Year: 2022-2023

Verification Status: Verified by Professor




Q1. Why ecological significance of forest is more important in present day context? Explain.

Ans) As previously indicated, forests serve a variety of purposes, including regulating the global climate and sustaining natural ecological systems and processes.


Moderation of global climate

Forests have a huge impact on natural cycles including the hydrological and carbon cycles, which stabilise the climate on a worldwide scale. When you were in school, you could have read something about these cycles. As you are aware, forests have a significant impact on both the geographical and temporal patterns of rainfall. The amount of tree cover affects how much water is held in the soil and how much drains out, occasionally producing floods. Forests can similarly affect the amount of carbon dioxide in the atmosphere. Carbon dioxide is fixed in the biomass of trees. The ability of forests to absorb carbon dioxide from the atmosphere makes them a significant source of carbon sinks. Or to put it another way, a carbon sink is a natural or man-made reservoir that gathers and preserves a carbon-containing chemical component for all time. CO2 is released into the atmosphere when wood is burned. The magnitude of the greenhouse effect and global warming are directly impacted by this. In other words, as there are more forests, there is a larger removal of atmospheric carbon dioxide during photosynthesis, which leads to a decrease in the atmospheric concentration of greenhouse gases. As a result, extensive afforestation has been implemented as a strategy to lessen the greenhouse impact.


Protection of biodiversity

As they offer the best circumstances for the survival and development of living things, forests are the largest reservoir of biodiversity on earth. In comparison to other terrestrial ecosystems, forests have a significantly higher species density per unit area. For instance, more than half of all known species are found in the tropical rainforest, which occupies less than 7% of the planet's land area. These rainforests include about 62% of all known plant species. Because of this, a growing push to preserve the Amazon and Nile basin rain forest has been launched. Humans are beginning to understand the value of forests thanks to the growing knowledge of the requirement and importance of conserving biodiversity. Do you believe that this awareness-raising effort will be enough to safeguard the rain forest? Considering it? In the final section of this unit, we'll talk about several conservation measures.


Supporting natural ecological systems and processes

As was already established, certain tasks carried out by forests are essential for directly supporting ecological systems and processes. The following are a few of these activities and procedures:

  1. By stopping the activity of wind and water, forests control soil erosion, preserving the fertile topsoil.

  2. It lessens the severity of cyclones and floods and prevents landslides.

  3. Forests reduce silting of water bodies, particularly reservoirs, by limiting soil erosion.

  4. Through the absorption of harmful gases and particulates, forests enhance air quality.

  5. It safeguards watersheds and guarantees enduring access to clean water.


Socio-cultural significance

Since the dawn of civilization, forests have played a significant role in shaping our social and cultural values, as was noted in the introduction. Even in the contemporary, materialistic world, we may still see evidence of these cultural ties. This is largely attributable to the aesthetic, recreational, and spiritual importance of woods.


Q2. Answer the following questions in about 125 words each.


Q2.a) Explain the characteristics of Western Ghats for inclusion as Biodiversity hotspots.

Ans) One of India's largest tropical evergreen forest zones are the Western Ghats. The Western Ghats cover over 160,000 square kilometres in total. The zone has a border with the Deccan peninsular zone in the east and is bound by the coast in the west. Approximately one-third of the entire area of this zone is taken up by tropical evergreen forests. Due to the recent loss of a significant portion of the forest cover and the outstanding biologisscal diversity of this area, there are now serious conservation concerns. This area is home to almost two thirds of India's indigenous plants. But many of these species' potential has yet to be realised. The trees in this area not only support a variety of ecological communities but are crucial to supporting the hydrological cycle.


Q2.b) Why hydropower is regarded as the best source of energy? Explain it in detail.

Ans) The best energy source is considered to be hydro power because it is the cheapest and cleanest. One of the earliest and most significant types of renewable energy, hydropower or hydroelectric power harnesses the naturally occurring flow of moving water to produce electricity. Currently, 31.5 percent of all renewable electricity produced in the US and around 6.3 percent of all electricity produced in the country comes from hydropower. Small hydro power facilities are emerging as practical alternatives to the controversial mega dams that have recently generated so much controversy. These plants meet the energy needs of isolated and rural communities without access to the grid. Water flowing in on one side and out, far below, on the other is used by hydropower technologies to create electricity by taking advantage of the elevation difference formed by a dam or other diversion construction. The "Hydropower 101" video from the Department of Energy discusses the principles of hydropower and displays some of the work being done in this field by the Waterpower Technologies Office (WPTO).


