基于MIKE URBAN的西安市中心城区雨洪过程模拟

城市排水管网的分布与建设是城市基础设施建设的重要组成部分,城市的排水能力关系到城市服务功能的正常运转。通过城市雨洪过程的分析,可以评价城市洪涝灾害。以西安市中心城区为研究对象,利用MIKE URBAN构建排水管网模型,根据模拟结果对研究区管网排水能力进行评估,分析易涝成因。结果表明:MIKE URBAN能够较好地模拟城市管网水位、流量变化及易涝点的分布情况。根据西安市暴雨强度公式,设计不同重现期(1、2、3、5a)的降雨过程,在1a降雨过程下,研究区90%以上管道处于满流状态,60%以上的检查井发生溢流,满流管段数和溢流井个数会随着降雨频率的增加而增加,但增幅相对减少;管道设计标准普遍偏低、下垫面不透水率增大、地形等因素是导致地面积水的主要原因。研究成果可为城市内涝防治及海绵城市建设提供理论基础和技术支撑。

Simulation of flood process in the central urban area of XI'AN based on MIKE URBAN

The distribution and construction of urban drainage network is an important part of urban infrastructure construction, and the drainage capacity of the city is related to the normal operation of urban service function. Urban flood disaster can be evaluated through the analysis of urban flood process. The MIKE URBAN was used to construct a model of pipe drainage network to assess the drainage capacity of the central urban area of Xi''an City based on the simulation results and to analyze the causes of waterlogging. The results showed that MIKE URBAN can simulate the distribution of water level, flow rate and waterlogging point in urban pipeline network. According to the formula of rainstorm intensity in Xi '' an, the rainfall process of different return periods (1a, 2a, 3a, 5a) was designed. Under the process of 1a rainfall, more than 90% of the pipeline in the research area is in full flow state, and more than 60% of the inspection wells overflow, and the number of full flow pipes and overflow wells will increase with the increase of rainfall frequency, but the increase speed is relatively reduced. The general low pipeline design standards, the increase of impermeable rate of the underlay surface, topography and other factors are the main causes of water accumulation on the ground. The research results can provide theoretical basis and technical support for urban waterlogging control and Sponge city construction.