基于GIS的陕西省水土流失敏感性评价

GIS-Based Assessment on Sensitivity to Soil and Water Loss in Shaanxi Province

在对区域水土流失影响因素分析的基础上,建立了区域水土流失敏感性评价的指标体系,并应用GIS技术的空间分析功能对其进行叠加综合,辩识出陕西省水土流失潜在敏感性和现实敏感性不同等级的空间分布特征,得到了水土流失敏感性分布图。从潜在敏感性看,微-轻度敏感性分布面积较大,占全省总面积的75.77％,中度敏感性分布面积占20.41％,高度-极敏感性分布面积为3.82％。敏感性的区域分异规律十分明显,影响因子也不尽相同。水土流失现实敏感性与潜在敏感性相比发生了较大的变化,微-轻度敏感性分布面积占61.65％,中度敏感性面积明显增大,占34.15％,高度-极敏感性面积也增加,占4.2％。对比潜在敏感性和现实敏感性,在其它自然影响因子不易控制的情况下,植被作为侵蚀动力的重要抑制因子,保护植被,提高覆盖度对控制水土流失具有特别重要的意义。

Based on the analysis of district soil and water loss influence factors, the index system of soil and water loss sensitivity evaluation was established. By means of the function of spatial analysis of GIS, the spatial dis- tribute of different grade on realistic sensitivity and potential sensitivity to soil and water loss in Shaanxi province were identified. The result of potential sensitivity indicates that tioy-less sensitive region took up 75. 77% of the total area of the province, the sensitive region 20. 41 %, and the more-most sensitive region 3. 82%. The district separate regulation of sensitivity is very obviously , and the affect factors were not same alike. The result of realistic sensitivity shows that tioy-less sensitive region took up 61. 65%,the sensitive region increased obviously, which cover 34. 15% of the total study area, more-most sensitive area also increased ) which cover 4. 2% of the total study area. The difference between realistic sensitivity and potential sensitivity was compared in this study, due to the nature factors was not easi1y control, increasing vegetation cover to control the soil and water loss has special important meaning.