UNIT-1
The Multidisciplinary Nature of Environmental Science
1.1.1 Definition
The word Environment can be defined as the Cultural, Social and Physical conditions that encircle, affect and induce growth and development and survival of animals, plants and humans. The word environment is obtained from the French word “environner” meaning ‘to surround or encircle’. The definition is very broad and involves the technological environment and the natural world, which also includes the social and cultural background of human lives. The living and non-living factors are included that directly or indirectly affect an individual or the population. It is fundamentally a multidisciplinary approach to particular circumstances or occurrence that surround us.
Environment is divided into four section namely
- Atmosphere- consists of a range of gases
- Lithosphere- consists of various rocks and soil present on the earth
- Hydrosphere-the different water bodies present on the earth
- Biosphere-consists of living organisms, and their relation with the environment.
1.1.2 Scope
The scope of Environmental studies is very huge and covers large areas and aspects:
- Research and development in environment: Scientists who are skilled in environmental studies have played an important role in observing different environmental problems in a scientific way and further R&D work is carried out, that help in developing cleaner technology and promoting sustainable development.
- Green advocacy: As various laws and Acts are being implemented and the emphasis is increasing, necessity and demand for new lawyers has emerged, who can plead cases that are related to air, water, forest, wildlife and pollution control etc
- Green marketing: As people are more conscious of food in the new era, the quality and ISO mark in food products has gained importance, with the environment friendly and quality of good food sold its marketing also is equally important. Such products have Eco mark or ISO 14000 certification. Environmental auditors and environmental managers would be in great demand in the coming years.
- Green media: Educated people in the field of environment are required to spread Environmental awareness amongst masses through mass media like television, radio, newspaper, magazine, hoardings, advertisements etc.
- Environmental consultancy: Many non-government organizations, industries and government bodies are engaging environmental consultants for systematically studying and tackling environment related problems.
1.1.3 Importance
In a sustainable development, the experts and educated people of different communities play an important role in in explaining the importance of environmental studies and also, the current trend of environmental degradation can be reversed
In the present world the number of environmental issues has been increasing rapidly, posing a threat to the survival of mankind on earth. The issues here are taken care of along with suggestion given by individuals.
The environment studies give us enlightenment, about the importance of protection and conservation of our natural resources, and also indiscriminate release of pollution into the environment etc.
Environment studies have become significant for the following reasons:
1.Environment Issues being of International Importance: National issues that are related to the environment include ozone depletion, acid rain, pollution, global warming and loss of biodiversity have become global issues in recent times and has to be confronted with cooperation and efforts internationally.
2. Problems Cropped in The Wake of Development: As development in various sectors have emerged like Transportation Systems Industrial growth, Urbanization, Agriculture and housing etc However, it has become phased out in the developed world. In the Northern regions, efforts to make their environment cleaner have managed to dirty the factories in the south. When the west was developed their activities had a very bad impact on the environment. Evidently such a path is neither practicable nor desirable, even if developing world follows that.
3. Explosively Increase in Pollution: The census of the world shows that one in every seventh person is an Indian, then according to the data of the 16% of the world’s population only land area available is 2.4%, this leads to a heavy pressure on the natural resources. including land. Agricultural experts have recognized soils health problems like deficiency of micronutrients and organic matter, soil salinity and damage of soil structure.
4. Need for An Alternative Solution: It is vital for developing countries to develop alternative means to achieve alternative goals., to find these goals we need (1) A goal, that finally brings about a sound and sustainable environment (2) A goal common to all citizens of our country. (3) A goal distant from the developing world in the manner it is from the overconsuming wasteful societies of the “developed” world
. 5. Need to Save Humanity from Extinction: It is incumbent upon us to save the humanity from extinction. Consequences to our activities cause destructing the environment and depleting the biosphere, in the name of development.
6. Need for Wise Planning of Development: Our survival and sustenance depend. Resources withdraw, processing and use of the product have all to be synchronized with the ecological cycles in any plan of development. Our actions should be planned ecologically for the sustenance of the environment and development
1.1.4 PUBLIC AWARENESS
- Growing Population: The population per year grows at 2.11% every year, around 17 million people are added every year, this definitely puts a lot of pressure on the natural resources and also decreases developmental gains. The challenge here is to control the population that auto matically leads to development, yet the development leads to a decrease in population growth rates.
