Class 8 Geography Chapter 1 Question Answers - Resources and Development

Short Answer Type Questions

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.

Ans: 

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.

Ans: 

Forest fire mainly occurs due to the following reasons:

1. Natural fire due to lightning etc.
2. Fire due to heat generated in the litter due to the carelessness of people.
3. Fire purposely caused by local inhabitants, mischief-makers, miscreants, etc.

Some Control Measures:

1. Prevention of fires through education.
2. Prompt detection of fires through a well-coordinated network of observation points, efficient ground patroling and communication network.

Long Answer Type Questions

• 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.

1. Forest and wildlife help in maintaining the balance in the ecosystem.
2. Forest provides shelter to wildlife.
3. Forests provide us with timber, fruits, rubber, paper, gum, etc.
4. Many types of raw materials for industries are obtained from forests.
5. Forests help in preventing soil erosion.
6. Forest attracts rainfall, thereby maintaining the groundwater level.
7. We get many types of medicines from forests.
8. Wildlife provides us with milk, meat, hides, and wool.

Conservation of natural vegetation and wildlife:

1. National parks, wildlife sanctuaries, and biosphere reserves are made to protect our natural vegetation and wildlife.
2. Hunting of wildlife is banned.
3. Efforts have been made to control human activities in the forests.
4. Awareness programs should be encouraged at the regional and community level towards the natural vegetation and wildlife.
5. 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.