Class 8 Geography Chapter 2 | Land, Soil, Water, Natural Vegetation and Wildlife Resources | Important Questions And Answers
Here are important questions from NCERT Class 8 Geography chapter 2 Land, Soil, Water, Natural Vegetation And Wildlife Resources.
1. Why do places and living standards differ from one another?
Places and living standards differ from one another because the quality of soil, access to water, natural vegetation and technology are not the same everywhere. Some places have fertile soil, favourable weather, abundance of water and easy access to technology and they tend to become prosperous. By contrast, several other places lack in these fundamental aspects and tend to be backward.
2. Why is land one of the most important natural resources?
Land is one of the most important natural resources because only 30% of the earth’s surface is covered by land. Also, some parts of the land are not habitable. Actually, 90% of the world population occupies only 30% of the total land. The remaining 70% of the land is either uninhabited or sparsely populated. Because of the limited availability of land, it is an important natural resource.
3. Why is population distributed unevenly?
The characteristics of land and climate change from place to place. Places that have rugged topography or that are situated on the steep slopes of mountains are not suitable for habitation. Also, low lying areas susceptible to flooding, deserts and thick forests are also uninhabited or sparsely populated.
4. Why are plains and river valleys densely populated?
Plains and river valleys are densely populated because they offer suitable land for agriculture.
5. What are some uses of land?
Land is used for various purposes such as agriculture, mining, forestry, building houses, roads and factories.
6. What are the factors that determine the use of land?
Factors that determine the use of land are its topography, quality of soil, climate, presence of minerals and availability of water. Other factors that determine the use of land are the size of the human population and their access to technology.
7. What are common property resources?
These are community lands that are owned by a community for common uses like collecting fodder, fruits, nuts and medicinal herbs.
8. What are the environmental problems caused by expansion of agriculture and construction activities?
Land degradation, landslides, soil erosion and desertification are some of the major environmental threats caused by construction activities and expansion of agriculture.
9. What are some common methods used to conserve land resources?
Afforestation, land reclamation, regulated use of chemical fertilisers and pesticides and checks on overgrazing are some of the methods used to conserve land resources.
10. What is soil?
Soil is the thin layer of grainy substance covering the surface of earth.
11. What are the components of soil?
Soil is made up of organic matter, minerals and weathered rocks.
12. What makes soil fertile?
The right mix of minerals and organic matter makes soil fertile.
13. What is weathering?
Weathering is the breaking up and decay of exposed rocks due to changes in temperature, action of frost and activities of plants, animals and humans.
14. What are landslides?
Landslides are the mass movement of rock, debris and earth down a slope.
15. What are the factors that can trigger a landslide?
A Landslide can be triggered by earthquakes, floods and volcanoes. A prolonged spell of rainfall can also cause landslides.
16. What are some measures that can be taken to prevent landslides or mitigate their impact?
Hazard mapping can be done to identify areas that are prone to experience landslides. Such areas should not be used for building human settlements.
Retention walls can be built to stop land from slipping.
Roots can hold soil and prevent it from slipping. Hence, increasing vegetation cover is an effective way to prevent landslides.
Surface drainage control is another measure.
17. What are the factors affecting soil formation?
Nature of the parent rock and climate are the major factors affecting soil formation. Other factors include topography, role of the organic material and time taken for the composition of soil formation.
Temperature and rainfall in a particular region affect the rate of weathering and humus formation.
The parent rock determines the colour, texture, chemical properties, mineral content and permeability of the soil.
The altitude of the place and the slope of the land affect the accumulation of soil.
The flora, fauna and micro-organisms affect the rate at which humus is formed.
It takes hundreds of years to make just one centimetre of soil.
18. What are the different kinds of soil found in India?
Alluvial soil, black soil, red soil, laterite soil, desertic soil and mountain soil.
19. What are the factors that lead to soil degradation?
Some of the factors leading to soil degradation are deforestation, overgrazing, overuse of chemical fertilizers or pesticides, rain wash, landslides and floods.
20. Briefly explain some methods of soil conservation
Mulching involves covering the bare ground between plants with a layer of organic material like straw. This helps to retain soil moisture.
This involves building barriers along contours using stones, grass and soil. Trenches are made in front of the barriers to collect water.
Rocks are piled up to slow down the flow of water. This prevents soil loss and gullies.
Broad flat terraces are made on the steep slopes of mountains to grow crops. This way, mountain slopes can be used for agriculture. It also reduces surface run off and soil erosion.
Intercropping is the practice of growing different crops in alternate rows. The seeds are sown at different times to protect the soil from rain wash.
This is the practice of ploughing parallel to the contours of a hill slop to form a natural barrier for water to flow down the slope.
In coastal areas and dry regions, rows of trees are planted to check the wind movement to protect soil cover.
21. Why is earth called the water planet?
Three-fourth’s of earth is covered by water. Hence, it is called the water planet.
22. Where did life originate about 3.5 billion years ago?
In the oceans
23. Why is ocean water not fit for human consumption?
Ocean water is salty and hence it is not fit for human consumption.
