[Objective] This study was to provide references for the evaluation of water quality in aquaculture ponds by evaluating the pond water quality using fuzzy comprehensive evaluation method based on entropy weight. [Meth...[Objective] This study was to provide references for the evaluation of water quality in aquaculture ponds by evaluating the pond water quality using fuzzy comprehensive evaluation method based on entropy weight. [Method] The fuzzy compre- hensive evaluation method based on entropy weight was used to evaluate the water quality in the ponds with Ukraine scale carp （Cyprinus carpio） as the main cultivated fish. The average size of the fish was 71.4 g/ind, and totally three groups of pond were set with the population density of 6 000, 9 000, 12 000 ind/hm2. [Result] According to the GB3838-2002 Environmental Quality Standards for Surface Water of China, the water quality of 6 000 ind/hm2 group was Grade I, and the water quality of 9 000 and 12 000 ind/hm2 were Grade V. [Conclusion] With the increasing of feeding density, the pond water quality would worsen, however, there is no difference on water quality between 9 000 and 12 000 ind/hm2 groups.展开更多
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 w...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 was introduced. This improved method for determination of weight of the evaluating indicators was applied in water quality assessment of the Three Gorges reservoir area. The results showed that this method was favorable for fuzzy synthetic evaluation when there were more than one evaluating objects. One calculation was enough for calculating every monitoring point. Compared with the original evaluation method, the method predigested the fuzzy synthetic evaluation process greatly and the evaluation results are more reasonable.展开更多
The complex relationships between indicators and water conditions cause fuzzy and gray uncertainties in evaluation of water quality. Compared to conventional single-factor evaluation methods, the combination evaluatio...The complex relationships between indicators and water conditions cause fuzzy and gray uncertainties in evaluation of water quality. Compared to conventional single-factor evaluation methods, the combination evaluation method can consider these two uncertainties to produce more objective and reasonable evaluation results. In this paper, we propose a combination evaluation method with two main parts:(1) the use of fuzzy comprehensive evaluation and gray correlation analysis as submodels with which to consider the fuzzy and gray uncertainties and(2) the establishment of a combination model based on minimum bias squares. In addition, using this method, we evaluate the water quality of a ditch in a typical rice–wheat system of Yixing city in the Taihu Lake Basin during three rainfall events. The results show that the ditch water quality is not good and we found the chemical oxygen demand to be the key indicator that affects water quality most significantly. The proposed combination evaluation method is more accurate and practical than single-factor evaluation methods in that it considers the uncertainties of fuzziness and grayness.展开更多
This study focused on analysis of the chemical characteristics of mine waters. The aim of this study is to correlate the degree of different ionic components in mine water and the influence of their convergence using ...This study focused on analysis of the chemical characteristics of mine waters. The aim of this study is to correlate the degree of different ionic components in mine water and the influence of their convergence using a combination of the three-scale AHP and fuzzy evaluation methods for the comprehensive evaluation of water quality. Ion chromatography (ICS 1100) has been used to analyze the content of the water sample while portable pH/EC/TDS/Tem- perature meters (SX 811 and SX 813) were used to test physical-chemical parameters. The results of this study show that chemistry of in No.11 gushing mine is dominated by HCO3-Na and HCO3-Ca, and had a pH between 7.1 and 8.00, belonging to neutral or slightly alkaline water. In addition, water were found to have the hardness between 18 mg/L and 542.5 mg/L. Results also show that the TDS of the roof sandstone and goaves water are higher than Cambrian limestone water, while the turbidity of the mixed water is 20 NTU in the sump, again higher than in other samples such as Cambrian limestone water. Total dissolved solids and the total hardness of Cambrian limestone groundwater mainly depend on the content of K+ + Na+, Ca2+, B={b1,b2,…,bj} and SO2-4. Thus, chemical composition changes remarkably after mine water mixing. Results showed that the coal roof sandstone water is class V while that in the sump is class III, and the Cambrian limestone groundwater is class I. In gushing, the quality of water can vary greatly;thus, water from the coal face roof sandstone and the Cambrian limestone should be stored and treated separately before being utilized.展开更多
In order to study the water quality of the Shichuan River basin in Fuping,Shaanxi Province,based on improved Nemerow index method,comprehensive pollution index method and principal component analysis method,eight wate...In order to study the water quality of the Shichuan River basin in Fuping,Shaanxi Province,based on improved Nemerow index method,comprehensive pollution index method and principal component analysis method,eight water quality indexes such as pH,dissolved oxygen(DO),total dissolved solids(TDS),COD,total hardness,total phosphorus,total nitrogen and Zn in three monitoring sections of Fuping section of the Shichuan River in Shaanxi Province were detected and analyzed.The results show that the water quality of the surface water in the Shichuan River basin is gradeⅢorⅣwater,that is,the water is slightly polluted and moderately polluted.It is necessary to monitor the water quality after regulation and clarify the main factors causing the water pollution.展开更多
