Resultados preliminares sobre el comportamiento hidrológico y las tasas de erosión en pequeñas cuencas experimentales de La Calma (Montseny, Barcelona)

Abstract

The hydrological response of a 6.7 ha., heathland-covered watershed in N E Spain during three storm events is discussed. When the soils were dry only negligible runoff was produced. In two ocasions when rhe catchment was wet, storm runoff amounted lO between 45% and 85% of total rainfal!. This underlines the role of antecedent soil water condition in determining watershed response. Bedload transport delivered 21 kg. ha-I year-I of sediment in this watershedo A nearby, burned watershed with gentler relief produced 2 kg. ha-I year-I of bedload transport during the first year after the fire. Burning of heathlands on moderate slopes does not produce significant erosion through bedload transport, but other erosion pathways have not been yet assessed. Upon inspection of the burned watershed, it is strongly recommended that heathlands on slopes steeper than JO-15° be only burned with special precautions lo reduce erosión.