A Multi-criteria Decision-making Optimization Model for Flood Management in Reservoirs

Water Resources Management - Flood management in a reservoir-outlet system is a multi-criterion decision-making (MCDM) issue, in which preventing flood damage and flood overtopping, as well as...     

Flood Prevention and Watershed Management An Overview

Abstract

Web Sites are becoming mainstream, necessary components of every organization's mandate, whether that organization is governmental, academic or commercially based. With this popularity comes an increasing demand for intelligent web design: simple, attractive, easy-to-navigate style that balances well-written content with useful web technologies and freshness that will keep people coming back. The Great Lakes Information Network (GLIN) has been employing these principles of Web design since its beginnings in 1993, focusing first on supplying useful content and secondly, ensuring that the useful content is well-organized and easy-to-navigate. By forming online partnerships with hundreds of groups involved in management of the Great Lakes ecosystem, GLIN represents a united Web presence for the entire region.     

基于流溪河模型的连江流域洪水模拟

为了提高连江流域洪水预报的技术水平和精度,探讨流溪河模型在大流域洪水预报中应用的效果,该文采用SRTM和USGS的DEM数据,分别建立了连江流域洪水预报流溪河模型,采用1场实测洪水对模型参数进行了优选,并对2场实测洪水进行了模拟,发现流溪河模型可较好的模拟连江流域洪水过程。研究发现,采用空间分辨率为90 m的SRTM的DEM建立的流溪河模型计算量是以1000 m的USGS的DEM建立的模型的计算量的56倍,但两者洪水模拟的效果相当。     

Best Management Practices Optimization at Watershed Scale: Incorporating Spatial Topology among Fields

Best management practices (BMPs) are widely used to reduce nonpoint source pollutions. In order to obtain cost-effective BMPs configurations, optimization methods are introduced. Recent studies show that knowledge on BMP placement can be used to improve existing algorithms for BMPs optimization. However, some important knowledge has not been fully utilized yet, one of which is about the spatial topology among fields and BMPs interactions. In this paper, a new method for BMPs optimization was proposed, which incorporated knowledge of BMPs interactions into a multi-objective genetic algorithm (i.e., ε-NSGAII) based on spatial topology among fields. Then this method was applied to the BMPs optimization in a small agricultural watershed in Southern Manitoba of Canada, and the performance was compared with those of conventional method. In order to make a comprehensive comparison, experiments were conducted under different population sizes (i.e., 60, 100, and 200) and different numbers of fields (i.e., 29, 52, and 79). The results showed that the proposed method was superior to conventional method on the aspect of greater sediment reductions (2% - 17%) at the same cost, and the Pareto curves obtained by the proposed method were more complete. This study demonstrated that incorporating spatial topology among fields into BMPs optimization can lead to better results and this finding could provide valuable references to similar studies.     

A Decentralized Bi-Level Fuzzy Two-Stage Decision Model for Flood Management

Flood, as a serious worldwide environment problem, can lead to detrimental economic losses and fatalities. Effective flood control is desired to mitigate the adverse impacts of flooding and the associated flood risk through development of cost-effective and efficient flood management decisions and policies. A bi-level fuzzy two-stage stochastic programming model, named BIFS model is developed in this study to provide decision support for economic analysis of flood management. The BIFS model is capable of not only addressing the sequential decision making issue involving the two-level decision makers, but also correcting the pre-regulated flood management decisions before the occurrence of a flood event in the two-stage environment. The probabilistic and non-probabilistic uncertainties expressed as probability density functions and fuzzy sets are quantitatively analyzed. The overall satisfaction solution is obtained for meeting the goals of the two-level decision makers by compromising, reflecting the tradeoffs among various decision makers in the two decision-making levels. The results of application of the BIFS model to a representative case study indicate informed decision strategies for flood management. Tradeoffs between economic objectives and uncertainty-averse attitudes of decision makers are quantified.     

Dual-Interval Two-Stage Optimization for Flood Management and Risk Analyses

In this study, a dual interval two-stage restricted-recourse programming (DITRP) method is developed for flood-diversion planning under uncertainty. Compared with other conventional methods, DITRP improves upon them by addressing system uncertainties with complex presentations and incorporating subjective information within its optimization framework. Uncertainties in DITRP can be represented as probability distributions and intervals. In addition, the dual-interval concept is presented when the available information is highly uncertain for boundaries of intervals. Moreover, decision makers’ attitudes towards system risk can be reflected using a restricted-resource measure by controlling the variability of the recourse cost. The method has been applied to a case study of flood management. The results indicate that reasonable solutions for planning flood management practice have been generated which are related to decisions of flood-diversion. Several policy scenarios are analyzed, assisting in gaining insight into the tradeoffs between risk and cost.     

