Caracterização e Quantificação do Potencial Hídrico Subterrâneo do Baixo Curso do Rio Piracicaba (MG)

Abstract

The demand for hydric resources is a process that moves in the opposite direction of the quantity and quality of superficial hydric bodies majority. Considering this circumstance, three situations are identified: the high cost for recovering hydric bodies, water treatment aiming to achieve potability, and the exploitation of groundwaters, justified by its abundance and limpidity. The main goal of this work is to characterize and evaluate the ground hydric potential, based on the geological and hydrogeological characteristics of the low course of Piracicaba River, region in which the development of all activities depends on groundwater. The study of the drilled wells and granted flows, enabled the characterization of the aquifers. The quantification of the superficial and subterranean components, presented through hydrographs, led to the calculation of the contribution of the aquifers to the perpetuity of the water course, upon the evaluation of total and subterranean defluvium volumes. Considering the seven cities included in the studied area, only Jaguaraçu doesn’t use groundwater for public supply. In total, 1275 wells were registered, which are placed within four aquifer systems identified. Half of these wells are drilled in the fissural aquifer system of the crystalline rocks. In the fissural aquifer system formed by metasedimentary / metavolcanic rocks and in the porous aquifer system from the cenozoic formations, the wells with the highest flow rates are found. Estimates developed considering population growth, correlated to the regional hydric demand, for 2035, show that a new and efficient ground hydric resource management will be necessary in order to meet the necessities of a near future.