- Poverty: In India still 40% of the population still live below the poverty line. India is sometimes known as the Rich land with poor people, the majority of the population is directly dependant on the natural resources like fuel, food, shelter and fodder. The poverty and the environment degradation are often mutually connected to each other.
- Environment degradation: The economic degradation and the poverty has drastically affected the poor who directly depend on their immediate surroundings for their resources, the challenge thus remains on the improvement of poverty and environmental degradation.
- Agricultural Growth: People must be educated on the methods that sustain and increase the agricultural yield without causing damage to the environment. Some high yields have caused physical damage to the soil.
- Need to Increase Ground water: It is vital to justify the use of ground water, various factors such as industrial waste, community effluents, pesticides and fertilizers have polluted the water surface and also ground water quality is affected, therefore it’s very important to restore the quality of river water and other water bodies. Appropriate plans should be put forth for the conservation of water, safe drinking water and keeping water bodies clean.
- Development and Forests: Forests serve as catchments for the rivers. As water has been on high demand, plans are being made to attach large irrigation projects through these large rivers resulting in decrease of the forest, localities will be displaced and flora and fauna would be damaged. As the pressure for increase in agriculture and other uses have been increase there is a sharp decrease in the forests. Large areas that were green lie as waste lands today, it is necessary to bring back these waste lands into vegetative cover. The tribal communities inhabiting forests, respects the trees, birds and animals and give them sustenance. We must recognize the role of these people in restoring and conserving forests. The modern knowledge and skills of the forest department should be integrated with the traditional knowledge and experience of the local communities.
- Degradation of Land: At present out of the total 329 mha of land, only 266 mha possess any potential for production. Of this, 143 mha is agricultural land nearly and 85 suffers from varying degrees of soil degradation. Of the remaining 123 mha, 40 are completely unproductive. Forest land covers the remaining 83 mha of this half is divided for various purposes. Nearly 13 mha of land needs to occupy almost 406 million head of livestock or less than 4 per cent of the land classified as pasture land, most of which is overgrazed. Thus, out of 226 mha, about 175 mha or 66 per cent is degraded to varying degrees. 150mha of land has undergone further degradation due to water and wind erosion, this has to be avoided and checked.
- Evil Consequences of Urbanization: Industrialization and urbanization have given rise to a number of environmental problems, almost 27% of the Indians live in urban areas, and 30% of them live in slums, and only 21% have partial or full sewage treatment facilities, coping with this rapid urbanization is a big challenge.
- Air and water Pollution: Majority of our industrial plants are using outdated and pollution causing technologies and makeshift facilities devoid of any provision of treating their wastes. A great number of cities and industrial areas have been identified as the worst in terms of air and water pollution. Acts are enforced in the country, but the implementation is difficult great resources is required along with technical experts, and political and social permissions. The people need to be updated on the rules and their support is required to implement them.
Our environment has been providing us with a variety of goods and services necessary for our day to day lives since our existence. A resource is something that humans need and value. It can be things such as land, air, and water. These natural resources available in the environment include air, water, soil, minerals, along with the climate and solar energy, which form the non-living or ‘abiotic’ part of nature. The ‘biotic’ or living parts of nature are comprised of plants and animals, including microbes. Plants and animals can only survive as groups of different organisms, who are all closely linked to each other in their habitat.
The water cycle, through evaporation and precipitation, maintains hydrological systems that form rivers and lakes and support a variety of aquatic ecosystems. Wetlands are intermediate forms between the land and aquatic ecosystems and they consist of species of plants and animals that are highly dependent on moisture. All aquatic ecosystems are utilized by a large number of people for their daily activities such as drinking water, washing, cooking, watering animals, and irrigating fields. The world depends on a limited quantity of freshwater. Water covers 70% of the earth’s surface but only 3% of this is freshwater. One of the greatest challenges faced by the world in this century is the need to manage water resources. The world population has passed the 6 billion mark. Based on the number of young people in developing countries, the population will continue to increase significantly during the next few decades. This places enormous demands on the world’s limited fresh water supply. The total annual freshwater withdrawals today are estimated at 3800 cubic kilometres, twice as much as just 50 years ago (World Commission on Dams, 2000). Studies suggest that a normal 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. Examples are Ethiopia, which is upstream on the Nile, and Egypt, which is downstream and highly dependent on the Nile. International accords that will look at a fair distribution of water in such areas will become critical to world peace. India and Bangladesh have made a negotiation agreement on the water use of the Ganges.
