DAV Class 8 SST Solution Chapter 2 Natural Resources Land Soil and Water
DAV School Books Class 8 SST Solution Chapter 2 Natural Resources Land Soil and Water all Question Answer. DAV Class 8 2nd Chapter Natural Resources Land Soil and Water full Chapter explanation by expert teacher.
DAV School Books Class 8 SST Solution Chapter 2 Natural Resources Land Soil and Water:
(A) Tick the correct option –
(1) Which type of erosion leads to desertification?
Ans: Soil Erosion.
(2) Which one of the following is suitable for restoring soil fertility?
Ans: Rotation of crops.
(3) Which of the following is not in favour of multipurpose river valley projects?
Ans: Large scale displacement of people.
(4) Maintenance of lakes and ponds is essential for-
Ans: Recycling of water.
(5) Which factor is more responsible for the quick formation of soil in Rajasthan?
Ans: Extreme difference in day and night temperature.
(B) Fill in the blanks.
(1) Earth’s surface is divided into ______ and _____ zones.
Ans: land, water.
(2) To maintain ecological balance, _____ % of the land should be under forest.
Ans: 33
(3) Planting of trees is commonly known as ______.
Ans: afforestation.
(4) The main source of fresh water is ______.
Ans: rainfall.
(5) Earth is known as _____ planet due to the presence of water on it.
Ans: blue.
(C) Write a technical term or an appropriate word for each of the following statements.
(1) It is formed by decomposed parts of plants and animals.
Ans: Humus.
(2) The original rock from which the soil is formed.
Ans: Parent rock.
(3) It is formed as a result of long continued weathering process of rocks.
Ans: Soil.
(4) A project which serves various purposes at the same time.
Ans: Multipurpose River vally project.
(5) The process in which the top layer of the soil is removed by the natural and human activities.
Ans: Soil erosion.
(D) Answer the following questions in brief-
(1) Why is soil considered an important resource? Give any three reasons.
Ans: Soil is considered as an important resource because-
(i)The primary sector of economy- agricultural production is mainly dependent on the fertility of the soil.
(ii) Soil is a habitat of some insects and animals like rats, snakes, ants etc.
(iii) By giving nutrition to the plants soil also satisfy the basic need of some animals.
(2) Highlight any three causes of soil erosion.
Ans: Causes of soil erosion-
(i) deforestation
(ii) Mining
(iii) over grazing of animals.
(3) Explain hydrological cycle with the help of a diagram.
Ans: Hydrological cycle- Continuous recycling of rain water, which is the main source of fresh water through evaporation, condensation and precipitation in nature is called hydrological cycle.
Diagram-pg .13
(4) How does river water get polluted? Explain.
Ans: River water gets polluted through urban waste and industrial waste. Moreover few activities of human beings like washing clothes and utensils, bathing animals, using pesticides in the agricultural lands make the water of the river polluted. buildi
(5) Identify any three ecological problems caused by building large dams.
Ans: Ecological problems caused by building large dams are-
(i) Soil erosion
(ii) Diversion of river water
(iii) It effects the aquatic life .
(E) Answer the following questions-
(1) Explain any five factors responsible for the formation of soil.
Ans: Five factors responsible for the formation of soil are-
(i) The parent rock- It is an original from which soil can be formed. Soil can be formed through weathering.
(ii) The Topography- mountains, plateaus and plains are the topographical variations and they can affect the for the formation of the soil.
(iii) The climate- temperature, rainfall, these climatic factors put affect in the formation of the soil.
(iv) The vegetation cover- humus made by dead or decomposed plants and animals, plants grow in the cracks of the existing rocks help to form soil.
(V) Time- to develop the different layers of the soil it takes thousand years.
(2) What is meant by land use pattern? Why is it important to study the land use pattern? List the factors influencing the utilisation of land.
Ans: The usage of land in different purposes such as cultivation, building of houses, construction of roads, railways etc. Is known as land use pattern.
The study of the land use pattern is important because it helps in the economic growth and planning of a country by a proper assessment of the usage of land under the development goals and availability of resources.
Factors influencing the utilisation of land are-
(i) Physical factors-reliefs,soil,climatic conditions etc
(ii) Human factors- technogical and social requirements, density of population etc.
(3) What are Multipurpose River Valley Projects? Name any two such projects. List the main objectives of a multipurpose river valley project.
Ans: To utilize water some projects have been developed and they can serve different objectives together is called multipurpose River valley projects. For example- Damodar river valley project, Asswan in Egypt etc.
Main objectives of multipurpose River valley projects are- irrigation, hydroelectricity, navigation, controlling flood etc.
(4) Suggest any five steps to conserve soil.
Ans: To conserve soil-
(i) Plantation of more trees which is called afforestation.
(ii) by building dams floods should be avoided.
(iii) Should take legal action against the reckless cutting of trees.
(iv) Terrace Farming and contour ploughing.
(v) Scientific research before ploughing.
(5) Suggest any five methods for the conservation of water.
Ans: Water conservation methods-
(i) By doing water harvesting we can save the surface water from running off.
(ii) To save water modern methods of irrigation should be implemented.
(iii) Rain water harvesting can be one of the methods of water conservation.
(iv) Methods should be taken to recycle water for the industrial sector.
(v) Spreading Education towards the basic needs of the conservation of water is the most important method to be implemented.
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Very good well done shabash