Soil conservation assessment in the Upper Yangtze River Basin based on invest model

Studying and revealing the spatial distribution of soil loss will play an important role in water and soil conservation planning. In this study, the Geographic Information System (GIS) technology and the Integrated Valuation of Ecosystem Services and Tradeoffs Tool (InVEST) model were applied to estimate the amount of soil loss and assess the soil conservation capacity by the main ecological system in the Upper Yangtze River Basin (UYRB). The results show: (1) the annual potential soil erosion is 92.92×10⁸ t year^-1. The area of average annual soil loss bellow 500 km^-2 year^-1 occupies 35.08% and above 5000 km^-2 year^-1 occupies 36.8%. (2)The annual actual soil erosion is 12.30×10⁸ t year^-1. Slight and moderate soil loss is in majority, about 68.15% of the watershed area is found out to be under moderate degree. (3)The annual soil conservation is 80.61×10⁸ t year^-1, and the contributing percent of main individual ecosystems was as follows: the forest occupies 46.11%, grassland 24.21%. Forest ecosystem does best in soil conservation.