Streamflow response during rainfall events in a small forested catchment (Basque Country)

摘要

Hydrological response of a catchment depends on the combination of many different factors that determine the active processes taking place during rainfall-runoff events. The study of this kind of events provides information on the hydrological behaviour of a catchment, even if it is not enough to differentiate between processes or water origin. 234 rainfall-runoff relationships at the event scale were studied in a humid-temperate small catchment (almost 5 km2) in the Basque Country (Aixola catchment) between 2003 and 2008. The study aims to report on the complexity of hydrological response of a small forested catchment by means of studying the relationship between rainfall and discharge during the event and discharge prior to the event. A seasonality of the runoff coefficient has been observed, showing an evolution from wetter conditions in winter to drier ones in summer with transition periods during spring and the beginning of autumn. In fact, the runoff coefficient is higher for a comparable total precipitation amount, if discharge prior to the event has been larger.