【作者】 李博；

【导师】 杨凯；

【作者基本信息】 华东师范大学 ， 环境科学， 2008， 硕士

【摘要】 近年来,随着城市化进程的不断加快,相当部分的下垫面变为不透水地面(路面、屋面),主要透水下垫面——城市绿地不断减少,使得城市水文循环发生剧烈的变化,导致城市中洪涝灾害风险不断增加。同时由于城市绿地系统的植被、土壤均受到不同程度的人为干扰,这就使得产流过程中植物截留、土壤的下渗等的水量减少,造成的最终结果就是径流量和洪峰到来的时间均发生了改变,极易出现城市暴雨积水。为了解决由于土地利用变化所引起的城市雨水径流问题,缓解城市排水系统的压力,目前最主要采用的方法是增加铺设雨水排放基础设施,扩大排水管径,增加泵站的数量以及提升原有泵站的排水能力和服务面积,提高整个城市的雨水输出能力,尽可能避免洪水的产生。然而,从建设生态城市的角度而言,这种传统的雨水排放系统并不能真正地解决这个问题,其诸多弊端也会逐渐显现。本文在国内外研究进展资料收集,上海市中心城区(2000年～2006年)土地利用资料和降雨径流资料,结合室内室外实验分析的基础上,重点论证了高度城市化地区土地利用变化对雨水径流的影响。利用定量化工具——SCS模型对苏州河两岸25个排水片组成的研究区域进行降雨.径流产流模拟,初步获得土地利用变化对雨水径流的调蓄效应,并在此基础上采用幕景法分析不同土地利用和降雨强度的情况下,雨水径流和径流系数的变化情况,最终初步获得一些优化的土地利用配比。本文的结论可为缓解高度城市化地区暴雨积水问题和今后的土地利用规划提供部分参考,也可作为最终实现生态排水理念的规划依据。本文的主要研究内容和结论有以下几个方面:1)本文在综合国内外研究进展的基础上,结合上海市中心城区的土地利用、降雨径流资料,以及上海市暴雨积水和市政排水系统建设情况的资料,得出城市化导致的土地利用变化对雨水径流确实存在一定的影响。2)探讨了美国农业部水土保持局提出的降雨径流模型——SCS模型的研究进展,根据上海中心城区的实测资料,进一步对该模型进行修正,使其模拟结果的准确度大大提高,相对误差＜10%的降雨场次从2.8%提高到63.9%。3)利用修正后的SCS模型,采用幕景法,通过设置不同的下垫面类型和不同的降雨强度,模拟计算出各种情况下的雨水径流和径流系数,分析得出较为合理的土地利用类型。4)根据以上研究结论,针对上海中心城区的特殊性,提出不透水下垫面的较优比例和布局,提出构建城市化地区生态排水体系的措施以及解决城市暴雨积水的手段和方法,提出提高城市绿地对雨水径流调蓄能力的优化途径和措施,为今后的土地利用规划、绿地规划提供部分参考。更多还原

【Abstract】 Since urbanization is speeding up recently, most parts of underlying surface become impervious surface (road surface, house roof), meanwhile the mainly pervious surface——urban green land reduce continuously, which make huge changes for urban water cycle and lead to bigger risk of urban flood disaster. At the same time, vegetation and soil of urban green land system are disturbed by human being, which will reduce the amount of water from plant interception and soil infiltration. The final result is changes of runoff amount and flood peak time and high frequency of urban rainstorm waterlogging.In order to deal with urban rainwater runoff problem caused by the change of land use, and to relief pressure of urban drainage system, the primary method is to add rainwater drainage establishment, enlarge drainpipe dimension, increase quantity of pumping station, enhance its drainage ability and enlarge its servise area. The purpose of this method is to improve the whole rainwater drainage ability and avoid flood disaster. However, from the view of ecological city, traditional drainage system cannot solve the problem indeed, its many disadvantages appear gradually. The main research contents and conclusions can be summarized as the following:1) Based on domestic and overseas researches, data of land use and rain runoff in Shanghai central area, together with other information of urban rainstorm waterlogging and status of municipal drainage system construction, the result can be concluded that land use from urbanization has certain impact in rain runoff.2) Discuss researching status of SCS model——brought from Natural Resources Conservation Service, and modify this model depended on actual data of Shanghai central area, its result is the simulated precision has enhanced greatly, in which the correct amount of rain events increased from 2.8% to 63.9% with relative error less than 10%.3) Using modified SCS model and Scenarios Analysis method via setting different underlying surface and different rain force, calculate the simulated rain runoff and runoff coefficient, then analyse and obtain the better land use types.4) Based on the former conclusion, because of the particularity of Shanghai central area, better percent and layout of impervious surface will be brought out, measures on ecological drainage system construction and instruments on urban rainstorm waterlogging will be produced as well, which could give some advice and suggestions to land use plan and green land plan in the future.更多还原