Learning Objectives
- Understand the importance of land as a resource and factors affecting land use
- Learn about different types of soil and methods of soil conservation
- Understand the distribution and conservation of water resources
- Know about natural vegetation and wildlife and their conservation
Key Concepts
Land as a Resource
Land is among the most important natural resources. It supports natural vegetation, wildlife, human life, economic activities, and transport. Land use depends on physical factors (topography, soil, climate) and human factors (population density, technology, culture).
About 90% of the world population occupies only 30% of the total land area. The remaining land is either sparsely populated or uninhabited due to dense forests, deserts, high mountains, or extreme climates.
Soil
Soil is the thin layer of grainy substance covering the Earth's surface formed by weathering of rocks over millions of years. Factors of soil formation include: parent rock, climate, vegetation, relief, and time.
Soil Degradation: Deforestation, overgrazing, overuse of chemical fertilisers, rain wash, landslides, and floods cause soil degradation. This makes soil lose its fertility and become unsuitable for cultivation.
Soil Conservation Methods:
Mulching: Covering bare ground between plants with organic matter to retain moisture.
Contour Barriers: Stones, grass, or soil placed along contours to slow down water flow on slopes.
Rock Dams: Built to slow water flow and prevent gullies from forming.
Terrace Farming: Creating flat steps on steep slopes to reduce run-off and soil erosion.
Intercropping: Growing different crops in alternate rows to protect the soil from wind and rain.
Contour Ploughing: Ploughing parallel to the contours of a hill slope to slow water run-off.
Shelter Belts: Planting rows of trees to break the force of wind and protect soil in coastal and dry regions.
Water Resources
Water covers about 71% of the Earth's surface but only 2.7% is fresh water and most of it is locked in ice caps and glaciers. Only about 1% is available for human use. Problems: water scarcity, pollution, uneven distribution.
Conservation methods include rainwater harvesting, drip irrigation, recycling water, and building dams.
Natural Vegetation and Wildlife
Natural vegetation and wildlife exist only in the narrow zone called the biosphere, where the lithosphere, atmosphere, and hydrosphere interact. Vegetation types depend on temperature, moisture, slope, and soil thickness.
Threats: Deforestation, poaching, pollution, and climate change. National parks, wildlife sanctuaries, and biosphere reserves have been established for conservation. CITES (Convention on International Trade in Endangered Species) is an international agreement to protect wildlife.
Summary
Land, soil, water, natural vegetation, and wildlife are interdependent resources. Land use is determined by physical and human factors. Soil erosion and degradation threaten agriculture, but conservation methods like terrace farming and shelter belts can help. Fresh water is scarce and must be conserved. Natural vegetation and wildlife face threats from human activities and require active conservation through parks and international agreements.
Important Terms
- Land Use
- The way land is utilised for different purposes such as agriculture, forestry, mining, and habitation
- Soil
- Thin layer of grainy substance on Earth's surface formed by weathering of rocks
- Weathering
- Breaking down of rocks by physical, chemical, and biological processes
- Mulching
- Covering soil with organic matter to retain moisture and prevent erosion
- Terrace Farming
- Cutting steps on hill slopes to reduce run-off and soil erosion
- Biosphere
- Narrow zone where land, water, and air interact to support life
- CITES
- Convention on International Trade in Endangered Species of Wild Fauna and Flora
Quick Revision
- 90% of the world population lives on 30% of land area
- Soil formation factors: parent rock, climate, vegetation, relief, time
- Soil conservation: mulching, contour barriers, terrace farming, shelter belts, intercropping
- Only about 1% of Earth's water is usable fresh water
- Biosphere = zone where lithosphere, atmosphere, and hydrosphere interact
- CITES protects endangered species from international trade
Practice Tips
- Draw a diagram showing different soil conservation methods on a hill slope
- Memorise the percentages related to water distribution on Earth
- Know the difference between national parks, wildlife sanctuaries, and biosphere reserves