scholarly journals Application of a New Improved Weighting Method, ESO Method Combined with Fuzzy Synthetic Method, in Water Quality Evaluation of Chagan Lake

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1424
Author(s):  
Wenbin Zhao ◽  
Changlai Xiao ◽  
Yunxu Chai ◽  
Xiaoya Feng ◽  
Xiujuan Liang ◽  
...  
Keyword(s):  
Water Quality ◽  
Evaluation Method ◽  
Fuzzy Synthetic Evaluation ◽  
Single Factor ◽  
Entropy Weight ◽  
Weighting Method ◽  
Local Weight ◽  
Chagan Lake ◽  
Factor Evaluation

The existing weighting methods mainly comprise subjective and objective weighting and have a certain degree of subjectivity, with certain requirements for the professional ability of the users and unstable results. Therefore, an improved weighting method based on the entropy weight, over-standard multiple, and single-factor evaluation methods, referred to as the ESO method, is proposed. The advantages and advancements of the ESO method are demonstrated in this study by combining it with the fuzzy synthetic evaluation method to evaluate the water quality of Chagan Lake wetland from 2007 to 2016. The main conclusions of this study are as follows: 1. The ESO method has more comprehensive consideration factors, lower requirements for the professional ability of users, and more stable weighting results than the traditional weighting method. Therefore, it is highly suitable for beginners and frontline staff who are not professionally qualified and cannot accurately conduct subjective weighting. Meanwhile, owing to the amendment rule and emphasis on the local weight of the sample in the ESO method, it is applicable to time-series samples. 2. The ESO method better allocates the amendment weights to indicators with a higher degree of pollution; thus, the final comprehensive evaluation results are relatively conservative. However, in contrast to the single-factor evaluation, the conservatism of ESO method is the result of the comprehensive effect of all samples; thus, the conservative result of the ESO method is more reasonable. 3. The water quality of Chagan Lake in 2009 and 2015 was class IV, which did not meet the standard, while that in remaining the eight years was class III, which met the requirements of the national 13th Five-Year Plan. The results of this study can provide a new approach to weighting calculation methods and a basis for the protection and treatment of the ecological environment of the Chagan Lake wetland.

scholarly journals Water Quality Evaluation of Wenyu River Based on Single Factor Evaluation and Comprehensive Pollution Index Method

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
Li Linjin ◽  
Men Baohui ◽  
Peng Rui
Keyword(s):  
Water Quality ◽  
Evaluation Method ◽  
Pollution Index ◽  
Ammonia Nitrogen ◽  
Single Factor ◽  
Water Quality Evaluation ◽  
Index Method ◽  
Class V ◽  
Factor Evaluation

Wenyu River is the “mother river” in Beijing. In recent years, the research on the water quality of the Wenyu River has increased gradually. In this paper, the monitoring data at Shahe Reservoir, Lu Tuan Gate, Xin Bao Gate, and Ma Fang sections for each month in 2019 were adopted. The single-factor evaluation method and the comprehensive pollution index method were selected to analyze the current situation of the water quality of Wenyu River in the Chang Ping section and its temporal and spatial variation trend. The single factor evaluation method showed that the dissolved oxygen exceeded the standard seriously in all other months of the year except that the situation was better in May, June, and July. The ammonia nitrogen content reached the highest level in January, followed by a month-by-month decreasing trend. After June, each section basically met the requirements of Class v water quality. The comprehensive pollution index method shows that the water quality of Shahe reservoir varies greatly throughout the year, and it is in grade v for 6 months. The evaluation results of both methods show that the water quality of all sections of Wenyu River in 2019 was mostly in category v.

scholarly journals Analysis of the water quality condition of the Zijiang River in summer and the applicability of evaluation methods

2021 ◽  
Vol 237 ◽  
pp. 01027
Author(s):  
Tao Zhang ◽  
Peng Xiang ◽  
Shijiang Zhu ◽  
Yang Liu ◽  
Wen Xu ◽  
...  
Keyword(s):  
Water Quality ◽  
River Water ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Nutrient Status ◽  
River Water Quality ◽  
Single Factor ◽  
Index Method ◽  
Factor Evaluation ◽  
Status Index

The single-factor evaluation method, improved Nemerow index method, fuzzy mathematical synthesis evaluation method and comprehensive nutrient status index method were used to evaluate the water quality of the Zijiang River in summer, and to analyze the applicability of the evaluation methods. The results show that: (1) The Zijiang River is heavily polluted with nitrogen and TN is the main pollutant in the summer. The overall nutrient status index is 34.33, which is not eutrophic. (2) The single-factor evaluation method is simple and suitable for rapid identification of excessive pollutants, but cannot reflect the water quality. the Nemerow index method takes into account the weight of each evaluation factor in the river water quality, and is suitable for making a comprehensive evaluation of the river water quality, but has a certain degree of subjectivity when classifying the water quality. The fuzzy comprehensive evaluation method is suitable for reflecting the influence of different evaluation factors on water quality by calculating the weight and membership degree of each evaluation factor, but the calculation is complicated.The Integrated Nutrient Status Index method is suitable for determining whether eutrophication is occurring in a water body and cannot determine the water quality category.

