Dinámica de la humedad del suelo en una cuenca agrícola del sector central de la cuenca del Duero

Abstract

In this work the soil moisture dynamics was estudied in a small agricultural catchment in the central sector of the Duero basin. The experience took place in the 1 km2 Villamor experimental catchment, located in the southeastern part of the Zamora province. The evolution of the soil water contenr and its availability for plants was analyzed from the data measured in eleven soil profiles equipped with TDR (Time Domain Reflectometry) probes at different depths, between 2002 and 2006. The soil moisture data recorded in Villamor which were compared against the data simultaneously registered in the Network of Soil Moisture Measurement Stations (REMEDHUS) in the agricultural region of La Guarena over 1300 km2. This comparison allowed to assess the repre-sentativeness of the experimental catchment as an expression of the hydrological dynamics of a territory larger of which is part. The results of the study carried out in Villamor have shown the seasonal water content changes in the soil, as it is expected under Mediterranean conditions. However, these changes were much more attenuated than those observed in other nearby areas. The use of the Soil Water Index (IDH) allows the analysis in terms of availability of water for the plants and enables the comparison between different areas. IDH data have shown much more reduced water deficit conditions of what might be expected, given the semi-arid conditions in the area. The comparison with series of IDH of two forested basins and the identification of deficit situations much more intense in them, leads to reflection on the very prominent role of vegetation cover in the hydrological response of certain territories.