CBSE NCERT Class VIII (8th) | Social Studies | Geography
Chapter : Land, Soil, Water, Natural Vegetation and Wildlife Resources
CBSE NCERT Solved Question Answer
Q1. Why life is different in different parts of the world?
A1. The life is different in different parts of the world because of the differences in the quality of land, soil, water, natural vegetation, animals and the usage of technology.
Q2. How land can be conserved ?
A2. Land can be conserved by the following way:-
2) Land reclamation
3) Regulated use of chemical pesticide and fertilizers.
4) Checks on overgrazing.
Q3. What is soil?
A3. The thin layer of grainy substance covering the surface of the earth is called soil. Soil is made up of organic matter, minerals and weathered rocks found on the earth. This happens through the process of weathering. The right mix of minerals and organic matter make the soil fertile.
Q4. Name the factors that leads to soil degradation?
A4. Factors which lead to soil degradation are:-
3) Overuse of chemical feritilisers or pesticides.
4) Rain wash.
Q5. Define –1) National park 2) Biosphere reserve.
A5. 1) National park - A natural area designated to protect the ecological integrity of one or more ecosystems for present and future generations.
2) Biosphere reserve - Series of protected areas linked through a global network, intended to demonstrate the relationship between conservation and development.
Q6. What are the natural and human factors that are leading to forest and wildlife depletion?
A6. The natural and human factors that are leading to forest and wildlife resources are:-
2) Soil erosion
3) Constructional activities.
4) Forest fires.
Q7. Why animals are poached?
A7. The animals are poached for collection and illegal trade of hides, skins, nails, teeth, horns as well as feathers.
Q8. How do we get water back through water recycle?
A8. Water can neither be added nor subtracted from the earth. Its total volume remains constant. Its abundance only seems to vary because it is inconstant motion, cycling through the oceans, the air, the land and back again, through the processes of evaporation, precipitation and run-off. This is how we get water back through water recycle.
Q9. Name the physical and human factors that determine land use? A9. The use of land is determined by:-
1) Physical factors such as topography, soil, climate, minerals and availability of water.
2) Human factors such as population and technology are also important determinants of land use pattern.
Q10. Why land use pattern is changing?
A10. Land use pattern is changing because of following reasons:-
1) People started encroaching the common lands to build up commercial areas, housing complexes in the urban areas and to expand the agricultural land in the rural areas.
2) Cultural changes which are taking place in our society.
Q11. Name the regions of the world which are facing water scarcity?
A11. The regions of the water scarcity are Africa, West Asia, South Asia, parts of western USA, north-west Mexico, parts of South America and entire Australia are facing shortages in fresh water supply.
Q12. What are the reasons for the water scarcity/?
A12. Water shortage may be a consequence of variation in seasonal or annual precipitation or the scarcity is caused by over exploitation and contamination of water sources.
Q13. How is vegetation useful to us?
A13. Vegetation is useful to us in the following way:-
1) Plants provide us with timber
2) Give shelter to animals,
3) Produce oxygen we breathe,
4) Protects soils so essential for growing crops,
5) Act as shelter belts,
6) Help in storage of underground water,
7) Give us fruits, nuts, latex, turpentine oil, gum, medicinal plants
8) Provide the paper that is so essential for your studies.
Q14. Give the soil profile?
A14. The soil is made up of different layers as follows:-
1) Top soil with humus and vegetation.
2) Sub soil with sand, silt and clay.
3) Weathered rock material.
4) Parent rock.
Q15. Why there is uneven distribution of population?
A15. The uneven distribution of population in different parts of the world is mainly due to varied characteristics of land and climate.
1) Sparsely populated regions:- The rugged topography, steep slopes of the mountains, low lying areas suspectible to water logging, desert areas thick forested areas are normally sparsely populated or uninhabited.
2) Densely populated regions:- Plains and river valleys offer suitable land for agriculture. Hence, these are the densely populated areas of the world.
Q16. Define the following :
1) Land Use
2) Common property resource.
A16. 1) Land use - Land is used for different purposes such as agriculture, forestry, mining, building houses, roads and setting up of industries. This is commonly termed as Land use.
2) Common property resource - Privateland is owned by individuals whereas, community land is owned by the community for common uses like collection of fodder, fruits, nuts or medicinal herbs. These community lands are also called common property resources.
3) Biosphere - Natural vegetation and wildlife exist only in the narrow zone of contact between the lithosphere, hydrosphere and atmosphere that we call biosphere.
4) Ecosystem - In the biosphere living beings are inter-related and interdependent on each other for survival. This life supporting system is known as the ecosystem.
Q17. Explain the factors that help in soil formation?
A17. The major factors that help in the soil formation are as follows:-
1) Parent Rock - Determines colour, texture, chemical properties,mineral, content, permeability.
2) Climate -Temperature ,Rainfall influence rate of weathering and humus.
3) Relief - Altitude and slope, determine accumulation of soil
4) Flora, Fauna and Micro-organism - Affect the rate of humus formation
5) Time - Determines thickness of soil profile.
