Changes to soil conservation in the Three Gorges Reservoir Area between 1982 and 2015.

Soil erosion is a major threat in the Three Gorges Reservoir Area (TGRA) of China. Since 1990, the Chinese government has launched a series of ecological restoration projects to promote soil conservation in the TGRA. To understand the effects of ecological restoration on soil conservation in the TGRA, we used the abrupt change analysis of soil mass from 1982 to 2015 and its drivers; soil mass was obtained with the universal soil loss equation at continental scale. We found that soil conservation and annual rainfall decreased in the TGRA over the study period. Abrupt change points of soil conservation occurred in 1984 and 2007. Soil conservation in the TGRA showed a dramatic decrease before 1984, a slow increase after 1984 as a result of climate, and a rapid increase after 2007 due to an increase in vegetation cover. From 1982 to 2015, climate change played a primary role in soil conservation changes and was more influential than topography and vegetation. However, ecological restoration was an important factor affecting soil conservation in the TGRA, and it needs to be promoted.