Fuzzy Synthetic Evaluation for Wetland Water Quality Appraisal in Poyang Lake, China

2012 ◽  
Vol 610-613 ◽  
pp. 941-947
Author(s):  
Liu Yao ◽  
Jiang Hui
Keyword(s):  
Water Quality ◽  
Evaluation Method ◽  
Poyang Lake ◽  
Water Quality Assessment ◽  
Quality Parameters ◽  
Fuzzy Synthetic Evaluation ◽  
Normal Water ◽  
Mathematics Method ◽  
Synthetic Evaluation

Traditional evaluation methods of the water quality parameters exist more deficiency. Entropy right process and fuzzy mathematics method are combined to establish an improved fuzzy synthetic evaluation method. Total phosphorus (TP)、total nitrogen (TN) and index of permanganate (CODMn) are selected as observed indicators in this paper. According to Mensal measured data of water quality at 5 points from 2008 and 2009 years，based on fuzzy synthetic evaluation method for water quality assessment analysed in Poyang lake. The assessment results showed that Water quality of measure stations in different water seasons changed to take turns: normal water season > flood season > dry season. the pollution`s degree at town`s stations was smaller than counties` stations, at which sample were affected greater by industry and agriculture, and we must pay attention to let contamination in counties.

Fuzzy Synthetic Evaluation of Power Quality Based on Combination Weighting Method

2011 ◽  
Vol 201-203 ◽  
pp. 2470-2475
Author(s):  
Yuan Sheng Huang ◽  
Li Ming Yuan
Keyword(s):  
Power Quality ◽  
Fuzzy Theory ◽  
Evaluation Model ◽  
Weight Coefficient ◽  
National Standard ◽  
Fuzzy Synthetic Evaluation ◽  
Entropy Weight ◽  
Weighting Method ◽  
Evaluation Indexes ◽  
Synthetic Evaluation

According to the national standard, this paper presents the evaluation indexes of power quality and the classifications of each index. The method integrates advantages of both G1 and entropy weight coefficient method. Also, it establishes an fuzzy synthetic evaluation for power quality evaluation by fuzzy theory. 5 observation points on the power quality was graded. The test shows that the combination weighting evaluation model based on fuzzy synthetic evaluation can evaluate the power quality comprehensively and effectively.

scholarly journals Safety Evaluation Method of Antifloating Anchor System Based on Comprehensive Weighting Method and Gray-Fuzzy Theory

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Li Jingwen ◽  
Qiao Jiangang ◽  
Dou Yuanming ◽  
Fu Xu ◽  
Liu Xiaoli
Keyword(s):  
Risk Factors ◽  
Evaluation Method ◽  
Fuzzy Theory ◽  
Underground Structure ◽  
Safety Evaluation ◽  
Evaluation Index System ◽  
Grey Theory ◽  
Entropy Weight ◽  
Weighting Method ◽  
Anchor System

The risk factors in the safety evaluation of antifloating anchor system of underground structure have the characteristics of complexity, grey, and fuzziness. Based on the Delphi method, analytic hierarchy process (AHP), and entropy weight method, this paper establishes a three-level evaluation index system based on four main risk factors and calculates the subjective and objective comprehensive weights of the index according to the comprehensive weighting method. It not only takes into account the valuable experience of the expert group but also reflects the objective impact of the subjective score on the system. On the basis of the above research, the grey-fuzzy safety evaluation method of antifloating anchor system is established by using the grey theory and the relevant theory of fuzzy mathematics. The reliability of the method is verified by an example, which has certain theoretical significance and application value.

