Get summaries, questions, answers, solutions, notes, extras, PDF and guide of Chapter 8 Causes of Depletion of Resources, NBSE Class 9 Environmental Education textbook, which is part of the syllabus of students studying under Nagaland Board. These solutions, however, should only be treated as references and can be modified/changed.
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Summary
Natural resources are things we use every day. These include water, air, trees, minerals, oil, and food. Resource depletion happens when we use these resources faster than they can be replaced. This is a big problem because without these resources, humans cannot survive.
There are four main reasons why resources are depleting. The first is overusing resources. Overuse means using more of a resource than nature can replace. Many resources like forests, minerals, water, and soil are affected. Forests give us wood, paper, medicines, and more. But cutting too many trees too quickly harms the environment. It leads to soil erosion, loss of animal homes, and affects the ecosystem. Minerals take millions of years to form but are used up quickly in industries. Water is renewable but also needs time to replenish. Groundwater is being used faster than it can refill. Soil is losing nutrients because farmers grow crops back-to-back without giving the land time to recover.
The second reason is unequal distribution of resources. Some places have lots of resources while others have very little. This makes it hard for some areas to get what they need. For example, Japan has few minerals and must import them. In India, some regions depend heavily on groundwater because they don’t get much rain. Unequal distribution also causes disputes over shared resources like rivers.
The third reason is technological and industrial development. After the Industrial Revolution, machines began consuming resources faster. Factories need raw materials from mining or farming. They burn fossil fuels for energy, which pollutes the air. Urban growth brought changes like pollution and slums.
The fourth reason is population growth. As more people are born, the demand for resources increases. More land is cleared for farming or housing. Cities expand, merging with nearby towns. This puts pressure on resources like wood, minerals, and water. Groundwater levels drop in cities as more people draw from it.
Forests provide many things but are being cut down too fast. Mining disrupts ecosystems and pollutes water. Rivers are dammed, changing how water flows naturally. Farmers use fertilizers and pesticides that harm soil and water. Burning agricultural waste adds to pollution. To solve these problems, efforts are being made to control population growth and manage resources better. Scientists and environmentalists are working to find solutions before resources run out.
Textbook solutions
Multiple Choice Questions (MCQs)
1. Resources that are replenished by natural process are called:
A. Renewable resources
B. Non-renewable resources
C. Equitable resources
D. Non-equitable resources
Answer: A. Renewable resources
2. Oceans contain around ___ percent of water but this water is saline and is of little use to man.
A. 90
B. 95
C. 97
D. 100
Answer: C. 97
3. Loss of nutrients is compensated by:
A. Adding fertilizers
B. Adding manures
C. Adding humus
D. All of these
Answer: D. All of these
4. Study of types of soil and its properties is called:
A. Zoology
B. Pedology
C. Microbiology
D. None of these
Answer: B. Pedology
5. As a result of growing human population, the rate of exhaustion of resources is also:
A. Decreasing
B. Increasing
C. Neither decreasing nor increasing
D. Remains same
Answer: B. Increasing
Very Short Answer Questions
1. What do you understand by clear cutting of forests?
Answer: Clear cutting of forests refers to a technique of felling trees that is very harmful as it allows the trees of an area to be removed abruptly, making the soil naked and leading to excessive soil erosion.
2. Which building material is provided by the minerals?
Answer: Minerals provide building materials such as limestone, marble, slate, and granite, which are used in the construction of buildings.
3. What are the chief sources of groundwater pollution?
Answer: The chief sources of groundwater pollution include the overuse of fertilizers, where soluble forms of nitrogen leach down to groundwater, and the continuous use of insecticides and pesticides, which lead to adverse effects on water sources.
4. What is the chief cause of population growth of cities?
Answer : The chief cause of population growth of cities is the migration of people from rural areas to urban areas.
5. What do you mean by overuse of resources?
Answer : Overuse of resources refers to when a resource is used more than it is replaced by nature. This includes the use of either renewable or non-renewable forms of resources.
