Cost Analysis of Water Quality Assessment Using Multi-Criteria Decision-Making Approach

In modern competitive markets, cost and quality parameters are the two main factors. So, it is essential to study their relationship, especially in leading industries such as urban public service companies. Consequently, manufacturers always try to reduce production costs and improve product quality and services to consumer expectations. Also, the concerns of the new century in the field of fresh water and the reduction of its resources related to global warming have increased the costs of quality and supply of freshwater. Therefore, in this research, in order to estimate the quality costs in the field of water resources and wastewater management and identify the option that creates the most cost, in the first step, the “Prevention, Assessment, and Failure (PAF)” model was used to select cost-imposing options in organizational quality analysis. After determining the main options, appropriate criteria and sub-criteria were selected under the main study area (water and wastewater resources management). In the next step, a “Multiple-Criteria Decision-Making (MCDM) “ method based on the “Fuzzy Analytical Hierarchy Process (FAHP)” and “Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS)” method was used to identify the option that creates the most cost. The results show that The highest cost of quality in the water and wastewater industry and its management are related to “Assessment Costs” and account for 36.55% of total costs. Also, The lowest cost of quality in the water and wastewater industry is related to “Preventive Costs” and accounts for only 12.18% of the total cost. In addition, the expert’s opinion shows that the effect of increasing credit with 34.01% has the greatest weight, and this criterion is the most essential in water and wastewater resources management.

     

水库对河流生态系统服务功能影响的生态足迹评价研究

基于层次分析法的基本原理,构建了水库对河流生态系统服务功能影响的生态足迹评价指标体系,运用 AHP 确定各个评价指标权重。以大伙房水库为例,进行了水库对河流生态系统服务功能影响的综合评价,最后应用生态足迹评价模型定量地核算了大伙房水库 4 项生态供给足迹和 3 项生态需求足迹。     

基于多元统计分析的黄河山东段水质评价研究

以黄河山东段为例,在利用方差分析(ANOVA)对高村、孙口、艾山、泺口和利津5个断面2015—2017年各水质监测指标月度监测值进行时空尺度显著差异性分析的基础上,采用层次聚类分析法将180个水质样本分成12组,并以各组样本均值为基础,运用综合水质标识指数法对河流综合水质进行评价。结果表明:黄河山东段综合水质状况良好,综合水质类别为Ⅰ类或Ⅱ类;时间上,2015—2017年综合水质状况逐渐好转;空间上,利津断面综合水质状况最差,其余断面从上游到下游综合水质状况呈好转趋势。     

基于可变模糊识别的黄河下游河道健康评价

为合理评价黄河下游河道健康状况,将可变模糊识别方法引入河道健康评价中,并以二元比较法确定指标权重,对黄河下游河道1986—2005年各河段的健康状况进行评价。结果表明:从河段来看,花园口—高村河段的河道健康状况优于其他河段;从时段来看,1986—1999年黄河下游河道健康状况整体呈现下滑趋势,而2000—2005年则处于逐步恢复时期。总的来说,黄河下游河道各河段从2003年开始基本恢复到亚健康水平,整体趋于好转之中。将评价结果与实际状况及经典模糊数学综合评价结果进行对比,表明可变模糊识别在河道健康评价中能准确反映河道健康状况。     

Assessment of Upstream Human Intervention Coupled with Climate Change Impact for a Transboundary River Flow Regime: Nile River Basin

Water Resources Management - The aim of this article is to determine how human interventions in upstream countries coupled with drought events are affecting the flow regime of downstream countries...     

Assessment of River Water Quality Based on Theory of Variable Fuzzy Sets and Fuzzy Binary Comparison Method

There has been an increasing need for the proper evaluation of river water quality in order to safeguard public health and to protect the valuable fresh water resources. In order to overcome the own limitations of the traditional evaluations which can only use a point value instead of an interval for grading standards, on the basis of the fuzzy binary comparison method (FBCM) and the theory of variable fuzzy sets (VFS), an integrated variable fuzzy evaluation model (VFEM) is proposed for the assessment of river water quality in this paper. This model possesses the preciseness of the algorithm and operability in practice, can well solve the grading standards which are interval form. In order to explore and compare the present method with other traditional methods, two cases studies in the Three Gorges and Tseng-Wen River are made. The results show that the proposed VFEM method can convey water cleanliness to certain degree by using the eigenvector of level H, which is much stricter in the superior level, and that it can improve the veracity for the assessment of water quality.     

