Proposta metodológica para identificação de áreas potencias de recarga subterrânea da Bacia do Pratagy em Maceió-AL

Abstract

As a result of the population increase, which required several resources, including water, there were several studies in order to promote the evolution of technologies for groundwater pump, which represents about 26% of water abstraction in the world and has been growing during the last few years (WWAP, 2012). One of the alternatives to delimit the recharge áreas is through Geographic Information Systems (GIS), which have the potential to estimate, from thematic maps, the areas that might be priority for aquifer supply. The aim of the study, therefore, was to evaluate a methodological proposal for the delimitation of groundwater recharge areas in the Pratagy watershed, in a GIS environment. In order to assess the regions which have the greatest susceptibility to infiltration into the soil, and subsequent aquifer recharge, was gathered information from environmental characteristics, such as geology, geomorphology, soil type, land use and occupation and precipitation, provided by administration entities, and then this information has been classified, with their respective weights, in terms of how easy it is to recharge the aquifer. All this data handling and operation was performed using the QGIS geoprocessing software v. 3.10.14. The result showed that most of the area of the Pratagy watershed has medium and low recharge potential, corresponding to, respectively, 46.6% and 43.2% of the total area of the basin. Only 10.2% of the area has a high potential for recharge and this region is close to water courses. Among the factors studied, land use and occupation were the environmental factor that determined the main areas of high recharge potential, as in its greatest extent it is composed by classifications with low soil permeability and in the perimeter close to the watercourse by native vegetation, which has a high recharging coefficient.