An Evaluation Method for Water Quality Based on the Improved SOM Neural Network

2013 ◽  
Vol 373-375 ◽  
pp. 1220-1223
Author(s):  
Hong Yi Li ◽  
Ze Xi Li ◽  
Chao Jie Wang ◽  
Yuan Feng Han ◽  
Di Zhao ◽  
...  
Keyword(s):  
Neural Network ◽  
Water Quality ◽  
Drinking Water ◽  
Evaluation Method ◽  
Epidemic Spreading ◽  
Main Medium ◽  
Som Neural Network ◽  
Highly Correlated ◽  
Chemical Material

In recent years, people have been paying increasingly attention on monitoring the quality of drinking water, which becomes rather necessary after natural disasters such as the Beijing 7.21 rainstorm, considering that the drinking water is one of the main medium for epidemic spreading. Most of the existing evaluation methods have their bases on concise mathematical models, which often fail to describe the complex essential nonlinear relations between the water quality and the chemical material in it. In this paper, we propose the evaluation method by using the SOM neural network, a unsupervised method that is able to classify, and therefore evaluate, given water samples. In order to promote the convergence rate and the precision of SOM neural network when dealing with high dimensional and highly correlated samples, we add a PCA preprocessing procedure. Experiment results demonstrate that the improved SOM neural network could evaluate the water quality with high precision.

Fuzzy Comprehension Evaluation of Sunny Sports Activity Using Entropy Weight

2014 ◽  
Vol 539 ◽  
pp. 908-910
Author(s):  
Feng Yu ◽  
Yi Wu ◽  
Xian Ming Shao ◽  
Jian Chun Guo
Keyword(s):  
Evaluation Method ◽  
Sport Activity ◽  
Evaluation Process ◽  
Entropy Method ◽  
Evaluation Index System ◽  
Evaluation Index ◽  
Fuzzy Synthetic Evaluation ◽  
Entropy Weight ◽  
Sports Activity ◽  
Synthetic Evaluation

By proceeding from practice of the sunny sport activity in higher education institutes, the principles of selecting evaluation index of the campaign have been put forward. Base on the No.17 document of the central committee and related principles, the paper establishes the evaluation index system of the activity. Considering the difficulty of fuzzy synthetic evaluation method in calculation of the multiple factors and ignorance of the relationship among evaluating objects, a new weight evaluation process using entropy method is introduced. This improved method for determination of weight of the evaluating indicators is applied in synthetic evaluation of the sunny sport activity. Compared with the original evaluation method, the method predigests the fuzzy synthetic evaluation process greatly and the evaluation results are more reasonable.

The Evaluation of the Water Quality of Shenwo Reservoir Based on Fuzzy Comprehensive Evaluation Method

2012 ◽  
Vol 594-597 ◽  
pp. 2061-2065
Author(s):  
Dan Liu ◽  
Na Hu ◽  
Han Yong Liu ◽  
An Gong
Keyword(s):  
Water Quality ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Fuzzy Comprehensive Evaluation ◽  
Quality Data ◽  
River Section ◽  
Water Quality Data ◽  
Fuzzy Comprehensive Evaluation Method ◽  
Comprehensive Evaluation Method

The water of Shenwo reservoir has been seriously polluted. In order to avoid the inaccurate evaluation results of a single index, the variable fuzzy comprehensive evaluation method has been adopted to comprehensively evaluate the water quality of Shenwo reservoir based on the water quality data of Lan River section of Shenwo reservoir in 2011. The evaluation results have shown that the water quality of Shenwo reservoir belongs to grade Ⅳ, which tends to be grade Ⅲ. The evaluation results based on this approach will be more stable and reliable.

scholarly journals Water quality assessment of an urban river receiving tail water using the single-factor index and principal component analysis

2018 ◽  
Vol 19 (2) ◽  
pp. 603-609 ◽  
Author(s):  
Weiwei Lu ◽  
Juan Wu ◽  
Zhu Li ◽  
Naxin Cui ◽  
Shuiping Cheng
Keyword(s):  
Water Quality ◽  
Principal Component Analysis ◽  
Principal Component ◽  
Component Analysis ◽  
Urban River ◽  
Single Factor ◽  
Sampling Points ◽  
Factor Index ◽  
Tail Water

Abstract Tail water from wastewater treatment plants (WWTP) serves as a major supplementary water source for scenic water bodies, whose water quality is one of the major focuses of public and scientific inquiries. This study investigated the temporal and spatial variations in water quality of Tangxihe River, a eutrophic urban river receiving tail water from a nearby WWTP in Hefei City, using the single-factor index (SFI) and principal component analysis (PCA). The results of SFI indicated that the most important parameters responsible for low water quality were total nitrogen (TN) and ammonia (NH4+-N). PCA showed that tail water from the WWTP greatly reduced water quality, as demonstrated by the significantly increased SFIs and integrated principal component values (F values) of the sampling points around the drain outlet of the WWTP (T3, T4 and T5). The sampling points located at the upstream of the river (T1) and up the water-gate of Chaohu Lake (T6) had negative F values, indicating relatively higher water quality. In addition, the season had a significant effect on the water quality of the river. Moreover, we discuss measures to improve the water quality of urban rivers in order to maintain their ecological functions.

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