Q2.c) The importance of Biomass has been increasing day by day in our surroundings among renewable resources. Explain it with suitable examples.

Ans) Biomass is a popular fuel in many nations, particularly for heating and cooking in underdeveloped nations. In many industrialised nations, the use of biomass fuels for electricity production and transportation is rising as a way to reduce carbon dioxide emissions from burning fossil fuels. Approximately one-third of the fuel consumed in India is made up of biomass. Approximately 15% of urban families and over 90% of rural households utilise biomass fuels (e.g., wood, cow dung cakes, crop residues and sawdust). The inefficient combustion of these fuels in conventional chulhas is a major contributor to indoor air pollution and its associated health risks. Additionally, using fuel wood at an unsustainable rate damages the environment by causing deforestation and desertification. Therefore, it is crucial to manage biomass as a resource properly. The energy we obtain from fossil fuels today, such as coal, is actually solar energy that was stored in plants millions of years ago. Photosynthesis, which is powered by sun energy, is how plants produce food and thrive. Huge trees that were submerged in the earth's crust millions of years ago underwent intense pressure and heat transformation into coal and oil, earning coal and oil the name "fossil fuels."


Q2.d) How does air pollution affect the atmospheric processes?

Ans) When air pollution reaches high enough concentrations, it can be harmful to humans. Millions of Americans reside in places where toxic chemicals, urban haze, and particle pollution offer major health risks. Pollutant emissions into the atmosphere have the potential to alter the climate. The term "climate forcers" is frequently used to describe these pollutants, which include greenhouse gases. The climate is warmed by ozone in the atmosphere, and it can be warmed or cooled by various PM constituents. For instance, particulate sulphates cool the earth's atmosphere whereas black carbon, a particulate pollution from burning, contributes to warming the planet. A delicate equilibrium of naturally occurring gases in the Earth's atmosphere traps part of the sun's heat close to the planet's surface. The Earth's temperature is maintained by this "greenhouse effect." Unfortunately, there is growing evidence that shows that by releasing enormous volumes of certain of these greenhouse gases, such carbon dioxide and methane, people have upset this natural equilibrium. As a result, it appears that more solar energy is being trapped by the Earth's atmosphere, raising the planet's average temperature – a phenomenon known as global warming.


Q2.e) What is Disposal of waste? Why is segregation of waste needed?

Ans) Cities' local corporations embrace trash disposal. Figure 10.5 illustrates the enormous potential for waste reduction, reuse, and recycling in this process. Hospital trash, including soiled bandages, disposables, cultures, anatomical wastes, chemical wastes, and expired medications, poses the greatest environmental danger of all the waste types. Because of how contagious this garbage is, it needs to be handled carefully. Waste is a major issue. According to estimates from the World Bank, the annual global production of solid waste is at 2.01 billion tonnes. Even with that highly cautious estimate, at least 33% of the trash is not managed in an environmentally responsible way. We no longer have the luxury of ignoring the significance of waste segregation.


In the UK, the situation is largely the same. Only 44.1% of municipal garbage was successfully recycled in 2018. It must be stated that this percentage was higher than the rate of 43.8 percent in the previous year. Low recycling rates can be partly ascribed to insufficient facilities for processing our waste, which historically has been exported abroad to be processed in nations like China. But because China has banned the import of foreign paper and plastic trash, the UK may face a 6 million tonne capacity constraint in waste treatment by 2030.


Q3. Explain the human-environment relationship by taking examples of biotic and abiotic components?


Biotic Factors

The word "biotic" is made from of the phrase’s "bio" and "ic," which together refer to live things or those that are similar to living things. Therefore, it may also be said that all living things on earth are considered to be biotic components.


Examples include plants, animals, people, yeast, insects, and decomposers. All of these biotic elements work together to create new generations, or to create new creatures, in order to keep the food chain stable.


Abiotic Factor

Abiotic elements are ecosystem components that are not biological. They are essential in forming ecosystems because the interaction of biotic and abiotic components is necessary for the stability of the ecosystem.


Examples of abiotic elements include things like air, weather, water, temperature, humidity, height, pH, soil type and level, water flow rate, and water depth.


