Water Quality Assessment Based on Combined Multi-Criteria Decision-Making Method with Index Method

This work presents combined approach to water quality assessment based on both Water Quality Indices (WQI) and Multi-Criteria Decision-Making (MCDM) methods. Using weights from the official WQI calculation algorithm, the model for MCDM was formed and presented on the case of the Danube River water quality in Serbia. By applying PROMETHEE method, locations of potential environmental risk were determined and ranked according to the quality of water. Using its visual modeling option GAIA, the most dominant variables that affect the quality of water at certain locations were identified as polluting parameters (suspended matter, BOD-5, total N, NH4-N and PO4-P). Concentrations of identified pollutants were compared with limits of both EU and national recommendations so the actual water quality of the river was determined. The results showed that although WQI analysis indicated good and very good water quality, extension with MCDM methods revealed that there is a significant excess in values of PO4-P and E.coli at almost every location on the course of the river, as well as in values of total N and NH4-N. Proposed combined approach could serve to engineers and decision makers involved in water quality management in creating more detailed reports on water quality while facilitating the process of decision-making in the choice of selection of particular locations with critical water quality, where appropriate measures for remediation of pollution should be taken.     

A Flexible Approach for the Reinforcement of Water Networks Using Multi-Criteria Decision Analysis

Water Resources Management - This work proposes a multi-criteria decision analysis (MCDA) as a useful tool for supporting interventions to overcome problems faced by water utilities due to...     

Water Quality Sensor Placement: A Multi-Objective and Multi-Criteria Approach

To satisfy their main goal, namely providing quality water to consumers, water distribution networks (WDNs) need to be suitably monitored. Only well designed and reliable monitoring data enables WDN managers to make sound decisions on their systems. In this belief, water utilities worldwide have invested in monitoring and data acquisition systems. However, good monitoring needs optimal sensor placement and presents a multi-objective problem where cost and quality are conflicting objectives (among others). In this paper, we address the solution to this multi-objective problem by integrating quality simulations using EPANET-MSX, with two optimization techniques. First, multi-objective optimization is used to build a Pareto front of non-dominated solutions relating contamination detection time and detection probability with cost. To assist decision makers with the selection of an optimal solution that provides the best trade-off for their utility, a multi-criteria decision-making technique is then used with a twofold objective: 1) to cluster Pareto solutions according to network sensitivity and entropy as evaluation parameters; and 2) to rank the solutions within each cluster to provide deeper insight into the problem when considering the utility perspectives.The clustering process, which considers features related to water utility needs and available information, helps decision makers select reliable and useful solutions from the Pareto front. Thus, while several works on sensor placement stop at multi-objective optimization, this work goes a step further and provides a reduced and simplified Pareto front where optimal solutions are highlighted. The proposed methodology uses the NSGA-II algorithm to solve the optimization problem, and clustering is performed through ELECTRE TRI. The developed methodology is applied to a very well-known benchmarking WDN, for which the usefulness of the approach is shown. The final results, which correspond to four optimal solution clusters, are useful for decision makers during the planning and development of projects on networks of quality sensors. The obtained clusters exhibit distinctive features, opening ways for a final project to prioritize the most convenient solution, with the assurance of implementing a Pareto-optimal solution.

     

Mapping Urban Water Demands Using Multi-Criteria Analysis and GIS

A multi-criteria spatial data analysis method is presented to seek and model major determinants of future growth of urban water demands based on the urban growth trend by a case study performed in the city of Mytilene (Lesvos island) in north-eastern Aegean archipelagos, Greece. Domestic water use/demand is a complex element of socio-economic and physical characteristics, urban planning strategies, infrastructures and public water policies. Under a GIS environment, these factors correspond to different thematic layers, such as road network distance, distance from the city centre, distance from the coastline, topographic slope, land use/land cover, General Urban Plan of Mytilene, areas in which buildings with less than two storeys are allowed, the respective areas of buildings with more than two storeys, present population density and existing water supply and sewerage system. The Analytical Hierarchy Process applied in the evaluation of these factors led to spatial potential water demand map, which was classified into five priority zones. Results showed that a large percentage of the study area was identified as very high and high priority areas for future domestic water demand. The applied method was verified against the prepared maps showing the varying rates of water consumption and active water connections. The comparative evaluation of these maps validated the accuracy of the proposed method which can be used by the local officials of Mytilene in adopting policies and strategies aiming towards sustainable water resource management and development.     

