基于地表-管道-河道耦合模拟的城市内涝风险评估

Urban Flood risk assessment based on integrated simulation of surface-pipe-river

为评估城市排水不畅引发的内涝风险,提出地表-管道-河道耦合的城市内涝风险评估方法,建立常州市城市产汇流与内涝试验基地模型,选取不同设计降雨情景进行内涝风险模拟。结果表明:受管道埋深和排水能力的影响,检查井溢流主要发生在管道下游段;随着重现期的增大,满管流管段比例平均由72.46%上升至82.27%,溢流节点比例由1.95%上升至4.11%;尽管大部分检查井并未发生溢流冒水,研究区域内仍然存在多处内涝积水,研究区域内涝面积比例由4.31%(重现期P=5 a)上升至6.19%(P=50 a)。地表-管道-河道耦合的城市内涝风险评估方法能够更全面地反映城市内涝风险过程,可为城市内涝风险评估提供新思路。

To assess the risk of urban flood inundation due to inadequate drainage,this paper proposes an urban inundation risk assessment method based on a coupled surface-pipe-river system.An urban runoff and flood inundation risk assessment model was established for Changzhou urban runoff and flood inundation experimental site and conducts flood risk simulations under various designed rainfall scenarios.Results indicate that manhole overflows predominantly occur in the downstream section of the pipe,influenced by the pipe burial depth and drainage capacity.As the return period(P)increases,the proportion of fullness pipe increases from an average of 72.46%to 82.27%,and the proportion of overflow manhole increases from 1.95%to 4.11%.Although most areas did not experience manhole overflow,multiple urban flood sites still occurred within the study area,with the risk area ratio increasing from 4.31%(P=5 a)to 6.19%(P=50 a).The urban flood inundation risk assessment method based on a coupled surface-pipe-river system can more comprehensively reflect the urban inundation risks,offering new insights for assessing urban flood inundation risks.