Short Answer Questions
1. What is the physical impact of clear cutting of forests?
Answer : The physical impact of clear cutting of forests includes:
(i) The land becomes barren as the removal of forests gives it a bad shape.
(ii) It leads to excessive soil erosion because the soil becomes naked after the trees are removed abruptly.
2. Describe the biological effect of clear cutting of forests.
Answer : The biological effect of clear cutting of forests includes:
(i) The food chain is disturbed.
(ii) Several plants and animals die, and their reproduction is adversely affected.
(iii) There is a fall in photosynthesis activity, leading to reduced oxygen release and carbon dioxide absorption.
(iv) There is also a fall in the formation of various organic acids during the decomposition of fallen leaves.
3. Why is the pressure on groundwater of cities increasing?
Answer : The pressure on groundwater of cities is increasing because:
(i) Cities are places where there is maximum freshwater exhaustion due to millions of people living in a small surface area.
(ii) This exerts enormous pressure on groundwater resources, leading to water scarcity problems.
4. Why is the use of fertilizers increasing day by day?
Answer : The use of fertilizers is increasing day by day because:
(i) To enhance agricultural production, the soil is overused, and its nutrients need to be replenished after every crop harvest.
(ii) Farmers plant another crop immediately after harvesting one, leaving no time for the soil to replenish naturally.
(iii) Loss of nutrients is compensated by adding fertilizers to maintain or increase production.
5. What are the major uses of agriculture residue?
Answer : The major uses of agriculture residue are:
(i) It can be used as fodder for animals.
(ii) It serves as raw material in agro-based industries and the paper industry.
6. What problems are posed by the non-equitable distribution of resources?
Answer : Problems posed by the non-equitable distribution of resources are:
(i) Unequal distribution leads to heavy transportation costs. Areas which have scarcity of minerals have to import minerals from other areas.
(ii) Japan is an industrialized country but it hardly possesses any mineral. Therefore, it imports all the minerals from other countries.
(iii) In India, there are very short reserves of petroleum and natural gas. Hence, India has to depend on the Middle East to fulfill its requirement of petroleum and natural gas.
(iv) In India, regions having less rainfall depend on groundwater for irrigation of their crops. This leads to depletion of the underground water table.
(v) Unequal distribution of resources leads to disputes. Some natural resources like rivers cross political boundaries of countries or states. The water, therefore, has to be shared, which results in disputes.
7. How does technological advancement affect the industrial development?
Answer : Technological advancement affects industrial development as follows:
(i) Technology provides new, fast, and efficient machinery for industries, leading to faster consumption of resources.
(ii) All industries need raw materials, most of which are obtained from agriculture or mining.
(iii) Mineral-based industries exhaust minerals at a rapid rate, depleting resources like coal, iron-ore, mica, and petroleum.
(iv) Urbanization, associated with industrial revolution, brought changes such as shifts in land use, pollution, and the growth of slums.
(v) Energy, required by all industries, is generated by burning fossil fuels, leading to pollution.
(vi) Many countries shifted from an agricultural base to an industrial base of their economy, with developing countries still undergoing this transition.
(vii) The Industrial Revolution, which started in the 18th century in England, replaced handmade goods with machine-manufactured goods, dramatically increasing production and bringing tremendous environmental change.
8. Describe the effects of Industrial Revolution.
Answer : The effects of the Industrial Revolution are:
(i) Goods that were made in homes or small workshops began to be manufactured in large industries.
(ii) Work done by hand was replaced by work done by machines.
(iii) Production of goods grew dramatically.
(iv) It caused a revolution because it brought tremendous changes in the environment.
(v) The process of urbanization was associated with the Industrial Revolution, which led to changes such as shifts in land use, pollution, and the growth of slums.
(vi) Industries required energy, which was generated by burning fossil fuels, causing pollution.
(vii) Many countries shifted from an agricultural base to an industrial base of their economy.
(viii) Developing countries are still transitioning from an agricultural base to an industrial base.