Q4. “As humans civilisation progressed, man started altering the environment in the pursuit of creating an economic, social and cultural environment of his own choice. This slowly resulted in the depletion of natural resources and degradation of environment.” Explain it in context of national legislations of water acts?

Ans) The Water (Protection and Control of Pollution) Act, 1974 was approved by Parliament to offer statutory backing for the prevention of water pollution. This Act's primary goal is to stop and reduce water pollution. The following list of key provisions from the Water Act of 1974 and Amendment of 1988:


The Water (Prevention and Control of Pollution) Act of 1974 and Amendment, 1988

  1. The Act grants state boards regulatory authority and gives these boards the jurisdiction to set and enforce effluent standards for factories that discharge pollutants into water bodies. The same tasks are carried out for union territories by a Central Board, which also organises state-level operations.

  2. The boards regulate the release of industrial and sewage waste by granting, rejecting, or modifying requests for consent to discharge.

  3. By advising state governments on suitable locations for new business, the state boards also help to reduce water pollution.

  4. The Board was given authority under the Act to ensure compliance with the law, including the right to access property for inspection, equipment testing, and other purposes, as well as the right to collect samples of sewage, commercial effluents, or water from any stream or well for the purpose of analysis.

  5. The Act's implementation clauses were tightened by the 1988 revision. The penalties are now more severe, and a citizen's suit provision supports the enforcement machinery. A board may now close a defaulting industrial plant or cut off its supply of power or water by administrative order.


The Water (Prevention and Control of Pollution) Cess Act of 1977

The Act imposes a cess (tax) on local governments and some specified companies for water consumption and provides financial incentives for pollution reduction. The Water Act is put into effect using these revenues.


Q5. “Biosphere reserves are internationally recognised areas established to promote and demonstrate a balanced relationship between Humans and the Biosphere.” Elaborate this statement in the context of conservation of nature?

Ans) The protected areas known as biosphere reserves are designed to preserve plants and animals. Additionally, it revives the local tribes' traditional way of life. They protect the region's biodiversity. The government of India created 18 Biosphere Reserves to save sizable tracts of natural environment. These areas are given the buffer zones, which are available for some commercial activities. The people who live there are likewise protected, in addition to the local flora and fauna.


The preservation of naturally created resources is referred to as "conservation of nature." Water, sunlight, the atmosphere, minerals, the land, plants, and animals are a few of them. Due to overuse, many of these resources are exhausting quickly. It is crucial to comprehend the value of protecting the environment and to take action to maintain the ecological equilibrium. The preservation of resources that are created naturally, without human involvement, is implied by the conservation of nature. Natural resource conservation is crucial for sustaining a stable environment on earth, as has been emphasised time and time again.



Q6. Explain the following terms in about 60 words each:


Q6. (a) Seed Bank

Ans) One method of ex-situ preservation of plant species is the preservation of plant germplasm in seedbanks (or gene banks). Given the right circumstances, the natural dormancy trait of seeds allows for their suspended storage over lengthy periods of time with little damage. As a form of "genetic insurance," banking dormant seeds permits the preservation of genetically representative samples of rare and endangered plant species.


Q6. (b) Incineration

Ans) By incinerating garbage, waste is burned. If there aren't enough open spaces nearby for disposal sites, many industries and big cities turn to this alternative technique. In this process, the majority of hazardous wastes are detoxified. This is a great way to reduce waste, clean it up, and dispose of it, but if the waste's heat content is not used, the cost of operation is very high. The nature and qualities of the garbage determine the best method of combustion.


Q6. (c) Biological Oxygen Demand

Ans) Biochemical oxygen demand (BOD) represents the amount of oxygen consumed by bacteria and other microorganisms while they decompose organic matter under aerobic (oxygen is present) conditions at a specified temperature. Biochemical Oxygen Demand (BOD) reduction is used as a gauge of the effectiveness of wastewater treatment plants. BOD of wastewater effluents is used to indicate the short-term impact on the oxygen levels of the receiving water.


Q6. (d) Public Health

Ans) The term "aspect of public health that is concerned with all external conditions" (which includes all forms of life, substances, forces, problems, and challenges, as well as any other condition in a person's surroundings that could have an impact on their health and well-being) is environmental health. In this perspective, disease is a result of a person's environment-related maladjustment.


Q7. Answer the following questions in about 150 words each.


Q7 (a) What is lentic and lotic ecosystem? Explain these two with suitable examples.

