Robustness,Uncertainty and Sensitivity Analyses of the TOPSIS Method for Quantitative Climate Change Vulnerability: a Case Study of Flood Damage

Multi-criteria decision making (MCDM) techniques have been used to evaluate and rank the spatial flood vulnerability to climate change. However, various sources of uncertainty, such as the determination of evaluation criteria, the assignment of criteria weights and performance values, exist in the application of MCDM methods. In this study, three existing methods were combined to quantify the risk and uncertainties inherent to the process of climate change vulnerability assessment, which is called the TOPSIS-based Robustness-Uncertainty-Sensitivity (RUS) approach. The A1B scenario was used to assess the vulnerability of seven metropolitan cities in South Korea to climate change. Twenty indicators that are closely related to the cause of and deterioration from the flood risk and the resulting damages were selected by two surveys of experts, and the weights of these factors were determined by using the Delphi technique, which can derive the subjective weights. Based on the derived weights, the vulnerability ranking was calculated using the TOPSIS method, one of the most popular MCDM methods. This TOPSIS-based RUS approach was used to analyze the robustness of the vulnerability rankings for the assessed cities, to derive the minimum changed weights of the single and multiple criteria that determine the rank equivalence (or reversal) between any two cities and to check the sensitivities of the performance values to the vulnerability rankings. This study showed the effectiveness of the RUS approach for assessing the vulnerability to climate change, demonstrating the application of flood vulnerability.     

A New Integrated MADM Technique Combined with ANP,FTOPSIS and Fuzzy Max-Min Set Method for Evaluating Water Transfer Projects

In sustainable water resources management, it is essential to rank inter-basin water transfer projects. This task is difficult due to many different conflict criteria, complex relations among criteria and various judgments of decision makers. In this paper, an integrated multiple attribute group decision making method consists of ANP (Analytical Network Process), fuzzy TOPSIS and fuzzy max-min set methods is proposed for evaluating water transfer projects. A set of over 60 criteria in social, environmental and economic sectors are used for ranking four water transfer projects in Karun River based on three decision maker judgments. A key novelty of the proposed methodology is its ability to model both complex relations among different criteria in water management and the influence of decision maker judgments’ weights on the final ranking in group decision making problem. The procedure starts by obtaining the priority of water transfer projects and the weight of each decision maker judgments by employing ANP and fuzzy TOPSIS, respectively. These weights are used as inputs in the fuzzy max-min set method. Then the effects of decision maker weights on the final ranking are determined in fuzzy environment. Finally, the sensitivity analysis of decision makers’ weights has been conducted. The results show that the proposed method is an effective tool for group decision making problems by considering different criteria and decision makers’ weights.     

改进的TOPSIS模型在地下水水质评价中的应用

地下水水质评价是保护水环境实现地下水资源可持续利用的重要基础工作。为了克服使用TOPSIS模型评价水质时常受到多指标决策的局限性,对原模型进行了两点改进:一是采用以主观赋权(AHP法)与客观赋权(熵权法)相结合确定组合权重;二是采用Kullback-Leibler距离代替传统方法中的欧式距离计算贴近度。利用改进后的TOPSIS模型,分别对邯郸市、焦作市地下水水质进行评价,评价结果分别与参考文献对比基本一致,表明改进后的TOPSIS模型,计算方法基本合理可行,具有一定的探索价值。     

Developing Strategies for Agricultural Water Management of Large Irrigation and Drainage Networks with Fuzzy MCDM

Sustainable water resources management aims at increasing the efficient use of water and achieving food security. This work proposes a generalized novel spatial fuzzy strategic planning (SFSP) in combination with multi-criteria decision making (MCDM) and a conceptual agricultural water use model for determining sustainable agricultural water management strategies. The proposed framework is applied to an irrigation and drainage network in Iran, which constitutes a large-scale water resource system. A spatial strength, weakness, opportunity, and threat (SWOT) analysis of internal and external factors related to agricultural water management is applied in this work. Possible water management strategies were ranked with the MCDM approach that combines the Analytic Hierarchy Process (AHP) and the Fuzzy technique for order-preference by similarity to ideal solution (TOPSIS). The AHP estimates the criteria weights and the TOPSIS model prioritizes the agricultural water management strategies. The results of SWOT analysis show that the final scores of the internal and external factors are equal to 2.9 and 2.73, respectively. Accordingly, the most attractive strategic type is a SO (aggressive) strategy, and a combination of structural and non-structural strategies (SO, ST, and WO strategies) are the top-ranked ones. Proposed strategies for water supply and demand management are the development and rehabilitation of the physical structure of water resources system of irrigation network, improvement of operation management and maintenance of water resources system, wastewater management, and inter-basin water transfer within the irrigation network. The results indicate that the total annual volume of agricultural water under normal conditions is about 1.8 billion cubic meters, of which about 1707 million cubic meters (95%) issue from surface water sources and 90 million cubic meters (5%) from groundwater sources. The proposed model and the calculated results provide viable and effective solutions for the implementation of sustainable management of water resources and consumption in large-scale water resources systems.

