为评估建成区外客水汇入对山东省某市城区管网排水压力的影响,基于InfoWorks ICM构建一维、二维耦合雨洪模型,在不同模拟条件下分析城区管网排水能力及内涝积水情况,并基于模型结果提出优化方案.结果表明:建成区外客水汇入是导致该市主城区管网超负荷、节点溢流及内涝积水的主要原因;在2 a、3 a 一遇2 h设计降雨下,客水汇入时超过1/2管道超负荷运行,溢流节点分别占1.38％和3.1％;在20 a、30 a 一遇24 h设计降雨下,淹水面积占城区研究区域面积的35.9％及38.7％,其中9.60％及9.94％为高风险积水区;综合考虑经济性及有效性,采用建设地表方涵、排洪沟的方式截流地表径流客水的方式以缓解城区管网排水压力.经验证,优化方案能有效削减客水汇入对城区内涝积水的影响,对高风险积水区面积削减最明显.在20 a、30 a一遇24 h设计降雨下,研究区域高风险积水区面积优化后比优化前削减了 75％、71％,最大积水深度下降至1 m以下.
IMPACT OF EXTERNAL WATER INFLOW ON FLOODING RISK IN URBAN AREAS AND OPTIMIZATION SCHEMES
To evaluate the impact of the external water inflow on the urban drainage pressure in a city in Shandong Province,a one-dimensional and two-dimensional combined model was established on InfoWorks ICM to analyze the drainage capacity and flooding distribution in the urban under different rainfall conditions.Then the optimization schemes were proposed.The results showed that the inflow of external water was the main reason for the drainage pipe network overloading,nodes overflowing,and flooding in the main urban area of the city.More than half of the pipes were overloaded under the design rainfall recurrence of 2 a and 3 a with a duration of 2 h,and the overflow nodes accounted for 1.38％and 3.1％,respectively.The proportion of flooded areas was 35.9％and 38.7％under the design rainfall recurrence of 20 a and 30 a with a duration of 24 h,respectively,among which 9.60％and 9.94％of the area were posted at high risk.Considering both economy and effectiveness,the construction of surface culverts and flood discharge ditches was adopted to intercept surface runoff and alleviate the drainage pressure of urban pipeline networks.The optimized plan can effectively reduce the flooded areas in urban under external water inflow,especially for high-risk areas.The high-risk area was reduced by 75％and 71％under the design rainfall recurrence of 20 a and 30 a with a duration of 24 h,respectively,and the maximum flooding depth decreased to 1 meter below.
external waterdrainage capacityflooding riskInfoWorks ICM model
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