基于GIS的祖厉河流域土壤侵蚀治理模式模拟研究

Control Model of Soil Erosion in Zuli River Basin Using GIS Method

借助RS图像信息提取技术,对祖厉河流域遥感影像进行校正与信息提取。利用GIS栅格数据空间分析功能,将研究区空间化为30m×30m的栅格单元。根据土壤流失方程RUSLE生成各因子栅格图,借助GIS空间分析功能,实现该区土壤侵蚀评估模拟。结果表明:祖厉河流域1995年、2005年、2015年土壤侵蚀模数分别为2 877,3 372,3 713t/(km2·a);从侵蚀量变化来看,1995年总土壤流失总量为29 608 397t/a,2005年总土壤流失总量为34 694 588t/a,2015年总土壤流失总量为38 202 817t/a,年平均流失模数为3 713t/(km2·a)。从土壤侵蚀空间分布和侵蚀量变化来看,研究区土壤侵蚀度呈现南北低、中部高;河流深切区低,高山林立区高的特点。针对研究区,提出4种模拟治理并进行验证,分析得出完全采取人工提升林区植被增长速度,主要包括全力发展坡地退耕还林还草的高效治理模式是该区最佳治理模式,可有效改善土壤流失状况,使平均土壤流失模数降为2 656t/(km2·a)。

This study used quantitative remote sensing method,in combination with RUSLE model,and GIS software,utilizing a series of data such as digital elevation model（DEM）,rainfall and soil properties,the characteristics of spatial-temporal differentiation of soil erosion of Zuli river basin from 1995 to 2015was estimated.By analysis of the temporal variation of the erosion modulus,temporal variation of erosion intensity and spatial pattern of erosion intensity,the results of this research were summed as follows：The erosion modulus was 2 877.87t/（km2·a）in 1995,3 372.24t/（km2·a）in 2005,and 3 713.23t/（km2·a）in2015,respectively,suggesting the increasing erosion rates.In the case of the spatial pattern of soil erosion,the erosion modulus was high value on the high side place in the middle of the study area and low value in the south and north.Besides,the soil erosion mounts was high on the side in the mountains and low near the river valley.Four types of simulation were proposed according to the characteristics of study area.The results showed that the efficient governance model（EGM）was the best governance model area,which could effectively control soil loss,the average modulus properties was 2 656t/（km2·a）.