SIMULAÇÃO GEOESTATÍSTICA APLICADA À AVALIAÇÃO DAS VARIAÇÕES DO NÍVEL POTENCIOMÉTRICO EM UM AQUÍFERO LIVRE: UMA ABORDAGEM POSSÍVEL PARA GESTÃO DE RECURSOS HÍDRICOS SUBTERRÂNEOS

Abstract

Effective water resource management, particularly regarding groundwater systems, requires methodological rigor and analytical precision. This challenge is further intensified by the ongoing climate crisis, which is characterized by increasingly extreme hydrometeorological events and growing unpredictability.This study employs a geomathematical approach to assess potentiometric level based on pre-processed cokriging data within a 44 km² area in the northeastern sector of Fortaleza, Northeastern Brazil. The analysis was conducted through Direct Sequential Simulation (DSS), a geostatistical method that enables the generation of stochastic realizations of the potentiometric surface in an unconfined (or predominantly unconfined) sedimentary aquifer. This aquifer is lithostratigraphically composed of dunes, paleodunes, and sandy-clayey sediments from the Barreiras Group. A total of 100 simulations were performed, followed by statistical post-processing enabling the construction of probabilistic scenarios based on the Q₂₅, Q₅₀, and Q₇₅ quartiles, as well as an assessment of extreme potentiometric values (minimum and maximum). These scenarios reveal the presence of distinct zones within the study area exhibiting relatively high or low potentiometric levels, likely influenced by seasonal variations in aquifer recharge driven by rainfall patterns and drought cycles. Furthermore, DSS method enabled the generation of a spatial uncertainty map, which highlights a central sector of the study area with a notably higher degree of unpredictability in potentiometric levels. This variability is reflected in the distribution of standard deviations, which were found to be high in this region. The observed uncertainty is presumably due to potential lithological heterogeneity affecting specific levels of the potentiometric surface.