The water quality in the Danjiangkou Reservoir has attracted considerable attention from the Chinese public and government since the announcement of the Middle Route of the South to North Water Diversion Project （SN...The water quality in the Danjiangkou Reservoir has attracted considerable attention from the Chinese public and government since the announcement of the Middle Route of the South to North Water Diversion Project （SNWDP）, which commenced transferring water in 2014. Integrated research on the evaluation, prediction, and protection of water quality in the Danjiangkou Reservoir was carried out in this study in order to improve environmental management. Based on 120 water samples, wherein 17 water quality indices were measured at 20 monitoring sites, a single factor evaluation method was used to evaluate the current status of water quality. The results show that the main indices influencing the water quality in the Danjiangkou Reservoir are total phosphorus （TP）, permanganate index （CODM,）, dissolved oxygen （DO）, and five-day biochemical oxygen demand （BODs）, and the concentrations of TP, BODs, ammonia nitrogen （NH3--N）, CODM,, DO, and anionic surfactant （Surfa） do not reach the specified standard levels in the tributaries. Seasonal Mann--Kendall tests indicated that the CODMn concentration shows a highly significant increasing trend, and the TP concentration shows a significant increasing trend in the Danjiangkou Reservoir. The distribution of the main water quality indices in the Danjiangkou Reservoir was predicted using a two-dimensional water quality numerical model, and showed that the sphere of influence from the tributaries can spread across half of the Han Reservoir if the pollutants are not controlled. Cluster analysis （CA） results suggest that the Shending River is heavily polluted, that the Jianghe, Sihe, and Jianhe rivers are moderately polluted, and that they should be the focus of environmental remediation.展开更多
[Objective] The aim was to study the construction and application of combined evaluation model of regional water quality plan. [Meth- od] By dint of layer analysis, subjective and objective model of entropy evaluation...[Objective] The aim was to study the construction and application of combined evaluation model of regional water quality plan. [Meth- od] By dint of layer analysis, subjective and objective model of entropy evaluation, the water quality plan in Jinghe was evaluated. Combined evalu- ation model based on information entropy were constructed, and considering the single model evaluation result, the optimal water quality plan was selected. [ Result] The combination weight result suggested that COD amount was the most essential indicator in water quality plan and embodied the importance of water environment protection, which met basic objective of environment protection and social, economic effects. Combined evalu- ation indicated that in the sixteen plans, plan 16 was of highest comprehensive evaluation value, and can be considered as optimum water quality plan. [ Conclusion] Combined evaluation model can effectively list the advantages of each evaluation model and improve the dependability of water quality plan, and provided a new research idea for the optimal evaluation of water pollution control plan.展开更多
Fuzzy comprehensive evaluation method was used to develop a standard model to analyze and evaluate nearness degree of water environment quality at breeding area of Shuidong Bay in China.Results showed that certain env...Fuzzy comprehensive evaluation method was used to develop a standard model to analyze and evaluate nearness degree of water environment quality at breeding area of Shuidong Bay in China.Results showed that certain environment contamination factors in some areas seriously exceeded the standard value and led to the whole water quality at the third class level.The measurements should be taken to promote the sustainable development of breeding area in Shuidong Bay.展开更多
For natural water, method of water quality evaluation based on improved fuzzy matter-element evaluation method is presented. Two important parts are improved, the weights determining and fuzzy membership functions. Th...For natural water, method of water quality evaluation based on improved fuzzy matter-element evaluation method is presented. Two important parts are improved, the weights determining and fuzzy membership functions. The coefficient of variation of each indicator is used to determine the weight instead of traditional calculating superscales method. On the other hand, fuzzy matter-elements are constructed, and normal membership degrees are used instead of traditional trapezoidal ones. The composite fuzzy matter-elements with associated coefficient are constructed through associated transformation. The levels of natural water quality are determined according to the principle of maximum correlation. The improved fuzzy matter-element evaluation method is applied to evaluate water quality of the Luokou mainstream estuary at the first ten weeks in 2011 with the coefficient of variatiola method determining the weights. Water quality of Luokou mainstream estuary is dropping from level I to level II. The results of the improved evaluation method are basically the same as the official water quality. The variation coefficient method can reduce the workload, and overcome the adverse effects from abnormal values, compared with the traditional calculating superscales method. The results of improved fuzzy matter- element evaluation method are more credible than the ones of the traditional evaluation method. The improved evaluation method can use information of monitoring data more scientifically and comprehensively, and broaden a new evaluation method for water quality assessment.展开更多