9. Explain overuse of resources in detail.
Answer : Overuse of resources refers to when a resource is utilized more than it can be replenished by nature. Overuse is primarily caused by the rising population, which exerts enormous pressure on resources. Although all resources are affected by over-utilization, the most impacted ones include forests, minerals, water, and soil. Forests are overexploited due to increasing dependence on them for goods such as wood, paper, medicines, and chemicals. Minerals, which take millions of years to form, are consumed rapidly due to industrialization and urbanization. Water resources face exhaustion in cities due to high demand and contamination. Soil is overused in agriculture to enhance production, leading to nutrient depletion and pollution from excessive use of fertilizers and pesticides.
10. Why do resources fall short with the growth of population?
Answer : Resources fall short with the growth of population because natural resources are limited, while the human population continues to grow. As the population increases, the demand for resources like wood, minerals, water, and agricultural land also rises. For example, more area is brought under cultivation by clearing forests to meet food demands. Minerals that take millions of years to form are extracted at a rapid rate due to heavy mining. Similarly, freshwater resources face pressure in cities where millions of people depend on limited supplies. The constant growth of urban centers and migration from rural areas further intensify the burden on resources, making them insufficient to meet the growing needs.
Long Answer Questions
1. Discuss the various impacts of forest depletion.
Answer : The various impacts of forest depletion are:
(i) Forest depletion occurs due to rocketing population growth, which increases the demand for wood as it is a major building material.
(ii) The clear-cutting technique of felling trees is very harmful as it removes trees abruptly, leaving the soil exposed and leading to excessive soil erosion.
(iii) The loss of habitat for animals disrupts ecosystems and has serious consequences on the balance of nature.
(iv) Physically, the removal of forests degrades the land, making it barren and reducing its ability to support life.
(v) Chemically, the environment is negatively affected due to reduced photosynthesis activity, decreased oxygen release, reduced absorption of carbon dioxide, and diminished formation of organic acids during the decomposition of fallen leaves.
(vi) Biologically, the food chain is disturbed, causing several plants and animals to die, and their reproduction is adversely affected.
(vii) Ethically, overexploitation of forests reflects irrational use of natural resources, showing disregard for future generations.
2. Elaborate the consequences of heavy mining.
Answer : The consequences of heavy mining are:
(i) Heavy mining disturbs the ecosystem. In areas of heavy mining, the forest cover is removed.
(ii) It destroys the habitat of organisms and breaks the food chain, severely disturbing the ecosystem.
(iii) Groundwater is not properly recharged in the absence of vegetation cover.
(iv) Rainwater goes waste as surface runoff and is not absorbed by the surface.
(v) Soil erosion is another problem in mining areas. The areas of heavy mining often lead to defacement of land, and such areas are termed ghost towns.
3. Explain the agricultural practices that deplete the soil.
Answer : The agricultural practices that deplete the soil are:
(i) To enhance agricultural production, the soil is overused. Soil has a limit to produce food and needs time to replenish its nutrients after every crop harvest. However, man does not keep the soil free even for a few weeks.
(ii) After harvesting one crop, another crop is planted immediately.
(iii) Loss of nutrients is compensated by adding fertilizers.
(iv) The use of fertilizers is increasing day by day to enhance production, but it pollutes the soil and water sources of the area.
(v) Soluble forms of nitrogen leach down to groundwater, adding to pollution.
(vi) Farmers use various insecticides and pesticides to protect crops from insects and diseases. Continuous use of these chemicals leads to adverse effects.
(vii) Nowadays, farmers focus more on commercial agriculture and high-yielding varieties, neglecting agricultural residue and fodder crops.
(viii) Most farmers burn agricultural residue in the fields after harvesting the crop.
(ix) Agricultural residue has economic and environmental benefits, such as being used as fodder for animals or raw material in agro-based industries and the paper industry.