     

Assessment and prioritization of eco‐revetment projects in urban rivers

Ecological revetment for slope protection in urban rivers requires consideration of economic and ecological aspects and also of social aspects including recreation. Taking the Hunhe River as an example, our study established an evaluation system and a decision‐making method for evaluating and prioritizing the eco‐revetment projects. The Delphi method was used for collecting the opinions of experts, which include the relative importance of the indicators and the relative preference of the alternatives. The former was surveyed by pair comparison and processed applied analytic hierarchy process (AHP). The latter was described via linguistic variables, which need to be changed into the quantitative values for TOPSIS analysis. For that reason, we introduced the fuzzy set theory and established a fuzzy multi‐attribute decision‐making method based on TOPSIS to assess and prioritize the projects. The evaluation system includes economic, social, environment and ecological several aspects totalling eight indicators. The evaluating and prioritizing result of the projects shows that the three‐dimensional vegetation net is the best slope protection measures in the study area. The sensitivity analyses of indicator weights and different calculation methods were performed to demonstrate the reliability of the results. The sensitivity analyses indicate that construction cost and maintenance cost are dominant factors during the alternatives prioritization. The distance calculation method and normalization technique are insensitive to the prioritization results. The methodology proposed by this paper offers an effective and feasible tool for managers to evaluate and choose the optimal engineering measures of riverbank protection. Copyright © 2008 John Wiley & Sons, Ltd.     

大连市水资源利用与宏观经济协调发展规划多目标群决策模型与方法

以大连市水资源开发利用与宏观经济协调可持续发展为研究背景，建立了大连市宏观经济水资源发展规划多目标群决策模型。根据该决策模型具有的多层次多目标多决策者的特点，结合陈守煜建立的工程模糊集理论与切比雪夫决策方法，提出了模糊切比雪夫多目标群决策方法。结果表明，该决策模型与模糊切比雪夫多目标群决策方法是有效和可行的。     

Flood Control Operations Based on the Theory of Variable Fuzzy Sets

Flood control decisions are often involved with quantitative and qualitative criteria. In this paper, a decision model is presented for flood control operations based on the theory of variable fuzzy sets. Using dual comparison, two models computing relative membership grades with qualitative and quantitative criteria are established, respectively. A method integrating subjective preference and iterative weights is proposed for weight-assessment. First, an initial solution of criteria weights is obtained by using proposed fuzzy optimal iteration model. Then, according to their knowledge related to real time flood operations, operators may modify the initial weights if necessary. When the relative membership grades of alternatives belonging to all rankings are fixed by using multi-criterion variable fuzzy model proposed, the decision alternative is chosen according to the ranking characteristic value computed using a defuzzification equation. The case study of Fengman Reservoir flood operation (in China) is provided to illustrate the application of the proposed method. With the incorporation of operator’s knowledge related to flood operations, the proposed model is flexible and practical.     

Identification of Spatial Ranking of Hydrological Vulnerability Using Multi-Criteria Decision Making Techniques: Case Study of Korea

Potential flood damage (PFD), potential streamflow depletion (PSD), potential water quality deterioration (PWQD), and watershed evaluation index (WEI) have been developed to spatially quantify the hydrological vulnerability using multi-criteria decision making (MCDM) techniques. All criteria are selected on the basis of a sustainability evaluation concept (pressure-state-response model), and their weights are estimated by an Analytic Hierarchy Process, which is also a type of MCDM technique. The MCDM techniques used for the evaluation are composite programming, compromise programming, ELECTRE II, Regime method, and Evamix method; these techniques can be classified according to data availability and objectives (prefeasibility and feasibility). Furthermore, the WEI is improved to reflect the preferences of the residents with regard to management objectives through weights (of PFD, PSD, and PWQD) obtained from questionaires of residents. Finally, this study derives a procedure to identify the spatial investment prioritization using four indices.     

