Abstract

In the central-southern zone of Chile, the Renegado River presents an irregular behavior during the dry season, with dry and high flow sections along the river at the same time. The objective of this study was to identify interactions between surface and groundwater that explain this behavior. Through a flow measurement campaign along the river, an analysis of the geological conditions of the basin and the use of a numerical groundwater flow model, the interactions between the water table and the river were described and represented. As a result, it was identified that the combination of topography and geology given by the volcanic nature of the catchment leads the river to gain or lose surface water along the river. It is recommended to analyze the interaction surface and groundwater to address hydrological design studies and water management in volcanic systems with similar characteristics.