Development of Groundwater Quality Index Using Fuzzy-Based Multicriteria Analysis for Buraydah, Qassim, Saudi Arabia

Saudi Arabia is currently facing serious challenges related to both the quality and quantity of its limited groundwater sources. Deep confined aquifers are being contaminated due to presence of naturally occurring minerals and radionuclides in soil and rocks, while the shallow aquifers have been affected due to anthropogenic activities. Generally, groundwater is extracted through several wells having varying concentrations of pollutants with consequential impacts on the performance of treatment processes, human health, and the natural environment. Assessing each parameter individually for raw and treated water all the time is a time-consuming and tedious job for decision-makers. In this research, a framework is developed for groundwater quality assessment based on aggregated water quality indices. Fuzzy set theory is applied to address the uncertainties associated with limited observations, measurement errors, and vagueness in expert opinion. Fuzzy analytical hierarchical process is used to establish the weighting scheme while the fuzzy technique for order preference by similarity to ideal solution has been employed for aggregation. The framework has been implemented on groundwater extracted for the city of Buraydah (Qassim) to evaluate its pragmatism. Twenty-four groundwater wells are ranked on the basis of their water quality; subsequently an overall index is developed to linguistically (i.e., very low, low, medium, high, very high) define the groundwater quality in the well field. The proposed hierarchical-based framework may include additional parameters and can be used to evaluate the performance of different treatment processes in future depending on data availability.