极端暴雨洪水及侵蚀产沙对延河流域植被恢复响应的比较研究

黄河支流延河在2013及1977年7月发生极端暴雨事件,但由于所处时间流域下垫面的差异,暴雨的灾害表现迥异。论文比较分析延河流域2013和1977年7月暴雨的降雨量、强度、频率及其水沙变化特征,讨论了产生灾害不同的主要原因。结果表明：2013年7月延河流域降雨总量、笼罩面积、降雨强度、暴雨频率均大于1977年,而日最大径流量、最大输沙量、最大含沙量、洪峰流量、峰值沙量、高含沙量历时却低于1977年。2013年延河流域暴雨灾害以地质灾害为主,1977年则以河道洪水灾害为主。退耕还林（草）工程实施后流域内植被大面积恢复,导致降雨产流产沙关系发生变化是产生上述现象的主要原因。

Comparative Analysis of the Responses of Rainstorm Flood and Sediment Yield to Vegetation Rehabilitation in the Yanhe River Basin

Yanhe River Basin suffered from rainstorm events in July 1977 and 2013. However, the disasters showed different features due to the changes of underlying surface condition. This paper investigated the amount, intensity and frequency of these two rainstorm events and analyzed their relations with the runoff and sediment variations in the Yanhe River Basin. The results showed that the amount, intensity, frequency of the rainstorm in 2013 were all higher than those in 1977. However, the maximal daily runoff, maximal daily sediment, maximal daily sediment concentration, peak runoff discharge, peak sediment discharge and the duration of high sediment concentration in 2013 were all lower than those in 1977. The disasters in July 2013 were mainly caused by landslide and debris flow, while the disasters in July 1977 were mainly caused by flood. Large-scale vegetation rehabilitation in the Yanhe River Basin after the launch of “Grain for Green” program, which has changed the processes of runoff sediment, was the main reason of the different results of the disasters.