Hydrological processes in forested catchment of the Central System range : experimental catchment of Rinconada

Abstract

In the present work we analyse the hydrological processes characterising a forested catchment on the northern face of the Sistema Central range. The Rinconada experimental catchment (at Rinconada de la Sierra, province of Salamanca), which has been running since autumn 1999, is mainly occupied by a dense forest of semi-deciduous oak (Quercus pyrenaica Willd.). It is equipped with different experimental devices (automatic meteorological and hydrological stations, a soil moisture measurement network, plots to monitor plant water dynamics, interception control networks) for the monitoring of the variables involved in the soil-water-plant-atmosphere system. The results of the analysis reveal the crucial role of the forest in the hydrological dynamics of the catchment. The catchment has a low capacity to generate runoff, above all during the period coinciding with the biological activity of the oaks. Factors such as low summer rainfall, high evapotranspiration, interception and water consumption by the trees mean that the catchment produces very little runoff, even though it is subject to subhumid climatic conditions. Also important is the fact that the saturated areas, even though occupying a very reduced percentage of the catchment, are determinant in the generation of the runoff from the majority of the events.