北山水库洪水风险图编制与应用探讨

1概述 洪水风险图又称洪水危险区图,是反映洪水风险大小的地图。洪灾损失不仅与淹没范围有关,而且与洪水演进路线、到达时间、淹没水深及流速大小等有关,洪水风险图就是对可能发生的洪水的上述过程特征进行预测,标示洪泛区内各处受洪水灾害的危险程度。从国内外经验看,编制水库洪水风险图是一种被广泛采用的防洪非工程措施,     

基于兰江探讨山区性河道实时洪水风险分析与绘制

正洪水风险图作为一项重要的防洪非工程措施,直观反映了某一区域洪水风险信息。它融合了洪水风险区自然地理、经济社会、防洪工程及非工程措施、洪水风险分布和洪水风险管理等相关信息。传统的洪水风险图侧重于展现不同计算方案下的洪水淹没情况,难以体现洪水风险的动态变化。在实时防汛中,对当下水雨情     

基于GIS的太湖流域洪水风险图信息管理系统设计

太湖流域作为我国典型的平原河网地区,其特殊的自然地理属性使得该区域易发洪涝灾害。随着流域经济社会迅速发展,对流域防洪保安提出了更高的要求。洪水风险图作为一种非工程措施,可以大大提高洪水调度水平,减轻洪涝灾害损失,也可为今后开展洪水保险提供重要依据。因此,其越来越受到人们的重视。本文在明确洪水风险图分类、功能和洪水风险图涵盖信息的基础上,提出了基于GIS的太湖流域洪水风险图信息管理系统的功能和结构设计。     

洪水风险图的制作及其应用——以天津市黄庄洼蓄滞洪区为例

洪水风险图是标识区域洪涝成因、量级、特性、危及对象及应急对策等风险信息分布特征的一系列图的总称,当前已成为国内外城市防洪减灾工作中重要的非工程措施之一。以天津市黄庄洼蓄滞洪区洪水风险图编制项目为例,论述洪水风险图的作用,介绍洪水风险图的编制过程,探讨洪水风险图编制工作存在的问题,并提出进一步完善洪水风险图编制工作的建议。     

动态洪水风险图在佛山城区防洪中的应用

洪水风险图作为一种防洪非工程措施在全国众多城市已经开展推广应用,利用预测降雨信息制作实时、动态的洪水风险图,在目前暴雨频发、多发的城市防洪救灾中更具有现实指导意义。以佛山城区内涝预警系统为例,介绍动态洪水风险图的绘制方法,绘制时需要的基础、实时、预测等关键信息,阐述动态洪水风险图在自动预警、实时预报、历史查询、方案设计、城市防汛决策指导等方面的应用,对佛山城区的防灾减灾具有一定的指导作用。     

福建省南平市延平中心城区洪水风险研究

该文针对福建省南平市延平中心城区流域特点,基于基础资料收集和现场调查测量,重点考虑闽江及建溪、西溪的洪水,构建本区域一、二维耦合水力学模型,模拟分析6个漫溢计算方案的洪水淹没情况,开展洪水风险要素(淹没范围、水深、流速等)分析研究,绘制洪水风险图件,以进一步完善该区域防洪减灾非工程措施,提高防汛抢险能力。     

洪水灾害危险性评价方法的研究与改进

洪水风险分析是防洪非工程措施的重要组成部分,而洪水危险性评价是风险分析的基础。现有的洪水危险性评价方法由于需要获得淹没水深,在对洪水风险预测时要求复杂的水力学模型和高分辨率数据的支撑,但业务化过程中常常无法满足数据要求,为了简化洪水危险性评价的过程,确保评价结果的准确性,提出了一个新的简单且综合的洪水危险性评价指标(FHI,Flood Hazard Index)。该指标以GisNet和ArcGIS为软件平台,结合分布式水文模型,依据洪灾的形成机理,综合考虑分布式流量与地形指数。结合北京山区红螺谷流域的具体情况,对新指标进行了对比检验。结果显示,FHI能够真实地反映区域洪灾随空间变化的趋势,为未来洪水危险性评价与预测的研究,提供了一个全新的思路,对洪水风险研究体系的完善具有重要的现实意义。     

