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河流中大坝建设会使该坝上游的水流条件发生重大的改变，而下游影响往往被完全忽视。然而，下游影响恰恰与上游影响一样必然发生，所不同的是下游影响是逐渐发展，只在一定的时段后才显现作用。分析了由大坝下游条件的变化所产生的实际现象和不同原因，并对必须面临的后果进行了评估。不利的副作用可能使河道偏移和岸坡侵蚀，造成河床的下降和延伸河段的环境恶化。可通过传统的治导工程、采用适当的方法加固河床及根据有关大坝和水库运行规则加以控制，以避免不利的下游影响。
Dam construction in the river will cause significant changes in the flow conditions upstream of the dam, while downstream impacts are often completely ignored. However, the downstream impacts are just as inevitable as the upstream ones. The difference is that the downstream impacts are gradually developing and only appear after a certain period of time. The actual phenomena and different causes resulting from changes in downstream conditions of the dam were analyzed and the consequences that had to be faced were evaluated. Adverse side effects may cause channel offset and bank erosion, resulting in declines in the riverbed and environmental degradation in extended reach. The river bed may be consolidated by conventional methods of harnessing the river bed and controlled according to the dam and reservoir operating rules to avoid adverse downstream impacts.