Selecting the Best Flood Flow Frequency Model Using Multi-Criteria Group Decision-Making

Several criteria should be considered when selecting a probability distribution to describe hydrological data. This study examines how multiple criteria can be combined to make the best selection. Selection becomes more difficult and subjective when more than two criteria are used to determine the best distribution. Under these conditions, multi-criteria decision-making is necessary. In this study, 12 distributions were tested and compared for flood frequency analysis based on five selection criteria: root mean square error, Kolmogorov-Smirnov test statistic, relative average bias, modified Anderson-Darling test, and deviation in skewness and kurtosis. The comparisons are made using a multi-criteria group decision-making (MCGDM) based on ordered weighted averaging (OWA). Two preemptive goal programming models based on variance and entropy methods for a predetermined level of optimism by a group of decision-makers, determined the weight of the OWA operator. The model was applied to a case study of Mahabad River, a major river flowing into Lake Urmia in northwestern Iran. A sensitivity analysis of the results of MCGDM was done by changing the degree of optimism of the decision-makers. The results of sensitivity analysis showed the dependence of the rankings to the optimism degrees of the decision-makers. The 3-parameter Weibull (WBL3) and Pearson type 3 (PE3) distributions had the best results for Mahabad River flood data. A Monte Carlo simulation was conducted to test the ability of the models. It was concluded from the findings of the simulation that the PE3 distribution is the most appropriate for short sample sizes, while WBL3 is preferable for larger sample sizes.     

Advanced Evaluation Methodology for Water Quality Assessment Using Artificial Neural Network Approach

Water Resources Management - The increasing rate of water pollution and consequent increase of waterborne diseases are compelling evidence of danger to public health and all living organisms....     

Multi-Criteria Approach for Evaluating Long Term Water Strategies

Abstract

Long-term national water strategies, which are formulated to cope with the socio-economic development plans, have either positive or negative impacts in several domains including environment, economy, and social life. Intuitive evaluation of policies and actions on the basis of their social, economic, and environmental utilities is ambiguous and very complex. Setting water resources policies for a country like Egypt is a good example of this type of complexity due to its multisectoral, interdisciplinary, interrelated environment. There is a classical assumption in water resources planning and management that stipulates decisions based on optimization of a well-defined single objective. In reality, the decision-making process is much more complex. Decision makers seek an optimal compromise among several objectives or try to achieve satisfying levels of their goals. Therefore, the present study proposes the multi-criteria analysis as an approach for evaluating Egypt's long term plans to reveal their rank and behavior throughout the foreseen planning horizon. Several evaluation criteria (indicators) have been articulated and grouped into four main categories: water, environment, social, and economy. A simple empirical simulation model was used to score different criteria. Four cases have been compared and evaluated by the suggested approach. Each case represents an anticipated national water-related development plan. This is carried out under specific scenarios for uncontrolled variables such as population growth rate, hydrological river flow into the system, and others. The application showed that a multi-criteria approach could contribute significantly to the decision making process in Egypt. It provides a systematic way of presenting the tradeoffs among policy choices considering many issues.     

Spatio-Temporal Multi-Criteria Optimization of Reservoir Water Quality Monitoring Network Using Value of Information and Transinformation Entropy

