GIS支持下的城市雨水出水口汇水区自动划分研究

鉴于传统城市雨水汇水区依靠人工方法划分存在的效率和质量低下的弊端,本文利用GIS等技术方法,通过开发雨水管网达标信息系统,建立了雨水管网和地形图形数据库,构建了雨水管网数据模型,设计了城市雨水出水口汇水区的自动划分算法。以南京雨水管网为例,基于对雨水管网数据的校验以及道路边界的处理,依次设计了雨水管网系统获取、雨水管网外接多边形提取、分配雨水管网系统所服务汇水区域、合并综合生成出水口汇水区等雨水出水口自动划分方法和相关算法。应用结果证明,本文的雨水出水口汇水区的自动划分方法不仅操作性较强,而且大大提高了汇水区划分的效率和质量。     

基于USRAMS的城市雨水管网排水能力分析

现行《室外排水设计规范》(GB 50014-2006,2014年版)指出应用推理公式法计算雨水设计流量适用于小尺度排水流域,排水流域大于2km2的宜采用数学模型法。为了分析城市雨水管网排水能力,采用USRAMS模型软件构建雨水管网模型,应用芝加哥降雨生成模块计算不同重现期的芝加哥降雨雨型,通过USRAMS管网运行模块选用等流时线法和动力波法进行不同重现期情景的地表产汇流和管网汇流模拟计算,可以统计各重现期情景下的管段最大充满度结果,并以管段最大充满度为依据将雨水管段划分为不同的排水能力标准区间,评估管网的排水能力。以哈尔滨市五道街流域为例介绍了该方法的具体应用情况。     

基于SWMM和SCS法的城市内涝模拟及雨水管网系统评估

针对郑州市高新区城市排水特点,应用暴雨洪水管理模型(stom water management model, SWMM)模型建立城市排水模型,其中下渗模型采用径流曲线数(soil conservation service curve number, SCS-CN)法体现城市下垫面对城市内涝的影响。利用该模型对不同重现期实测降雨条件下的超载管段和积水节点进行模拟分析:根据超载时长将超载管段划分为安全超载管段、积水超载管段和内涝超载管段;根据积水时长将积水节点划分为积水点、内涝点和洪涝点;同时根据不同重现期降雨条件下的管网流量与管网最大充满度,将超载管段分为4种情况。研究结果表明:模型能较好地模拟郑州市高新区城市暴雨内涝情况,但高新区雨水管网系统不能很好地应对郑州市排水规范中的设计重现期暴雨;郑州市高新区排水管网超载管段和积水节点产生原因各有不同,但二者具有紧密的正相关关系,超载管段两端的节点更易产生溢流,由此形成4个明显的易涝区。     

SWMM模型在内涝灾害防治中的应用——以宁波市溪口镇为例

浙江省宁波市溪口镇经常发生内涝灾害现象,造成了严重的经济损失。为解决此问题,采用SWMM(Storm Water Management Model)模型对溪口镇中心城区现状雨水管网系统进行模拟,通过分析模拟结果中检查井的溢流量和溢流位置,找出了造成节点溢流的原因并提出了相应的改造措施。研究结果表明:由于管网淤堵和管径过小的问题,中心城区现状管网系统排水能力较弱,不足以抵御2 a一遇的降雨事件。针对以上问题,提出了清淤和增大管径的改造措施,其中清淤措施可在一定程度上提高管网排水能力,改造措施1(49个管段管径由原来的400 mm增加到800 mm)和措施2(57个管段管径由原来的400 mm增加到800 mm)分别可抵御3 a一遇和5 a一遇的降雨事件。研究结果可为溪口镇中心城区排水系统改造提供参考依据。     

海绵机场低影响开发设施设计及效果评价

根据国内外海绵城市、海绵机场建设理论与成效,探讨了海绵机场建设的原则和目标,针对我国不同分区的实际情况设计了适宜不同地区机场的低影响开发（LID）设施,并以某机场为例,基于SWMM模型验证LID设施的雨洪控制效果。结果表明：建设LID设施后,机场径流总量削减率和峰值流量削减率最大分别为74.0%、51.0%,峰现时间最多延迟16 min;机场飞行区在增设LID设施后溢流节点数减少13.1%,超载管段数量减少20.4%;机场停车场在增设LID设施后溢流节点数减少了6.3%,超载管段数量减少了10.0%;管段最大积水深度减幅为68%,最大流量减幅达63%。机场规划建设LID设施对雨水径流、峰值流量控制效果显著,降低了机场雨水管网系统排水压力的同时,对机场防洪排涝也具有重要意义。     

