Hydrological functions of a small mountain cathment with badland morphologies in the Central Pyrenees

Abstract

The Araguás catchment has been monitored since 2004 to study weathering, erosion and the hydrological and sediment response in order to understand the dynamics of a badland area in a relatively humid environment. This paper studies the main hydrological characteristics of the Araguás catchment, a representative badland area in a subhumid mountain environment. 79 floods have been recorded between October 2005 and April 2007. The results obtained confirm the temporal variability in the hydrological response within a small catchment with badland areas, and its high capacity of reaction against precipitation. Storm-flow mainly depends on the combination between rainfall volume and antecedent baseflow. On the other hand, a significant correlation was observed between maximum rainfall intensity and peak flow values. Moreover, seasonal differences were observed: during the dry season, significant correlations were observed between maximum rainfall intensity and peak flow; during the wet season this significant correlation disappeared and relationships with antecedent moisture conditions improved. Finally, the shape of the different hydrographs suggests two different hydrological patterns, due to runoff generation mechanisms.