The Danjiangkou Reservoir is the water source for the middle route of the South-to-North Water Diversion Project in China. Thus, its water quality status is of great concern. Five water quality indicators （dissolved ...The Danjiangkou Reservoir is the water source for the middle route of the South-to-North Water Diversion Project in China. Thus, its water quality status is of great concern. Five water quality indicators （dissolved oxygen, permanganate index, ammonia nitrogen, total nitrogen, and total phosphorus）, were measured at three monitoring sites （the Danjiangkou Reservoir dam, the Hejiawan and the Jiangbei bridge）, to investigate changing trends, and spatiotemporal characteristics of water quality in the Danjiangkou Reservoir area from January 2006 to May 2012. We then applied a Bayesian statistical method to evaluate the water quality comprehensively. The normal distribution sampling method was used to calculate likelihood, and the entropy weight method was used to determine indicator weights for variables of interest in to the study. The results indicated that concentrations of all five indicators increased during the last six years. In addition, the water quality in the reservoir was worse during the wet season （from May to October）, than during the dry season （from November to April of the next year）. Overall, the probability of the water＇s belonging to quality category of type lI, according to environmental quality standards for surface water in China, was 27.7%-33.7%, larger than that of its belonging to the other four water quality types. The increasing concentrations of nutrients could result in eutrophication of the Danjiangkou Reser- voir. This method reduced the subjectivity that is commonly associated with determining indicator weights and artificial classifications, achieving more reliable results. These results indicate that it is important for the interbasin water diversion project to implement integrated water quality management in the Danjiangkou Reservoir area.展开更多
基金Supported by the Major Project of Application Foundation and Advanced Technology of Tianjin (the Natural Science Foundation of Tianjin) (09JCZDJC19200),China~~
文摘[Objective] This study was to provide references for the evaluation of water quality in aquaculture ponds by evaluating the pond water quality using fuzzy comprehensive evaluation method based on entropy weight. [Method] The fuzzy compre- hensive evaluation method based on entropy weight was used to evaluate the water quality in the ponds with Ukraine scale carp （Cyprinus carpio） as the main cultivated fish. The average size of the fish was 71.4 g/ind, and totally three groups of pond were set with the population density of 6 000, 9 000, 12 000 ind/hm2. [Result] According to the GB3838-2002 Environmental Quality Standards for Surface Water of China, the water quality of 6 000 ind/hm2 group was Grade I, and the water quality of 9 000 and 12 000 ind/hm2 were Grade V. [Conclusion] With the increasing of feeding density, the pond water quality would worsen, however, there is no difference on water quality between 9 000 and 12 000 ind/hm2 groups.
基金The National Natural Science Foundation of China (No. 50378008)
文摘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 was introduced. This improved method for determination of weight of the evaluating indicators was applied in water quality assessment of the Three Gorges reservoir area. The results showed that this method was favorable for fuzzy synthetic evaluation when there were more than one evaluating objects. One calculation was enough for calculating every monitoring point. Compared with the original evaluation method, the method predigested the fuzzy synthetic evaluation process greatly and the evaluation results are more reasonable.
基金supported by the National Key Research and Development Program of China (No. 2017YFC0405006)the Innovative Research Groups of the National Natural Science Foundation of China (No. 51621092)the Natural Science Foundation of Tianjin (No. 16JCYBJC23100)
文摘The complex relationships between indicators and water conditions cause fuzzy and gray uncertainties in evaluation of water quality. Compared to conventional single-factor evaluation methods, the combination evaluation method can consider these two uncertainties to produce more objective and reasonable evaluation results. In this paper, we propose a combination evaluation method with two main parts:(1) the use of fuzzy comprehensive evaluation and gray correlation analysis as submodels with which to consider the fuzzy and gray uncertainties and(2) the establishment of a combination model based on minimum bias squares. In addition, using this method, we evaluate the water quality of a ditch in a typical rice–wheat system of Yixing city in the Taihu Lake Basin during three rainfall events. The results show that the ditch water quality is not good and we found the chemical oxygen demand to be the key indicator that affects water quality most significantly. The proposed combination evaluation method is more accurate and practical than single-factor evaluation methods in that it considers the uncertainties of fuzziness and grayness.