考虑暴雨中心的子流域划分在洪水预报中的应用

为研究降雨分布不均对水库近坝区洪水预报精度的影响,以五强溪近坝区流域为研究区域,选取 2014—2020 年 20 场历史洪水资料,采用反距离权重法绘制流域暴雨中心图,并据此进行子流域划分,其中,13 场 洪水用于模型率定,7 场洪水用于模型验证。选取 2021 年 4 场洪水进行检验,对比分析仅依据自然子流域划分和 考虑暴雨中心的洪水预报结果。结果表明：两种子流域划分方法在其最优参数下的洪水模拟精度相似,考虑暴雨 中心划分的洪水模拟确定性系数均值为 0.83,略高于仅依据自然子流域划分洪水模拟确定性系数,4 场洪峰误差 均在 10％以内,洪量误差均在 20％以内,达到了甲级精度标准,说明考虑暴雨中心对子流域进行划分是合理的。     

流域水资源丰富度监督模糊模式识别

利用模糊模式识别的概念 ,以主观权重为监督 ,建立加权广义欧氏权距离平方和最小为目标函数的非线性规划 ,在流域水资源丰富度识别过程中用样本数据逐步修正权重 ,迭代得到较为客观的指标权重和评价结果 ,与对辽西沿海诸河流域水资源丰富度的评价结果对比分析表明 ,得到的结果较为客观合理 ,为解决复杂系统多目标决策、评价问题提供了一条新途径。     

FUZZY OPTIMAL DECISIONS FOR MULTIOBJECTIVE FLOOD CONTROL SYSTEM OF CASCADE RESERVOIRS

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Editorial Comments on the World Commission on Water for the 21stCentury

Abstract

In this study, in order to create a decision-making model on water resources projects, a hierarchy of criteria has been developed by public participation. The Value Management methodology has been used for extraction of the effective criteria and attributes in the scope of Integrated Water Resources Management (IWRM). The hierarchy is generic for water resources management in the Islamic Republic of Iran. Since the evaluations of alternatives with respect to some attributes are uncertain and vague, fuzzy set theory has been used. By merging fuzzy set theory and multi-attribute decision-making a new Decision Support System (DSS), namely FDM, has been developed to compare different alternatives. As an innovation, FDM accepts evaluations of alternatives with respect to the attributes as crisp variables, fuzzy variables, and linguistic variables. FDM embodies an expert system whose duty is to choose an appropriate method among the SAW, Fuzzy SAW, TOPSIS or Fuzzy TOPSIS based on the characteristics of the problem.

The central and Southeastern regions of Iran are considered arid regions, suffering from water shortages. In this paper, water transfers to the Zayanderud basin in Iran have been modeled by FDM. Successful application of this DSS in this study allows for its application by water authorities in other case studies.     

Multiple Kernel Learning with Maximum Inundation Extent from MODIS Imagery for Spatial Prediction of Flood Susceptibility

Identifying flood prone areas is essential for basin management. In this paper, a spatial prediction technology of flood susceptibility based on multiple kernel learning (MKL) is proposed. We establish the flood susceptibility model by using EasyMKL, nonlinear MKL (NLMKL), Representative MKL(RMKL), Generalized MKL(GMKL), support vector machine(SVM) with linear kernel and SVM with Gaussian radial base function(RBF) kernel, The spatial prediction of flood susceptibility in Sanhuajian basin of the Yellow River is carried out. We use MODIS remote sensing images to obtain historical flood inundation sites in the study area. Then, ten flood conditioning factors are used as inputs to the flood susceptibility model. The model performance is evaluated in terms of accuracy (ACC), balanced F Score (F1 score), and areas under the curve (AUC). According to the results, MKL significantly outperforms the SVM adopting single kernel, and NLMKL(ACC=0.833,F1=0.841,AUC=0.889) demonstrates the best comprehensive performance. The flood susceptibility map generated by MODIS remote sensing images and MKL, therefore, can provide effective help for researchers and decision makers in flood management.

     

Assessing flood vulnerability using a rule-based fuzzy system

Population growth and urbanization in the last decades have increased the vulnerability of properties and societies in flood-prone areas. Vulnerability analysis is one of the main factors used to determine the necessary measures of flood risk reduction in floodplains. At present, the vulnerability of natural disasters is analyzed by defining the various physical and social indices. This study presents a model based on a fuzzy rule-based system to address various ambiguities and uncertainties from natural variability, and human knowledge and preferences in vulnerability analysis. The proposed method is applied for a small watershed as a case study and the obtained results are compared with one of the index approaches. Both approaches present the same ranking for the sub-basin's vulnerability in the watershed. Finally, using the scores of vulnerability in different sub-basins, a vulnerability map of the watershed is presented.     

