Aquifer recharge on a Native Deciduous Seasonal Forest, Turvo State Park (RS)

ABSTRACT

Considering the relevancy of the forests to retain rainfall waters and their strategic role to the recharge of subjacent aquifers, this study aimed to estimate the direct and natural recharge of the phreatic aquifer of the weathering zone from the Serra Geral Formation basalts. The studied aquifer is under a Native Deciduous Seasonal Forest from an Atlantic Forest biome. In order to estimate the recharge to the phreatic aquifer, the Water Table Fluctuation (WTF) method was applied based on the time series analysis of water table and rainfall. The data was collected in the State Park of Turvo - PET (RS) during a 50 days period (from January to March). Sub-hourly groundwater level data were collected with automatic pressure meters (CTD) from three piezometers, for the systematic analysis. At the same time, rainfall data were collected inside the PET, from an experimental pluviometric station. The direct and natural recharge to the phreatic aquifer was estimated in 23% of the rainfall, for summer time. Mean time for the water table initial response was 8 to 10 hours.

Keywords:
Groundwater; Subtropical forest; Forest hydrology; Fractured aquifer