Use and over utilization of surface and groundwater: With the growth of the human population there is an increasing need for larger amounts of water to fulfil a variety of basic needs. At this point, in many areas of the world, this requirement cannot be met. Overutilization of water occurs at various levels. Most people use more water than they need. Most of us waste a lot of water during a bath by using a shower or during washing of clothes. Many agriculturists use more water than necessary to grow crops. There are ways in which farmers can try to use less water without reducing yields like using the drip irrigation technique. Agriculture also pollutes surface water and underground water stores by the excessive use of chemical fertilizers and pesticides. Methods such as the use of biomass as a fertilizer and non-toxic pesticides such as neem products and using integrated pest management systems reduce the agricultural pollution of surface and groundwater. The industry tends to maximize short-term economic gains by not bothering about its liquid waste and releasing it into streams, rivers, and the sea. In the longer term, as people become more conscious of using ‘green products’ made by eco-sensitive industries, the polluter’s products may not be used. The industry causing pollution which does not care for the environment and pays off bribes to get away from the cost needed to use effluent treatment plants may eventually be caught, punished, and even closed down. Public awareness may increasingly put pressure on the industry to produce only eco-friendly products which are already gaining in popularity. As people begin to learn about the serious health hazards caused by pesticides in their food, public awareness can begin putting pressure on farmers to reduce the use of chemicals that are injurious to health.
Drought: In most arid regions of the world the rains cannot be predicted. This leads to periods when there is a serious scarcity of water to drink, use in farms, or provide for urban and industrial use. Drought prone areas are thus faced with irregular periods of famine. Agriculturists have no income in the years of scarcity, and as they have no steady income, they have a constant fear of droughts. While it is not entirely possible to prevent the failure of the monsoon, good environmental management can reduce its ill effects. The scarcity of water during drought years affects households, agriculture, and industry. It also leads to food shortages and malnutrition which especially affects children largely. Several measures can be taken to minimize the serious impacts of drought. However, this must be done as a preventive measure so that if the monsoons fail its impact on local people’s lives is minimized. In the time when the monsoon is adequate, we use up the ample supply of water without trying to conserve it and use the water judiciously. Thus, during a year when the rains are scarce, there is no water even for drinking in the drought area. Deforestation is one of the factors that worsen the effect of drought. Once hill slopes are cleared of forest cover, the rainwater rushes down the rivers and is lost. Forest cover permits water to percolate in the area permitting it to seep into the ground. This increases the underground stores of water level in natural aquifers. This can be used in the time when drought hits if the stores have been filled during a good monsoon. If water from the underground storage is overused, the level of water table reduces and vegetation suffers. Soil and water management and afforestation are long-term measures that reduce the impact of droughts.
Conflicts over water describes the conflict that is present between states, countries or groups over the right to access all the water resources. The main reason of water disputes emerges from the water users who use it in public or private, who have opposing interests with the usage of water. Historically a wide range of water conflicts have occurred and sometimes even wars have outraged for issues such as water alone. Water has been a natural resource that has created a lot of tension and also a reason for other conflicts in society. However, conflicts with water occur due to several reasons that include territorial disputes. Strategic advantage and fight for resources.
These conflicts in water take place both in salt and fresh water between the nations and within states. As fresh water is very essential the conflicts are more regarding fresh water. The fresh water is scarce and becomes a major factor for dispute due to the need for potable water, irrigation, and energy generation. Fresh water is very unevenly distributed vital natural resource, the availability often effects the living and economic conditions of a country or region. However, the lack of water supply that is cost effective in middle east puts severe pressure on all the water users whether individual, government or corporate leading to aggression and possible tension.
Dams: As of today, there are more than 45,000 large dams around the world, which play a very important role in communities and economies that harness these water resources for their economic development. The world’s two most populous countries – China and India – have built around 57% of the world’s large dams.
Dams problems
• Fragmentation and physical transformation of rivers.
• Serious impacts on riverine ecosystems.
• The social consequences of large dams caused due to displacement of people.
• Waterlogging and salinization of surrounding lands.
• Dislodging animal populations, damaging their habitat, and cutting off their migration routes.
• Fishing and travel by boat disrupted.
