基于RUSLE的藉河示范区土壤侵蚀时空动态特征研究

Spatial-temporal Variation Characteristics of Soil Erosion in Ji River Demonstration Zone Based on RUSLE

探究区域土壤侵蚀变化特征,为区域水土保持效益评价、土壤侵蚀防治提供依据。基于GIS和RS技术,采用降雨数据、DEM数据、土壤数据以及遥感影像等数据,运用RUSLE模型,定量分析了藉河示范区1997-2015年土壤侵蚀时空动态特征。结果表明:4个时期土壤侵蚀模数分别为1 326.18、2 790.39、2 025.23和1 366.32 t/(km^2·a),呈现先加剧后改善的趋势。土壤侵蚀以微度侵蚀和轻度侵蚀为主,在2005年之前,土壤侵蚀以向更高侵蚀等级转移为主,2005年之后以向更低侵蚀等级转移为主。不同坡度等级上,出现随坡度增加,土壤侵蚀先趋于严重后缓和的特征,15°~45°的坡度上是研究区土壤侵蚀主要分布坡段。不同海拔等级上,土壤侵蚀随海拔升高呈现先增加后降低的趋势,在中海拔区(1 562~1 782 m)和中低海拔区(1 335~1 562 m)土壤侵蚀分布面积最广、强度最大,此类区域是藉河示范区土壤侵蚀防治的重点区域。

The variation characteristics of regional soil erosion is explored to provide the basis for the benefit evaluation of regional soil and water conservation and soil erosion control.Based on GIS and RS technology and by using rainfall data,DEM data,soil data and remote sensing image data,and RUSLE model,the spatial-temporal characteristics of soil erosion in Ji River Demonstration Zone from 1997 to 2015 were quantitatively analyzed.The results showed that the soil erosion modulus of the four periods was 1 326.18,2 790.39,2 025.23 and 1 366.32 t/(km^2·a),respectively,the tendency was going from bad to worse at first and was then improving.Soil erosion was mainly micro erosion and slight erosion.Before 2005,soil erosion was transferred to higher erosion grade,and after 2005 to lower erosion grade.With the increase in slope,soil erosion tended to be serious first and then moderate.The slope of 15°~45°is the main slope section of soil erosion distribution in the study area.At different elevations,soil erosion increased first and then decreased with elevation.Soil erosion in middle altitude area(1 562~1 782 m)and middle-low altitude area(1 335~1 562 m)was the most widely distributed and the intensity was the largest.This kind of area is the key area of soil erosion control in Ji River Demonstration Zone.