4. Differentiate between over-utilized and under-utilized areas.
Answer : Over-utilized areas are regions where natural resources are excessively consumed, leading to depletion and environmental degradation, while under-utilized areas are those where resources remain unused or are not fully exploited due to various factors such as lack of infrastructure, technology, or accessibility. Unequal distribution of resources results in some areas being overexploited while others remain under-utilized, posing challenges in resource management.
5. How does industrialization affect the depletion of resources?
Answer : Industrialization affects the depletion of resources in the following ways:
(i) All industries require some form of raw material, most of which is obtained from agriculture or mining.
(ii) Mineral-based industries are exhausting minerals such as coal, iron-ore, mica, and petroleum at a very rapid rate.
(iii) The process of urbanization linked with industrialization has brought changes like altered land use, pollution, and the creation of slums.
(iv) Energy is a major requirement for all industries, which is generated by burning fossil fuels, leading to pollution and the depletion of these non-renewable resources.
(v) Many countries have shifted from an agricultural-based economy to an industrial-based economy, further accelerating resource consumption.
(vi) The Industrial Revolution, which began in the 18th century in England, marked the start of mass production in industries using machines instead of manual labor, causing a dramatic increase in resource use.
(vii) This revolution brought tremendous environmental changes, contributing significantly to the fast depletion of resources.
6. What role does population growth play in depleting the resources?
Answer : Population growth plays a significant role in depleting resources as follows:
(i) Minerals show the fastest rate of depletion because all minerals were formed through complex processes over millions of years, but heavy mining removes those materials in just a few years.
(ii) As the population increases, the demand for wood also increases because it is a major building material.
(iii) The clear-cutting technique of felling trees becomes more prevalent due to rising demands, which allows the trees of an area to be removed abruptly, leading to resource depletion.
(iv) Increasing human population requires more food, necessitating bringing more area under cultivation. This is often done by removing forests, and at some places, forests are deliberately burnt to use the area for cultivation immediately.
(v) The growth of the human population has significantly affected urban settlements, especially in cities.
(vi) Constant growth of urban centers, a notable impact of human population growth in the twentieth century, leads to cities crossing their administrative boundaries during expansion. In some cases, adjoining towns merge to form a single urban area.
(vii) To relieve the burden of increasing population, governments create satellite towns, indicating the pressure on resources in main urban areas.
(viii) Migration of people from rural to urban areas is a major cause of population growth in cities, further straining resources.
(ix) Growing human population has resulted in altering land-use patterns, contributing to resource depletion.
(x) The issue of resource depletion due to population growth has drawn the attention of many scientists and environmentalists.
(xi) Efforts are being made to control the growth rate of the human population, and some success has been achieved.
Extras
Additional questions and answers
1. Define resource depletion?
Answer : Resource depletion is the consumption of a resource faster than it can be replenished. It happens when the consumption of renewable or non-renewable resources becomes scarce, as they are consumed at a faster rate than they can be replenished.
32. How has the industrial revolution affected resource depletion?
Answer : The industrial revolution has affected resource depletion in the following ways:
(i) All industries require raw materials, most of which are obtained from agriculture or mining.
(ii) Mineral-based industries exhaust minerals at a rapid rate, leading to the fast depletion of resources like coal, iron-ore, mica, and petroleum.
(iii) Urbanization associated with the industrial revolution brought changes such as altered land use, pollution, and the growth of slums.
(iv) Energy requirements for industries are met by burning fossil fuels, contributing to pollution and resource exhaustion.
(v) Many countries shifted from an agricultural base to an industrial base for their economies, further accelerating resource consumption.
(vi) The industrial revolution, which began in the 18th century in England, marked a shift where goods previously made in homes or small workshops were now manufactured in large industries using machines, dramatically increasing production and resource depletion.
Additional MCQs
1. What does resource depletion refer to?
A. Fast consumption
B. Slow consumption
C. Balanced usage
D. Natural growth
Answer: A. Fast consumption
50. What causes cities to expand beyond boundaries?
A. Population growth
B. Regulation
C. Reforestation
D. Stability
Answer: A. Population growth
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