• The emission of green-house gases from reservoirs which occur due to rotting vegetation and carbon inflows from the catchment is a recently identified impact.
Large dams have had serious impacts on the lives, livelihoods, cultures, and the existence of indigenous and tribal peoples. They have suffered disproportionately from the negative impacts of dams and have often been excluded from sharing the benefits. Conflicts over dams have heightened in the last two decades because of their social and environmental impacts and failure to achieve targets for sticking to their costs as well as achieving promised benefits. Recent examples show how failure to provide a transparent process that includes effective participation of local people has prevented affected people from playing an active role in debating the pros and cons of the project and its alternatives. The loss of traditional, local controls over equitable distribution remains a major source of conflict.
Today our food is sourced almost entirely from agriculture, animal husbandry, and fishing. Although India is self-sufficient in food production, it is only because of modern patterns of agriculture that are unsustainable and which pollute our environment with excessive use of fertilizers and pesticides. The Food and Agriculture Organisation (FAO) defines sustainable agriculture as that which conserves land, water, and plant and animal genetic resources does not degrade the environment and is economically viable and socially acceptable. Most of the large farms grow single crops (monoculture). If this crop is hit by a pest, the entire crop can be devastated, leaving the farmer with no income during the year. On the other hand, if the farmer uses traditional varieties and grows several different crops, the chance of complete failure is lowered considerably. Many studies have shown that one can use alternatives to inorganic fertilizers and pesticides. This is known as Integrated Crop Management.
• Our fertile soils are being exploited faster than they can recuperate.
• Forests, grasslands, and wetlands have been converted to agricultural use, which has led to serious ecological questions.
• Our fish resources, both marine, and inland, show evidence of exhaustion.
• There are great disparities in the availability of nutritious food. Some communities such as tribal people still face serious food problems leading to malnutrition, especially among women and children.
These issues bring in new questions as to how demands will be met in the future even with a slowing of population growth. Today the world is seeing a changing trend in dietary habits. As living standards keep on improving, people are eating more non-vegetarian food. As people shift from eating grain to meat, the world’s demand for feed for livestock based on agriculture increases as well. This requires more land per unit of food produced and this results in the world’s poor not getting enough to eat.
Women play a very vital role in food production as well as cooking the meal and in feeding children. In most rural communities they have the least exposure to technical training and health workers trained in teaching/learning on issues related to nutritional aspects. Women and girls frequently receive less food than men. These disparities need to be corrected.
In India, there is a shortage of cultivable productive land. Thus, farm sizes are too small to support a family on farm produce alone. With each generation, farms are being subdivided further Poor environmental agricultural practices such as slash and burn, shifting cultivation, or ‘rabi’ (wood-ash) cultivation degrade forests.
Globally 5 to 7 million hectares of farmland are degraded each year. Loss of nutrients due to overuse of agricultural chemicals are major factors in land degradation. Water scarcity is an important aspect of poor agricultural outputs. Salinization and waterlogging have affected a large amount of agricultural land worldwide.
Loss of genetic diversity in crop plants is another issue that is leading to a fall in agricultural production. Rice, wheat, and corn are the staple foods of almost two-thirds of the world’s population. As wild relatives of crop plants in the world’s grasslands, wetlands, and other natural habitats are being lost, the ability to enhance traits that are resistant to diseases, salinity, etc. is lost. Genetic engineering is an untried and risky alternative to traditional cross-breeding.
Effects of Modern Agriculture
The land available for agriculture is a recent event, Agriculture is considered a way of life, with the increasing population, there is an increasing demand on agriculture and its produce to meet the growing food supply of the population. Through food the agricultural development has successfully increased everywhere, but the fact is it has failed to match the growing demands of the ever-increasing population in developing countries like Africa, Asia and Latin America.
Over the years, the pace in agricultural development has been maintained by the following ways, so that millions do not starve.
1. The Agricultural lands are converted or expanded.
2. Productivity of agriculture is increased.
3. Pattern that involve multiple cropping.
4. Conversion of single-cropping system to two tier and / or three tier cultivation
5.Natural Limits are expanded.
In due course of time, agricultural development became possible due to (a) development of modern scientific techniques; (b) advanced technology; (c) expansion of irrigational facilities: (d) use of chemical fertilizers; (e) use of pesticides and insecticides; (f) development and use of high yielding varieties of seeds; (g) changed agricultural practices; (h) mechanization of agriculture; (i) varying crop sequences and (j) land ownership and the land tenure.
