平原感潮河网地区河道洪水对村镇内涝的影响

随着平原感潮河网地区城市化快速发展,下垫面变化落后导致河道泄洪能力不足,河道洪水水位明显上涨,村镇内涝灾害日益频繁,已明显制约当地经济发展。在分析平原感潮河网地区村镇内涝影响因素基础上,以典型村镇为例,通过数值模拟方法分析该地区河道洪水对村镇内涝影响。结果显示50 a一遇与100 a一遇河道洪水分别导致村镇排涝水量减少25.17%,55.24%,排涝水量减少对村镇内部河流洪水过程的影响明显。降雨量增大加剧了排涝水量减少对村镇内涝淹没面积扩大的影响。河道洪水可导致村镇内涝淹没面积扩大22%,加剧了村镇内涝灾情。此研究成果可为该地区村镇内涝风险管理提供参考。

Influence of Channel Flood in Plain Tidal River Network on Waterlogging in Villages and Towns

In plain tidal river network area, rapid urbanization with delayed corresponding changes of underlying surface have resulted in insufficient discharging capacity of river channels, together with uprising flood levels and more frequent waterlogging in villages and towns, severely impeding the local economic development. On the basis of expounding influential factors of waterlogging in villages and towns in plain tidal river network area, the impact of channel flood on waterlogging is quantified via numerical simulation with some typical villages and towns as case study. To simulate channel flood and inundation process in town precisely, both of the processes are simulated with hydrodynamic model. Results indicate that influenced by 50-year event flood and 100-year event flood, the discharge in town decreases by 25.17% and 55.24%, respectively, which evidently affects the river flood process in town. Moreover, the increase in return period of rainstorm intensifies the impact of discharge reduction on the expansion of inundated area. Extreme channel flood would expand the waterlogging area by approximately 22%, and would aggravate the waterlogging in villages and towns. The research findings provide reference for the waterlogging risk management for villages and towns in plain tidal river network areas.