Temporal and Spatial Dynamics of Soil Erosion in North-South Pan River Watershed in 2000–2010

摘要

In this study, the Revised Universal Soil Loss Equation (RUSLE) was applied to analyze the spatial and temporal dynamics of soil erosion in North-South Pan River watershed from 2000 to 2010, and the driving factors were discussed. The results showed that: (1) The average annual soil loss per area in North-South Pan River watershed was 14.6 t/hm^{2/yr from 2000 to 2010, and the mean annual total soil loss was about 118 million tons. (2)In 2000-2010, the soil erosion showed an obvious decreasing trend with an annual variation of -0.87 t/hm2/yr in North-South Pan River watershed. The soil erosion decreased in 75.1% of this watershed, and the soil erosion intensity decreased in 23.6% of this watershed which were mainly changed from slight to trivial (10.0%), from moderate to slight (7.7%) and from intensive to moderate (2.9%). (3) The declining of soil erosion in North-South Pan River watershed was mainly caused by the joint effect of climate change and ecological projects. The rainfall erosivity factor decreased greatly according to the observations of meteorological stations. Meanwhile the implementation of ecological projects helped the restoration of forest and grassland, and the vegetation coverage raise greatly with 0.35%/yr increase which can better prevent the occurrence of soil erosion. (4) Though the soil erosion have decreased a lot recently, the ecological environment of North-south Pan River watershed is still extremely vulnerable to further curb the occurrence of soil erosion in this watershed, a long-term mechanism of ecological protection needs to be established.}