Fertilizer-Pesticide problems
Problems in using fertilizers
a. Excess of fertilizers causes micronutrient imbalance. In Haryana and Punjab, the deficiency of the nutrient Zinc in the soil caused an impact on the productivity of soil.
b. Blue baby syndrome (nitrate pollution): Blue baby syndrome is caused when fertilizers show presence of Nitrate, if the levels of nitrate exceed the given limits it leads to death.
c. Eutrophication: This occurs in water bodies, the presence of Nitrogen and phosphorus in crop fields are washed off by these water bodies, resulting in the increase of algae in the lakes as they are nourished with phosphorus and nitrogen, the life span of the species is lost and they decompose easily, hence water gets polluted and affects aquatic life.
Problems in using pesticides
1. The non target organisms face death.
2. Super pest are the new pest produced.
3. Bio magnification – The pesticides are nonbiodegradable and keep increasing its content in the food chain causing harm to the human beings.
4. Risk of cancer: they indirectly support the immune system and can at directly as a carcinogenic.
Water logging: It is a condition when the soil is saturated by ground water that is sufficient enough to prevent agriculture, sometimes the soil is saturated with water for almost a year, in such cases the air phase is restricted and the anaerobic conditions prevail.
Causes of water logging:
1. Excessive water supply
2. Heavy rain
3. Poor drainage
Remedy:
1. Excess irrigation should be prevented
2. Technology involving Subsurface drainage should be implemented
3. Bio drainage of trees like Eucalyptus
Salinity
It is the amount of salt that is in water or the saltiness in water is known as saline water.
Salinity becomes an essential factor in determining many aspects in the chemistry of natural waters, and also various biological processes. It is a thermodynamic variable state, along with parameters like pressure and temperature that govern the physical characteristics like the heat capacity and density of water.
Theoretically, salinity is the quantity of salt dissolved in water. Salts include sodium chloride, magnesium sulphate, potassium nitrate and sodium bicarbonate, that dissolved in ions.
Here are our parameters for saline water:
- Fresh water - Less than 1,000 ppm
- Slightly saline water - From 1,000 ppm to 3,000 ppm
- Moderately saline water - From 3,000 ppm to 10,000 ppm
- Highly saline water - From 10,000 ppm to 35,000 ppm
- By the way, ocean water contains about 35,000 ppm of salt.
Use and overexploitation: Scientists estimate that India should ideally have 33 percent of its land under forests. Today we have only about 12 percent. Thus, there is not only the need to protect existing forests but also to increase our forest cover. People who live in forests or nearby, know the value of forest resources because their lives and livelihoods depend directly on these readily available resources. However, the rest of the people also derive great benefits from forests which we might not be aware of. The water we use depends on the existence of forests and the watersheds around river valleys. Our homes, furniture, and paper are made from wood from the forest. We make use of many medicines that are based on forest produces. And we depend on the oxygen that plants give out and also on the removal of carbon dioxide we breathe out in the air. People have used forests in our country for thousands of years. As agriculture spread, the forests were cleared or left in patches that were controlled mostly by the tribal people. They hunted animals and gathered plants and lived entirely on forest resources. Deforestation became a major concern when a large amount of timber was extracted for building ships. This led to a great loss in the forest cover and gradual degradation of forests.
Forest functions.
Watershed protection:
• Reduce the rate of surface run-off of water.
• Prevent flash floods and soil erosion.
• Produces prolonged gradual run-off and thus prevents effects of drought. Atmospheric regulation:
• Absorption of solar heat during evapotranspiration.
• Maintaining carbon dioxide levels for plant growth.
• Maintaining the local climatic conditions.
Erosion control:
• Holding soil (by preventing rain from directly washing soil away).
Landbank:
• Maintenance of soil nutrients and structure.
Local use - Consumption of forest produce by local people who collect it for subsistence – (Consumptive use)
• Food - gathering plants, fishing, hunting from the forest.
• Fodder - for cattle.
• Fuelwood and charcoal for cooking, heating.
• Poles - building homes especially in rural and wilderness areas.
• Timber – household articles and construction.
• Fibre – the weaving of baskets, ropes, nets, string, etc.
• Sericulture – for silk.
• Apiculture – production of bees for honey, forest bees also pollinate crops.
