Short Answer Type Questions
Q1. How is land being degraded? Suggest methods to conserve land resource.
Ans: The ever-growing population has increased demand for living space, due to which forests are being destroyed, thus causing land degradation. The rate of degradation of land resources can be checked by promoting afforestation, land reclamation, regulated use of chemical pesticide and fertilizers and checking overgrazing.
Q2. What is weathering?
Ans: Weathering refers to the breaking up and decay of exposed rocks. This breaking up and decay is caused by temperature fluctuations between too high and too low, frost action, plants, animals and even human activity. Weathering is the major process involved in the formation of soil. It takes millions of years to form soil by this process.
Q3. How is water an important resource?
Ans: Water is an indispensable resource of life. Firstly water serves the most basic purpose of drinking, without which life is impossible. It is helpful in cleaning our bodies, clothes and utensils. Farmers depend on water for irrigation. Water is also used in cooking food. Water is a source of electricity as well. Plants require water for their growth. Water is required for various industrial purposes in factories.
Q4. Write a short note on wildlife.
Ans: The animal kingdom, which consists of animals, birds, aquatic creatures and insects, is called wildlife. These creatures provide us various important products such as milk, meat, hides and wool. Bees give us honey and help in pollination. They play the role of decomposers in the environment. Birds like the vulture are scavengers and they help in cleansing the environment. All forms of wildlife are an integral part of our ecosystem.
Q5. What are the major types of vegetation in the world? Describe vegetation in different rainfall conditions.
Ans: The major types of vegetation in the world are grouped as forests, grasslands, scrubs and tundra.” In areas of heavy rain, huge trees can be found. Forests are abundant in areas of heavy rainfall. With moisture and rainfall the density of forests declines. In moderate rainfall areas, grasslands are found. In dry areas we find thorny shrubs and scrubs. Plants here have deep roots and leaves have thorny surface to reduce loss of moisture. The tundra vegetation consists of mosses and lichens.
Q6. What is a landslide? Explain the measures to prevent this.
Ans: Landslides are simply defined as the mass movement of rock, debris, and earth down a slope They often take place in conjunction with earthquakes, floods, and volcanoes.
Measures to prevent landslides are:
- Hazard mapping to locate areas prone to landslides. Hence, such areas can be avoided for building settlements.
- Construction of retention wall to stop land from slipping.
- Increase in the vegetation cover to arrest landslide.
- The surface drainage control works to control the movement of landslides along with rainwater and spring flows.
Q7. Describe any two methods for preventing soil erosion.
1. Terrace farming: Broad flat steps of terraces are made on the steep slopes so that flat surfaces are available to grow crops. They reduce surface run-off and soil erosion.
2. Contour barriers: Stones, grass, and soil are used to build barriers along contours. Trenches arc made in front of the barriers to collect water.
Q8. Why is freshwater the most valuable substance on Earth?
Ans: The oceans cover 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. Freshwater accounts for only about 2.7 percent. Nearly 70 percent of this occurs as ice sheets and glaciers in Antarctica, Greenland and mountain regions. Due to their location, they are inaccessible. Only l percent of fresh water is available and fit for human use. It is found as groundwater, as surface water in rivers and lakes and as water vapour in the atmosphere. Freshwater is, therefore, the most precious substance on earth.
Q9. Explain the causes for forest fire. Write some control measures.
Forest fire mainly occurs due to the following reasons:
- Natural fire due to lightning etc.
- Fire due to heat generated in the litter due to the carelessness of people.
- Fire purposely caused by local inhabitants, mischief-makers, miscreants, etc.
Some Control Measures:
- Prevention of fires through education.
- Prompt detection of fires through a well-coordinated network of observation points, efficient ground patroling and communication network.
Long Answer Type Questions
Q 1. Describe methods of soil conservation.
Ans: Some common methods of soil conservation are mentioned below: Mulching. Mulching is the process of covering the bare ground between plants with a layer of organic matter like straw. It contributes in retaining soil moisture.
Terrace Farming: Terrace farming is the method of farming in which broad flat steps or terraces are made on the steep slopes so that flat surfaces are available to grow crops 4 They reduce run-off and soil erosion.
Intercropping: In intercropping, different crops are grown in alternate rows and are sown at different times to protect the soil from being washed away by rain.
Contour Ploughing: Ploughing parallel to the contours of a hill slope to form a natural barrier for water to flow down a slope is called contour ploughing.
Shelter Belts: Rows of trees that are planted in certain areas to check wind movement are called shelter belts. Contour Barriers. Stones, grass and soil are used to build barriers along contours. Trenches are made in front of the barriers to collect water.
Rock Dams: This prevents gullies and further soil loss since rocks are piled up to slow down the flow of water.
Q 2. Explain the importance of forests and wildlife and also explain the conservation of natural vegetation and wildlife. [V. Imp.]
Ans: Importance of vegetation and wildlife:
- Forest and wildlife help in maintaining the balance in the ecosystem.
- Forest provides shelter to wildlife.
- Forests provide us with timber, fruits, rubber, paper, gum, etc.
- Many types of raw materials for industries are obtained from forests.
- Forests help in preventing soil erosion.
- Forest attracts rainfall, thereby maintaining the groundwater level.
- We get many types of medicines from forests.
- Wildlife provides us with milk, meat, hides, and wool.
Conservation of natural vegetation and wildlife:
- National parks, wildlife sanctuaries, and biosphere reserves are made to protect our natural vegetation and wildlife.
- Hunting of wildlife is banned.
- Efforts have been made to control human activities in the forests.
- Awareness programs should be encouraged at the regional and community level towards the natural vegetation and wildlife.
- A number of national and international organizations have been set up to protect natural vegetation and wildlife.
Q3. Explain the problem of water availability and clarify the measures to conserve water resources.
Ans: The problem of water availability:
- Water, a crucial renewable natural resource, covers 75% of Earth's surface.
- Oceans, spanning two-thirds of the planet, support diverse plant and animal life.
- However, ocean water is saline, unsuitable for human consumption.
- Freshwater is a mere 2.7%, with 70% trapped in inaccessible ice sheets and glaciers.
- Only 1% of usable freshwater exists, strained by overuse and pollution.
- Pressing factors include growing populations, elevated food/crop demands, urbanization, and improved living standards.
- These factors lead to dwindling freshwater supply due to source depletion or contamination.
- The outcome is a widespread water crisis, affecting numerous countries.
- Many regions grapple with water scarcity due to these challenges.
Conservation of water resources:
Access to clean and adequate water sources is a major problem facing the world today. Hence, conservation of water resources is necessary. The following measures can be taken to conserve water resources:
- Discharge of untreated or partially treated sewage, agricultural chemicals and industrial effluents in water bodies are major contaminants. Pure water should be saved from them.
- Polluted water should be treated by various methods and reused.
- Forest and other vegetation cover slow the surface run-off and replenish underground water therefore forests should be expanded.
- The canals used for irrigating field should be properly lined to minimise losses of water seepage.
- Sprinklers effectively irrigate the area by checking water losses through seepage and evaporation.