文摘This study focused on analysis of the chemical characteristics of mine waters. The aim of this study is to correlate the degree of different ionic components in mine water and the influence of their convergence using a combination of the three-scale AHP and fuzzy evaluation methods for the comprehensive evaluation of water quality. Ion chromatography (ICS 1100) has been used to analyze the content of the water sample while portable pH/EC/TDS/Tem- perature meters (SX 811 and SX 813) were used to test physical-chemical parameters. The results of this study show that chemistry of in No.11 gushing mine is dominated by HCO3-Na and HCO3-Ca, and had a pH between 7.1 and 8.00, belonging to neutral or slightly alkaline water. In addition, water were found to have the hardness between 18 mg/L and 542.5 mg/L. Results also show that the TDS of the roof sandstone and goaves water are higher than Cambrian limestone water, while the turbidity of the mixed water is 20 NTU in the sump, again higher than in other samples such as Cambrian limestone water. Total dissolved solids and the total hardness of Cambrian limestone groundwater mainly depend on the content of K+ + Na+, Ca2+, B={b1,b2,…,bj} and SO2-4. Thus, chemical composition changes remarkably after mine water mixing. Results showed that the coal roof sandstone water is class V while that in the sump is class III, and the Cambrian limestone groundwater is class I. In gushing, the quality of water can vary greatly;thus, water from the coal face roof sandstone and the Cambrian limestone should be stored and treated separately before being utilized.
基金Supported by the National Natural Science Foundation of China(41901012)Project of Shaanxi Provincial Education Department(21JP040)+1 种基金Talent Fund Project of Weinan Normal University(2021RC04)National Innovation and Entrepreneurship Training Program for College Students(22XK019)。
文摘In order to study the water quality of the Shichuan River basin in Fuping,Shaanxi Province,based on improved Nemerow index method,comprehensive pollution index method and principal component analysis method,eight water quality indexes such as pH,dissolved oxygen(DO),total dissolved solids(TDS),COD,total hardness,total phosphorus,total nitrogen and Zn in three monitoring sections of Fuping section of the Shichuan River in Shaanxi Province were detected and analyzed.The results show that the water quality of the surface water in the Shichuan River basin is gradeⅢorⅣwater,that is,the water is slightly polluted and moderately polluted.It is necessary to monitor the water quality after regulation and clarify the main factors causing the water pollution.
基金supported by the National Natural Science Foundation of China(Grants No.41101250 and 51309031)the Chinese 12th Five-Year Science and Technology Support Program(Grant No.2012BAC06B00)
文摘The water quality in the Danjiangkou Reservoir has attracted considerable attention from the Chinese public and government since the announcement of the Middle Route of the South to North Water Diversion Project （SNWDP）, which commenced transferring water in 2014. Integrated research on the evaluation, prediction, and protection of water quality in the Danjiangkou Reservoir was carried out in this study in order to improve environmental management. Based on 120 water samples, wherein 17 water quality indices were measured at 20 monitoring sites, a single factor evaluation method was used to evaluate the current status of water quality. The results show that the main indices influencing the water quality in the Danjiangkou Reservoir are total phosphorus （TP）, permanganate index （CODM,）, dissolved oxygen （DO）, and five-day biochemical oxygen demand （BODs）, and the concentrations of TP, BODs, ammonia nitrogen （NH3--N）, CODM,, DO, and anionic surfactant （Surfa） do not reach the specified standard levels in the tributaries. Seasonal Mann--Kendall tests indicated that the CODMn concentration shows a highly significant increasing trend, and the TP concentration shows a significant increasing trend in the Danjiangkou Reservoir. The distribution of the main water quality indices in the Danjiangkou Reservoir was predicted using a two-dimensional water quality numerical model, and showed that the sphere of influence from the tributaries can spread across half of the Han Reservoir if the pollutants are not controlled. Cluster analysis （CA） results suggest that the Shending River is heavily polluted, that the Jianghe, Sihe, and Jianhe rivers are moderately polluted, and that they should be the focus of environmental remediation.
