Soil erosion and lake eutrophication-The case of Chaohu Lake

Several hypothesis of nonpoint pollution mechanisms，with emphasis of soil erosion，are discussed．The multistepped landscape with multipond systems makes it ditficult to apply existing soil erosion models based on universal soil loss equation(USLE)to simulate nonpoint ponution in Chaohu Lake catchment．The subrecent sediments in the lower reaches of some tributaries of the lake are suggested the most important and decisive natural nutrient pooh to the eutrophication of the lake．