Land, Soil, Water, Natural Vegetation and Wildlife

This geography chapter studies the natural resources of land, soil, water, natural vegetation and wildlife, and how to conserve them. Land covers only about thirty per cent of the Earth's surface, yet ninety per cent of the world's people live on about thirty per cent of its land area, mostly on fertile plains and river valleys. You will learn about land use, causes of land degradation such as deforestation, overgrazing and mining, and about landslides and how to reduce their damage. You will also learn how soil forms from weathered parent rock under the influence of climate, relief, living organisms and time, and how mulching, contour barriers, rock dams, terrace farming, intercropping, contour ploughing and shelter belts conserve it. Only about 2.7 per cent of the Earth's water is fresh, and most of it is frozen in ice sheets. You will study water scarcity and pollution, and conservation through rainwater harvesting and drip irrigation. Finally, you will learn how temperature and moisture decide the type of natural vegetation, and how national parks, wildlife sanctuaries and biosphere reserves protect wildlife.

Detailed Worksheet: Land, Soil, Water, Natural Vegetation and Wildlife Section A - Definitions (10 marks) 1. What is land use? Name two factors that determine land use. (2 marks) 2. What is soil? Name two factors that affect soil formation. (2 marks) 3. What is a landslide? Give one mitigation technique. (2 marks) 4. What is a biosphere reserve? How is it different from a national park? (2 marks) 5. What is rainwater harvesting? Why is it useful? (2 marks) Section B - Calculations and Applications (15 marks) 6. About 70% of the Earth's surface is covered by water and 30% by land. If the total surface area of the Earth is about 510 million square km, find the area of land and of water. (3 marks) 7. Of all the water on Earth, about 97.3% is salty ocean water and 2.7% is fresh water. Of the fresh water, about 70% is frozen in ice sheets and glaciers. What percentage of all water on Earth is fresh water not frozen as ice? (3 marks) 8. A village of 800 hectares has 480 hectares under crops, 120 hectares under forest, 80 hectares of pasture and the rest under houses and roads. Find the percentage of each type of land use and draw a conclusion about the village. (3 marks) 9. A house has a roof area of 100 square m. If the yearly rainfall is 800 mm and 80% of the rain falling on the roof can be harvested, find the volume of water harvested in a year in cubic metres and in litres. (1 cubic metre = 1,000 litres.) (3 marks) 10. Match each soil conservation method with its description: mulching, contour barriers, rock dams, terrace farming, intercropping, shelter belts. Descriptions: (i) broad flat steps cut on slopes (ii) rows of trees planted to check wind (iii) bare ground between plants covered with organic matter (iv) piles of rocks to slow the flow of water (v) barriers of stones, grass or soil along contours (vi) different crops grown in alternate rows. (3 marks) Section C - Diagrams (10 marks) 11. Draw a labelled diagram of a soil profile showing the topsoil, subsoil, weathered rock and parent rock. (4 marks) 12. Draw a labelled diagram of terrace farming on a hill slope and explain how it reduces soil erosion. (3 marks) 13. Draw a labelled diagram of a rooftop rainwater harvesting system. (3 marks) Section D - Analysis and Higher-order Thinking (15 marks) 14. Explain the main causes of land degradation and suggest four methods to conserve land resources. (5 marks) 15. Explain why many parts of the world face water shortage even though three-fourths of the Earth is covered by water. Suggest four ways to conserve water at home and in agriculture. (5 marks) 16. Why is wildlife declining in many parts of the world? Describe five steps, including those by governments and individuals, that can help conserve natural vegetation and wildlife. (5 marks) Instructions: Time allowed 2 hours. Attempt all sections. Draw diagrams neatly and show all steps in data-based questions.