１９８６年以来，受气候变化、工农业用水增加及大型水库调节的影响，黄河下游出现枯水少沙、大洪水几率减小、 高含沙洪水频繁发生、年内水沙分配改变的情况，致使河道主槽发生严重淤积、河道萎缩、平滩流量减小、河道排洪能力 降低，中常洪水即可出现高水位，洪峰传播时间长且沿程变形复杂，小水大灾。 Since 1986, due to the impacts of climate change, increase of industrial and agricultural water use and the regulation of large reservoirs, the low and low flow of the Yellow River, the decrease of flood disasters and the frequent occurrence of high silt floods have caused the change of water and sediment distribution during the year, Severe siltation occurred in the main channel, the river channel shrank, the flow of the flat beach reduced, the drainage capacity of the river channel decreased, the flood level of the middle reaches could reach high water level, the propagation time of the flood peak was long, and the deformation along the route was complex and the floods and catastrophes occurred.