A large proportion of soil loss from farmlands did not reach the watershed outlet, most of transported soil (from rills and ephemeral gullies) apparently being redistributed and accumulated within the watershed. Consequently, the sediment delivery to the watershed outlet was determined by the spatial distribution of land-use types, as well as by the connection of sediment-producing areas and the runoff. The transfer of sediments and plant nutrients from the watershed to the runoff varied temporally and took place mainly during intense rainfall events.
The suspended sediment yield was relatively low, especially in comparison with more degraded areas in the Mediterranean mountains subject to high geomorphic activity from intense farming and grazing.
Forest and farmland areas have shrunk within the watershed over the last 30 years due to wildfires and the abandonment of agricultural and traditional practices. The effects of land-cover dynamics on the stream discharge could be partially explained, corroborating the complexity of the interaction between the hydrological response and land use in Mediterranean watersheds. Assessment results of long-term annual discharge suggest an alteration trend in the last 12 years relative to the regular rates yielded in the past. This implies the loss of the buffer capability of the watershed in controlling discharge in the headwater region, suggesting a strong impact of land-use change.
The agroforestry watershed produces the highest floods in autumn and winter with a large spatial and temporal variability in terms of both sediment- and runoff-contributing areas. Finally, the watershed reacts to all rainstorm events throughout the year, with high soluble-salt loads.These findings confirm that the hydrological response in Mediterranean environments is complex, depending not only on the watershed features but also on prior conditions and the characteristics of the rainfall episodes, particularly intensity.