Fonts de les Guilleries: hidrologia, relació amb recàrrega subterrània i escenaris de futur

Abstract

Springs are elements of the environment with significant importance in many fields of

knowledge. They are indicators of the quantity and quality of the water stored in the subsurface.

The study of the flow rate and physicochemical parameters of springs allows for determining

the characteristics of groundwater and studying its evolution over a period of time through the

calculation of a water balance. The Guilleries massif is part of the large Montseny-Guilleries granite aquifer, which has a large number of springs and hydro-meteorological conditions that favor high groundwater recharge. With global warming, the average annual precipitation falling on the massif is decreasing, and the average temperature is increasing. These two variables together lead to a significant reduction in the water that infiltrates the subsurface and comes out through the springs.

To understand the hydrological functioning of the Guilleries springs and determine their current

state, a combined water balance of twelve springs and their respective drainage basins has

been conducted. Different future scenarios have also been estimated using climate projections

for precipitation and temperature for the period 2031-2050, along with various options

regarding soil cover types. The results show a high correlation between spring flow rates and precipitation, but temperatures and precipitation distribution are also important factors as they influence the amount of infiltration that occurs. As for the future scenarios, a clear decrease in water

available for the subsurface compared to the average period of 1961-1990 is observed, with a

slight decrease when open spaces increase. These results lead to the conclusion that there is a clear relationship between the changes in the hydro-meteorological regime caused by global warming and the state of springs and groundwater bodies. Although this decrease is inevitable, it can be slightly mitigated by reducing forest covers and increasing open spaces, thus reducing evapotranspiration and increasing infiltration