24. Why is water an important natural resource?
Although three-fourth’s of the earth’s surface is covered by water, fresh water accounts for only 2.7% of it. Nearly 70% of the fresh water occurs as ice sheets and glaciers in the Antarctic, Greenland and mountain regions. Due to their remote location, they are not accessible to humans or animals. Only 1% of the fresh water is available and fit for human use. It exists as groundwater, surface water in rivers and lakes and water vapour in the atmosphere. Because of these reasons water is an important renewable natural resource.
25. Is water a renewable resource?
26. Total volume of water remains constant. Explain
The amount of water present on earth cannot be increased or decreased. Its quantity seems to vary because it is in constant motion cycling through the ocean, the air, land and back again through processes called evaporation, precipitation and run off.
27. What are the main uses of water?
Water is used for a variety of purposes such as drinking, washing, cooking and bathing. It is also used for growing crops, to generate electricity and in industries.
28. What are the reasons for water shortage?
As population increases, the demand for food and cash crops also increases. Since water is essential for growing crops, this rise in demand increases the consumption of water. Increasing urbanisation leads to the drying up of water sources. Industrialization often pollutes water bodies. The rising living standards also increase the consumption of water. All of these factors lead to water shortage. Countries located in climatic zones that do not receive much rainfall face greater scarcity of water. Thus, water shortage could be a consequence of changes in seasonal and annual precipitation or it could be caused by overexploitation or contamination of water sources.
29. Name some countries or parts of the world where water scarcity is a major problem?
Water scarcity is a problem in most of Africa, West Asia, South Asia, parts of western USA, north-west Mexico, parts of South America and entire Australia.
30. What are the main causes of water pollution?
Discharge of untreated or partially treated sewage, agricultural chemicals and industrial effluents into water bodies are the main causes of water pollution.
31. How can water pollution be controlled?
The main cause of water pollution is the discharge of untreated sewage, agricultural chemicals and industrial effluents into water bodies. These effluents contain nitrates, metals and pesticides. By treating these effluents before they are released into the water, water pollution can be controlled to a great extent.
32. How can water resources be conserved?
Planting more trees and increasing vegetation cover help to reduce surface runoff and replenish underground water reserves. Water harvesting is another method to conserve water. Water seepage can be prevented by properly lining canals used for irrigating land. Using sprinklers for irrigating land will help reduce water loss through evaporation. In extremely dry regions, drip irrigation is useful as it prevents water loss through evaporation.
33. What is rain water harvesting?
Rain water harvesting is the process of collecting rain water from roof tops and directing it to an appropriate place where it can be stored for future use.
34. What is biosphere?
Biosphere is the narrow zone of earth where land, water and air interact with one another to support life. Life exists only in the biosphere.
35. What is ecosystem?
Biosphere is the zone of earth supporting life. All living beings in the biosphere are interrelated and dependent on one another for survival. It is this life supporting system that is known as the ecosystem.
36. How are plants useful to us?
Plants produce the oxygen we breathe, give shelter to animals, protect soil, provide timber, give us food, oil, gum and even medicines.
37. How is wildlife useful to us?
Wildlife includes animals, birds, insects and aquatic life forms. Birds and animals provide us with milk, meat, eggs, hides and wool. Insects like bees provide us honey. They also help in the pollination of flowers and act as important decomposers in the ecosystem.
38. How are vultures useful to us?
Vultures feed on dead livestock and act as a vital cleanser of the eco-system.
39. Why is the population of vultures dwindling in India?
Indian vultures are on the brink of extinction because their numbers reduced rapidly during the last few decades. Millions of them died of kidney failure after scavenging on livestock treated with the painkiller diclofenac. Now efforts are on to ban this drug for livestock use and breed vultures in captivity.
40. Name the two factors that mainly affect the growth of vegetation
Temperature and moisture
41. What are the four main types of vegetation in the world?
Forests, grasslands, scrubs and tundra
42. The type of vegetation that is likely to be found in an area receiving abundant rainfall will be ………………………………..
43. Grasslands are found in areas receiving ……………………………….. rainfall.
43. Why do thorny shrubs and scrubs grow in dry areas?
Thorny shrubs and scrubs have deep roots. Their thorny leaves have a waxy surface to prevent water loss through evaporation.
44. Name the kind of vegetation found in the Polar region
45. Tundra vegetation comprises of …………………………….
Lichens and mosses
46. Name some factors that lead to the extinction of natural vegetation and wildlife
Deforestation, soil erosion, constructional activities, forest fires, tsunami and landslides are some of the human and natural factors leading to the extinction of natural vegetation and wildlife.
47. What is poaching?
Poaching is the illegal hunting and capturing of wildlife for collection and illegal trade of hides, skins, nails, teeth, horns and feathers.
48. Name some measures taken by the government to protect our natural vegetation and wildlife.
The government has built national parks, wildlife sanctuaries and biosphere reserves to protect natural vegetation and wildlife.
49. What is a national park?
A national park is a designated natural area to protect the ecological integrity of ecosystems for the present and future generations.
50. What is CITES?
CITES is the Convention on International Trade in Endangered Species of Wilf Fauna and Flora.