Lakhmir Singh & Manjit Kaur: Natural Resources, Solutions- 2 | Science Class 10 PDF Download

Q1. What is meant by “sustainable development” ?
Ans: Sustainable development refers to the process of development that meets the current basic human needs while also ensuring the preservation of resources for future generations. This approach aims to balance economic growth, social inclusion, and environmental protection.

Q2. What is silviculture ? What are its advantages ?
Ans: Silviculture is a vital practice aimed at replenishing depleting forests. Its advantages include:

• Producing a large quantity of raw materials for industry, such as the timber and paper sectors.
• Increasing the area of land covered by forests, which supports wildlife conservation.
• Maintaining a balanced water cycle in nature.
• Preventing soil erosion.
• Reducing the risk of floods.

Q3. Write a short note on ‘Chipko Andolan’ (Hug the Trees Movement).
Ans: The Chipko Andolan (Hug the Trees Movement) originated in the early 1970s from an incident in the remote village of Reni in Garhwal. A logging contractor had received permission to cut down trees in a forest near the village. One day, while the men of the village were away at work, the contractor's workers entered the forest to begin cutting down the trees. In the absence of the men, the women of the village quickly reached the forest and embraced the tree trunks with their arms, effectively preventing the workers from felling the trees. As a result, the forest was saved. The Chipko Movement rapidly spread across various communities, significantly contributing to the conservation of forests.

Q4. Why should we conserve forests and wildlife ?
Ans: The conservation of forests and wildlife is crucial to prevent harm to the environment. These ecosystems play a vital role in maintaining ecological balance in nature and preserving the genetic diversity within species.

Q5. Describe briefly the ‘khadin’ system of rainwater harvesting practised in Rajasthan.
Ans: The Khadin system of rainwater harvesting in Rajasthan involves the construction of a long earthen embankment, known as a Bund, which typically measures between 100 to 300 meters. This Bund is built across the lower edge of sloping farmland. During rainfall, water from the catchment area flows down the slopes, where it is halted by the Bund, forming a reservoir. The rainwater that collects in this reservoir, as well as in nearby wells, seeps slowly into the ground. This saturated land is then utilised for growing crops.

Q6. What measures would you take to conserve electricity in your house ?
Ans: The measures for the conservation of electricity in our house include:

• Switch off lights, fans, televisions, and other electrical appliances when they are not needed.
• Utilise energy-efficient electrical appliances to save electricity.
• Use stairs instead of the lift for climbing up to three floors of a building.

Q7. Although coal and petroleum are produced by the degradation of biomass, even then we need to conserve them. Why ?
Ans: Coal and petroleum must be conserved because once they are exhausted, they will not be available for our use in the near future. This is due to the fact that these resources are formed extremely slowly over a very long period of time.

Q8. Is water conservation necessary ? Give reasons.
Ans: Yes, water conservation is essential because it addresses the basic necessities for all forms of life, including human beings, animals, and plants. Here are some key reasons why water conservation is important:

• It ensures a sufficient supply of water for drinking and sanitation.
• It supports agricultural activities, which are crucial for food security.
• Conserving water helps to protect ecosystems and maintain biodiversity.
• It reduces the energy required for water treatment and distribution, leading to lower carbon emissions.

Q9. Name the products of combustion of fossil fuels like coal and petroleum products. How do they affect us and our environment ?
Ans: When coal and petroleum-based fuels are burned, the products of combustion include: carbon dioxide, water, sulphur dioxide, and nitrogen oxides. If combustion occurs with an insufficient supply of air, then carbon monoxide is also produced. These products can be harmful to humans and contribute to environmental pollution in the following ways:

• Sulphur dioxide attacks the lungs, causing bronchitis and other respiratory diseases. It also leads to acid rain.
• Nitrogen oxides also affect the respiratory system and contribute to acid rain.
• Carbon dioxide traps the sun’s heat energy, increasing the Earth's temperature and contributing to global warming.
• Carbon monoxide is a poisonous gas; if it enters the bloodstream, it prevents red blood cells from carrying oxygen, leading to suffocation and potentially death.

Q10. Why should fossil fuels like coal and petroleum be used judiciously ?
Ans: We should use fossil fuels judiciously because:

• Fossil fuels like coal and petroleum are limited resources that will be exhausted soon.
• The products of combustion from fossil fuels contribute significantly to environmental pollution.

Q11. What are the three R’s to save the environment ? Explain with one example of each.
Ans: The three R’s to save the environment are:

• Reduce: This means using fewer natural resources by minimising practices that lead to wastage. For example, we can reduce electricity wastage by turning off unnecessary lights and fans.
• Recycle: Recycling involves collecting used and discarded items such as paper, plastic, glass, and metals, and sending them to the appropriate industries to create new products. For instance, recycled paper can be used to make fresh paper products.
• Reuse: Reusing means using the same items again. For example, plastic jars from food items like jams and pickles can be repurposed for storing items such as salt and sugar.

Q12. What are the main uses of coal and petroleum products ?
Ans: Coal is primarily used as a fuel in homes and industries. It is also utilized to generate electricity at thermal power plants. On the other hand, petroleum products, such as petrol and diesel, serve as fuels for transportation, powering vehicles like scooters, cars, and buses.

