Original paper

Sediment production of an alpine catchment with SWAT

Palazón, Leticia; Navas, Ana


Sediment delivery to streams is an important environmental problem and a major concern in sustainability of soil quality and water resources. Modeling runoff and sediment transport at catchment scale are key tools to predict sediment yield with the purpose of preserving soil resources in order to minimize soil loss as other indirect impacts such as reservoir siltation and degradation of water quality. This study uses Soil and Water Assessment Tool (SWAT) model in an alpine catchment of the Central Spanish Pyrenees as a simulator of processes related to hillslope water induced erosion. The model was applied to the dammed alpine headwater of the Ésera River, a catchment limited by the Linsoles reservoir, in the Central Spanish Pyrenees. Lithology influenced the distribution of the geomorphic processes. The rugged topography and the climatic heterogeneity of the area controlled the activity of the geomorphologic processes in the catchment. At the headwater there is a karst system, which subtracts discharge out of the catchment and an intermediate reservoir (Paso Nuevo reservoir), which regulates the river. The simulated period (2003 - 2005) produces an average sediment yield for the catchment of 10,119 t year-1, but large variations are found between the subcatchments included in the Linsoles catchment due to differences in percentages of rock outcrops, land covers and slope gradients. Results of this research proved that SWAT is useful for identifying areas where geomorphologic processes relating to erosion are important and also for assessing discharge losses by the karst system and the sedimentary role of the reservoirs.


erosionsediment yieldswat modelreservoiralpine catchmentpyrenees