Diagnóstico hidroambiental da Bacia do Ribeirão Caracol na cidade de Andradas – MG

Abstract

Springs are critical ecohydrological components of watersheds, yet they are often neglected in environmental assessments and land-use planning. This study presents a hydro-environmental diagnosis of the Ribeirão do Caracol watershed, located in the Atlantic Forest biome in southeastern Brazil. Land use and land cover play a central role in watershed hydrological dynamics, influencing groundwater recharge, the integrity of Permanent Preservation Areas (PPAs), and the conservation status of springs. In the Ribeirão do Caracol watershed, thematic mapping revealed a predominance of mixed land uses, followed by forest formations and pasture areas, composing a fragmented landscape with distinct levels of environmental conservation. Although most spring PPAs maintain vegetation cover, spatial analysis identified a spring in the intermediate portion of the watershed without forest protection, indicating ecological vulnerability and risk to recharge. Within this land-use context, seven springs were evaluated through macroscopic assessments, georeferencing, hydrological measurements, and the determination of water quality during dry and wet periods. The results demonstrated strong hydrological heterogeneity: three headwater springs, historically considered perennial, showed no flow during any sampling period, indicating a possible reduction in groundwater recharge; the urban spring exhibited emergence at three distinct points and signs of degradation; and only one spring was classified as “Excellent” according to the IIAN index. Analyses of the main channel water revealed critical values at the municipal abstraction point, with high BOD₅ levels and low dissolved oxygen concentrations, contrasting with better conditions recorded in the upstream reach. Overall, the findings indicate a direct influence of land use on spring conservation and, indirectly, on stream water quality, reinforcing the need to integrate spring monitoring into environmental planning, strengthen the protection of PPAs, and apply the legal management guidelines established by the Brazilian Forest Code. Springs, more than mere points of water emergence, are sensitive indicators of environmental change in the landscape and fundamental elements for regional water security.