Q13. State any five steps to reduce the consumption of coal and petroleum products.
Ans: The steps that can be taken to reduce the consumption of coal and petroleum products are:

• Switch off lights, fans, televisions, and other electrical appliances to save electricity.
• Use energy-efficient electrical appliances, such as CFL and fluorescent tube lights, to conserve electricity.
• Use stairs to climb at least three floors of a building instead of taking the lift to save electricity.
• Utilise pressure cookers for cooking food to save fuels like kerosene and LPG.
• Employ solar cookers for cooking whenever possible.

Q14. Explain why, despite good rains, we are not able to meet the demand for water of all the people in our country.
Ans: Despite good rains, we are unable to meet the demand for water for all people due to several factors:

• The rapidly increasing population places a significant strain on limited water resources.
• A lack of sufficient vegetation cover means that only a small amount of rainwater seeps into the ground and is stored as groundwater.
• High-yielding varieties of crops require considerably more water for irrigation compared to traditional types.
• The discharge of untreated sewage and industrial waste into water bodies further exacerbates water quality issues.

Q15. Give one example to show how the participation of local people can lead to the efficient management of forests.
Ans: People's participation in the management of forests can significantly enhance both forest productivity and conservation efforts. One notable example is the revival of degraded sal forests in West Bengal. In 1972, the West Bengal Forest Department initiated a unique scheme to restore these forests by involving local communities. Under the guidance of forest officer A. K. Banerjee, villagers living near the forest were engaged in the protection of 1,272 hectares of degraded sal forest. In exchange for their efforts, the villagers received:

• Employment in silviculture and forest harvesting operations.
• 25% of the final harvest produce.
• Permission to collect firewood and fodder from the forest for a nominal fee.

Q16. Explain briefly, how rainwater harvesting is done from open spaces around the buildings in city areas.
Ans: Rainwater harvesting from open spaces around buildings in city areas involves several key steps to ensure effective collection and recharge of the groundwater.

• The process begins with the construction of percolation pits that are covered with concrete slabs featuring holes. These holes allow rainwater to flow into the pits.
• The percolation pits are connected to a recharge well via an outlet pipe.
• When rainwater falls on the open spaces, it enters the percolation pit through the holes in the slab.
• After undergoing filtration in the percolation pit, the rainwater then flows through the pipe into the recharge well.
• Finally, the water gradually seeps into the soil, thus replenishing the groundwater.

Q17. (a) What is a natural resource ? Name three important natural resources.
Ans: Natural resources are anything in the environment that can be used by humans. Three important natural resources include forests and wildlife, water, and coal. We need to manage our natural resources for several reasons:

• The resources of the earth are limited, while our population is increasing daily.
• Proper management of natural resources considers a long-term perspective and prevents their exploitation for short-term gains.
• Effective management ensures equitable distribution of resources, allowing all people to benefit from their development.
• It also considers the damage caused to the environment during the extraction or use of these resources and finds ways to minimise this damage.

Q18. (a) State the advantages of constructing dams across the rivers.
Ans: The advantages of constructing dams across rivers include:

• Water from a dam is used for irrigation in fields through a network of canals.
• Water from a dam is supplied to towns and cities through pipelines after suitable treatment.
• The falling water from the dam is harnessed for generating electricity.

• Social Problems: The construction of high-rise dams can result in the submergence of numerous human settlements under the water of the large reservoir formed by the dam, rendering many people homeless. This creates significant social challenges.
• Environmental Problems: The construction of high-rise dams contributes to deforestation and loss of biodiversity. A vast variety of flora and fauna get submerged in the reservoir, disturbing the ecological balance.

Q19. (a) Name any five sources of water (other than rivers) (b) Describe how, the water of river Ganga has been highly polluted.
Ans: Sources of water (other than rivers) include:

• Lakes
• Rain
• Ponds
• Wells
• Glaciers

• Discharge of untreated sewage and industrial waste.
• Human activities such as bathing, washing clothes, and the immersion of ashes.
• Dumping of unburnt corpses into the river.
• Industries releasing effluents directly into the river water.

Q20. (a) Name the major industries which are based on forest produce. (b) State the main aim of the management of forests and wildlife. (c) Name the four main stakeholders in the management of forest resources.
Ans: Answer: (a) The various industries based on forest produce include the timber industry, paper manufacturing industry, lac industry, and sports equipment industry. (b) The primary aim of managing forests and wildlife is to conserve the biodiversity we have inherited. (c) The main stakeholders in the management of forest resources are:

• Government authorities
• Local communities
• Non-governmental organizations (NGOs)
• Private sector companies

Q21. (a) What is meant by rainwater harvesting ? Name some of the ancient structures used for rainwater harvesting by the rural people. (b) What are the various advantages of water stored in ground ?
Ans: Rainwater harvesting is the practice of collecting rainwater that falls on land to recharge the groundwater supply. Some ancient structures used for rainwater harvesting by rural communities include:

• Khadin
• Tanks
• Kulhs
• Ponds
• Eris
• Tals
• Kattas

• It helps in maintaining the water table.
• It provides a reliable source of water during dry periods.
• It enhances biodiversity in the ecosystem.
• It reduces soil erosion and runoff.