黄土高原丘陵沟壑区小流域次降雨径流系数的影响因素研究

Factors Affecting the Runoff Coefficient in the Hilly-gully Region of the Loess Plateau

黄土高原是我国水土流失最严重的地区,本文收集黄土高原丘陵沟壑区第Ⅰ、Ⅱ、Ⅲ、Ⅴ副区23个小流域814场次降雨径流资料及对应的流域特征因素,通过数理统计分析,找出黄土高原丘陵沟壑区各分区内小流域次降雨径流系数的影响因素并建立回归模型。结果表明:黄土高原丘陵沟壑区小流域的降雨径流系数与流域形状系数、沟道比降、降雨量、雨强、植被覆盖率有着较好的相关性,且径流系数随沟道比降、降雨量、雨强增大而增大,随植被覆盖率的增大而减小。研究将为该区小流域次降雨产流预报工作提供科学依据。

The Loess Plateau is the most serious area of soil and water loss in China. In this paper,the data of 814 rainfall runoff events in 23 small watersheds in the hilly and gully region of the Loess Plateau,Ⅰ,Ⅱ,Ⅲ and Ⅴ,and the corresponding watershed characteristic factors are collected. Through mathematical statistics and analysis,the factors influencing rainfall runoff coefficient of small watershed in hilly and gully region of Loess Plateau were found out and the regression model was established. The results show that the runoff coefficient of small watershed in the hilly and gully region of the Loess Plateau has a good correlation with the watershed shape coefficient,channel ratio,rainfall,rainfall intensity and vegetation coverage,and the runoff coefficient decreases with the channel ratio and the rainfall. The rain intensifies as it increases. The vegetation coverage decreases with the increase of vegetation coverage. The research will provide a scientific basis for the prediction of secondary rainfall and runoff in the small watershed in this area.