A procedure for assessing the impacts of land-cover change on soil erosion at basin scale

摘要

Accelerated soil erosion is an undesirable process that adversely affects the conservation of water and soil. This paper used a procedure linking the Revised Universal Soil Loss Equation (RUSLE) and geographic information system (GIS) to map the soil erosion level from 1990 to 2010 caused by land-cover change in the Dongjiang River basin, China. Results indicate that the significant land-cover change greatly impacted soil erosion. The overall soil erosion level of the basin belonged to Level Ⅱ (mild erosion) but the erosion amount shown an uptrend. Erosion areas of Levels Ⅰ and Ⅱ occupied more than 90% and other levels (Levels Ⅲ-Ⅵ) occupied less than 10% of the total area. Approximately 90.85% of the area maintained the original levels, 5.84% converted from lower levels to higher levels, and 3.32% converted from higher levels to lower levels. The erosion in the downstream regions was more serious than that in the central and upstream regions. Although soil erosion was mild as a whole in the study region, some local areas underwent intense erosion. The study demonstrated that linking RUSLE with GIS tools is an efficient procedure for mapping soil erosion levels at basin scale. The gradual deterioration condition caused by land-cover changes at present or in the future requires further study.