Robust spatial flood vulnerability assessment for Han River using fuzzy TOPSIS with α-cut level set

This study aims to improve the general flood vulnerability approach using fuzzy TOPSIS based on α-cut level sets which can reduce the uncertainty inherent in even fuzzy multi-criteria decision making process. Since fuzzy TOPSIS leads to a crisp closeness for each alternative, it is frequently argued that fuzzy weights and fuzzy ratings should be in fuzzy relative closeness. Therefore, this study used a modified α-cut level set based fuzzy TOPSIS to develop a spatial flood vulnerability approach for Han River in Korea, considering various uncertainties in weights derivation and crisp data aggregation. Two results from fuzzy TOPSIS and modified fuzzy TOPSIS were compared. Some regions which showed no or small ranking changes have their centro-symmetric distributions, while other regions whose rankings varied dynamically, have biased (anti-symmetric) distributions. It can be concluded that α-cut level set based fuzzy TOPSIS produce more robust prioritization since more uncertainties can be considered. This method can be applied to robust spatial vulnerability or decision making in water resources management.     

基于MIKE FLOOD的洪泽湖周边滞洪区洪水演进模拟研究

基于实测断面资料建立了研究区的一维水动力模型,基于高精度DEM以及1∶10000地形图建立了研究区的二维水动力模型,并用MIKE FLOOD将一维模型和二维模型进行耦合,构建了洪泽湖周边滞洪区一、二维耦合的洪水演进数学模型。利用2003年历史洪水资料对模型参数进行了率定,并以2007年历史洪水资料进行了验证。以洪泽湖百年一遇设计洪水为模型上边界,二河闸、三河闸以及高良涧闸的现行调度方案的水位-流量关系为模型下边界,对洪泽湖百年一遇设计洪水方案进行模拟计算,当蒋坝水位达到14.33m时,洪泽湖周边滞洪区开始滞洪,得到开始滞洪后不同时段研究区内各类洪水风险要素的动态分布情况以及最大淹没水深、淹没历时,验证了模型的合理性,可用于蓄滞洪区洪水演算分析。     

Flood Inundation Modelling for Mid‐Lower Brisbane Estuary

This study utilizes a two‐dimensional hydrodynamic model to calibrate and validate an inundation model for the Brisbane River estuary in Queensland, Australia. The bathymetry data used in the hydraulic model are derived from one arc second (1 s) shuttle radar topography mission digital elevation model, and the two‐dimensional hydraulic model is parameterized using the generated bathymetry with four open boundaries with water level observations and roughness coefficients. The calibration performance is evaluated by comparing the simulated results with the digitized records during the January 2013 flood event (a low magnitude event) at three gauging stations. The calibrated model is validated with water level data and available discharge data during the January 2011 flood (a large magnitude event) at four gauging stations located along the Brisbane River. Different performance indices are applied to demonstrate that the developed model performs well during calibration and validation. A sensitivity analysis is presented to assess the influence of riverbed elevation changes on the model because the main uncertainty of the model is the bathymetry data. The proposed model with the shuttle radar topography mission digital elevation model‐derived riverbed elevation for the Brisbane estuary is able to predict the flood inundation extent at an accuracy of 66.9% which is higher than or comparable with the accuracies of the existing studies. However, it is expected that the accuracy will increase if some improved bathymetry data become available in the future. Copyright © 2016 John Wiley & Sons, Ltd.     

溪源泄洪洞出口处闽江设计水位分析研究

溪源泄洪洞出口位于闽江之上,为分析泄洪洞出口处的设计水位,采用设计流量和水位流量关系推求法及实测水位资料推求法两种方法对工程设计水位进行计算,经过合理性分析,工程所在地近年水位变化剧烈,采用设计流量和水位流量关系推求法更符合现状情况,为工程建设提供可靠的设计成果。     

面板堆石坝垫层渡汛离心模型试验研究

西北口水库大坝是我国建设的第一座百米级钢筋混凝土面板堆石坝,其百年一遇洪水渡汛水位降落幅度21.63 m,水位骤降速度最大可达3.65 m/h。面板尚未浇筑前的堆石坝体需临时拦洪渡汛,坝体垫层既起面板垫层作用,还要保证堆石坝体安全渡汛,水位骤降对垫层将产生拖拽力作用,影响到垫层的稳定性。本文通过面板堆石坝垫层渡汛离心模型试验,对不同渗透性垫层安全渡汛进行了试验研究,试验研究成果被西北口面板堆石坝工程施工期安全渡汛设计采纳,为面板坝工程建设特别是施工期安全渡汛提供了技术支撑。     