防洪非工程措施

防洪非工程措施（non—engineering measures of flood control）通过法令、政策、行政管理、经济和防洪工程以外的技术手段等,以减少洪泛区洪水灾害损失的措施。防洪非工程措施一般包括防洪法规、洪水预报、洪水调度、洪水警报、洪泛区管理、河道清障、超标准洪水防御措施、洪水保险、洪灾救济等。防洪非工程措施主要考虑洪灾程度和风险程度,被保护对象重要程度不同,     

基于图像识别技术的测压管群水深智能获取方法

为在水工模型试验中准确同步获取过水建筑物不同部位水压力,提出并设计了基于图像识别技术的测压管群水深智能获取方法与系统。该系统采用非接触式（侧拍）影像采集方式,实时拍摄多个测压管内水面浮标的运动影像（反映水深变化过程）,将影像资料导入计算机;利用软件识别系统,采用灰度化、二值化及开操作等对图像进行预处理,然后使用findContours获取各个测压管水面浮标质心坐标,通过标定系数转换为实际水位数据,最终得到各个测压管内水深同步变化的时间序列。通过水工模型试验验证,该方法较传统人工测量方法获得的数据误差在±1.5%内,且获取方式更快捷、数据更丰富,可为水工模型试验中测压管群水深测量提供新的思路。     

不同比例尺下单波束测深数据的插值方法精度分析

以某内河航道局部航段作为试验区域，对不同比例尺单波束测深数据采用空间插值方法进行格网化，同时与多波束测深系统的实测数据进行对比，统计插值方法精度特征指标。结果表明，不同比例尺水深源数据密度对空间插值方法影响显著，随着测量比例尺不断减小，空间插值方法的内插精度下降明显；对于比例尺大于1:500的水深数据源，克里金插值法、最小曲率法和线性插值三角网法3种插值方法的精度基本相当，反距离加权插值法不满足插值精度要求；综合考虑内插精度特征参数，在类似区域建议采用线性插值三角网法。     

无高精度地形资料地区溃坝洪水演进模拟研究 ——以金沙江叶巴滩-巴塘段为例

为准确高效计算缺乏高精度地形资料地区河道中洪水演进过程,在空间分辨率为30 m的ASTER GDEM V2地形数据基础上采用不同方法对金沙江叶巴滩-巴塘区间河道地形进行重建,采用基于显卡加速的地表水及其伴随输移过程模型模拟了2018年"11·03"堰塞坝险情洪水过程,并与实测洪水过程进行对比验证。结果表明:①不同空间插值方法对河道地形特性的插值表达精度相差较大,样条函数法和根据河流走势的趋势平滑法生成的河道地形能较好表达河道地貌形态;②不同断面间距下趋势平滑法河道地形洪水演进模拟精度随断面间距增大而增加,仅使用入流口和出流口断面高程模拟效果在不同断面间距中最好;③使用趋势平滑法生成河道地形时,洪水模拟精度随河道下挖深度的增加呈增加趋势,下挖深度为50 m时NSE达到0.937,R~2达到0.976。研究分析了河道地形重建方法、插值断面间距及下挖深度对洪水演进模拟精度的影响,可为洪水应急抢险快速预测提供数据处理方法。     

基于GIS格网模型的洪水淹没分析方法

在遥感与GIS技术的基础上，应用数字高程模型(DEM)生成的格网模型进行洪水的淹没分析。在给定洪水水位和洪量两种条件下，对基于三角形格网模型和任意多边形格网模型，分别得出洪水淹没结果。并对洪水遥感监测获得的淹没范围，利用格网模型进行水深分布计算。结果表明，以GIS技术为支持，采用平面模拟方法进行洪水淹没范围和水深分布的模拟是可行的，使遥感监测与一般洪涝灾害损失评估模型比较好地结合，得出更准确的灾情损失评估结果。     