基于模糊综合指数法的渭河宝鸡段水质评价

为了解渭河宝鸡段的水环境污染状况,以2009年渭河6个断面的7个主要污染指标为研究对象,运用模糊综合指数法进行了水质评价.结果表明:渭河宝鸡段主要污染物为有机物和氮磷,水质类别主要为Ⅱ类和Ⅲ类,河流从上游到下游污染逐渐加重,蔡家坡桥断面的污染最为严重.     

基于改进TOPSIS与哈斯图耦合的水质评价模型

将KL散度与TOPSIS结合优化了传统TOPSIS水质评价模型,为了使评价结果直观、可视化,将优化后的TOPSIS模型与哈斯图技术耦合,建立了基于KL散度的TOPSIS与哈斯图耦合的水质评价模型.北京某厂区周边村落地下水水样的实例分析表明,建立的水质评价模型的评价结果与实际情况相符,证明了该评价模型的有效性及合理性;最...     

引桥式高桩码头对弯道河道水流影响的数值模拟研究

为研究引桥式高桩码头对弯道河道水流的影响,建立了平面二维数学模型,基于弯道水流的运动机理,首先对数学模型进行了典型试验验证,然后模拟西江一多引桥式高桩码头对西江某弯道段水流的影响,指出了此类码头使弯道河道水流发生的独特变化,并指出数值计算中存在的不足及今后研究的努力方向。     

A Novel Approach Using Hybrid Fuzzy Vertex Method-MATLAB Framework Based on GMS Model for Quantifying Predictive Uncertainty Associated with Groundwater Flow and Transport Models

Identification of the uncertain parameters, which affecting on the qualitative behavior of the aquifer, and determining their effect on the uncertainty of the simulated nitrate concentration (NC) is one of the major challenges in the qualitative monitoring of aquifers. In this study, in order to determine the quantitative amount of uncertainty related to the simulated nitrate, an approach based on a hybrid of Groundwater Modeling System (GMS) model and Fuzzy Vertex Method (FVM) method was developed using the developed code for the relationship between aquifer simulation model and MATLAB environment. In this model, hydraulic conductivity, NC in aquifer recharge sources, longitudinal dispersivity coefficient, and specific storage parameters were considered as uncertain parameters in the distributed simulation model of the Ardabil aquifer. In the proposed approach, first the quantitative and qualitative (QQ) model of the aquifer was prepared using the GMS model and calibrated. Then, using the FVM method and developed MATALB code, the uncertain values appropriate for each of the aquifer active cells were determined. The results obtained from the monthly NC uncertainty show that with increasing the level of uncertainty, the uncertainty of the simulated NC increases significantly. For example, can be mentioned a 14-fold increase in the number of cells with variation of NC less than 10% in the September month. Also, the lowest and highest variation in the deterministic amount of NC is related to the months of Nov. and Sep. with concentration variations equal to [??8.5, 8.35] and [??23.43, 19.8] mg/L, respectively. The findings of this study show that the application of at least 10% uncertainty in the deterministic values of the simulated NC is necessary to provide a suitable view for quality monitoring of aquifer. A quantitative amount of monthly uncertainty in areas with nitrate concentrations greater than 50 mg/L indicates that the amount of uncertainty in these areas is higher than areas with nitrate concentrations less than 50 mg/L. This leads to errors in the monitoring of contaminated areas to eliminate contamination and quality restoration. Also, centralization of uncertainty is mainly concentrated in the northeastern, western and southwestern parts of Ardabil plain and the severity of uncertainty in the mentioned areas increases with the intensification of uncertainty and continues to the central areas. Finally, it must be said that hydraulic conductivity and NC in aquifer recharge sources, respectively, play the most important role in creating uncertainty and is necessary to be considered in the NC simulation models.

