QUANTITATIVE STUDY OF SOIL EROSION AND ELEMENT RUN-OFF IN THE SONGHUA LAKE VALLEY

Under the condition of different precipitation intensities, different gradients, different land-use types and different vegetation coverage, the soil erosion and transference of element(or pollutant) are studied by simulating and analyzing the surface run-off of experimental plots in the catchment area of Songhua Lake, with an area of about 43 370.8km². And the influencing factors that produce the spatial difference are analyzed and assessed. It is put forward that the irrational land utilization is the reason of soil erosion and pollutant run-off. The gradient of farmland, the growing season of vegetation and the vegetation coverage are chiefly restricting factors that lead to the soil erosion and pollutant run-off. This study can provide the fundamental data for comprehensive planning and harnessing of the non-point source pollution in the valley.