title: A multidimension cloud model-based approach for water quality assessment.
abstract: Lakes are vitally important, because they perform a multitude of functions, such as water supply, recreation, fishing, and habitat. However, eutrophication limits the ability of lakes to perform these functions. In order to reduce eutrophication, the first step is its evaluation. The process of evaluation entails randomness and fuzziness which must therefore be incorporated. This study proposes an eutrophication evaluation method, named Multidimension Normal Cloud Model (MNCM). The model regards each evaluation factor as a one-dimension attribute of MNCM, chooses reasonable parameters and determines the weights of evaluation factors by entropy. Thus, all factors of MNCM belonging to each eutrophication level are generated and the final eutrophication level is determined by the certainty degree. MNCM is then used to evaluate eutrophication of 12 typical lakes and reservoirs in China and its results are compared with those of the reference method, one-dimension normal cloud model, related weighted nutrition state index method, scoring method, and fuzzy comprehensive evaluation method. Results of MNCM are found to be consistent with the actual water status; hence, MNCM can be an effective evaluation tool. With respect to the former one-dimension normal cloud model, parameters of MNCM are improved without increasing its complexity. MNCM can directly determine the eutrophication level according to the degree of certainty and can determine the final degree of eutrophication; thus, it is more consistent with the complexity of water eutrophication evaluation.
authors.affiliation: Key Laboratory of Surficial Geochemistry, Ministry of Education, Department of Hydrosciences, School of Earth Sciences and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, PR China. Electronic address: wangdong@nju.edu.cn.
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.affiliation: Key Laboratory of Surficial Geochemistry, Ministry of Education, Department of Hydrosciences, School of Earth Sciences and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, PR China.
authors.forename: Debiao
authors.initials: D
authors.lastname: Zeng
authors.affiliation: Department of Biological and Agricultural Engineering and Zachry Department of Civil Engineering, Texas A & M University, College Station, TX 77843-2117, USA.
authors.forename: Vijay P
authors.initials: VP
authors.lastname: Singh
authors.affiliation: Key Laboratory of Surficial Geochemistry, Ministry of Education, Department of Hydrosciences, School of Earth Sciences and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, PR China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Xu
authors.affiliation: Key Laboratory of Surficial Geochemistry, Ministry of Education, Department of Hydrosciences, School of Earth Sciences and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, PR China.
authors.forename: Dengfeng
authors.initials: D
authors.lastname: Liu
authors.affiliation: Key Laboratory of Surficial Geochemistry, Ministry of Education, Department of Hydrosciences, School of Earth Sciences and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, PR China.
authors.forename: Yuankun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Surficial Geochemistry, Ministry of Education, Department of Hydrosciences, School of Earth Sciences and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, PR China.
authors.forename: Xiankui
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Surficial Geochemistry, Ministry of Education, Department of Hydrosciences, School of Earth Sciences and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, PR China.
authors.forename: Jichun
authors.initials: J
authors.lastname: Wu
authors.affiliation: School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, China.
authors.forename: Lachun
authors.initials: L
authors.lastname: Wang
mesh_terms: D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D005068:Eutrophication; D060106:Lakes / Q000032:analysis*; D008962:Models, Theoretical; D060753:Water Quality
keywords: Entropy weight; Eutrophication evaluation; Multi-dimension normal cloud model