An Operational Model for Support of Integrated Watershed Management

This paper presents a computer simulation-based methodology for operational support of integrated water resources management. The methodology is based on the systems approach, and use of feedback to capture physical and socio-economic processes occurring within a watershed. The approach integrates well established simulation models of physical processes with simulation models that describe socio-economic processes. The proposed methodology is illustrated by the evaluation of risk and vulnerability to changing climatic and socio-economic conditions in the Upper Thames watershed (south-western Ontario, Canada).The model results indicate that flooding in the watershed will be more severe as a result of climate change, while low flows are expected to remain at their current level. The most significant socio-economic factor in the Upper Thames watershed is water availability, shown to become under climate change a limiting factor for future growth and development.     

Grid-Based Land-Use Composition and Configuration Optimization for Watershed Stormwater Management

This paper demonstrates a new method of optimizing land-use patterns to reduce the negative impacts of urbanization on watershed stormwater systems. The Yong-Ding watershed in western Beijing, China, serves as a case study for this research. A regression model that estimates watershed hydrology response to land use pattern changes is integrated with a land-use allocation model to determine the optimal landuse pattern for minimizing peak flow or total volume at the watershed outlet. This system also uses the CLUE-S model to generate empirical land-use patterns under different development intensities and then determines the land use pattern change constraints for each optimization process. The impacts of optimization are detected by comparing the land use pattern characteristics and watershed hydrology of empirical and optimal scenarios under the same development intensity. The results of the hydrological evaluation suggest that, compared to land-use location control, land-use composition and configuration control may be a more powerful method for minimizing the negative hydrological impact of urbanization.     

An Interval Fuzzy Multiobjective Watershed Management Model for the Lake Qionghai Watershed, China

Integrated watershed management is required to ensure the reasonable use of resources and reconcile interactions among natural and human systems. In the present study, an interval fuzzy multiobjective programming (IFMOP) method was used to solve an integrated watershed management problem. Based on system analysis, an IFMOP model suitable for a lake watershed system {IFMOPLWS} was developed and applied to the Lake Qionghai watershed in China. Scenario analysis and an interactive approach were used in the solution process. In this manner, various system components were incorporated into one framework for holistic consideration and optimization. Integrality and uncertainty, as well as the multiobjective and dynamic characteristics of the watershed system, were well addressed. Using two scenarios, two planning schemes were generated. Agriculture, tourism, macroeconomics, cropland use, water supply, forest coverage, soil erosion, and water pollution were fully interpreted and compared to identify a preferable planning alternative for local agencies. This study showed that the IFMOPLWS is a powerful tool for integrated watershed management planning and can provide a solid base for sustainable watershed management.     

受冻土影响流域洪水预报方法分析

对受冻土影响较明显的永翠河流域下垫面自然地理和洪水规律特征进行了分析。在分析流域下垫面冻土的种类组成、分布特点、以及对雨水的下渗和蒸发影响规律的基础上,利用经验相关图和回归方程模型探讨性地提出了流域下垫面受冻土影响期间的洪水预报方法。所用方法洪水影响因素和物理成因比较明确,实际应用简便高效,为提高受冻土影响时的流域洪水预报精度做了尝试。     

小流域设计洪水计算方法的探讨

利用实例对各常用设计洪水流量计算方法进行比较分析,指出各方法的特点。     

基于广义联系度函数的城市防洪标准方案优选模型

城市防洪标准方案优选是城市洪水灾害风险管理系统的重要组成部分,可为城市适应环境变化和应对洪水带来的自然灾害等方面提供科学的决策依据。城市防洪标准方案优选的本质是复杂系统多因素评价问题,其研究难点是如何有效地将多属性指标综合成一维单指标形式,由此实现一维单指标的方案优选。为此,针对标准集对分析方法(SPA)联系度计算时如何确定差异度系数i的难点,从投票模型原理出发,进一步分解差异度,再次分解为同一度、差异度和对立度,提出了基于集对分析广义联系度函数的复杂系统方案优选模型。将上述模型进行应用,计算结果表明:该模型物理概念清晰、计算过程直观、易于理解,能较好地表征不同方案不同指标之间的差异情况。     

洪水管理模型及其应用

１洪水管理概化模型假设某区域A有两片除洪水风险外其他条件完全相同的土地资源A１、A２，一片（A２）有洪水风险，另一片（A１）没有，区域人口为M，单位面积年均产出为分别为e１和e２（见图１）．在A２未建防洪工程以前，洪水年期望损失为D１，A１和A２的年均产出分别为E１＝A１·e１E２＝A２·e２－D１（１）设合理的人口分布模式以人均收益在两个区域相等，则人口分布（设A１，A２区的人口分别为M１，M２）与产出的关系M＝M１＋M２A１·e１／M１＝（A２·e２－D１）／M２（２）在有风险区域A２的人口M２占总人口的比例为M２…     

