Effects of Ecological Restoration Measures on Soil Erosion Risk in the Three Gorges Reservoir Area Since the 1980s

Ecosystem degradation accompanied by soil erosion risk is caused by the interaction of many factors, including climate change and human activities. Therefore, before attempting the optimal form of ecological restoration, we must know the key factors responsible for soil erosion risk and determine their impacts on the ecosystem health. To test this approach, we conducted a case study in the Three Gorges Reservoir Area from 1980 to 2015, where extensive restoration (primarily afforestation) has been conducted. The results showed that climate was most important during Period I (1980 to 1984), and explained 84% of the variation in erosion. However, vegetation became equally important during Period II (1985 to 2006), when it accounted for 51% of the variation. Climate became as important as vegetation during Period III (2007 to 2015), when it accounted for 51% of the variation. The temporal variation in the dominant factors that controlled soil erosion risk suggests that the ecological effect of vegetation improvement resulting from ecological restoration in Three Gorges Reservoir Area has been gradually enhanced since the 1980s.