2. 5 th SCIENCE 8.SOIL EROSSION Sub Unit- 8.1 Introduction Formation of soil layer 8.2 Formation of soil layer Erosion 8.3 Erosion Terracing 8.4 Terracing Preventing Soil erossion 8.5 Preventing Soil erossion

3. What is soil erosion ? »The reduction of soil cover on the land by water or wind is called soil erosion

4. Erosion: Is the natural process of soil being moved from one place and deposited in another. Is radically expedited by humanity’s use of land. Occurs primarily due to wind or water movement, or agricultural practices.

5. The thickness of the layer of soil on the land is not same in all places.

6. Formation of soil layer The action of the sun,wind and rain results in the wearing down or weathering of rock and stones in to fine particles. These particles form a layer of the land.

7. Soil on land is carried away by flowing water and wind this is called soil erossion

8. The movement of stray animals increases the danger of soil erosion.

9. It takes 800 to 1000 years for a 2.5 cm thick layer of soil to form from rocks

10. Terracing: Terraced bean fields in Iowa Terraced rice paddies in Yunnan Province, China Stretch of sloping agricultural land is divided in to smaller plots of the flat land called terraces. Low mud walls or bunds are built on the outer sides of plots to block flowing water are called bunds

11. Designed as a method to make steep areas arable, as well as retain valuable topsoil from water erosion by slowing down the movement speed of the water from one step to another. Many terrace designs include either a small lip at the edge or a band of native vegetation on lower gradient slopes. Sa Pa, Vietnam

12. Preventing Soil erossion 1)Planting trees

13. 2)Growing grass

14. Planting trees around fields and growing grass on open stretch of land are simple ways of preventing soil erosion.

15. Reserve areas for grazing of animals

16. Q1). What are the causes of soil erosion? flowing water and wind,The movement of stray animals are the causes of soil erosion Q2).What are the advantages of planting trees? Roots of plants hold soil particles in which they grow, leaves that fall from trees cover the soil beneath so rain cannot loosen the soil. These are the advantages of planting trees

17. Reference – Text Book, Cbsc,Web.

18. Rayat Shikshan Sanstha, Karmveer Vidhyaprabhodhini Madhya Vibhag,Satara Created By –