Q18. Explain the methods that help in the conservation of soil? A18. Some methods of soil conservation are:-
1) Mulching: The bare ground between plants is covered with a layer of organic matter like straw. It helps to retain soil moisture.
2) Contour barriers: Stones, grass, soil are used to build barriers along contours. Trenches are made in front of the barriers to collect water.
3) Rock dam: Rocks are piled up to slow down the flow of water. This prevents gullies and further soil loss.
4) Terrace farming: These are made on the steep slopes so that flat surfaces are available to grow crops. They can reduce surface run-off and soil erosion
5) Intercropping: Different crops are grown in alternate rows and are sown at different times to protect the soil from rain wash.
6) Contour ploughing:-Ploughing parallel to the contours of a hill slope to form a natural barrier for water to flow down the slope
7) Shelter belts: In the coastal and dry regions, rows of trees are planted to check the wind movement to protect soil cover.
Q19. Give the distribution of water?
A19. The oceans covers two-thirds of the earth’s surface and support a rich variety of plant and animal life. The ocean water is however saline and not fit for human consumption.
Fresh water accounts for only about 2.7 per cent.
Nearly 70 per cent of this occurs as ice sheets and glaciers in Antarctica, Greenland and mountain regions. Due to their location they are inaccessible. Only 1 per cent of Fresh water is available and fit for human use. It is found as ground water, as surface water in rivers and lakes and as water vapour in the atmosphere.
Q20. Explain the factors leading to water scarcity? A20. The factors leading to water scarcity are:-
1) Increasing population- The population is increasing therefore there is rising demands for food and cash crops ,increasing urbanisation and rising standards of living causes water scarcity.
2) Decreasing water resource - Drying up of water sources, over usage of water, lowering of water table and water pollution due to untreated chemical and industrial waste causes water shortage.
Q21. How we can conserve water resource?
A21. We can conserve water resource by the following way:-
1) Water pollution can be controlled by treating these effluents suitably before releasing them in water bodies.
2) Forest and other vegetation cover slow the surface runoff and replenish under groundwater.
3) Water harvesting is another method to save surface runoff.
4) The canals should be properly lined to minimise losses by water seepage.
5) Sprinklers effectively irrigate the area by checking water losses through seepage and evaporation.
6) In dry regions with high rates of evaporation, drip or trickle irrigation is very useful.
7) Treatment of effluents-Discharge of untreated or partially treated sewage, agricultural chemicals and industrial effluents in water bodies are major contaminants which should be treated before discharging it in the river.
Q22. Animals big or small, all are integral in maintaining balance in the ecosystem’ Eleborate the statement with the help of examples.
A22. Wildlife includes animals , birds, insects as well as the aquatic life forms. 1) Animals provide us milk, meat, hides and wool.
2) Insects like bees provide us honey, help in pollination of flowers and have an important role to play as decomposers in the ecosystem.
3) The birds feed on insects and act as decomposers as well.
4) Vulture due to its ability to feed on dead livestock is a scavenger and considered a vital cleanser of the environment. So animals big or small, all are integral in maintaining balance in the ecosystem.
Q23. What are the features of vegetation found in the regions of heavy, moderate and low rainfall regions of the world ?
A23. 1) In areas of heavy rainfall, huge trees may thrive.
2) In the regions of moderate rainfall short stunted trees and grasses grow forming the grasslands of the world.
3) In dry areas of low rainfall, thorny shrubs and scrubs grow. In such areas plants have deep roots and leaves have thorny and waxy surface to reduce loss of moisture by transpiration. Tundra vegetation of cold Polar Regions comprise of mosses and lichens.
Q24. Differentiate between Evergreen and Deciduous forest? A24.
They do not shed their leaves simultaneously in any season of the year.
They shed their leaves in a particular season to conserve loss of moisture through transpiration.
Mahogony, ebony, rosewood, cidar, cinchona trees are found here.
Sal, teak and sesum trees are found here.
It has tropical climate throughout the year with an average annual rainfall of more than 200 cm.
It has spread over the areas where two distinct seasons – rainy and dry are found, with an average annual rainfall of 75-200 cm.
They are little importance as their wood is hard and unusable in economic activities.
The wood is soft and durable. Hence they are economically important. The wood is used as timber.
Q25. List the steps that can be adopted to conserve the forest and wildlife resource.
A25. The steps that can be adopted to conserve forest and wildlife resource are-
1)National parks, wildlife sanctuaries, biosphere reserves are made to protect our natural vegetation and wildlife.
2) Conservation of creeks, lakes, and wetlands is necessary to save the precious resource from depletion.
3) Awareness programmes- like social forestry and Vanamohatasavashould be encouraged at the regional and community level. School children should be encouraged for bird watching and visiting nature camps so that they appreciate thehabitat of varied species.
4) Laws- Many countries have passed laws declaring that the trades as well as killing of birds and animals are illegal. In India, killing of lions, tigers, deers, great Indian bustards and peacocks have been banned.
5) CITES- An international convention CITES has been established that lists several species of animals and birds in which trade is prohibited.