Ans) Lotic ecosystems, including rivers and streams, are aquatic ecosystems that are characterised by flowing water. The typical locations for these ecosystems are those with a steady supply of freshwater and a slope or gradient that allows the water to flow. A mountain stream that runs through a forest and provides a habitat for fish, insects, and other aquatic animals is an example of a lotic ecosystem. a sizable river that passes through a city and offers a home for fish, birds, and other wildlife.


Lentic ecosystems are aquatic ecosystems that include ponds and lakes with relatively calm water. These habitats are often found when there is a lack of a reliable source of fresh water or where water is trapped by barriers that are either natural or man-made. Lentic habitats include, for instance: a tiny body of water in a park that is home to a wide range of aquatic plants and creatures, including frogs, turtles, and dragonflies. a sizable lake in a rural location that is inhabited by numerous fish and ducks. a marshland that supports a wide range of aquatic species as well as migrating birds, otters, and snakes.


Q7 (b) What is ecological succession? Explain the types of succession with suitable diagrams.

Ans) A biotic community is another name for a community. Abiotic communities are characterised as a collection of interacting populations residing in a certain location. The biological component of an ecosystem is represented by a biotic community, which works as a dynamic unit with the trophic levels, energy flow, and nutrient cycle system previously mentioned. Biotic communities experience gradual change as a natural element of their growth. Community development, or more formally ecological succession, is the systematic process of the eradication or replacement of some local residents or species over time.


Primary Successions

When plants and animals begin to colonise a new area that has never before supported an ecological community, primary succession is started. This might be on recently exposed rock surfaces caused by lava flows or landslides. Thus, primary succession happens in places where there has never been a community, including rocky outcroppings, recently formed deltas, sand dunes, nascent volcanic islands, and lava flows. The invasion and colonisation of bare rock, such as on a recently formed volcanic island, is an example that can be used as a model to show the evolution of primary succession.


Secondary succession

Secondary succession happens when a community in a place is severely uprooted, destroyed, and a new community then settles in that place. Primary succession is less frequent than secondary succession, which is frequently brought on by logging and tree-cutting as well as natural calamities like fires, floods, and storms. The fundamental characteristics of secondary succession are comparable to those of primary succession, but the series develop more quickly. This is so that the soil is ready and already created.




Q7 (c) Explain the biocentrism and ecocentrism in context of human’s attitude towards nature?

Ans) Stewardship is criticised by many contemporary environmentalists as being overly anthropocentric. Instead, they favour a biocentric viewpoint that holds that all living things have rights and worth, regardless of whether they are beneficial or not. In his renowned article on the Land ethic, Aldo Leopold includes the entire biotic community as a component of the land. Leopold noted that throughout the development of civilization, inherent values and rights have been gradually extended, first to men, then to women, children, and minorities, and more recently to nonhuman entities like companies and states. Leopold contends that moral principles should be applied to acknowledge the inherent value of all living things.


According to some thinkers, even inanimate landscape elements like rocks, rivers, and mountains, as well as biological processes like succession and the hydrological cycle, have the right to exist in their natural state without human interference. Because it asserts moral values and rights for both organisms and natural systems, this approach is referred to as ecocentric. People who have an anthropocentric perspective think that the ecosystem was in perfect equilibrium before contemporary humans broke the web of life in their ambition to dominate nature. If they do not re-learn how-to live-in peace with nature, their quest will end in their own destruction.



Q7 (d) Define natural calamities and its types with suitable examples.

Ans) Many individuals are negatively impacted by natural disasters, which also significantly harm infrastructure and property. Due to a lack of readiness, procedures for adequate warning, and infrastructure for speedy access to the disaster site, the negative consequences are more severe in developing nations. On a global scale, Asia is more vulnerable to natural disasters. According to reports, there are ten in Latin America and Africa and fifteen in Asia for every major natural disaster that strikes Europe and Australia. The CRED World Disaster Report (1998) states that the type of disaster, level of preparedness, and population density all determine how many people are killed compared to how many are affected.



Rains, Hailstorms, winds, lightning, fog, heat/cold waves, etc.



Floods, sea-shore waves, glacier advances, water logging, etc.



Landslides, avalanches, earthquakes, volcanic eruptions, shifting sands etc.



Severe epidemics (in humans, plants, animals), forest fires, pest invasions (locusts) etc.