基于海绵城市理念的北京永定河文化新区雨水系统规划研究

以"海绵城市"建设理念为指导,将内涝防治和污染负荷控制作为目标,开展北京永定河文化新区低影响开发(LID)雨水系统、雨水管道系统和超标雨水径流排放系统等规划;利用SUSTAIN软件对地块和道路层面LID雨水设施进行布局规划和规模计算,采用传统方法开展雨水管道规划;利用Micro Drainage Windes软件在对LID雨水系统和雨水管道系统暴雨模拟分析基础上,确定超标雨水径流排放系统中道路坡度调整及调蓄设施规划方案。通过案例分析,旨在介绍基于"海绵城市"理念的雨水系统规划内容和方法,为同行提供借鉴。     

考虑城市管网的分布式水文模型子流域划分及编码研究

在基于子流域划分的分布式水文模型应用中,城市区域雨水管网的存在使得原先不相连通的区域具备了汇流的条件,从而改变了天然地表径流汇流路径。另一方面,城市区域还存在着污水管网汇流,其对子流域编码的上下游关系要求往往会和通常的天然水系上下游关系相冲突。因此,在城市区域进行子流域划分和编码的时候,需要考虑雨水管网和污水管网的影响。通过将雨水管网等同于天然河道,参与DEM高程修正,实现雨水管网对汇流路径改变作用。通过对基于天然水系汇流关系得到的子流域进行重新编码,得到能够同时满足天然水系汇流以及污水管网汇流要求的编码序列。以深圳坪山河流域为例进行的实例应用表明该方法可有效地解决雨水管网和污水管网的影响问题。     

研究生论文摘要

城市雨水管网系统优化设计研究 研究生:李立军 导师:柯水洲 (湖南大学土木工程学院 410082) 对以下问题进行了研讨:①采用曲面最小二乘法推求暴雨强度公式和我国城市雨水径流模型。②运用遗传算法编制雨水管网优化设计程序。③利用湿地系统对雨水管网及雨水泵站进行优化设计。④以广州科学城的雨水系统专项规划为例,对所提出的设计方法和编制的程序进行工程应用分析。 研究所得如下结论:①用曲面最小二乘法计算降雨强度     

GIS支持下的城市暴雨积水计算的可视化

利用GIS对空间数据进行处理和分析的功能,建立雨水管网达标规划GIS系统,实现了雨水管网设备的属性数据及空间数据的一体化管理,为城市暴雨积水计算提供可视化分析的手段;同时,建立了汇水区的达标体系,并可以动态划分调整汇水区,计算分析城市各汇水区在不同降雨条件下的积水状况;对不符合要求的管网提出可行性设计建设方案。最后以南京市为例,分析了该市主城区雨水管网系统,为管网的规划及防洪排洪提供了决策支持手段。     

基于SWMM模型的城市排水模拟应用研究

城市积水、内涝问题随城镇化进程的不断加快而日益严重。为有效解决这一问题,分析其出现的原因,以武汉市谌家矶片区为例,基于SWMM模型,结合城市DEM数据和雨水管网规划数据构建了城市排水模型,以溢流雨水井数量和超载管段长度为评价指标,模拟了不同雨峰位置系数和径流系数下雨水管的排水能力,并对评估指标做归一化处理,评估了雨峰位置系数和径流系数对城市排水的影响。结果表明：(1)积水雨水井数量、超载管段长度均正相关于径流系数和雨峰位置系数,城市积水内涝情况随径流系数和雨峰位置系数的增大而加剧,且受径流系数的影响更为严重;(2)不同评价指标下的相对敏感度有明显差异,径流系数对地面积水影响较大,雨峰位置系数对管段超载影响较大。     

