Assessment of Water Quality using Fuzzy-AHP and TOPSIS

Abstract

The quality of water available to people has deteriorated because of the vast increase in global industries. The overall quality of water has reduced due to the high use of fertilizers in farms and chemicals in sectors such as mining and construction. The quality of water has a direct impact on the health of humans and hence it is necessary to evaluate the quality of drinking water. The quality of water is dependent on various substances like pH, ammonia, iron, arsenic etc. present in water. If these parameters are available in an appropriate amount in water then only the water is considered as of good quality. The problem of assessing water quality is usually considered as multi-criteria decision problem. In this paper an approach to evaluate quality of water using Fuzzy Analytical Hierarchical Process (Fuzzy-AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is proposed. The parameters which are considered for evaluation include Arsenic, Ammonia , Iron , Nitrate , Dissolved Oxygen and Ph. The relative importance of these parameters is utilized while applying the Fuzzy-AHP process and weights for each parameter are computed. The various datasets containing values for considered parameters are collected and the weights are used to assign quality levels to these water samples. The paper also gives the performance analysis of the proposed method in terms of accuracy. The accuracy is measured in terms of how many water samples are assigned correct quality level and the results show that the proposed method has better accuracy as compared to traditional AHP and Fuzzy-AHP method.

Applying Harmony Degree Equation and TOPSIS Combined with Entropy Weights in Surface Water Classification

“…This indicates that if the parameters are considered as a whole, water quality at each location is significantly affected by seasonal changes in activity. According to the classification of Sonavane et al [27], the closeness coefficient is divided into four groups to evaluate water quality, including very good (CC ≥ 0.8), good (0.6 ≤ CC < 0.8), bad (0.3 ≤ CC < 0.6), and unsuitable (CC < 0.3). According to this classification, water quality in the dry season in the region has 8 locations unsuitable for use (accounting for 21.05%), 21 locations at a bad level (accounting for 55.26%), 8 locations at a good level (accounting for 21.05%), and 1 location with excellent quality (2.63%).…”

“…Furthermore, many mathematical methods have been applied to evaluate water quality and propose management solutions, such as the water quality index (entropy-weighted water quality index (EWQI), integrated water quality index (IWQI), modified water quality index (MWQI) [15,16], Set Pair Analysis (SPA) [17,18], Technique of Order Preference by Similarity to Ideal Solution (TOPSIS) [19,20], and other multivariate statistical analysis methods (Principal Component Analysis (PCA), Cluster Analysis (CA), Factor Analysis (FA), Discriminant Analysis (DA) [4,8,15,[21][22][23]. Among them, TOPSIS is commonly used in assessing water quality and identifying alternative solutions [19,[24][25][26][27]. In addition, the harmonic degree equation (HDE) is also used in water quality assessment studies [4,[28][29][30].…”