Modelagem hidrológica para monitoramento do lençol freático em cenários de pastagem e agrofloresta na microbacia do IFMG, São João Evangelista

The study analyzed the water dynamics of a micro-watershed on the campus of the Federal Institute of Minas Gerais, in São João Evangelista, comparing the current scenario, dominated by pastures, to a simulated situation in which these areas are converted into agroforestry systems. Over six months, the water table level was monitored using piezometers installed in boreholes drilled with an auger. Additionally, an aerial photogrammetric survey was conducted to obtain an orthomosaic and a Digital Elevation Model (DEM), along with the delineation of the piezometer head and topographic analysis. Land use was mapped through manual vectorization, supported by field observations, and the classification of hydrological soil groups was established. To estimate soil retention capacity and surface runoff, the Curve Number (CN) method was applied, assigning specific values based on land use type and the corresponding hydrological soil group. The water storage (A = P – ET – Q) was calculated using precipitation data from CHIRPS and evapotranspiration estimated by MOD16, allowing for an assessment of storage variations in the system. Infiltration capacity was determined through linear regression between piezometer readings and the components of the water storage. The results indicate that, in the current scenario, low infiltration contributes to increased surface runoff and abrupt fluctuations in groundwater levels, particularly during dry periods. In contrast, the adoption of agroforestry systems significantly enhanced infiltration, leading to consistent recharge and greater stability of the water table.