Factors controlling hydro-sedimentary response during runoff events in a rural catchment in the humid Spanish zone

In Galicia (NW Spain) studies on the suspended sediment (SS) transported in river catchments are scarce. Using a dataset comprising three hydrological years (2004/05–2006/07) in the Corbeira catchment (NW Spain), the relationships between rainfall, runoff and SS are analysed at event scale. The catchment was instrumented to measure rainfall, water level and SS in the stream. Several event (rainfall, discharge and SS concentration and load) and pre-event (rainfall and discharge) variables were calculated for all the events analysed. Correlation matrices were developed using these data. Discharge characteristics and rainfall depth showed good correlations with SS concentration and load. Suspended sediment and discharge relationships were also examined. In most of the events, the SS peak preceded peak discharge (clockwise hysteresis), implying that zones near the stream are the main sediment source areas.