Erosión Y Redistribución Del Suelo En Agroecosistemas Mediterráneos

Resumen del Libro

Control of soil erosion is necessary under the current scenario to preserve natural resources and croplands. The Estana catchment (Spanish Central Pre-Pyrenees) is the study area and is representative of the mid-mountain Mediterranean agroecosystems with natural vegetation and croplands. This area is a hydrological closed and karstic system with fifteen sub-catchments and three permanent lakes. In this work it is characterized the DEM and geomorphology, the soil types and uses, the physical, chemical and radiometric properties and climatic parameters. Average soil erosion with RMMF model (3.6 Mg ha -1 yr-1) is 54% higher than average rate with RUSLE model (2.3 Mg ha-1 yr-1). Soil erosion in natural land uses is lower than soil loss in croplands (5.0 and 5.3 Mg ha-1 yr-1 with RUSLE and RMMF). The highest rates of erosion appear in bare soils, paths, croplands and scrublands in steep areas. Three different erosive periods have been identified. EP-I (J1-Oc) has the highest values of EI30, I30 and monthly soil loss. EP-II (My-Jn) has the lowest values of soil loss due to the protection role of the vegetation and EP-III (Nv-Ap) has the lowest values of EI30 and I30, the highest values of the K factor and high values of monthly soil loss. Assessment of effective cumulative runoff improves predictions of RMMF. The combined flow algorithm associated with gullies represents best the runoff path-ways. The new SERT model (Pilot sub-catchment) is very sensitive in changes of 130, top-soil saturation and runoff generation parameters. SERT predicts at monthly scale areas with erosion and no erosion obtaining the highest values of soil loss in September and October and mean and maximum annual rates of 17.5 and 324 Mg ha-1 yr-1. Soil redistribution (Pilot sub-catchment) with 137Cs is -0.6 Mg ha-1 yr -1 with values of soil loss higher than 20 Mg ha-1 yr-1 and soil deposition higher than 5 Mg ha-1 yr-1 affecting 8 and 25% of the sub-catchment area. Validation of SERT with 137Cs is…