A multidimension cloud model-based approach for water quality assessment

• Published in: Environmental research Vol. 149; pp. 113 - 121
• Main Authors: Wang, Dong, Zeng, Debiao, Singh, Vijay P., Xu, Pengcheng, Liu, Dengfeng, Wang, Yuankun, Zeng, Xiankui, Wu, Jichun, Wang, Lachun
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.08.2016
• Subjects: China; Entropy weight; Environmental Monitoring - methods; Eutrophication; Eutrophication evaluation; Freshwater; Lakes - analysis; Models, Theoretical; Multi-dimension normal cloud model; Water Quality; China, People's Rep; Multi-dimension normal cloud model; Entropy weight; Eutrophication evaluation
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2016.05.012

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. •A new approach using multidimension normal cloud model is proposed for assessment water quality.•This approach yields detailed information on the water status without increasing its complexity.•This approach is reasonably accurate and representative of other methods including ONCM.