The affection of geological condition on water loss and soil erosion in Guizhou Karst mountainous area
GAO Huaduan(Department of Forestry, Forestry College, Guizhou University, Guizhou Guiyang 550025,China)
By investigating and researching on water loss and soil erosion in Guizhou Karst mountainous areas, it indicates that the geological condition is a main factor controlling water loss and soil erosion, that carbonate rocks have the characteristics of slow soil formation and small soil quantity, of being difficult to form surface run off , and of having small quantity and great potential danger on soil erosion. Carbonate rock'types on water loss and soil erosion could be classified by rock's clay quantity into pure limestone, marlite , pure dolomite and pelitic dolomite. The soil's hardness values of limestone are stable, which is between 4.0 to 8.0, but that is unstable by dolomite, which is between 3.0 to 13.5. On the other hand, the characteristics of water loss and soil erosion are affected by geologic structures of faults, the relation between the rock formation and the slope direction.