Soil Erosion Sensitivity Evaluation of Hilly Region of Red Soil Based on Quantitative Remote Sensing - a Case Study in Changsha City
The development of remote sense (RS) and geographic information system (GIS) provides an effective means for studying sensitivity of regional vulnerable ecology and environment. Aiming at the hilly region of red soil with vulnerable ecosystems and supported by the RS and GIS, this study establishes a soil erosion sensitivity evaluation information system database for hilly region of red soil. The quantitative indicates system for soil erosion sensitivity evaluation has been established, guided by four natural factors in the Revised Universal Soil Loss Equation (RUSLE) which are rainfall erosivity factor, soil erodibility factor, slop length and gradient factor, crop factor, the soil erosion sensitivity of a typical area in this region, i. e. , Changsha city is evaluated. The K factor and C factor values used for Changsha soil erosion sensitivity evaluation are obtained by interpreting Land-sat TM/ETM + image data, the R factor map and relief map( LS factor) are obtained by Digitizing and space analyzes in GIS; the weights of factors for evaluation are decided by PCA( Principal Component Analysis) ; the result of soil erosion sensitivity evaluation of Changsha is calculated by Multi - factor superposing with weight. The results showed that 20. 3 percent of the total land ( approximately 2618km2) are maintaining at high or extremity sensitivity, moderate sensitivity, 42. 5 percent of the total land (approximately 5073km2) are maintaining at mild or none sensitivity; it concludes that entire soil erosion sensitivity of Changsha city is high. The space distributing of all classificatory soil erosion sensitivity evaluation of Changsha is analysized. Reasons of soil erosion sensitivity are analysized from two points view which are relief and vegetation fraction.
environment sciencesoil erosion sensitivityquantitative remote sensinghilly region of red soil
NETL
NSTL
万方数据
维普
