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基于香溪河流域土壤流失脆弱性评估与区划结果,在影响土壤流失脆弱性的流域5个自然物理因素中,通过分析年降雨量、土壤可蚀性、坡度、植被覆盖率、沙源与河道距离和土壤流失脆弱性均值之间的统计关系来识别影响土壤流失脆弱性的关键因素。结果显示,地形坡度、沙源与河道距离为香溪河流域土壤流失脆弱性的关键影响因素。在此基础上,进一步分析香溪河流域土壤流失脆弱区的分布与地形坡度、沙源与河道距离这2个关键影响因素之间的关系。结果表明,香溪河流域土壤流失脆弱区集中分布在25°以上的坡地以及河道两侧2km特别是1km以内的区域:25°以上的陡坡区域以占流域41.19%的面积承载了全流域72.1%的土壤流失脆弱区;河道两侧2 km以内的区域以占流域37.01%的面积承载了全流域87.57%的土壤流失脆弱区,特别是河道两侧1km以内的区域以仅占流域20.33%的面积承载了全流域64.48%的土壤流失脆弱区。
Based on the assessment and zoning results of soil erosion vulnerability in Xiangxi River Basin, from the five natural physical factors affecting the vulnerability of soil erosion, we analyzed the effects of annual rainfall, soil erodibility, slope, vegetation coverage, Distance and the average value of soil erosion vulnerability to identify the key factors affecting soil erosion vulnerability. The results show that the topographic gradient, the distance between sand source and river course are the key factors affecting the soil erosion vulnerability in Xiangxi River Basin. On this basis, we further analyze the relationship between the distribution of the vulnerable areas of soil erosion in Xiangxi River Basin and the two key influencing factors of terrain gradient, distance between sand source and river channel. The results show that the fragile soil loss area in Xiangxi River Basin is concentrated on the slope above 25 ° and within 2 km on both sides of the channel, especially within 1 km. The steep slope above 25 ° holds 72.1% of the whole basin with an area of 41.19% . The area within 2 km on both sides of the river channel accounts for 87.57% of the total soil loss area, accounting for 37.01% of the total river basin area, especially the area within 1km on both sides of the river channel to account for only 20.33% of the area of the river basin Carrying the whole basin 64.48% of the soil loss vulnerable areas.