Q8. Explain the causes of ozone depletion? How do ultraviolet rays affect human health, animals, plants, micro-organisms, water and air quality.

Ans) A multitude of reasons are linked to the ozone layer's depletion, which is a serious problem. The following is a list of the primary factors that contribute to the ozone layer's destruction:



The primary factor for the ozone layer to thin out is chlorofluorocarbons, or CFCs. Solvents, spray aerosols, refrigerators, air conditioners, and other appliances all release these. UV rays degrade the chlorofluorocarbon molecules in the stratosphere and release chlorine atoms as a result. Ozone is destroyed when these atoms interact with it.


Unregulated Rocket Launches

According to studies, the ozone layer is destroyed considerably more quickly by uncontrolled rocket launches than it is by CFCs. By 2050, the ozone layer might have lost a significant amount of its thickness if this is not regulated.


Nitrogenous Compounds

The nitrogenous substances NO2, NO, and N2O are largely to blame for the ozone layer's thinning.


Natural Causes

It has been discovered that some natural processes, such solar flares and stratospheric winds, degrade the ozone layer. However, it only contributes to 1-2 percent of the ozone layer loss.


Ozone depletion's increased UV radiation exposure to Earth's surface can have a number of detrimental consequences on people's health as well as the health of animals, plants, and microorganisms as well as the quality of the water and air.


Human Health

Increased UV exposure can cause cataracts, skin cancer, and other health issues. Additionally, it can weaken the immune system of humans, leaving them more vulnerable to illness.



Animals that reside on or close to the Earth's surface may suffer damage from increased UV radiation. It can affect an animal's food supply as well as induce skin cancer and cataracts in them.



Increased UV exposure can harm plant cells, resulting in slower growth and lower agricultural yields. The algae and plankton at the base of the food chain can also be harmed by it.


Q9. “Education for environmental awareness is essential for the younger generation as well as for the older generation.” Explain the statement with suitable examples.

Ans) It is crucial to educate people of all ages about environmental issues and what they can do to safeguard the environment, as stated in the quote "education for environmental awareness is necessary for the younger generation as well as for the older generation." Environmental education can aid in increasing public awareness of environmental issues and equip individuals with the knowledge and abilities necessary to take action to safeguard the environment.


Schools are one place where younger generations can learn about the importance of environmental awareness. Programs that educate kids about issues like recycling, conservation, and sustainability can be incorporated into the curriculum. This can encourage youngsters to take environmental responsibility from a young age and increase their likelihood of doing so. The workplace is another setting where educating older generations about environmental issues is crucial. In order to encourage sustainable business practises and increase knowledge of environmental issues, several companies are increasingly providing environmental training programmes for their personnel. This can help the business save money, become more efficient, and have a smaller negative impact on the environment. Overall, environmental education is essential for conserving the world and guaranteeing a sustainable future for all. It gives people the power to decide for themselves and take action to lessen their impact on the environment.

Q10. “Water Harvesting is one of the effective measures to combat drought.” Explain this statement with suitable arguments.

Ans) A practise called "water harvesting" collects, redirects, and stores rainfall for future use. Because it enables the collecting and storage of water during times of heavy precipitation, which can subsequently be used during times of low precipitation or drought, it is an efficient method of battling drought.


Increased Water Availability

With the use of water harvesting, water can be gathered and stored during periods of heavy precipitation so that it can be used later, such as during droughts or periods of low precipitation. This can lessen the effects of drought and provide a steady flow of water.


Reduced Dependence on Surface Water

Water harvesting can lessen reliance on surface water sources, including rivers and lakes, which can be impacted by drought, by collecting and storing water from rain and other sources.



Due to the fact that it doesn't necessitate the development of extensive infrastructure or the application of high-priced treatment techniques, water harvesting can be a cost-effective strategy to manage drought.


Improving Soil Health

By decreasing soil erosion and increasing the amount of water available to plants, water harvesting can also aid in the improvement of soil health. This is especially advantageous when there is a water shortage due to drought.


Reducing Water Waste

By lowering soil erosion and increasing the water accessible to plants, water harvesting can also help to improve soil health. When there is a drought and water is scarce, this is especially advantageous.


Combating Climate Change

By lowering the demand for ground water and surface water, both of which are susceptible to fluctuations, water harvesting can also assist to mitigate the effects of climate change.

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