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泥沙淤积导致黄河下游中小洪水灾害发生次数及损失大小发生了变化。利用90系列洪水资料,分析了小浪底水库和黄河下游河道系统不同组合条件下滩区中小洪水风险变化特点。水库和下游河道淤积都导致了黄河下游中小洪水漫滩淹没损失发生的次数增多、损失值变大。在维持黄河下游平滩流量4 000m3/s条件下,泥沙淤积导致滩区中小洪水漫滩次数由小浪底水库拦沙运用初期的年均0.10次增大到拦沙运用后期的年均2.18次,相应的洪水灾害损失值也由年均0.220亿元增大到年均2.400亿元。
Sedimentation has led to changes in the number and size of small and medium-sized floods in the lower Yellow River. Based on the 90 series flood data, the characteristics of risk changes of small and medium-sized floods in the beach area under different combinations of the Xiaolangdi Reservoir and the Lower Yellow River system are analyzed. The siltation of reservoirs and downstream channels all led to the increase in the number of submerged floodplains in the middle and lower reaches of the Yellow River, resulting in larger losses. Under the condition of 4 000m3 / s of flat beach flow in the lower Yellow River, the number of floodplains caused by sedimentation was increased from 0.10 in the initial stage of silt settling in Xiaolangdi Reservoir to 2.18 times in the late stage of sediment storage. Corresponding flood damage losses also increased from an average of 0.220 billion yuan to an annual average of 240 billion yuan.