基于RS-GIS的湖北丹江库区土壤水力侵蚀定量分析

湖北丹江库区是南水北调中线工程的主要淹没区和水源区,土壤水力侵蚀是影响水质安全和工程实施的重要因素。以1998年和2003年的TM遥感影像为主要信息源,建立了以植被覆盖度、坡度和土地利用为指标的水力侵蚀遥感分析方法,将水力侵蚀强度分为六级,并结合GIS的空间分析功能对1998年和2003年库区水力侵蚀强度变化及空间分布进行了划分。结果表明五年间库区微度侵蚀、中度侵蚀和强度侵蚀面积呈增加趋势,而轻度侵蚀和极强度侵蚀面积呈减少趋势;并将库区水力侵蚀空间分布划分为北部中低山丘陵中强度侵蚀区和中部河谷城区轻度流失区。分析结果对库区土壤侵蚀的治理和生态环境的改善具有指导意义。

Quantitative analysis of water erosion in Danjiangkou reservoir area of Hubei province based on RS-GIS

Danjiangkou reservoir area of Hubei province is the main water source area and flood area of the South-to-North Water Transfer (middle line) project, water erosion is an important influence factor in water quality and the project. In this paper, water erosion was classified into six types and an erosion analysis method was established based on TM image of 1998 and 2003 through synthetically analyzing the vegetation cover ratio, slopes and land use. Intensity change and spatial distribution of water erosion be- tween 1998 and 2003 in reservoir area was analyzed. The result shows that slight water erosion (no soil loss or inconspicuous loss feature), moderate water erosion (quite obvious soil loss) and strong water erosion (relatively high soil loss) area show an increase trend, and light water erosion (relatively obvious soil loss) and very-strong water erosion (high soil loss) area show a decrease trend. Spatial distribution of water erosion was divided into two areas: north hilly area of medium erosion intensity and central district of light erosion intensity. The result has an important significance on soil erosion control and eco-environment improvement in the res- ervoir area