重庆市土壤侵蚀与其背景的空间分析

Spatial Analysis of Soil Erosion and Its Background in Chongqing City

为了比较不同单元之间的土壤侵蚀情况 ,在定义土壤侵蚀指数的基础上 ,利用遥感和地理信息系统技术 ,对重庆市不同背景条件下的土壤侵蚀情况进行了分析 ,具体表现在对不同坡度等级、不同坡向、不同高程带上、不同土地利用类型、不同土地利用方式、线状水体和面状水体不同缓冲带上的土壤侵蚀情况的分析。此外 ,还对重庆市各县的土壤侵蚀情况进行了分析 ,通过分析揭示出了土壤侵蚀与其背景的空间关系。

In order to compare the soil erosion status in different background, a soil erosion index is defined here to describe the heavy of soil erosion in per unit. Technologies of Remote Sensing and Geographical Information System were used to analyze the relationship of soil erosion and its background in Chongqing city.Firstly, soil erosion map was generated from Landsat TM image by experts interpretation. Secondly, soil erosion map was overlayed respectively with slope and aspect maps from DEM, DEM and landuse to analyze erosion status. Different buffers were generated along rivers, lakes and pools,and overlayed with soil erosion map to analyze erosion status.Thirdly, index were computed for each county. It is shown that soil erosion index is highest respectively in 15 to 25 degree slope, south aspect, elevation area of 500 to 1000 meter,buffer areas of 500 to 1 000 meter along narrow river, buffer areas of 1 500 to 2 000 meter along wide water body such large river and lake. Among all county, index is highest in Yunyang county and Qianjiang county.