• Medicinal plants - traditionally used medicines, investigating them as a potential source for new modern drugs.
Market use - (Productive use)
• Most of the products used for consumptive purposes are also sold as they serve as a source of income for supporting the livelihoods of forest-dwelling people.
• Minor forest produce - (non-wood products): Fuelwood, fruit, gum, fibre, etc. which are collected and sold in local markets as a source of income for forest dwellers.
• Major timber extraction - construction, industrial uses, paper pulp, etc. Timber extraction is done in India by the Forest Department, but illegal logging continues in many of the forests of India and the world.
Deforestation is the practice of permanent removal of trees to make room for something besides the forest. This can include clearing the land for agriculture or grazing or using the timber for fuel, construction, or manufacturing. The places where civilizations have looked after their forests by using forest resources cautiously, they have prospered; whereas the places where the forests were destroyed, the people gradually impoverished. Today, logging and mining are serious causes of the loss of forests. Dams that were built for hydroelectric power or irrigation submerged the forests and have now displaced the tribal people whose lives depended on the forests.
Forests cover more than 30% of the Earth's land surface, according to the World Wildlife Fund. These areas can be the source of provision of food, medicine, and fuel for more than a billion people. Today, most deforestation takes place in the tropics. Areas, where access couldn’t be gained in the past, are now within reach as new roads are constructed through dense forests.
Often, deforestation occurs when a forested area is cut and cleared to make way for agriculture or grazing. Deforestation in tropical regions can affect the way water vapor is produced over the canopy, which causes reduced rainfall. A study published in the journal of Ecohydrology in 2019 showed that some parts of the Amazon rainforest were converted to agricultural land. These parts had higher soil and air temperatures, which can intensify drought conditions. In comparison, forested land had rates of evapotranspiration that were almost three times higher, which helped in adding more water vapor to the air.
Trees absorb carbon dioxide, thus removing greenhouse gas emissions produced by human activity. Deforestation, along with removing vegetation that is important for the removal of carbon dioxide from the air, also produces greenhouse gas emissions themselves. Deforestation accounts for nearly 20% of greenhouse gas emissions.
Developing alternatives to deforestation can help decrease the need for tree clearing. For example, the desire to expand the amount of land used for agriculture is an attractive reason to deforest an area. But if people tried adopting sustainable farming practices or implemented new farming technologies on crops, the need for more land might be diminished. Forests can also be restored, through replanting trees in cleared areas or simply allowing the forest ecosystem to regenerate over time. The goal of restoration is to return the forest to its original state, before it was cleared, the sooner a cleared area is reforested, the quicker the ecosystem can start to repair itself. Gradually, wildlife may return, water systems might get re-established, carbon will be sequestered and soils will be replenished.
Effect of Deforestation on Tribal People
- The tribal people are not capable of carrying out their traditions as their homes are often destroyed
- The cutting of trees can affect their food and water sources, mostly tribals live in rainforest and trees are cut for logs of woods, this makes living and searching for food very difficult.
- As more and more trees are being cut, the tribal people are losing their homes, they are adapted to the forest environment and may not be able to live in an urban lifestyle
- The tribal people are unaware of all the modern technology, their main occupation being agriculture, they cannot shift to an urban area and find a job, as they have been living in rainforests for generations.
- The people slowly loose their culture and way of life that had lasted for many generations, they will also lose their traditional beliefs and patterns of sustenance through which they have been living in harmony in the rainforest for many generations.
Land on earth is as finite as any of our other natural resources. While mankind has learned to adapt his lifestyle to various ecosystems the world over, he cannot live comfortably for instance on polar ice caps, under the sea, or in space in the foreseeable future.
Man needs land for building homes, cultivating food, maintaining pastures for domestic animals, developing industries to provide goods, and supporting the industry by creating towns and cities. Equally importantly, man needs to protect wilderness areas in forests, grasslands, wetlands, mountains, coasts, etc. to protect our vitally valuable biodiversity. Thus, rational use of land needs careful planning.
Land degradation
Farmland is under threat due to extensive utilization. Every year, between 5 to 7 million hectares of land worldwide is added to the existing degraded farmland. When soil is used by farming extensively, it is eroded more rapidly by wind and rain. Over irrigating farmland leads to salinization, as evaporation of water brings the salts to the surface of the soil on which crops cannot grow. Over irrigation also creates waterlogging of the topsoil so that crop roots are affected and the crop deteriorates. The use of more and more chemical fertilizers poisons the soil so that eventually the land becomes unproductive.
