一、概况头屯河多年平均径流量2.40亿立方米,年输沙量76.4万立方米(悬移质66.4万立方米,推移质10万立方米)。洪水期(6、7、8月份)河道来水量占全年来水量的75—80%,输沙量占全年的86.2%。流域内海拔1500米以下的浅山带,降水量小于200毫米,植被差,岩石风化破碎严重,许多山间干沟土壤疏松,平时无水,一遇暴雨常出现 I. Overview Toutun River has an average annual runoff of 240 million cubic meters with an annual sediment discharge of 764,000 cubic meters (660,000 cubic meters suspended and 100,000 cubic meters fixed). During the flood season (June, July and August), the river water amount accounted for 75-80% of the annual water volume and the sediment discharge accounted for 86.2% of the whole year. Basin within the 1500 meters below sea level with shallow mountain, less than 200 mm precipitation, poor vegetation, rock weathering broken serious, many mountain ditch loose soil, usually no water, a case of heavy rain often appear