Zonation of groundwater quality in terms of drinkability, using Fuzzy Logic and Schoeller deterministic method for Northern Dezful - Andimeshk Plain, Iran

Abstract In the Northern Dezful-Andimeshk Plain, the primary source of drinking water is groundwater, which has low quality in some places. Thus, groundwater quality in this area needs an accurate evaluation. In this research, the fuzzy and Schoeller deterministic method assessed the Northern Dezful-Andimeshk Plain drinking water, and the results of both methods were used to zone and compare the drinking quality of the plain groundwater in the Arc GIS environment. The deterministic method classifies drinking water quality from good to bad. According to this method, 56.81% of the total area of the plain has good quality, 20.83% of the total area is acceptable, 18.77% of the total area has inappropriate quality, and 3.57% of the total area has bad quality. However, in the fuzzy method, groundwater in 21.6% of the total area of the plain with a confidence percentage of 70% to 81% is desirable, in 75.23% of the total area of the plain with a confidence percentage of 32% to 70% is acceptable, and 3.69% of the total area of the plain with drinking confidence of 20% to 22% is nonacceptable. The results showed that the fuzzy method is better than the Schoeller deterministic method because it reduces uncertainties, increases accuracy in the evaluation, increases flexibility in the threshold limits of water quality parameters, and provides a quantitative and qualitative assessment of drinking water. Also the zoning map obtained from this method is more compatible with environmental and pollution realities. Graphical Abstrac