Estimation of Urban Impervious Fraction from Satellite Images and Its Impact on Peak Discharge Entering a Storm Sewer System

The runoff coefficient in an urban basin is highly influenced by the impervious and pervious surface fractions since they affect the entity of rainwater entering a storm sewer system. Today these fractions can be estimated by reading high resolution satellite images that are readily available at a relatively low cost. However, this approach involves a certain margin of error when it comes to identifying the various types of cover and hence the total extent of impervious and pervious surfaces. The first problem addressed in this paper thus lies in assessing to what degree the error in the estimation of the two fractions—as derived from a reading of satellite images of the area taken into consideration—may impact the estimation of peak discharge which will be used in turn as a basis for designing or verifying a storm sewer system. A further aspect affecting the entity of rainwater that flows into a storm sewer system is the manner in which the impervious and pervious fractions are connected to the system itself. This type of information may not be deduced from satellite images, but only from an extensive field survey. However, such surveys are feasible only for areas of limited size, whereas they become prohibitive in terms of time and cost in the case of large catchments. An investigation was thus made into whether disregarding the type of connection would significantly affect the peak discharge taken as reference for the design or verification of a storm sewer system. The two above-mentioned problems were addressed in reference to a real case, represented by the town of Codigoro (Ferrara, Italy), in which five small basins with different types of land cover were selected. The results of our analysis show that an estimation of impervious and pervious fractions from high resolution satellite images is sufficiently precise and acceptable for estimating the peak discharge entering the sewer system. By contrast, disregarding the information on how the different areas are connected to the sewer system may lead to a marked overestimation of discharges.     

城镇化背景下平原河网区暴雨洪水重现期变化分析——以太湖流域武澄锡虞区为例

以太湖流域武澄锡虞区典型雨量水文站为例,基于长时间序列逐日降雨与水位数据,采用累积距平法、皮尔逊频率曲线和克里金插值等方法对水位进行还现分析以及对暴雨洪水重现期进行分析,探讨了城镇化背景下典型平原河网区暴雨洪水重现期变化规律及成因。结果表明:(1)武澄锡虞区不同量级降雨重现期均有提前,极端降雨频率增大;武澄锡虞区小量级洪水事件(T=5, 10, 20 a)发生频率有所增加,而量级较大(T=50 a)的洪峰水位重现期在城区与郊区则差异显著。受圩垸影响的常州站1960年50年一遇洪峰水位在2010年增至68年一遇,洪峰水位整体降低,而郊区白芍山站1960年50年一遇洪峰水位在2010年则提前至32年,洪峰水位整体有所增加。(2)小量级洪水事件发生频率增加主要是由降雨增加、城镇扩张以及河网水系衰减所致,同等量级的暴雨导致洪峰水位不断增长;而闸泵和圩垸等水利工程建设加强了对较高量级洪水的调节作用,使高量级洪峰水位有所降低,减小了城区圩垸内洪水风险。对于不同量级的洪峰水位,下垫面特征变化和水利工程建设对其影响的程度则有所不同。分析结果可为研究该地区防洪安全提供技术支持。     

低地坪高潮位地区的雨水管道淹没出流计算

根据水力学理论,阐述了重力流雨水管道淹没出流的水力计算方法,并结合工程实例,介绍了低地坪高潮位地区雨水管道淹没出流的简化计算方法。提出低地坪高潮位地区的重力流雨水管道应优先采用小坡降、低流速、大管径系统,以尽可能降低水位壅高对管道的不利影响。     

分流制雨水与合流制溢流水质的比较

排水管道系统是城市基础设施的重要组成部分,它的完善程度影响着整个污水处理和水污染控制系统的运行状况和效率.而排水体制的选择需要结合当地的地形、降雨类型、管理情况等实际情况出发,综合分析确定.从实测数据和理论计算两个方面对分流制雨水和合流制溢流的浓度和污染负荷量进行了初步的比较,简要地讨论了两种排水系统的适用条件,为排水体制的选择和城市水污染控制的战略决策提供参考.     

