黄河上游西柳沟流域土壤侵蚀对土地利用变化响应

为科学认识土地利用变化对流域土壤侵蚀的影响,研究基于黄河上游西柳沟流域1980年、2015年两期土地利用变化和相应的土壤侵蚀强度变化,研究了土地利用变化对流域土壤侵蚀的影响。结果表明:(1)西柳沟流域草地、林地和耕地3种主要的土地利用类型转出面积大小为草地>林地>耕地,耕地主要转化为草地,林地大部分转为未利用土地,草地大部分转为耕地和未利用土地;(2)西柳沟流域1980年、2015年平均土壤侵蚀模数分别为1946.56,1 873.55 t/(km²·a),其中草地土壤侵蚀模数最大,其次为林地,土壤侵蚀量主要来自于草地;(3)西柳沟流域35年间微度侵蚀和轻度侵蚀占主导,土壤侵蚀程度总体上呈降低的趋势,具体表现为草地的部分面积向林地和耕地分别转化了4.47,17.54 km²,说明土地利用结构的改变是影响流域土壤侵蚀变化的关键因素。研究成果以期为黄河上游小流域水土流失治理提供参考。

Research on the Response of Soil Erosion to Land Use Change in Xiliugou Watershed of the Upper Yellow River

To scientifically understand the impact of land use changes on watershed soil erosion, based on the changes in land use and the corresponding changes in soil erosion intensity in the Xiliugou watershed of the upper reaches of the Yellow River in 1980 and 2015, we studied the impact of land-use changes on soil erosion in the watershed. The results show that:(1)the converted areas of three main land use types of grassland, woodland, and cultivated land in the Xiliugou decreased in the order: grassland>forest land>cultivated land. The cultivated land was mainly converted into grassland, most of the forestland was converted to unused land, and most of the grassland was converted into cultivated land and unused land;(2)the average soil erosion modulus of Xiliugou watershed in 1980 and 2015 were 1 946.56 and 1 873.55 t/(km²·a), respectively, of which grassland had the largest soil erosion modulus, followed by forestland, and the amount of soil erosion mainly came from grassland;(3)In the past 35 years, slight erosion and mild erosion dominated in Xiliugou watershed, and the degree of soil erosion showed a downward trend on the whole; specifically, part of the area of grassland was transformed into forestland and cultivated land by 4.47 and 17.54 km², respectively, indicating that the change of land use structure was an inevitable factor affecting the change of soil erosion in Xiliugou watershed. The research results are expected to provide references for soil erosion control in the small watershed of the upper reaches of the Yellow River.