基金Supported by Science and Technology Initiation Fund of Anhui Polytechnic University (2009YQQ012)
文摘[Objective] The aim was to study the construction and application of combined evaluation model of regional water quality plan. [Meth- od] By dint of layer analysis, subjective and objective model of entropy evaluation, the water quality plan in Jinghe was evaluated. Combined evalu- ation model based on information entropy were constructed, and considering the single model evaluation result, the optimal water quality plan was selected. [ Result] The combination weight result suggested that COD amount was the most essential indicator in water quality plan and embodied the importance of water environment protection, which met basic objective of environment protection and social, economic effects. Combined evalu- ation indicated that in the sixteen plans, plan 16 was of highest comprehensive evaluation value, and can be considered as optimum water quality plan. [ Conclusion] Combined evaluation model can effectively list the advantages of each evaluation model and improve the dependability of water quality plan, and provided a new research idea for the optimal evaluation of water pollution control plan.
基金Supported by China Postdoctoral Science Foundation (20090460873)
文摘Fuzzy comprehensive evaluation method was used to develop a standard model to analyze and evaluate nearness degree of water environment quality at breeding area of Shuidong Bay in China.Results showed that certain environment contamination factors in some areas seriously exceeded the standard value and led to the whole water quality at the third class level.The measurements should be taken to promote the sustainable development of breeding area in Shuidong Bay.
基金supported by the National Natural Science Foundation of China (No. 41071322, 71031001)
文摘For natural water, method of water quality evaluation based on improved fuzzy matter-element evaluation method is presented. Two important parts are improved, the weights determining and fuzzy membership functions. The coefficient of variation of each indicator is used to determine the weight instead of traditional calculating superscales method. On the other hand, fuzzy matter-elements are constructed, and normal membership degrees are used instead of traditional trapezoidal ones. The composite fuzzy matter-elements with associated coefficient are constructed through associated transformation. The levels of natural water quality are determined according to the principle of maximum correlation. The improved fuzzy matter-element evaluation method is applied to evaluate water quality of the Luokou mainstream estuary at the first ten weeks in 2011 with the coefficient of variatiola method determining the weights. Water quality of Luokou mainstream estuary is dropping from level I to level II. The results of the improved evaluation method are basically the same as the official water quality. The variation coefficient method can reduce the workload, and overcome the adverse effects from abnormal values, compared with the traditional calculating superscales method. The results of improved fuzzy matter- element evaluation method are more credible than the ones of the traditional evaluation method. The improved evaluation method can use information of monitoring data more scientifically and comprehensively, and broaden a new evaluation method for water quality assessment.
基金Acknowledgements This study was supported by the National Science and Technology Support Program （No. 2011BAC12B02）, the National Science Foundation for Innovative Research Group （No. 51121003）, and the Outstanding Doctoral Thesis Fund of Beijing Normal University （No. 105512GK）. We are grateful to the editors and anonymous reviewers＇ careful review of this paper, whom have contributed substantially to improving the paper.
文摘The Danjiangkou Reservoir is the water source for the middle route of the South-to-North Water Diversion Project in China. Thus, its water quality status is of great concern. Five water quality indicators （dissolved oxygen, permanganate index, ammonia nitrogen, total nitrogen, and total phosphorus）, were measured at three monitoring sites （the Danjiangkou Reservoir dam, the Hejiawan and the Jiangbei bridge）, to investigate changing trends, and spatiotemporal characteristics of water quality in the Danjiangkou Reservoir area from January 2006 to May 2012. We then applied a Bayesian statistical method to evaluate the water quality comprehensively. The normal distribution sampling method was used to calculate likelihood, and the entropy weight method was used to determine indicator weights for variables of interest in to the study. The results indicated that concentrations of all five indicators increased during the last six years. In addition, the water quality in the reservoir was worse during the wet season （from May to October）, than during the dry season （from November to April of the next year）. Overall, the probability of the water＇s belonging to quality category of type lI, according to environmental quality standards for surface water in China, was 27.7%-33.7%, larger than that of its belonging to the other four water quality types. The increasing concentrations of nutrients could result in eutrophication of the Danjiangkou Reser- voir. This method reduced the subjectivity that is commonly associated with determining indicator weights and artificial classifications, achieving more reliable results. These results indicate that it is important for the interbasin water diversion project to implement integrated water quality management in the Danjiangkou Reservoir area.
