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

• Mulching: Covering bare ground with organic matter, such as straw, helps retain soil moisture.
• Terrace Farming: Creating broad flat steps on steep slopes provides flat surfaces for crops, reducing run-off and soil erosion.
• Intercropping: Growing different crops in alternate rows and at different times protects soil from rain wash.
• Contour Ploughing: Ploughing parallel to hill contours forms natural barriers that slow water flow down slopes.
• Shelter Belts: Planting rows of trees in coastal and dry regions reduces wind movement, protecting soil cover.
• Contour Barriers: Building barriers with stones, grass, and soil along contours, with trenches to collect water.
• Rock Dams: Piling rocks to slow water flow prevents gullies and further soil loss.

• Forests and wildlife maintain the balance in the ecosystem.
• Forests provide shelter for wildlife.
• Forests prevent soil erosion.
• They attract rainfall, helping to maintain the groundwater level.
• We obtain various medicines from forests.
• Wildlife provides milk, meat, hides, and wool.

Conservation of natural vegetation and wildlife:

• National parks, wildlife sanctuaries, and biosphere reserves protect natural vegetation and wildlife.
• Hunting of wildlife is banned.
• Efforts are made to control human activities in forests.
• Numerous national and international organisations work to protect natural vegetation and wildlife.

Q3. Explain the problem of water availability and clarify the measures to conserve water resources.

Ans:  Water is a vital renewable resource, covering 75% of the Earth's surface. However, only about 2.7% of this is freshwater, with 70% trapped in ice sheets and glaciers, making it inaccessible. Just 1% of usable freshwater is available, which is increasingly threatened by:

• Growing populations
• Increased food demands
• Urbanisation
• Improved living standards

These factors contribute to a significant water crisis, leading to water scarcity in many regions, particularly in Africa, West Asia, South Asia, Parts of the USA and Mexico, Australia.

Conservation of Water Resources:

• Prevent the discharge of untreated sewage and industrial waste into water bodies.
• Implement proper treatment of polluted water for reuse.
• Expand forest cover to slow surface runoff and replenish groundwater.
• Use lined irrigation canals to reduce water seepage.
• Utilise sprinklers for efficient irrigation, minimising evaporation losses.