基于水文水动力耦合模型的山区小流域洪水预报

Flood Forecasting of Small Watershed in Mountainous Area Based on Hydrological-Hydrodynamic Coupling Model

开展无资料地区洪水模拟研究具有重要意义。针对于无资料地区洪水预报的挑战性,以我国东南沿海典型山区小流域—梅溪流域为例,构建了山区水文-城区水动力耦合模型。山区水文模型经河道计算流量率定后,模拟了2016年“莫兰蒂”台风场景下的城区洪水淹没过程。结果表明,模拟最大淹没水深结果与城区17处洪水淹没痕迹吻合较好,验证了耦合模型的适用性。分析了“莫兰蒂”台风场景下重点区域的淹没水深与历时。此外,根据不同重现期的设计降雨,分析了城区淹没水深与淹没范围。同时,重现期越大,城中心区域洪水滞后时间越短。

It is of great significance to carry out flood simulation research in ungauged areas.Taking Meixi watershed,a typical mountainous watershed in southeast of China,as an example,the hydrological-hydrodynamic coupling model was constructed.After validating the hydrological model with the measured discharge at the outlet of the mountain area,the flood inundation process in the urban area of typhoon Molandi in 2016 was simulated.The results show that the simulated maximum inundation depth agrees well with the validated values of 17 flood traces in the urban area.The inundation depth and elapse time of the key points under typhoon Molandi scenario were analyzed.In addition,according to the design rainfall in different recurrence periods,the inundation depth and the inundation range of urban area were analyzed.At the same time,the larger the recurrence period,the longer lag time of flood in the central area.