Soil Erosion and Sediment Deposition in Dongting Lake
Zou Wenfa (Department of Geography, Hunan Teachers' College, Changsha)
Dongting Lake is an alternately filled lake with large amount of sediment deposition. Sediment deposited from 1951 to 1983 added up to about 4807 million tons with an average sediment deposition of 150 million tons per year. The sediment deposited mainly in the flood season, of which, majority were alluvial deposits coming from the Yangtze River. Serious silt accumulation reflects the intensive soil erosion in the upper and middle Yangtze River. The disasters due to silt deposition took place in the lake area and mainly expressed in flooding, soil gleization and snail fever. Soil erosion took place in mountainous area and led to soil deterio-ration and the sharpenness of slide and debris flow. Strengthening the prevention of soil loss in the key areas in upper Yangtze River basin and the establishment of forest system in the upper and middle basin, increas-ing per capita output and eliminating or lessening the pressure of population growth on the ecologic environ-ment can basically put the disasters ,due to soil erosion and sediment deposition under control.