不同降雨情景下城市河道防洪分析

Analysis of urban river flood prevention under different rainfall scenarios

摘要

【目的】受全球气候变化的影响，加之我国城镇化的快速发展，使得近几年城市洪涝灾害频繁发生，造成了难以估量的人员伤亡与社会经济损失。因此，探究不同降雨条件对河流水位的影响，以期为城市防洪工作提供科学支撑。【方法】基于石马河流域现行水闸调度规则，耦合MIKE11模型及SWAT模型，构建石马河流域水文水动力模型，分析不同的降雨次数、降雨空间分布以及降雨过程的降雨情景下，城市河流水位的变化，探究不同降雨条件对石马河河口水位的影响。【结果】结果显示：流域普降连续的集中降雨会使得河口闸前水位超过4.5 m警戒水位的13%,流域普降间断的集中降雨会使得河口闸前水位超过警戒水位的5%;集中降雨下的旗岭水闸调度次数为分散降雨下水闸调度次数的7倍；流域普降大雨会使得河口闸前水位多次达到4.5 m的警戒水位。【结论】结果表明：(1)多场次降雨、流域内普降大雨、短历时且高强度的集中降雨这三种情况同时出现会提高石马河流域洪涝灾害发生的风险；(2)集中降雨与流域内普降大雨这两种情况的降雨对水闸调度的影响最大；(3)降雨场次越多、降雨过程越集中以及流域普降的降雨量越大时，对河口闸前水位的影响越大。只有流域上游降大雨会导致河口闸前水位在雨后有一定的上涨，只有流域下游降大雨以及流域普降中雨对河口闸前水位影响很小。研究所建立的石马河流域水文水动力模型，对不同降雨条件与河口水闸闸前水位变化的分析，可为石马河流域城市防洪与防汛调度工作提供借鉴。

Abstract

[Objective] Due to the impact of global climate change and rapid urbanization in China, urban flood disasters have occurred frequently in recent years, causing immeasurable casualties and socioeconomic losses. Therefore, it is important to explore the influence of different rainfall conditions on river water level to provide scientific support for urban flood control. [Methods] Based on the current sluice operation rules of the Shima River basin, coupled with MIKE11 and SWAT models, a hydrological and hydrodynamic model of the Shima River basin was constructed. The model was employed to analyze the changes of urban river water level under different rainfall scenarios with variations in rainfall frequency, spatial distribution, and temporal processes, and to explore the impacts of different rainfall conditions on the water level of the Shima River estuary. [Results] The result showed that: continuous and concentrated rainfall in the basin caused water levels at the estuary sluice to exceed the 4.5 m alert level by 13%, while intermittent concentrated rainfall caused an exceedance of 5%. The number of sluice operations at Qiling Sluice under concentrated rainfall was 7 times higher than under dispersed rainfall conditions, and widespread heavy rainfall across the basin caused the estuary water level to reach the 4.5 m warning level multiple times. [Conclusion] The findings indicate that:(1) the simultaneous occurrence of multiple rainfall events, widespread heavy rainfall, and concentrated rainfall of short duration and high intensity increases the risk of flooding in the Shima River basin.(2) Concentrated rainfall and widespread heavy rainfall across the basin have the greatest impact on sluice operation.(3) The greater the rainfall frequency, concentration, and intensity, the greater the impact on the water level at the estuary sluice. Only heavy rainfall in the upper basin causes a rise in the estuary water level, and only heavy rainfall in the lower basin or moderate rainfall across the basin has minimal impact on the estuary water level. The hydrological and hydrodynamic model of the Shima River basin established by the study, which analyses the changes of water level at the estuary sluice under different rainfall conditions, can be used as a reference for the urban flood control and flood control scheduling in the Shima River basin.

关键词

河口水位 / 降雨情景 / 水闸调度 / 城市防洪 / 水文水动力模拟 / MIKE11模型 / SWAT模型 / 东莞市石马河

Key words

estuary water level / rainfall scenario / sluice scheduling / urban flood control / hydrological and hydrodynamic simulation / MIKE11 model / SWAT model / Shima River in Dongguan

基金资助

国家自然科学基金项目“基于海量模拟数据深度学习的闸泵群调度快速响应模型”(52179009)

国家自然科学基金项目“长江流域生态补偿机制研究”(U2040206)

国家自然科学基金项目“基于水-能耦合的长距离调水工程优化调度理论与应用”(51909035)