Evaluating Flood Hazard for Land-Use Planning in Greater Dhaka of Bangladesh Using Remote Sensing and GIS Techniques

Floods are a common feature in rapidly urbanizing Dhaka and its adjoining areas. Though Greater Dhaka experiences flood almost in every year, flood management policies are mostly based on structural options including flood walls, dykes, embankments etc. Many shortcomings of the existing flood management systems are reported in numerous literatures. The objective of this paper is to assess flood hazard in Greater Dhaka for the historical flood event of 1998 using Synthetic Aperture Radar (SAR) data with GIS data. Flood-affected frequency and flood depth calculated from the multi-date SAR imageries were used as hydrologic parameters. Elevation heights, land cover classification, geomorphic division and drainage network data generated from optical remote sensing and analogue maps were used through GIS approach. Using a ranking matrix in three dimensional multiplication mode, flood hazard was assessed. All possible combination of flood hazard maps was prepared using land-cover, geomorphology and elevation heights for flood-affected frequency and floodwater depth. Using two hazard maps which produced the highest congruence for flood frequency and flood depth, a new flood hazard map was developed by considering the interactive effect of flood-affected frequency and floodwater depth, simultaneously. This new hazard map can provide more safety for flood countermeasures because pixels belonging to higher hazard degrees were increased due to the consideration of higher degrees of ranks. The estimation of flood hazard areas revealed that a major portion of Greater Dhaka comprised moderate to very high hazard zone. Only a little portion (8.04%) was found to be the least vulnerable to potential flood hazard. Conversely, 28.70% of Greater Dhaka was found within very high hazard zone. Based on this study, comprehensive flood hazard management strategies for land use planning decision were proposed for the efficient management of future flood disasters.     

Flood hazard assessment of Atrato River in Colombia

The flood hazard caused by Atrato River in Quibdó, northwest of Colombia is assessed using statistical modeling techniques (Gumbel and GRADEX), hydraulic modeling with HEC-RAS and the Geographic Information Systems (GIS). Three flood hazard maps for return periods of 10, 20 and 50 years are generated. The flood hazard modeling reveals that the flooded zone is more significant out of the left (West) bank than out of the right (East) bank of Atrato River. For the three return periods the maximum depth of water reached by the river and extent of flooding are estimated. Sensitivity analysis on roughness coefficient and peak discharge is performed. For 50 year return period (Q =3054 m³/s), water depth on the left and right bank of Atrato River is 3.7 m and 3.1 m, respectively. This information is useful in defining the minimum height of flood protection structures such as dikes to protect the area from flooding. The results can be useful for evacuation planning, estimation of damages and post flood recovery efforts.     

A Spatially Explicit Multi-Criteria Analysis Method on Solving Spatial Heterogeneity Problems for Flood Hazard Assessment

Flood hazard assessment and mapping of flood prone area are of great importance for flood management, as well as the reduction of potential losses of life and property caused by flooding. In this study, a spatially explicit multi-criteria analysis approach which emphasizes on spatial heterogeneity in decision-making process is developed for flood hazard assessment, and it has been applied to the area including Hanyang, Caidian and Hannan of Wuhan, China, where flood events occur frequently. Factors associated with flood mechanism and characteristics of the watershed itself were selected, and primary analysis was implemented to make the factors concise and essential. This paper emphasized the spatial heterogeneity problem in flood hazard assessment by incorporating spatial ordered weighted averaging (OWA) method into windows-based local spatial multi-criteria analysis (MCA). On one hand, the local normalization was applied to normalize the criteria, and entropy-based local criteria weights were calculated to adjust the criteria weight at local level. On the other hand, spatial OWA method with spatially variable risk preference was applied to assign different order weights at different locations. The results indicate that the proposed approach focused on the flood hazard at local level, and the flood hazard map presented more dispersive distribution of the high and very high hazard area than that derived by global MCA. Furthermore, flood hazard in important and unimportant area was distinguished by paying more attention to the former one. And the distribution of high hazard area tends to be mainly located in populated and developed areas.     