Soil erosion: The characteristics of natural ecosystems such as forests and grasslands depend on the type of soil. Soils of various types support a wide variety of crops. The misuse of an ecosystem leads to the loss of valuable soil through erosion by the monsoon rains and, to a smaller extent, by the wind. The roots of the trees in the forest hold the soil. Deforestation thus leads to rapid soil erosion. Soil is washed into streams and is transported into rivers and finally lost to the sea. The process is more evident in areas where deforestation has led to erosion on steep hill slopes as in the Himalayas and in the Western Ghats. These areas are called ‘ecologically sensitive areas’ or ESAs. To prevent the loss of millions of tons of valuable soil every year, it is essential to preserve what remains of our natural forest cover. It is equally important to reforest denuded areas. The linkage between the existence of forests and the presence of soil is greater than the forest’s physical soil binding
Environmental Effect of Mining
Mining operations are considered one of the main sources of environmental degradation. The extraction of all these products from the lithosphere has a variety of side effects. Depletion of available land caused due to mining, waste from industries, conversion of land to industry, and pollution of land, water, and air by dumping industrial wastes, are environmental side effects of the use of these non-renewable resources. Public awareness of this problem is global and government actions to stem the damage to the natural environment has led to numerous international agreements and laws directed toward the prevention of activities and events that may adversely affect the environment.
Mining is a very hazardous occupation, and the safety of mine workers is an important environmental consideration of the industry. Surface mining is less hazardous as compared to underground mining. Metal mining is less hazardous than coal mining. In underground mines, falling of rocks and roof, flooding, and inadequate ventilation are the greatest hazards. Large explosions have occurred in coal mines, killing many miners. Many miners suffer from disasters due to the use of explosives in metal mines. Mining poses several long-term occupational hazards to the miners. Dust produced during mining operations is injurious to health and causes a lung disease known as black lung or pneumoconiosis. Fumes generated by incomplete dynamite explosions are extremely poisonous. Methane gas, emitted from coal strata, is a health hazard although not poisonous in the concentrations usually encountered in mine air. Radiation is a hazard in uranium mines.
Man induced landslides
Human activities like the construction of roads, dams, buildings etc have led to landslides. The Himalayan regions are usually slopy that are being modified now. The land slides are increasing due to the sheer stress factor that is exceeding the strength factor, as the roads are being introduced the landslides have also become frequent. The construction of roads and landslides are always corelated.
The Built-up land area is also increased in the recent times therefore the slopes also have been modified. The deforestation and many areas being disabled have eventually increased the frequency of landslides.
However, villagers in these areas have reported that earlier landslides were rare but after the construction of roads and dams, landslides have become a common phenomenon. About 80 per cent of the total landslides occurring now in the reserve are a result of road construction.
Soil Erosion and desertification
Soil erosion is a natural process, wherein the top soil in a field is carried away due to physical sources like water or wind, it is a continuous process that may occur slowly or at an alarming rate, resulting in the continuous loss of the topsoil, soil collapse or ecological degradation
In soil erosion the soil particles are loosened and gets washed away into the oceans, valleys, rivers, streams, the main cause being human activities like agriculture and deforestation.
Causes of Soil erosion
Intense and High rainfall are the main causes for soil erosion. The rainfall disperses the soil that gets washed away into the rivers and streams, large amounts of soil loss is seen in places with heavy and frequent rainfall. Potholes and rock-cuts are created when the flowing water erodes a lot of soil.
Farming has become a major concern for soil erosion, the agricultural activities interrupt the ground, also clearing the trees and ploughing the land to sow seeds disrupt the ground.as most of the crops are grown in spring season, the land becomes fallow and eroded during winters.
The movement of tractors paves way for grooves in the land making it easier for water to enter, the fine soil particles are eroded by wind.
Grazing
The animals often feed on plants and grasses and remove vegetation from land, this loosens the soil and is liable to erosion, the hooves of animals churn up the soil.
Large number of trees are cut for logging, large trees help in holding the soil firmly, the shade of the trees plays a very important role in protecting the soil from heavy rainfall, the falling of leaves also protects soil from erosion however all this is lost due to logging process.
Mining activities also erupt the land and make the soil more prone to erosion.