A GIS-Based Spatial Multi-Criteria Approach for Flood Risk Assessment in the Dongting Lake Region,Hunan, Central China

Floods, the most common natural hazard in the world, cause serious loss in terms of lives, buildings, and infrastructures. As a consequence, the need for flood risk assessment has become critical. Using a semi-quantitative model and fuzzy analytic hierarchy process (FAHP) weighting approach, this paper assessed flood risk in the Dongting Lake region, Hunan Province, Central China, an area where flood hazards frequently occur. The model was designed using spatial multi-criteria analysis (SMCA) techniques in a Geographic Information System (GIS). A GIS database of indicators for the evaluation of hazard and vulnerability was created. Each indicator was analyzed, standardized, and weighted; after which, the weights of the indicators were combined to obtain the final flood risk index map. Using the flood risk index, the study area was classified into five categories of flood risk: very low, low, medium, high, and very high. The high and very high risk zones are mainly concentrated in the northern and central plains. The results obtained can provide useful information for decision makers and insurance companies.     

地形指数与流域退水特征的关系分析

地形指数可反映流域土壤蓄水能力以及产流的空间分布,是表征流域水文相似性的一个重要指标。以新安江流域的8个子流域为研究对象,利用DEM提取了各子流域的地形指数,分析了地形指数与退水特征的关系。研究发现,地形指数均值及其标准差大的流域,其调蓄作用强,洪水退水指数较小,退水速率较慢,表明流域的地势起伏相对较小则含水层发育较好。通过研究,初步揭示了流域地形指数与退水特征之间存在的联系,成果可为新安江流域无资料区水文过程预测提供依据和参考。     

Managing Water Supply and Demand to Achieve Economic and Environmental Objectives: Application of Mathematical Programming and ANFIS Models

The integrated management of water supply and demand has been considered by many policymakers; due to its complexity the decision makers have faced many challenges so far. In this study, we proposed an efficient framework for managing water supply and demand in line with the economic and environmental objectives of the basin. To design this framework, a combination of ANFIS and multi-objective augmented ε-constraint programming models and TOPSIS were used. First, using hydrological data from 2001 to 2017, the rate of water release from the dam reservoir was estimated with the ANFIS model; afterwards, its allocation to agricultural areas was performed by combining multi-objective augmented ε-constraint models and TOPSIS. To prove the reliability of the proposed model, the southern Karkheh basin in Khuzestan province, Iran, was considered as a case study. The results have showed that this model is able to reduce irrigation water consumption and to improve its economic productivity in the basin.

     

Fuzzy Risk Assessment of Flash Floods Using a Cloud-Based Information Diffusion Approach

The assessment of flash flood risks is the basis on which flash flood prevention measures and early-warning systems can be proposed and reasonably implemented. However, inadequate monitoring of flash flood data which mainly occurs in remote areas restricts quantitative risk assessment. This study aimed to address the problems of limited data availability. A new model that integrating the Cloud-based Information Diffusion (CID) model and Analytic Hierarchy Process (AHP) approach is developed to assess flash flood risks. The proposed method improves the information diffusion function by introducing cloud model, while converting single-valued observations with incomplete information into fuzzy set-valued samples. The new approach can perform comprehensive risk assessment tasks with various indexes that are composed of incomplete information. Another advantage of this approach is that it can illustrate fuzzy uncertainty, fuzziness, and randomness of risk indexes by coupling with the cloud model, the risk magnitude is quantified with membership degree. A mountainous watershed in Southern China named Yangshan County was selected as the study area. Compared with information diffusion (ID) and entropy-based information diffusion (EID), the assessment results of the three models are, in general, consistent with one another, and agree with the reported values. According to the principle of maximum membership degree, Yangshan County is determined as a high-risk region when confronting with flash flood hazards. This model provides a feasible and effective method on fuzzy risk assessment of flash flooding, and is expected to be applied in other multi-criteria decision with limited available information or small sample problems.

     

平原河道生态护坡工程评价和方案决策方法

本文从成本、生态景观及施工工艺3个方面,建立了平原河道生态型护坡的评价指标体系.另外,引入模糊集理论,依据经典TOPSIS方法的基本思想,建立了基于TOPSIS的模糊多属性决策模型.用以对工程的方案进行优选决策.该评价体系和决策模型应用于沈阳市浑河生态护坡工程方案优选,结果表明,评估结果能较好地反映平原河道生态型护坡的特点并符合当地河道的实际情况.     

水电项目评标决策中的层次分析法

针对水电项目评标中常用方法存在的问题,将评标看成一个系统,把层次分析这一系统分析方法引用到水电项目评标决策中。层次分析法结构模型中结合专家的经验提出了评标决策的5项准则,通过判断矩阵为每一准则确定了相应权重,量化评标信息,最终为评标决策提供参考依据。