Uncertainty Estimation in Flood Inundation Mapping: An Application of Non‐parametric Bootstrapping

Disaster prevention planning is affected in a significant way by a lack of in‐depth understanding of the numerous uncertainties involved with flood delineation and related estimations. Currently, flood inundation extent is represented as a deterministic map without in‐depth consideration of the inherent uncertainties associated with variables such as precipitation, streamflow, topographic representation, modelling parameters and techniques, and geospatial operations. The motivation of this study is to estimate uncertainties in flood inundation mapping based on a non‐parametric bootstrapping method. The uncertainty is addressed through the application of non‐parametric bootstrap sampling to the hydrodynamic modelling software, HEC‐RAS, integrated with Geographic Information System (GIS). This approach was used to simulate different water levels and flow rates corresponding to different return periods from the available database. The study area was the Langat River Basin in Malaysia. The results revealed that the inundated land and infrastructure are subject to a flooding hazard of high‐frequency events and that the flood damage potential is increasing significantly for residential areas and valuable land‐use classes with higher return periods. The proposed methodology, as well as the study outcomes, of this paper could be beneficial to policymakers, water resources managers, insurance companies and other flood‐related stakeholders. Copyright © 2017 John Wiley & Sons, Ltd.     

考虑圩区分布的平原河网区暴雨洪涝分析模型建立

针对圩区众多的平原河网区域,基于已有的一、二维非恒定流水动力学理论建立的城市洪涝仿真模型,引入"小蓄水面"的概念,将圩区内外在水动力学模型中未被概化但对降雨的调蓄作用不可忽略的小河、塘坝、小湖泊等根据其实际空间分布统一概化为所在网格的小蓄水面,并考虑圩区堤防标准、抽排能力和调度运行规则对河网区域洪涝时空分布的影响,对模型中网格淹没水深、圩区排涝和闸泵调度的计算方法进行了改进。选择嘉兴市为案例区域建立了暴雨洪涝分析模型,利用模型对嘉兴市近年来典型场次暴雨进行模拟计算,与河道实测水位及洪涝分布调查结果对比表明,模型对区域的概化合理,能反映嘉兴市在受本地降雨和上游洪水影响、下游潮位顶托及复杂的工程调度规则综合作用下水流的运动特点和洪涝的分布特征,模拟结果可靠,模型可以为区域洪水风险图编制和防汛风险管理提供支持。     

基于拉格朗日插值的挡潮排涝涵闸调洪演算

为了探究涵闸进口水位—流量关系未知且外江潮水对内江洪水具有顶托作用的调洪演算过程,在传统的列表试算方法基础上提出了单时段内根据涵闸运行原则且基于拉格朗日n次插值多项式的泄流前及泄流后容积水深插值调洪算法,为了计算方便,采用C++编写拉格朗日插值程序。将改进算法的计算结果代入传统的列表试算法中进行验证,计算结果表明只有个别时段水深值具有微小偏差,改进后的算法具有较高的精度。改进后的算法不仅可以避免传统算法的大量试算,为传统算法提供准确的试算初始点,而且对于类似实际工程的调洪演算具有一定的参考价值。     

基于栅格DEM 的沙兰河流域河网提取及局地暴雨洪水模拟

本文基于美国Global Land Cover Facility（GLCF）的全球90m精度的DEM数据源，采用作者开发的DEM凹陷区域识别与处理、河网自动生成与流域划分软件，提取了黑龙江省沙兰镇以上沙兰河流域河网相关信息。同时结合沙兰河暴雨洪水的相关报道，采用内含简化水文过程的二维水动力学模型，直接用假设的降水过程作为输入，估算了沙兰河流域局地暴雨的洪水过程与低洼地的洪水淹没过程。结果表明，从公开的高分辨率全球DEM数据自动提取指定流域信息，并利用降雨数据作为模型输入，采用上述模型，可以为山洪灾害防治分析提供有力的技术工具和手段。