地理信息影像化在长江上游土壤侵蚀敏感性评价中的应用

Assessment of Sensitivity of Soil Erosion with Imagewise Method in the Upper Reaches of Yangtze River

应用地理信息影像化方法,从土壤侵蚀的影响因素出发,在ERDAS软件支持下,建立长江上游降雨侵蚀力、地形起伏、土壤可蚀性、植被覆盖信息的专题数字模型。在此基础上,进行综合分析得到土壤侵蚀敏感性指数影像化图,并探讨长江上游土壤侵蚀敏感性空间分异特征。研究表明,评价结果信息客观细致,适用于生态环境的综合评价;长江上游土壤侵蚀敏感性总体水平较高,中度敏感和高度敏感面积占总面积82.8%;长江上游土壤侵蚀敏感性空间分异显著。

Thematic digital model of influencing factors of soil erosion such as rainfall erosivity, terrain rise, soil erodibility and vegetation cover information in the upper reaches of the Yangtze River was built up in ERDAS using the imagewise method of geographic information. The imagewise map of soll erosion sensitivity index was created and the spatial differentiation characteristics of soil erosion sensitivity in the upper reaches of the Yangtze River was discussed based on the comprehensive analysis of the thematic digital model. Results show that, the output of the evaluation is objective and detailed which is suitable for the comprehensive analysis of the ecological environment. The overall soil erosion sensitivity in the upper reaches of the Yangtze River is at a high level. The area with a medium and high sensitivity accounts for 82. 8% of the total area. And there is significant spatial differentiation in the soil erosion sensitivity in the upper reaches of the Yangtze River.