城市下垫面地表径流过程模拟研究与分析

发布时间：2018-08-28 15:48

【摘要】：随着经济社会的快速发展，城市化过程不断扩张，城市下垫面特性发生很大的变化。由于不透水面积的增加，导致地表径流量增加，洪峰流量增大，径流系数加大，雨水产汇流时间缩短。给城市排洪防涝带来负担，容易引发城市内涝。为了减轻暴雨内涝的灾害，就必须深入的研究不同下垫面（下凹式绿地、多孔路面）对雨水产流、汇流的影响。因此，本文以苏州市某小区为例，借鉴国外低影响开发（LID）先进理念，结合研究区域的水文，地形等因素，研究了LID典型措施的雨洪效果，运用SWMM模型对研究区域进行雨洪模拟分析。首先，基于城市降雨地表径流模型的建立，提出了基础资料处理、子汇水区划分，模型参数确定的构建方法，运用芝加哥雨型合成了不同设计重现期（0.5a、1a、5a、10a），降雨历时为120min，雨峰时刻r=0.4的降雨过程线。其次，基于SWMM模拟城市化后的水文效应，计算分析地表产流、汇流，径流系数、总溢流量和下渗量的变化情况，结果表明，随着设计重现期的增加，总径流量，平均径流系数和总溢流量也随着增加，而下渗量基本没什么变化。最后，研究了加入下凹式绿地、多孔路面和两种措施组合对城市雨洪的影响，结果表明，在相同设计重现期下，与现状模式相比，加入下凹式绿地措施可以减少总径流量、平均径流系数和总溢流量，也可增加下渗量，总径流量分别减少30.6%、24.6%、24.6%、24.2%，平均径流系数分别减少24.9%、22.6%、19.1%、18.6%，总溢流量分别减少58.4%、43.1%、39.4%，下渗量分别增加18.6%、24.4%、42.8%、49.9%；加入多孔路面措施，总径流量分别减少24.7%、20.5%、15.4%、14.5%，平均径流系数分别减少30.2%、29.6%、27.2%、20.9%，，总溢流量分别减少88.5%、57.6%、49.5%，下渗量分别增加17.1%、20.4%、31.4%、36.1%；加入下凹式绿地和多孔路面组合模拟，总径流量分别减少46.3%、41%、33.9%、32.3%，平均径流系数分别减少39.2%、37.9%、37.5%、28%，总溢流量分别减少100%、83.9%、75.5%，下渗量分别增加31.9%、40.8%、68.8%、80%。
[Abstract]:With the rapid development of economy and society, urbanization continues to expand, and the characteristics of the underlying surface of the city change greatly. Due to the increase of impervious area, surface runoff increased, Hong Feng discharge increased, runoff coefficient increased, and the time of rainwater confluence was shortened. It is easy to cause urban waterlogging because of the burden of flood discharge and waterlogging prevention. In order to reduce the disaster of rainstorm waterlogging, it is necessary to deeply study the influence of different underlying surfaces (concave green space, porous pavement) on the flow and confluence of Rain Water. Therefore, this paper takes a small district in Suzhou as an example, draws lessons from the advanced concept of low impact development of (LID) in foreign countries, and studies the rain flood effect of typical measures of LID combined with the factors of hydrology and topography in the study area. The SWMM model is used to simulate the rain and flood in the study area. First of all, based on the establishment of urban rainfall surface runoff model, the method of basic data processing, sub-watershed division and model parameter determination is proposed. The precipitation process lines of different design recurrence periods (0.5 a ~ (-1) a ~ (5) a ~ (10) a) and rainfall duration of 120 min and rainfall peak time (r ~ (0.4) were synthesized by using Chicago rain pattern. Secondly, based on the simulation of the hydrological effect after urbanization by SWMM, the changes of surface runoff, runoff confluence, runoff coefficient, total overflow and infiltration are calculated and analyzed. The results show that the total runoff increases with the increase of design recurrence period. The average runoff coefficient and the total overflow amount also increased with the increase, but the infiltration rate basically did not change. Finally, the effects of concave green space, porous pavement and combination of two measures on urban rain flood are studied. The results show that under the same design recurrence period, the total runoff can be reduced by adding concave green space measures compared with the current model. The average runoff coefficient and the total overflow discharge can also increase the amount of seepage. The total runoff volume is reduced by 30.6% and 24.6%, respectively. The average runoff coefficient is reduced by 24.9% and 22.6% respectively. The total overflow volume is reduced by 58.4% and 43.1%, respectively, and the total overflow volume is reduced by 39.49.49.49.9. the total runoff volume is increased by 18.624.4%, respectively. The total runoff volume was reduced by 24.7and 20.5m, and the average runoff coefficient was reduced by 30.229.6 and 27.220.9, respectively. The total overflows were reduced by 88.57.6and 49.5, respectively, and the amount of seepage increased by 17.1nil 20.431.436.1. by adding the concave green space and the porous pavement combination simulation, The total runoff volume was reduced by 46.3and 41.The average runoff coefficient was reduced by 39.2% and 37.9%, respectively. The average runoff coefficient was reduced by 39.2% and 37.5%, respectively. The total discharge was reduced by 100% 83.9% and 75.5%, respectively, and the infiltration volume increased by 31.9% (40.8%) and 88.8% (80%), respectively, and the total discharge was increased by 31.9% (40.8%) and 88.8% (80%), respectively.
【学位授予单位】：苏州科技学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV121

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