黄土丘陵沟壑区坡地土壤侵蚀与降雨产流关系

Study on the Relationship Between Rainfall Runoff and Soil Erosion of Slopeland in Gullied Rolling Loess Area

基于2009—2012年安家坡小流域4个农田径流小区27场侵蚀性降雨的数据资料,分析了黄土丘陵沟壑区降雨产流与土壤侵蚀的关系。结果表明:相同降雨条件下坡耕地降雨产流、土壤侵蚀与坡度成正比;汛期侵蚀性降雨的分布极不均衡,表现出明显的单峰分布特征。造成黄土丘陵沟壑区坡耕地水土流失的产流性雨量级别以大雨为主,其中7月的侵蚀性降雨量最大,成为土壤侵蚀防治的最关键时期。

Based on the data of 27 erosive rainfalls from 2009 to 2012 of four farmland runoff plots in Anjiapo small watershed,this paper analyzed the relationship characteristics of the rainfall runoff and the soil erosion in gullied rolling loess area. The results show that rainfall runoff and soil erosion of cultivated land are proportional to the gradient variables under the same rainfall conditions. The erosive rainfall distributions are extremely uneven and show obvious distribution characteristics of one-peak in flood seasons. Leading to the soil and water loss of farmland rainfall about the runoff level is heavy rain in gullied rolling loess area. Especially,the erosive rainfall in July is the largest.Therefore,July becomes the most critical period to prevent and control the soil erosion of farmland in the gullied rolling loess area.