【摘要】 城市大排水系统是由道路、自然通道、明渠、滞水地与调蓄设施等构成的过量地表径流排蓄系统。大排水系统因其排蓄过程的开放性特点,极易引发溢流失控、交通中断或城市用地滞水等级联效应,是城市内涝问题的关键诱因之一。现有研究对大排水系统的定量分析不足,更缺乏对其在山地城市中的级联失效机制研究。本文以重庆市渝中区为靶区,采用复杂网络分析方法,构建大排水系统级联失效模型,刻画地表溢流传播过程,挖掘山地城市大排水系统级联失效原理及其基本规律。研究表明:(1)模拟大排水系统级联失效的区域与往年靶区内涝区域基本一致;(2)当其他不确定性因素稳定时,开敞的地表环境会降低靶区大排水系统的过载程度,减缓内涝持续时间及发生程度,而地表环境的开敞程度与内涝发生区域并不相关;(3)地表溢流在山地地形下更易集聚在构成大排水系统的部分物质要素当中,暴雨增大会加剧这种集聚趋势,而开敞的地表环境则会加大地表溢流的空间分流程度,以此减小这种集聚趋势;(4)靶区内小范围的低洼、平坦地形,会使地表溢流易集聚或蔓延,而大范围的山地起伏地形在加快地表溢流排蓄的同时,能控制靶区内地表溢流蔓延。本研究可为山地城市大排水系统规划建设提供科学依据,提升排涝防涝能力水平。更多还原

【Abstract】 Major drainage system is a rainwater drainage system in a city designed to extra-excessive runoff diversion composed of roads,natural passages,open channels,ponded rainwater(standing water or stagnant water) sites and storage facilities,etc.Due to the openness role of rainwater collecting and discharging process,the major drainage system is subjected to cascading aftermath,such as uncontrolled overflow,traffic interruption or inundation in urban land,which contribute to urban waterlogging.There was a lack of research on quantitative analysis of major urban drainage system,especially for its cascading failure mechanism in mountain cities.In this study,it took Yuzhong district of Chongqing,China as a case study to investigate the pattern of urban surface flow in a mountainous city and the inherent cascading failure mechanism of its major drainage system;it used complex network analysis method to build a cascading failure model to simulate mal-functionality of the major drainage system in the event of extreme rainstorm.The results include:(1) The full extent of cascading failure in Yuzhong delineated by simulation was generally consistent with the waterlogging areas observed in previous years;(2) As other uncertain factors were unchanged,the open ground environment was able to reduce the function overloading of the major drainage system and slow down the duration of local inundation and occurrence extent;the open level of the ground environment was not correlated with the occurrence sites of waterlogging;(3) Surface overflow in certain terrains was more likely to be drained shortly into the element structures of the major drainage system,particularly more in the case of intensified rainstorms;however,the open ground environment restricted this centralized drainage trend as a result of spatial diversion of surface flow;(4) A small range of depression and flat terrain in the city made surface overflow flowable to ponding or ramifying,while a large range of undulating terrain speeded up the surface overflow into drainage storage and impeded it in wandering.This research provides a scientific basis for planning of major drainage system in mountain cities,as well as drainage capacity refurbishing and waterlogging preventing.更多还原