Desenvolvimento de um índice para avaliação do risco à potabilidade integrando o e-IQUAS à análise multicritérios

Abstract

Groundwater from regional aquifers is a strategic source to meet water demand in the semi-arid region of Brazil, especially during drought periods. This study presents the assessment of the risk to the potability of these waters based on the e-IQUAS-ARAS index, developed from the e-IQUAS index and integrated with multicriteria analysis. Similar to e-IQUAS, the parameters are organized into “Alteration Groups” and scored through the minimum operator, followed by decision-making models: Gaussian AHP, applied to obtain the weights of the Alteration Groups, and the ARAS Method for the analysis of water samples. Thus, the two multicriteria analysis models calculate the distance of each sample from the optimal potability option, assigning weights that reflect the regional specificities of the selected area. Furthermore, the greater the number of samples analyzed, the more accurate the adjustment of these weights becomes, reducing uncertainties and increasing the precision of water sample classification. Data from 370 samples collected between 2023 and 2024 from the Rural Sanitation Integrated System of the Parnaíba River Basin (SISAR-BPA) were used. The results obtained were employed in the elaboration of traffic-light maps of potability risk, evidencing that the index allows a flexible selection of the most relevant physicochemical parameters for human supply and is sensitive enough to indicate critical areas through the evaluation of the region’s waters.