Based on the measured data,the variation and influence factors of flow ratio of floodplain and main channel during overbank floods in the Lower Yellow River have been analyzed.The results show that:The mean flow ratio of floodplain and channel in four overbank floods at Huayuankou is 0.18,which indicating that main channel is the main body for transporting flow and sediment in the Lower Yellow River.flow ratio increa-ses along the river course due to the wider upstream and narrower downstream.The flow ratio of floodplain and channel in the Lower Yellow River increased after 1986 with the channel shrinkage and the decreasing of bank-full discharge,and has been decreased since 2000 with river erosion and increasing of bank-full discharge after the operation of Xiaolangdi reservoir.The flow ratio decreases with the increase of roughness ratio of floodplain and channel,and increases with the increase of water surface width ratio and water depth ratio of floodplain and channel.To improve the flow capacity of the main channel,the comprehensive measures must be taken to maintain the appropriate scale of bank-full discharge in the Lower Yellow River,and to improve the flow ca-pacity of floodplain,it is necessary to reduce the impact of human activities,to keep sufficient flood discharge space,and to ensure the safety of flood discharge across the entire section.
关键词
黄河下游/漫滩洪水/滩槽分流比/平滩流量/洪水管理
Key words
Lower Yellow River/overbank flood/flow ratio of floodplain and channel/bank-full discharge/flood management
维普
万方数据