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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。
In 2013 and July 1977, the Yanhe River, a tributary of the Yellow River, experienced an extreme rainstorm event, but due to the difference in the underlying surface of the time-bound river basin, torrential rain disasters varied widely. The paper compares and analyzes the rainfall, intensity, frequency and the characteristics of water and sediment variation in heavy rain in Yanhe River Basin in July 2013 and July 1977, and discusses the main causes of different disasters. The results showed that the total rainfall, shrouded area, rainfall intensity and storm frequency in Yanhe River Basin in July 2013 were all greater than those in 1977, while the daily maximum runoff, maximum sediment load, maximum sediment concentration, peak flow, peak sediment, High sediment concentration lasted less than in 1977. In 2013, the heavy rain disaster in the Yanhe River Basin was dominated by geological disasters, while in 1977 the river flood disaster was the main factor. After the implementation of the Program of Conversion of Cropland to Forest and Grassland, the vegetation in the basin has been extensively restored, resulting in the change of the relationship between rainfall runoff and sediment production, which is the main reason for the above phenomenon.