基于3S和USLE的沱江流域中游土壤侵蚀定量评价

Quantitative Assessment of Soil Erosion in the Middle Reach of Tuojiang River Basin Based on 3S and USLE

以川中丘陵区沱江流域中游为研究区域,在3S的技术支持下,以美国通用土壤流失方程(USLE模型)为评价模型,利用ArcGIS 9.2的栅格数据空间分析功能,对该区域土壤侵蚀强度进行了预测和估算。结果表明:流域的年均土壤侵蚀模数为1 543t/(km2.a),侵蚀强度为轻度。其中土壤侵蚀中度以下占到流域面积的91.5%,强度侵蚀、极强度侵蚀和剧烈侵蚀分别为3.5%,2.8%和2.2%,极强度和剧烈侵蚀区分布于区域中西部的低山地带,流域土壤侵蚀与地形、土地利用方式相关性很大。

Quantitative research on the soil erosion intensity in the middle reach of Tuojiang River was esti- mated via utilizing USLE model supported by GIS and RS technology. The results showed that the mean soil erosion rate is 1 543 t/（km^2 a） in the study area. The soil erosion intensity below moderately accounted for 91.50/oo of the area, the highly erosion area account for 3.5%, the very high erosion area account for 2.8%, the severe erosion area account for 2.2%. The very high erosion and severe erosion area was mainly distributed in the middle and western part. The soil erosion was great relatives with terrain and land use type.