基于USLE模型分析剑湖入湖河流金龙河流域的土壤侵蚀动态

Soil Erosion Dynamic of Jinlong River Basin(an Inflowing River into Jian Lake)Based on USLE Model

剑川县金龙河作为剑湖淤积泥沙的主要产源,减少金龙河流域的土壤侵蚀,对治理剑湖泥沙淤积有至关重要的作用,以剑湖金龙河入湖口为研究对象,利用3S技术,实现剑湖流域地区土地利用类型数据的获取,进而分析1995—2015年间该区域土地利用的时空动态变化情况,借助修正土壤流失方程(RUSLE),对该时段流域内的土壤侵蚀状况进行定量估算。结果表明:1995—2015年剑湖金龙河流域轻度以上的侵蚀面积从123.79km^2减少到93.86km^2;土壤年均侵蚀模数从1 826.58t/(km^2·a)降到1 628.27t/(km^2·a);总侵蚀量由933 295.25t减小到832 241.67t。剑湖的泥沙淤积明显减少,生态环境得到有效改善。

Reducing soil erosion in Jinlong River basin has a crucial role in sediment accumulation management of Jian Lake because Jinlong River is the main source of sediment accumulation in Jian Lake. The spatial-temporal dynamic changes of land utilization in Jian Lake during 1995--2015 are analyzed by gaining the data about land utilization type in Jian Lake basin based on 3S technology and the soil erosion status in Jian Lake basin during 1995--2015 is quantitatively estimated by means of RUSLE. Result： The erosion area with above mild erosion intensity grade, average annual soil erosion modulus and total erosion amount decrease from 123.79 km^2 to 93.86 km^2, from 1 826.58 t/（km^2 · a） to 1 628.27 t/（km^2· a） and from 933 295.25 t to 832 241.67 t in Jinlong River basin during 1995 2015 respectively, which results in obvious reduction of sediment accumulation and effective improvement of ecological environment in Jian Lake.