Arid area ; Badland ; Clay mineral ; Ebro ; Grain size distribution ; Infiltration ; Microrelief ; Model ; Semi-arid area ; Slope ; Soil erosion ; Soil properties ; Spain ; Statistics ; Water erosion ; Watershed
of the main factors controlling piping processes in those conditions was obtained by statistical analysis based on multiple and stepwise regressions. Piping erosion is strongly related to a high sodium absorption ratio (SAR) which favours clay dispersion