Identifying optimal Water Quality Monitoring Stations (WQMS) with high values of information on the entire reservoir status, instead of all potential WQMS would significantly reduce the monitoring network expenditure while providing adequate spatial coverage. This study presented a new methodology for spatio-temporal multi-criteria optimization of reservoir WQMS based on Value of Information (VOI), Transinformation Entropy (TE), Non-dominated Sorting Genetic Algorithm II (NSGA-II), Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE), and IRanian Water Quality Index (IRWQI). Although, all mentioned methods and concepts are well-known and have been used in water resources management, but their integration into a specific application for spatio-temporal multi-criteria optimization of reservoir WQMS is definitely an innovation and a contribution to improvement of WQMS design. More specifically, maximizing VOI as a decision-makers’ design criteria for optimization of WQMS, and considering spatial and temporal variations of water quality at different reservoir depths are new innovations in this research. The multi-objective optimization model was based on three objectives: 1) minimizing costs; 2) maximizing VOI; and 3) minimizing TE (redundant information). Considering these objectives, the NSGA-II multi-objective optimization method was used to find Pareto-optimal solutions. The most preferable solution was then determined using PROMETHEE multi-criteria decision making method. The proposed methodology was applied to Karkheh Reservoir with more than 5 billion cubic meter capacity and 60 km length that is one of the largest reservoirs in Southwestern Iran, however, the proposed approach has the ability to be generalized for any generic reservoir. Considering equal weights for criteria, PROMETHEE method resulted in 6 optimized WQMS out of 60 potential ones and a period of 25 days for optimal sampling interval. The optimized monitoring stations were mainly located at deep parts where most water quality variations are expected to occur. To show sensitivity of the model to different weights, 4 scenarios with various relative weights were evaluated in the PROMETHEE method. Results indicated that by increasing the weight of the second criterion (maximizing VOI), the number of optimized WQMS increased and the sampling interval decreased.     

Reservoir Optimization for Energy Production Using a New Evolutionary Algorithm Based on Multi-Criteria Decision-Making Models

The study applies kidney algorithm for the optimization of reservoir operation for hydropower generation. The objective function defined for optimization is to minimize the hydroelectric power deficiency. Results of kidney algorithm are compared with those of bat algorithm (BA), water cycle algorithm (WCA), biogeography-based optimization algorithm (BBO), genetic algorithm (GA), particle swarm optimization algorithm (PSOA), and scatter matters search algorithm (SMSA). All algorithms are evaluated by Complex proportional assessment (COPRAS), Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), modified TOPSIS, and Weighted Aggregated Sum Product Assessment (WASPAS), as well as Borda count social choice theory. Then, vulnerability, time and volumetric reliability, as well as resiliency indices are used for comparison and multi-criteria decision-making indicators for selecting the best algorithm. It is found that no algorithm is ranked uniformly the best. Results indicate that kidney and particle swarm algorithms are ranked higher than other algorithms by most indices. Results of 10 random implementations of the objective function indicate that KA has a lower coefficient of variation and is computationally moe efficient. Further, most of the multi-criteria decision making models allocate the first rank to KA.     

Multi-Criteria Analysis of Water Allocation Scenarios in a Water Scarce Basin

In 2015, a “Post-2015 Development Agenda” is defined for future global developments in water management. The proposed goal is referred to as SDG’s or Sustainable Development Goals, which will balance the economic, social and environmental dimensions of sustainable development with a strong linkage between environment and socio-economic goals. One of the major concepts of SDG’s is water security, which is the basic element of the Global Goal on Water, now defined as: “Securing Sustainable Water for All”. The proposal for a Global Goal for Water is associated with targets and indicators to help countries reach the goal by 2030. Among the five main targets specified, two major ones emphasize “water allocation” as an important support of water security, particularly in conditions of water security. This paper focuses on this latter issue in the case of water scarce Gediz Basin along the Aegean coast of Turkey, where irrigation is the major water consuming activity. In addition to allocation of water among other water use sectors and irrigation, it is important in the basin how irrigation water is allocated to various crops, as previous droughts struck crop yields the most. Thus, 16 alternative allocation scenarios are developed to assess the crop yield produced by each scenario. These alternatives are represented by social, economic and environmental indicators as criteria for selection the most favorable alternative. The selection is realized by Multi Criteria Analysis (MCA) methodology, using the Reference Point Approach (RPA). In terms of methodology, presented paper shows that RPA is a powerful tool to guide engineers and decision makers to rationally select among several possible alternatives in water allocation.     