苗家坝-碧口梯级水库汛期水位动态控制研究

本文将单一水库预泄能力约束法,推广到梯级水库汛期水位动态控制中,并建立了梯级水库汛期水位联合运用和动态控制模型,假定预报信息准确,在不降低下游保护对象的防洪标准的前提下,最大限度发挥梯级水库的兴利效益。以苗家坝、碧口水库为对象进行了实时调度模拟,其结果相比于原设计汛限水位动态控制方案,减少了弃水,且保证最大出库流量均在可控范围内,达到在不降低防洪标准的前提下提高梯级水库兴利效益的目的,大大提高了洪水资源利用率。     

基于全概率公式直接推求管运洪水

本文为保证防洪安全的前提下充分发挥水库的综合效益,提出了基于全概率公式推求管运洪水的方法,并详细阐述了其基本原理;提出了在资料较短或前、后汛期洪水特性大致相同的情况下运用全概率公式推求管运洪水的实际方法;以马边站的洪水资料进行实例研究,其结果表明基于全概率公式推算出来的管运洪水既能使水库工程达到防洪标准,又能充分发挥水库的综合效益。     

设计降雨特征对城市内涝模拟结果的影响分析

降雨是城市内涝的主要诱因之一,不同降雨特征对于城市内涝风险的影响也有所区别。为了进一步挖掘降雨特征对城市内涝风险的影响,采用综合流域排水模型（InfoWorks ICM）构建了我国南方某城市的内涝模型,系统分析了设计降雨的雨型和历时特征对城市内涝模拟结果的影响。在4个重现期的3种降雨雨型和3个降雨历时条件下,共计36个不同降雨情景对研究区的内涝情况进行模拟。通过对比不同模拟情景下的积水深度、积水面积以及积水量等结果发现：在相同降雨雨型和重现期条件下,降雨历时对积水深度的影响有一定的差别;在不同降雨雨型和降雨历时模拟情景中,积水点的位置基本保持一致,而积水面积受降雨雨型和降雨历时的双重影响;峰值积水量受降雨雨型影响较大,受降雨历时影响较小,而积水总量受降雨历时影响较大,受降雨雨型影响较小。研究中量化分析了不同设计降雨特征对城市内涝模拟结果的影响,旨在为合理地开展城市内涝预警以及应急管理等工作提供依据。     

三峡工程泥沙问题研究60年回顾

对60 a来三峡工程泥沙问题研究的历程、主要研究结论作了简要综述。三峡水库初期蓄水运用以来的泥沙实测资料与预测对比分析表明:三峡水库上游来沙减少的趋势与初步设计阶段预测基本一致,但减少的进程有所提前;三峡水库泥沙淤积量远小于预测值;坝下游河床冲刷量与预测值基本一致,河床冲刷范围则大于预测;坝下游河床冲刷对防洪与航运的影响与预测基本一致;三峡工程泥沙问题总体上未超出论证与初步设计阶段的预测。在此基础上提出三峡工程正常运行期泥沙问题研究的建议,其中关于排沙调度方面,应按控制水库防洪库容年损失率小于1 000万m~3/a,以及变动回水区上、中段无累积性泥沙淤积的要求制定排沙调度方案,以长期发挥三峡工程的综合效益。     

两种溃坝模型在唐家山堰塞湖溃决模拟中的对比

基于唐家山堰塞坝溃决的实测数据,使用BREACH模型及中国水科院DB-IWHR模型,对唐家山堰塞坝溃决过程进行了反演分析,并对两种模型进行参数敏感性分析。研究结果表明:使用针对唐家山的参数,两种模型均可较好地反演唐家山溃决洪水的过程,BREACH模型的下游坡比和孔隙率是对结果影响比较敏感的输入参数;DB-IWHR模型在冲刷参数和下游水深计算两方面做了改善,较好地解决了这一问题;DB-IWHR提供了一个Excel格式的计算软件,数值分析稳定性好,使用简洁客观,可供类似堰塞湖应急处置时参考。