Construction of Roads and buildings expose the soil to erosion, for construction purposes the forests and grasslands are cleared, making the soil vulnerable to erosion..
The minute soil particles are carried away by heavy winds during dry weather or semi-arid conditions, resulting in degradation of soil and desertification.
This is a serious environmental issue, following are few ways to prevent soil erosion.
- Trees can be planted in barren land to limit erosion.
- Adding of rack and mulch prevents the underneath plants and grass to prevent soil erosion.
- Mulch matting can be used to reduce erosion on the slopes.
- Put a series of fibre logs to prevent any water or soil from washing away.
- A wall at the base of the slope can help in preventing the soil from eroding.
- Every household should have a proper drainage system so that water flows down into proper water collecting systems
Desertification – Degradation of Fertile Land
This involves a degradation process, where a fertile soil changes into a desert and loses its fauna and flora. There are various factors that cause desertification, most common are climate change, human activities, drought, deforestation, and improper agriculture. It is a process where the land undergoes degradation mainly due to human activities and climate change. Desertification takes place when a specific biome type changes into a desert biome.
- Overgrazing of animals
- Human activities like Deforestation
- Farming Practices
- Expansion and other land developments
- Changes in climate
- Land resources are scarce
- Natural Disasters
Growing energy resources
Our environment has been providing us with a variety of goods and services necessary for our day to day lives since our existence. A resource is something that humans need and value. It can be things such as land, air, and water. Resources are characterized as renewable or non-renewable; a renewable resource can replenish itself at the rate it is used, while a non-renewable resource has a limited supply. Renewable resources include timber, wind, and solar while non-renewable resources include coal and natural gas. These natural resources available in the environment include air, water, soil, minerals, along with the climate and solar energy, which form the non-living or ‘abiotic’ part of nature. The ‘biotic’ or living parts of nature are comprised of plants and animals, including microbes. Plants and animals can only survive as groups of different organisms, who are all closely linked to each other in their habitat. Many of these living organisms are used as our food resources. Others are linked to our food in a less direct way, such as pollinators and dispersers of plants, animals in the soil like worms, which recycle nutrients for the growth of plants, and fungi and termites that break up dead plant material so that micro-organisms can act on them to reform soil nutrients. Most traditional agriculturists depended largely on rain, streams, and rivers for water supply. Later on, the use of wells to tap underground water sources and to utilize water began. The land was irrigated by building dams. Recently, we began to use fertilizers and pesticides to further increase the production of food from the same land. However, we now realize that all this has led to several undesirable changes in our environment. Mankind has been overusing and depleting natural resources. The extensive usage of land has been found as a reason for exhausting the capability of the ecosystem to support the growing demands of more and more people. Industrial growth, urbanization, population growth, and the enormous increase in the use of 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
- Non-Renewable resources
Non-renewable resources consist of fossil fuels such as oil and coal, which if extracted at the present rate, will soon be consumed. The end products of fossil fuels are in the form of heat and mechanical energy and chemical compounds, which cannot be reconstituted as a resource. Non-renewable resources, once used, remain on earth in a different form and, unless recycled, become waste material.
- Renewable resources
Even though water and biological living resources might be considered renewable, they are, in fact, renewable only within certain limits. They are linked to natural cycles such as the water cycle. Freshwater is evaporated by the sun’s energy which forms water vapor and is reformed into clouds which later fall on 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 regrow into fully developed natural ecosystems with their full complement of species. Forests can, thus, be said to behave like non-renewable resources if they are 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 about their existence and other linked species are also affected by their loss.
Key takeaway
The word environment is obtained from the French word “environner” meaning ‘to surround or encircle’. The definition is very broad and involves the technological environment and the natural world, which also includes the social and cultural background of human lives. Resources are essential for the survival of humans. Resources can be classified into various types such as forest resources, water resources, food resources, mineral resources, energy, and land resources.
References:
1. A.K. De, Environmental Chemistry, Wiley Eastern Ltd.
2. E.P. Odum, Fundamentals of Ecology, W.B. Sunders Co., USA.
3. M.N. Rao and A.K. Datta, Waste Water Treatment, Oxford and IBK Publications.
4. Benny Joseph, Environmental Studies, Tata McGraw Hill, 2005.
5. V.K. Sharma, Disaster Management, National Centre for Disaster Management, IIPE,1999.