山区小流域城市东兰县城防洪措施探讨

在城市特别是山区城市，防洪工程的建设往往与城市号观、城市用地及拆迁等方面矛盾突出，另一方面，山区河流水土流失较大，河床淤积严重，给已建防洪工程的管理工作带来很大困难。东兰县城城区防洪工程通过采用复式断面、河床清淤及加强上游水土保持工作等措施成功解决上述矛盾，对实际工程有一定参考意义。     

富阳市小流域防洪避洪对策探讨

小流域暴雨洪水灾害作为当前防洪减灾工作中的重要问题,引起了各级政府的高度重视。通过对富阳小流域暴雨洪水灾害分析,划定风险区,找出重点防避区域,提出防避预案,探讨防洪避洪的非工程与工程措施,从而进一步保障富阳的公共安全。     

山区小流域城市东兰县城防洪措施探讨

在城市特别是山区城市,防洪工程的建设往往与城市景观、城市用地及拆迁等方面矛盾突出,另一方面,山区河流水土流失较大,河床淤积严重,给已建防洪工程的管理工作带来很大困难.东兰县城城区防洪工程通过采用复式断面、河床清淤及加强上游水土保持工作等措施成功解决上述矛盾,对实际工程有一定参考意义.     

Estimation of Design Flood Hydrograph for an Ungauged Watershed

Based on the physiographical features of the studied watershed of 102.5 km² in northern Ontario and the meteorological data of one nearby climatic station, through the combination of the regionalization of flood and the HEC-1 modeling, this article presents an approach that may be used to determine the desired peak flows for the ungauged watershed. The empirical equations used to determine the desired peak flows were developed by the Cumming Cockburn Ltd. (CCL) who has carried out the studies on flood regionalization by using flow data at 380 gauging stations in Ontario. CCL has proposed four methods to estimate peak flows, namely 1) regression method describing multiple linear relationships between flood flow and related parameters; 2) index flood frequency curve; 3) regional flood frequency curve and 4) isoline map for unit peak flow. The desired peak flows for studied watershed determined by CCL methods were used to calibrate the HEC-1 model for the rainfall-runoff simulation for this watershed which consists of 15 subwatersheds. Through slight adjustment in the CN number used in the HEC-1 model, the calibrated HEC-1 model could be used for rainfall-runoff simulation for this ungauged watershed. This approach could be recommended for hydrological design and watershed management for ungauged watersheds provided the analyses of flood regionalization could be conducted. In addition, comparing to the Bavaria forest region, Germany, some questions have been discussed in this article.     

基于水动力模型的花园湖行洪区优化调度研究

应用MIKE建立淮河干流蚌埠至浮山段水动力数学模型,利用典型年2007年实测洪水过程,对模型的参数进行率定和验证。通过建立一、二维模型,将淮河干流河道与行洪区进行耦合连接,进而对100 a一遇洪水演进过程进行模拟,建立行洪区不同启用条件下的水位—流量关系,从而对调整规划实施后行洪区启用条件进行合理性分析及优化,为行蓄洪区的调度运用提供依据。结果表明:遭遇100 a一遇洪水时,规划条件下花园湖行洪区按照临淮关水位达到20.60 m时启用,并且以进、退洪闸同时开启的闸门调度方式运用,行洪效果相对较好。     

白盆珠水库流域暴雨洪水特性研究

收集白盆珠水库流域37场次洪径流过程,通过径流系数、降雨时空分布、暴雨中心等来研究白盆珠水库流域洪水特性,阐述其洪水形成机制,为水库防洪减灾提供决策依据.     

A Needed Economic Framework for Flood Plain Management

ABSTRACT

This paper sets forth a desired economic framework for flood plain management. After expressing serious concern that efficient flood hazard mitigation may not be desired as a goal of public policy, six major management issues are outlined. First is the task of reformulation of the problem of flood hazard mitigation from an emphasis on hazard reduction per se to one of an efficient use of flood-prone lands and development of socially acceptable levels of residual risk. Second, there is need to specify more clearly what is the economic rationale for public action (particularly in a national system) in flood hazard mitigation in relation to the role of markets and private choice. Third, analysis is needed to specify in theoretical and in operational terms the efficient level of mitigation. Fourth, the question of what constitutes a proper measure of loss is of Critical importance. Fifth, economic evaluation of existing institutions and policies in the flood hazard field is clearly needed. Finally, benefit-cost studies of selected mitigation measures are proposed. An overlying concern throughout the paper is that present institutional arrangements may act as barriers to efficient policy and obscure the rationale for other kinds of economic analysis.