Water scarcity is a global issue, especially in semi-arid and arid regions where precipitation is irregularly distributed over time and space. Predicting groundwater flow in heterogeneous karst terrains, which are essential water sources, presents a significant challenge. This article integrates geology, hydrology, and water monitoring to develop a pioneering conceptual and numerical model of groundwater flow in the Montes Claros Region (Vieira River Watershed, Brazil). This model was evaluated under various climate change scenarios, considering changes in rainfall, groundwater consumption, and population growth over the current century. The results indicate that a decline in water table levels is inevitable, primarily driven by population growth and high pumping rates rather than rainfall fluctuations. This underscores the urgent need for improved monitoring, model upgrading, and more importantly, targeted water resource management for Montes Claros.

Water scarcity is a problem in Brazil’s northern semi-arid domain. Montes Claros is the most populated Minas Gerais city in this context, and its socio-economic problems are related to water consumption and management. Aiming to help assess these problems, this study presents a new hydrogeological characterization. The 3D geological model was developed using drilling data from 125 public wells, field campaigns and satellite images for hydrogeological interpretation. The area has two main different aquifer systems underlying the Vieira River Watershed. The first is a karstic fissured aquifer, located in the Lagoa do Jacaré limestone Formation. The second is fissured aquifer systems in metapelites from the Serra da Santa Helena and Serra da Saudade Formations, which are characterized by low hydraulic transmissivity and locally higher specific capacity zones related to their structural features or carbonate intercalations. Monitoring data from new manual and automatic methods carried out in 16 selected points highlight that variations are related to (1) hydrogeological domains, (2) oscillations related to interference from neighboring wells, and (3) seasonal variation and irregular pluviometry in the region. This is important information that can help update our hydrogeological knowledge, provide information on surface and groundwater flow dynamics, and improve water resource management, with the aim of ensuring sustainability in exploitation.

Wastewaters are valuable sources of metals and metalloids and can serve as essential resources for their recovery. Characterizing and understanding the occurrence of metals and other compounds, along with identifying the most effective recovery methods, are key steps in unlocking the potential for reusing these resources. The present study focused on analyzing waters from various mining dams in the Iron Quadrangle (IQ) region of Brazil, which contained metals such as Au, Cu, Ni, Zn, and sulfates resulting from the metallurgical treatment of Au. The results revealed a range of metal concentrations in the neutral zone in three tailings. Additionally, a 3D map was created, and a statistical analysis and an exploration of the processes governing mobility and partitioning were conducted to assess the potential for reuse. Notably, the study identified a high potential for Au recovery, particularly through the utilization of sustainable and cost-effective methods such as nanofibers with biosorbents. Overall, this research contributes to the understanding and exploration of potential reuse procedures for strategic metals in various industrial applications.