A Scenario Based Impact Assessment of Trace Metals on Ecosystem of River Ganges Using Multivariate Analysis Coupled with Fuzzy Decision-Making Approach

The growing consciousness about the health risks associated with environmental pollutants has brought a major shift in global concern towards prevention of hazardous/trace metals discharge in water bodies. Majority of these trace metals gets accumulated in the body of aquatic lives, which are considered as potential indicators of hazardous content. This results in an ecological imbalance in the form of poisoning, diseases and even death of fish and other aquatic lives, and ultimately affect humans through food chain. Trace metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn originated from various industrial operations containing metallic solutions and agricultural practices, have been contributing significantly to cause aquatic pollution. The present study develops a novel approach of expressing sustainability of river’s ecosystem based on health of the fish by coupling fuzzy sensitivity analysis into multivariate analysis. A systematic methodology has been developed by generating monoplot, two dimensional biplot and rotated component matrix (using ‘Analyze it’ and ‘SPSS’ software), which can simultaneously identify critical trace metals and their industrial sources, critical sampling stations, and adversely affected fish species along with their interrelationships. A case study of assessing the impact of trace metals on the aquatic life of river Ganges, India has also been presented to demonstrate effectiveness of the model. The clusters pertaining to various water quality parameters have been identified using Principal Component Analysis (PCA) to determine actual sources of pollutants and their impact on aquatic life. The fuzzy sensitivity analysis reveals the cause-effect relationship of these critical parameters. The study suggests pollution control agencies to enforce appropriate regulations on the wastewater dischargers responsible for polluting river streams with a particular kind of trace metal(s).     

An Approach to Elaborate Priority Preorders of Water Resources Projects Based on Multi-Criteria Evaluation and Fuzzy Sets Analysis

Water scarcity is one important problem among many water problems that are present today and will be even more noticeable in the future. Many developing countries have investigated water resources projects to satisfy their demand in water. There is no enough financial capability to execute all these projects in one lot, so it is important to elaborate a priority execution plan related to these projects to identify the sequence of projects to be executedin order of priority (priority preorder). First the conditions required for an accurate priority preorder elaboration are outlined and the evaluations of the different goals or criteria are presented. Then an appropriate methodology to determine the priority preorders of water resources projects with respect to the defined criteria is developed. Lastly, an example of application is given in order to examine the various steps of the proposed methodology and its applicability is discussed.     

深圳新洲河水质现状评价与分析

对深圳市新洲河5个断面进行监测,并对其水质进行评价与分析。结果显示,河流总体水质为劣Ⅴ类,有机物、氮磷污染物均超标。水质指标间的相关性则表明新洲河的污染主要来自固定的一个或几个生活污水的排放。新洲河水质随时间的变化波动幅度很大。上游到中游段,水体中污染物总体上沿程减少,其中有机物和氮磷污染物降解幅度达60%~85%;中游至下游,水体则沿程恶化,氨氮、总氮均上升30%以上,有机物和总磷均增加100%以上。     

基于贝叶斯理论的武烈河水质综合评价

选取2010年武烈河6个监测断面的水质监测数据作为研究对象,采用贝叶斯公式对其水质进行综合分析评价,结果表明:各监测断面水质评价均在Ⅲ类以上,总体水质结果较好,符合水功能区划要求;66.7%的断面达到Ⅰ类,包括高寺台上游、双峰寺水库坝址、雹神庙和污水处理厂出水口下游4个断面;高寺台下游断面只达到Ⅲ级,主要是由于高寺台镇及其矿区生活污水和农业退水未经处理直接排入河道造成的。为保障双峰寺水库运行后的流域水环境质量和供水安全,需从水源地建设、点源治理和面源治理3个方面采取水环境保护措施。     

A Distress-Based Condition Assessment Approach of Urban Water Assets Using Novel Deterioration Indices

Water Resources Management - This paper aims at proposing and demonstrating the application of a novel distress-based condition assessment approach to evaluate the physical condition of inspectable...     

