2.3   Additional Questions :

1.  Name the factors determining land use.

i) Factors determining the land use include physical factors like topography, availability of water,climate, minerals, soil, etc.
ii) Human factors like demography (population pattern), technology and education.

2.  Name some major threats to the environment.
Land degradation, landslides, soil erosion, desertification are major threats to the environment.

3.  What is (i) Deforestation (ii) Afforestation.
i) Due to the huge demand for land, people have also started reducing forest cover in order to make them habitable . This is called into deforestation.
ii) Afforestation (growing trees) ,regulated use of chemical pesticide and checking overgrazing by animals are some general methods to conserve these valuable natural resources.

4.  What is a) Soil b) Weathering c) Mulching  .

a) The word soil refers to the thin layer of grainy substance covering the surface of the earth. It is made of organic matter ,minerals and weathered rocks.
b) Weathering refers to the breaking up and decay of exposed rocks. This breaking up and decay is caused by temperature fluctuations , frost action ,plants ,animals and even human activity.
c) Mulching is the process of covering the bare ground between plants with a layer of organic matter like straw. This helps in retaining soil moisture.

5.  Explain what do you mean by degradation of soil.
Soil erosion and depletion pose major threats to the quality and resourcefulness of soil. Degradation takes place by both human and natural factors .Deforestation ,overgrazing ,overuse of chemical fertilizers or pesticides ,rain wash ,landslides and floods lead to degradation of soil.

6.  What is Terrace farming .
Terrace farming is the method of farming in which board flat steps or terraces are made on the steep slopes so that flat surfaces are available to grow crops .This helps in controlling soil erosion.

7.  What is inter-cropping.
In inter-cropping , different crops are grown in alternate rows and are sown at different times to protect the soil from being wasted away by rain.

8.  What is 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.

9.  What are belts.
These trees are supposed to bind the soil ,thus preventing them from being eroded away easily.

10.  What is water cycle.
The natural process of the constant motion of water through evaporation, condensation and rainfall is called Water Cycle.

11.  What is rain water harvesting.
The process of conserving water in which rainwater is collected so that it can be used in times of Water Scarcity is called Rain water Harvesting.

12.  What is biosphere.
The narrow zone of contact between the lithosphere, hydrosphere and atmosphere is called Biosphere.

13.  What are national parks.
A national Park is a natural area, supposed to be used to protect the ecological integrity of one or more ecosystems for the present and future generations.

14.  What is wildlife Sanctuary .
A wildlife Sanctuary is similar to a national park, but it is supposed to protect a particular animals, in some cases, or wildlife in general, in other cases.

15.  What is biosphere reserve.
These are series of protected areas linked through a global network, intended to demonstrate the relationship between conservation and development.

16.  What are the possible reasons behind the uneven distribution of population around the world.
The reason behind the uneven distribution is mainly the varied condition of land and climate.

17.  How is the bird like vultures important for ecosystem.
A vulture feeds on dead livestock and so it cleanses the environment.

18.  What are factors threatening soil as a resource.
Two factors Threatens soil a  resource are soil erosion and its depletion.

Fill in the blanks :

1)  The percentage of fresh water on earth ________ .

2)  The process responsible for soil formation is called ________ .

3)  The grainy layer on land is called ____________.

4)  The color, texture etc. of soil is determined by ______________ .

5)  70% of fresh water exists as _________ .

6)  Soil becomes fertile due to right mix of _________ and ________ .

Answers :
1) 2.7 %                        2) Weathering                3) Soil
4) Parent rock            5) Ice-sheet                     6) Mineral and organic matters.