     

基于模糊集对分析的黄河三角洲景观评价研究

应用景观生态学法计算了黄河三角洲地区的景观指数,并对其1996—2004年的变化进行分析,阐述了区域中斑块变化的成因和趋势。从集对分析的观点提出了模糊集对分析评价模型,对黄河三角洲湿地、整体及各个行政区进行景观评价。结果表明:黄河三角洲整体景观相对贴近度1996年、2000年及2004年先从0.500 2降低到0.498 9,然后升至0.500 1;湿地景观相对贴近度1996年、2000年及2004年分别为0.496 1、0.499 9和0.504 5,表现为持续变好,说明湿地的景观格局和景观的生态功能都在变好。     

Analysis of Irrigation Needs Using an Approach Based on a Bivariate Copula Methodology

The problem of drought probability has been investigated by several authors, who have usually analysed droughts using various drought indices such as the Standard Precipitation Index. Various aspects of time series of such indices (intensity, severity and duration) were investigated by several authors using a copula method. Because such analysis is based on only one basic climatic variable, this paper addresses a different approach, i.e., joint analysis of the severity and duration of the most demanding potential annual irrigation periods by a bivariate copula method. Characteristics of these periods are derived from both temperature and precipitation. Maximum annual duration of the potential irrigation period and corresponding rainfall deficit were inferred from these basic variables as inputs to two-dimensional probability analysis by the copula method, because this offers more direct answers to questions of irrigation needs. Results indicate the suitability of the proposed method for analysis of irrigation needs, with greater benefits than the typical one-dimensional analysis of individual climatic variables. A case study for testing the method was done for southwestern Slovakia, for which the frequency of irrigation needs was estimated. Example results indicate that every second year, a one-month period can be expected in which temperatures are >25^°C and there is a moisture deficit of ～30 mm. Even more significant periods of drought can be expected, for example, with a 5 or 10-year return period. These phenomena significantly damage agriculture yields, so requirements for irrigation structures in the study area are indicated by the proposed method.     

多元因子分析模型在河流健康评价中的应用——以苏子河水质特性研究为例

为顺应河流生态可持续发展,提出健康河流、生命河流等概念,维持河流生态系统健康已经成为流域综合管理的必然趋势。综合运用水文学、水力学、泥沙地貌学和水生生态学的基本理论和方法研究河流生态健康的表征因子,确定各因子的阈值,建立流域性水体水质可续发展评价体系。以河流可持续发展为基础,引用代表性的相关指标进行筛选,对流域水质指标进行数值化分析,以苏子河流域水质特性为研究对象,选取出评估河流健康状况的环境因子,客观反映出中小河流域健康状况,为河流的可持续管理和生态环境建设提供参考。     

基于TFN-SPA的河流水质评价模型

运用三角模糊数与集对分析耦合的方法构建河流水质评价模型,结合评价指标的主观权重和客观权重,利用最小相对熵原理确定评价指标的组合权重,同时兼顾专家的主观经验和数据本身携带的客观属性,以区间形式给出在不同截集水平下的评价样本等级区间,评价结果较为合理、可靠,更符合实际情况。     

A Community‐Level,Mesoscale Analysis of Fish Assemblage Structure in Shoreline Habitats of a Large River Using Multivariate Regression Trees

The mesoscale (10⁰–10² m) of river habitats has been identified as the scale that simultaneously offers insights into ecological structure and falls within the practical bounds of river management. Mesoscale habitat (mesohabitat) classifications for relatively large rivers, however, are underdeveloped compared with those produced for smaller streams. Approaches to habitat modelling have traditionally focused on individual species or proceeded on a species‐by‐species basis. This is particularly problematic in larger rivers where the effects of biological interactions are more complex and intense. Community‐level approaches can rapidly model many species simultaneously, thereby integrating the effects of biological interactions while providing information on the relative importance of environmental variables in structuring the community. One such community‐level approach, multivariate regression trees, was applied in order to determine the relative influences of abiotic factors on fish assemblages within shoreline mesohabitats of San Pedro River, Chile, and to define reference communities prior to the planned construction of a hydroelectric power plant. Flow depth, bank materials and the availability of riparian and instream cover, including woody debris, were the main variables driving differences between the assemblages. Species strongly indicative of distinctive mesohabitat types included the endemic Galaxias platei. Among other outcomes, the results provide information on the impact of non‐native salmonids on river‐dwelling Galaxias platei, suggesting a degree of habitat segregation between these taxa based on flow depth. The results support the use of the mesohabitat concept in large, relatively pristine river systems, and they represent a basis for assessing the impact of any future hydroelectric power plant construction and operation. By combing community classifications with simple sets of environmental rules, the multivariate regression trees produced can be used to predict the community structure of any mesohabitat along the reach. Copyright © 2015 John Wiley & Sons, Ltd.     

