Soil and Water Assessment Tool soil loss simulation at the sub-basin scale in the Alt Penedès-Anoia vineyard region (Ne Spain) in the 2000s

摘要

This paper evaluates soil loss due to water erosion in an area of 32,362 ha with a predominant land use of vineyards (Alt Penedès-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 0·15 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 0·13 and 9·73 Mg ha−1 y−1, with maximum values of between 26·32 and 42·60 Mg ha−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.