Soil and Water Assessment Tool Soil Loss Simulation at the Sub-Basin Scale in the Alt Penedes-Anoia Vineyard Region (Ne Spain) in the 2000s

This paper evaluates soil loss due to water erosion in an area of 32,362ha with a predominant land use of vineyards (Alt Penedes-Anoia region, Catalonia, Spain). The Soil and Water Assessment Tool (SWAT) was used incorporating daily climatic data for the period 2000-2010 and also detailed soil and land use maps. Particular attention was given to the universal soil loss equation cover and management factor (C factor) of vineyards, with a minimum value of 015 being determined for this crop. The model was calibrated using daily flow data for the year 2010, which yielded satisfactory results. Even so, significant differences were obtained on days with high-intensity rainfall events, when the model overestimated runoff and peak discharge. In these vineyards, the simulated average soil losses per sub-basin ranged between 013 and 973Mgha(-1)y(-1), with maximum values of between 2632 and 4260Mgha(-1)y(-1) registered in fine-loamy soils developed on unconsolidated Tertiary marls. Other findings were related to problems associated with SWAT calibration under Mediterranean conditions characterised by major climate variability and high-intensity rainfall events. Copyright (c) 2013 John Wiley & Sons, Ltd.