Uncertainty Analysis of Climate Change Impact on River Flow Extremes Based on a Large Multi-Model Ensemble

Water managers are faced with a changing climate in the decision-making process while adaptation and mitigation strategies need to be developed. The climate change impact towards the end of the century, however, is highly uncertain and coping with this is a great challenge for decision makers. Over the recent years, combined efforts of hydrologists and climatologists have led to many climate change impact studies on water resources. However, most studies only use a limited ensemble size and/or focus on only one contributing source and hence possibly underestimate the total uncertainty.

For two Belgian catchments, we simulated daily flow with five different lumped conceptual hydrological models and ten different parameter sets each, forced by the output of 24 global climate models covering four different emission scenarios, combined with 9 different downscaling methods over reference (1961–1990) and future (2071–2100) periods, resulting in a large multi-model ensemble with 41,850 members. Results show that both low and peak flows would become more extreme in the future, and these changes are stronger with increased radiative forcing. The most important uncertainty sources in low-flow projections are the global climate models (explaining 27–36% of the total variance) and the hydrological model structure (34–42%). For peak flow projections, these are global climate models (32–39%) and statistical downscaling methods (21–26%). Also, interaction effects account for a significant part of the uncertainty (24–38%). The results of this study illustrate that one might end up with biased results and overly confident conclusions when only focusing on some of the uncertainty sources in multi-model ensembles.

     

环境影响评价中多排口河段水质预测研究

环境影响评价导则所推荐的水质预测模型在实际工作中有时显得有些简单．实际情况是要预测拥有复杂结构的多排口的河道污染带分布。因此,通过建立平面二维水质模型数学模型．并以某具体城市河流为例．计算得出了河段污染带分布情况。计算结果有较好的精度,能为环境影响评价工作提供一定的科学依据。     

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.     

基于决策者偏好DE算法的模糊聚类迭代洪灾评估方法

权重的选择是各种洪水灾害评估模型中的一个关键而又难以确定的问题。根据现有主观赋权法和客观赋权法的特点,在差分进化(DE)算法的基础上,引入决策者偏好过滤掉不满足条件的个体,通过优化考虑决策者偏好的模糊聚类迭代模型获得洪灾样本的指标权重向量,结合洪灾损失样本特征值矩阵得出各样本的灾情综合评价值;然后依据灾情综合评价值与聚类矩阵求出各等级的特征值,并依此自动识别聚类矩阵中各行的类别属性;最后依据识别出的类别属性和各样本的灾情综合评价值,对洪灾样本在不同的决策者偏好下进行等级划分和灾情排序。以2013年四川省和1996年新疆的洪灾样本为例进行仿真试验,实现了不同决策者偏好下的洪灾等级评估,并为水利部门选择偏好类型提供了参考性建议。     

乌江下游水电梯级开发对陆生生态敏感区影响分析评价

为研究河流水电开发对其涉及陆生生态敏感区的实际影响,笔者选择乌江下游水电梯级开发作为研究对象开展环境影响后评价;采用图形叠置法,判断乌江下游流域陆生生态敏感区与水电梯级开发区位关系;选取麻阳河自然保护区和沿河乌江山峡风景名胜区作为典型代表,分析其受梯级水电站开发建设影响的程度,并以此结论代表该河段水电梯级开发对陆生生态敏感区的实际影响情况;最后,对该河段尚未建设的白马航电枢纽开发提出了工作建议。研究表明：乌江下游水电梯级开发对其涉及陆生生态敏感区的影响不大;且形成的宽阔水面,既可丰富生态敏感区景观内涵,也可改善局地小气候,对促进生态系统正向演替有一定的积极作用。此研究结论为决策管理部门今后判断类似工程建设对陆生生态敏感区的影响程度提供参考。