Spatial modeling of indicators for groundwater use in Brazil

Abstract

This study spatially characterizes the potential and pressure of the supply of groundwater resources in Brazil. Indicators obtained from ordinary kriging, kernel density estimation, and multivariate geovisualization techniques using the Brazilian Groundwater Information System (SIAGAS) were proposed. The cartographic results culminated in maps of the potential and pressure of groundwater use in Brazil and proved to be promising for the planning and management of water resources. Sedimentary basins had the highest specific yield (2.16 m3/h*m) and stabilization yield (11.19 m3/h), as well as the greatest total abstraction pressure (1054967 m3/h), although they had lower exploitation by aquifer area (0.54 m3/h*km2) than carbonate (1.91 m3/h*km2) and volcanic aquifers (0.80 m3/h*km2). Contrastingly, crystalline aquifers had the lowest specific yield (0.63 m3/h*m), and stabilization yield (5.71 m3/h). Specifically, it highlights the potential use of the Alter do Chão aquifer in northern Brazil and the western Guarani and Bauru-Caú aquifers, while they indicate a concern with the pressure of use on these last two aquifers, as well as on the Urucuia aquifer and on the metropolitan regions, especially of São Paulo.