1. Why plain and river valleys are densely populated area of the world?
Plains and river valleys offer suitable land for agriculture. They are suitable for human settlement and for industry set up. Hence, these are the densely populated areas of the world.
2. Which places on the earth are sparsely populated?
The rugged topography, steep slopes of the mountains, low-lying areas susceptible to water logging, desert areas and thick forested areas are normally sparsely populated or uninhabited.
3. What is ‘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.
4. By which factors use of lands is determined?
The use of land is determined by physical factors such as –
- Topography, soil, climate, minerals and availability of water.
- Human factors such as population and technology are also important determinants of land use pattern.
5. What is private land and community land?
Land can also be classified on the basis of ownership as – private land and community land.
Private land is owned by individuals whereas, community land is owned by the community for common uses like a collection of fodder, fruits, nuts, or medicinal herbs. These community lands are also called common property resources.
6. What are the methods to conserve the land resources?
Afforestation, land reclamation, regulated use of chemical pesticides and fertilizers, and checks on overgrazing are some of the common methods used to conserve land resources.
7. What is soil?
The thin layer of grainy substance covering the surface of the earth is called soil. It is closely linked to the land. Landforms determine the type of 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 makes the soil fertile.
8. What are landslides? What causes the landslides?
Landslides are defined as the mass movement of rock, debris or earth down a slope.
They often take place in conjunction with earthquakes, floods and volcanoes.
9. What are the factors responsible for the formation of the soil?
The major factors of soil formation are
- The nature of the parent rock
– It determines colour, texture, chemical properties, mineral, content, permeability of the
- Climatic factors
– Temperature, Rainfall influence rate of weathering and humus formation
- The topography
– Altitude and slope of the relief determine accumulation of soil
- Role of organic material.
- Time is taken for the composition of soil formation.
- Flora, Fauna, and Micro-organism
– Affect the rate of humus formation
10. What are the factors which lead to soil degradation?
Both human and natural factors can lead to degradation of soils.
Factors that lead to soil degradation are deforestation, overgrazing, overuse of chemical fertilizers or pesticides, rain wash, landslides, and floods.
11. List some methods of soil conservation.
Some methods of soil conservation are:
Mulching: In this method, the bare ground between plants is covered with a layer of organic matter like straw. It helps to retain soil moisture.
Contour barriers: Stones, grass, soil are used to build barriers along contours. Trenches are made in front of the barriers to collect water.
Rock dam: Rocks are piled up to slow down the flow of water. This prevents gullies and further soil loss.
Terrace farming: Broad flat steps or terraces are made on the steep slopes so that flat surfaces are available to grow crops. They reduce surface runoff and soil erosion.
Intercropping: Different crops are grown in alternate rows and are sown at different times to protect the soil from rain wash.
Contour ploughing: Ploughing parallel to the contours of a hill slope to form a natural barrier for water to flow down the slope.
Shelterbelts: In the coastal and dry regions, rows of trees are planted to check the wind movement to protect soil cover.
12. Define the followings:
- Contour barriers
- Rock dam
- Terrace farming
- Contour ploughing
- Shelter belts
- Mulching: In this method, the bare ground between plants is covered with a layer of organic matter like straw. It helps to retain soil moisture.
- Contour barriers: Stones, grass, soil are used to build barriers along contours. Trenches are made in front of the barriers to collect water.
- Rock dam: Rocks are piled up to slow down the flow of water. This prevents gullies and further soil loss.
- Terrace farming: Broad flat steps or terraces are made on the steep slopes so that flat surfaces are available to grow crops. They reduce surface runoff and soil erosion.
- Intercropping: Different crops are grown in alternate rows and are sown at different times to protect the soil from rain wash.
- Contour ploughing: Ploughing parallel to the contours of a hill slope to form a natural barrier for water to flow down the slope.
- Shelterbelts: In the coastal and dry regions, rows of trees are planted to check the wind movement to protect soil cover.
13. What is earth called ‘water planet’?
As three fourth of the earth’s surface is covered with water, so it is called the ‘water planet’.
14. Explain water cycle.
Water is always in constant motion. Water as water vapor rises from oceans, other water bodies, and land. When it rises, it condenses and starts forming clouds and when clouds get saturated it comes down to the earth in the form of precipitation and refills all the water resources again. This process going on again and again. This process is known as the ‘water cycle’.
15. What are the factors which leads to water shortage?
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. Some of the factors are –
- Consumption of huge amounts of water by humans for drinking and washing.
- Water for agriculture, industries, generating electricity through reservoirs of dams are the other usages.
- Increasing population rises demands for food and cash crops.
- Increasing urbanization and rising standards of living.
16. Mention few places on the earth which are facing scarcity of water.
Most of Africa, West Asia, South Asia, parts of western USA, north-west Mexico, parts of South America, and entire Australia are facing shortages in freshwater supply. Countries located in climatic zones most susceptible to droughts face great problems of water scarcity.
17. What is biosphere?
The biosphere is the narrow zone of contact between the lithosphere, hydrosphere, and atmosphere where the natural vegetation and wildlife exist.
18. What is ecosystem?
In the biosphere living beings are interrelated and interdependent on each other for survival. This life-supporting system is known as the ecosystem.
19. List some uses of plants.
Plants provide us with timber, give shelter to animals, produce the oxygen we breathe, protects soils so essential for growing crops, act as shelterbelts, help in the storage of underground water, give us fruits, nuts, latex, turpentine oil, gum, medicinal plants, paper and many other things which are very essential for our daily needs.
20. What are the major type of vegetation of the world?
The major vegetation types of the world are grouped as forests, grasslands, scrubs and tundra.
21. What kind of vegetation you will found in Tundra vegetation?
Tundra vegetation of cold Polar Regions comprise of mosses and lichens.
22. “Animals big or small, all are integral to maintaining balance in the ecosystem”. Explain.
Wildlife includes animals, birds, insects as well as aquatic life forms. They provide us milk, meat, hides, and wool. Insects like bees provide us, honey, help in the pollination of flowers, and have an important role to play as decomposers in the ecosystem. The birds feed on insects and act as decomposers as well. 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 to maintaining balance in the ecosystem.
23. What is Rain-water harvesting?
Rainwater harvesting is the process of collecting rainwater from rooftops and directing it to an appropriate location where it is stored for future use.
24. What is National park?
A natural area designated to protect the ecological integrity of one or more ecosystems for the present and the future generations
25. What is Biosphere reserve?
The biosphere is a series of protected areas linked through a global network, intended to demonstrate the relationship between conservation and development.
26. Why several birds and animals are either become extinct or on the verge of the extinction?
Human activities in several parts of the world have disturbed the natural habitats of many species. Due to indiscriminate killings, several birds and animals have either become extinct or are on the verge of extinction.
27. What is CITES?
CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) is an international agreement between governments. It aims to ensure that international trade in specimens of wild animals and plants does not threaten their survival. Roughly 5,000 species of animals and 28,000 species of plants are protected. Bears, dolphins, cacti, corals, orchids, and aloes are some examples.