Geomorphometry and aeromagnetometry as water management tools: A case study in hydrological planning units in southeastern Brazil

Abstract

Proper management of available groundwater and surface water reservoirs plays a crucial role in the sustainable distribution of natural resources in densely populated regions, while also contributing to water security. In this context, the development of straightforward and valuable cartographic interpretations plays a significant role in enhancing the understanding of fractured aquifer dynamics. The aim of this research is to investigate geospatial similarities between geological-geophysical lineaments and well production, with the purpose of determining whether aeromagnetometry and geomorphometry can contribute to the study of fractured aquifers and be utilized as tools in water resource management. Study areas were delineated based on previously defined hydrological units, often used in urban water supply planning. Additionally, geomorphometric structures were identified from a hydrologically consistent elevation model. To explore the potential of available magnetic data, filters were applied to magnetic lineaments, including vertical derivative and analytic signal amplitude. As a result, this study identified at least two productive hydrogeological units within a range of approximately 200 m along magnetic lineaments: 0.47 m3/h/m in granitoids with NNW-SSE and WNW-ESSE trending structures, and 0.27 m3/h/m in gneisses with NW-SE and ENE-WSW trends. These orientations are consistent with Cenozoic tectonic reactivation, and drilling sites located along these lineaments demonstrate higher productivity. Therefore, this study highlights that the integrated application of geophysical, geomorphometric, and hydrodynamic data can significantly improve correlations between subsurface structural configurations and hydrological productivity in fractured reservoirs, while also making a significant contribution to water management.