Soil Erosion2 Cause of soil erosion

1
Soil Erosion(2)----Cause of soil erosion

• ------Distance learning
• training exercise

2
Cause of Soil Erosion

• Climate factor
• Soil feature factor
• Geological erosion
• Biological erosion

3
Climate factor
4
Soil feature factor

• The soil factor is expressed in the erodibility
  of the soil. Erodibility, unlike the
  determination of erosivity of rainfall, is
  difficult to measure and no universal method of
  measurement has been developed.

5
Geological factor

• The steepness of slopes
• The length of slopes.

6
Biological factor

• (1) the interception of rainfall by the
  vegetation canopy
• (2) velocity decreasing of runoff, and the
  cutting action of water and its capacity hencing
  to entrain sediment

7
Biological factor

• (3) root effects in increasing soil strength,
  granulation, and porosity
• (4) biological activityies associated with
  vegetative growth and their influence on soil
  porosity
• (5) the transpiration of water, leading to the
  subsequent drying out of the soil
• (6) insulation of the soil against high and low
  temperatures which cause cracking or frost
  heaving and needle ice formation
• (7) compaction of underlying soil.