Heuristic Optimization Model for the Optimal Layout and Pipe Design of Sewer Systems

The design of urban stormwater systems and sanitary sewer systems consists of solving two problems: generating a layout of the system and the pipe design which includes the crown elevations, slopes and commercial pipe sizes. A heuristic model for determining the optimal (minimum cost) layout and pipe design of a storm sewer network is presented. The hierarchical procedure combines a sewer layout model formulated as a mixed-integer nonlinear programming (MINLP) problem which is solved using the General Algebraic Modeling System (GAMS) and a simulated annealing optimization procedure for the pipe design of a generated layout was developed in Excel. The GAMS and simulated annealing models are interfaced through linkage of Excel and GAMS. The pipe design model is based upon the simulated annealing method to optimize the crown elevations and diameter of pipe segments in a storm sewer network using layouts generated using GAMS. A sample scenario demonstrates that using these methods may allow for significant costs saving while simultaneously reducing the time typically required to design and compare multiple storm sewer networks.     

广州市中心城区典型合流制排水口污染负荷排放规律分析

随着广州市中心城区河道水环境治理力度的加大,合流制溢流污染问题越来越突出,对城市河道水体构成了日益严重的威胁。本文选取广州市中心城区典型合流制排水口进行了18场降雨的径流污染监测,总结了在典型小雨、典型中雨及典型大雨场次下排水口各水质指标随降雨历时的变化规律,同时分析了18场降雨的排水口最高浓度、平均浓度与总降雨量的关系,研究成果可为合流制污染控制工程的设计提供参考。     

Decision making in flood risk based storm sewer network design

It is widely recognised that flood risk needs to be taken into account when designing a storm sewer network. Flood risk is generally a combination of flood consequences and flood probabilities. This paper aims to explore the decision making in flood risk based storm sewer network design. A multiobjective optimization is proposed to find the Pareto front of optimal designs in terms of low construction cost and low flood risk. The decision making process then follows this multi-objective optimization to select a best design from the Pareto front. The traditional way of designing a storm sewer system based on a predefined design storm is used as one of the decision making criteria. Additionally, three commonly used risk based criteria, i.e., the expected flood risk based criterion, the Hurwicz criterion and the stochastic dominance based criterion, are investigated and applied in this paper. Different decisions are made according to different criteria as a result of different concerns represented by the criteria. The proposed procedure is applied to a simple storm sewer network design to demonstrate its effectiveness and the different criteria are compared.     

湖区真空下水道系统的设计

真空下水道系统凭借其自身优势在环境敏感地区(如湖区)具有较好的应用前景。与传统重力管网相比,真空下水道以阶梯敷设的方式输送污水,不受地形的限制。结合真空下水道的特点,提出了在湖区应用真空下水道系统的设计计算方法及经济分析。     

Suspended solids transport: an analysis based on turbidity measurements and event based fully calibrated hydrodynamic models.

Modelling suspended solids transport is a key issue for predicting the pollution load discharged by CSOs. Nonetheless, there is still much debate on the main drivers for suspended solids transport and on the modelling approach to be adopted. Current sewer models provide suspended solids transport models. These models, however, rely upon erosion-deposition criteria developed in fluvial environments, therewith oversimplifying the sewer sediment characteristics. Consequently, the performance of these models is poor from a theoretical point of view. To get an improved understanding of the temporal and spatial variations in suspended solids transport, a measuring network was installed in the sewer system of Loenen in conjunction with a hydraulic measuring network from June through December 2001. During the measuring period, 15 storm events rendered high-quality data on both the hydraulics and the turbidity. For each storm event, a hydrodynamic model was calibrated using the Clemens' method. The conclusion of the paper is that modelling of suspended solids transport has been and will be one of the challenges in the field of urban drainage modelling. A direct relation of either shear stress or flow velocity with turbidity could not be found, likely because of the time varying characteristics of the suspended solids.     

污水管网模拟模型节点平均流量的估算方法

建立排水管网模拟模型是城市排水实现科学化管理的一个重要手段。作为污水管网建模的基础部分,研究了污水管网节点平均流量估算的间接求解方法,即根据用水量推求污水量。该法包括污水排放系数的确定和节点服务区域属性值的计算两部分。污水排放系数根据生活用水量结构确定;在城市排水管网GIS平台上可以估算节点服务区域属性,如人口、面积(平面面积和建筑面积)等。