多维偏好分析技术在水资源系统规划中的应用

多目标决策是水资源系统规划和运行管理研究中一类常见问题，本运用多目标决策方法中多编偏好分析的线性规划技术，对若干个可行方案进行优选。根据可获知的方案信息，通过构造一相应的线性规划问题并求解，即可得到最优方案，利用方案信息和线性规划技术是本所使用方法的特点，对于具有更多方案的多指标决策问题，这一方法与层次分析法相比较，可以避免大量的矩阵运算。     

Multi-Criteria Decision Analysis and GIS Approach for Prioritization of Drinking Water Utilities Protection Based on their Vulnerability to Contamination

This work presents the use of multi-criteria decision analysis (MCDA) as a decision tool to facilitate the process of prioritization of drinking wells that would need more protection before contamination risk. In this study, three aspects of the protection of the groundwater quality were taken into account: natural, anthropic and technical. From these aspects, elements more representative were selected, which can be quantified with available and easily accessible information. Considering those elements, selection criteria were defined which have been represented by: population distribution indicator, human development index, land use, index for aquifer vulnerability to contamination, well age and well yearly pumping rate. The developed method has been applied to drinking supply wells located in the Toluca Valley aquifer (Mexico), and implied the generation of the thematic maps of the defined selection criteria. For the MCDA, the values of each map were converted to the same scale, each criterion was weighted in function of its importance according to the objective and there were aggregated by the way of a lineal combination. The obtained result is a map that shows the level of protection priority of the supply wells. This map can offer information to the stakeholder in a relative short time and contribute to accelerate the actions aimed to protect the quality of the vital underground liquid.     

Process Mining Approach of a New Water Quality Index for Long-Term Assessment under Uncertainty Using Consensus-Based Fuzzy Decision Support System

One of the biggest challenges in water quality monitoring is how to optimize big Data gathered from a wide range of resources. This paper presented a new software-based pathway of process mining approach for extending a flexible WQI (Water Quality Index) that would deal with uncertainties derived from missing data occurrence in short- and long-term assessments. The methodology is based on integration of four multi-criteria group decision-making models coupled with fuzzy simulation including AHP (Analytical Hierarchy Process), fuzzy OWA (Ordered Weighting Average), TOPSIS (Technique for Order Preference by Similarity to Ideal Solution), and fuzzy TOPSIS that were used for data mining and group consensus evaluation.. Examining the methodology on groundwater resources being supplied for drinking in Shiraz, Iran showed high integrity, accuracy, and proximity-to-real interpretation of water quality. This was the first study where decision-making risks such as Decision Makers’ risk-prone or risk-aversion attitudes (optimistic degree), DMs’ power, and consensus degree of each water quality parameter have been considered in WQI research. The proposed index offered a flexible choice in defining the intended project duration, stakeholders’ judgments, types of water use and water resource, standards, as well as type and number of water quality parameters. Thus, beside sustaining the unity in structure, this methodology could be suggested as a potentially WQI for other regions. The presented methodology would help more efficient monitoring of water resources for drinking purpose with respect to water quality.

     

河流水质评价综述

随着我国对水环境、水资源保护和供水安全的日益重视,河流水质评价的重要地位也逐渐凸显出来。该文从河流水质评价的研究背景入手,对国内外研究进展、国内外研究现状的比较、评价方法的简介和优缺点、权重的选取及分析、指标的权重折减等几方面进行了系统地述评。在此基础上,指出水质评价今后应优化的方向,除了定性定量评价水质之外,在评价方法上,应将各评价方法的优缺点进行整合,相互借鉴改进,使评价结果更合理;此外,在选择评价方法时,应选择与我国河流以及研究对象相适应的方法,切忌一味学习国外方式方法。     

基于底栖动物指标的赤水河流域水质生物学评价

针对长江流域现有水质评价方法的不足,在赤水河流域对以底栖动物为指示生物的水质评价方法进行了测试。2010年秋季枯水期,研究小组对赤水河干流及部分支流共10个断面开展了数据采集工作,通过对数据的分析,发现底栖动物群落结构能够反应一定的水质污染状况;对部分生物指数进行了测试,结果表明,ASPT计分系统最适宜用于该区域的水质评价,并可以此为基础构建赤水河流域水质生物学评价体系。