Detection of Hot Spots of Soil Erosion and Reservoir Siltation in Ungauged Mediterranean Catchments

The long-term average, distributed parameter PhosFate model was applied for erosion hot spot identification in unmonitored Mediterranean catchments. Based on experiences of previous case studies in well-monitored watersheds, the model was tested in a study over the entire area of Albania with success. The model results were validated by the sporadically available data on river discharge and sediment loads. With an optimization method cost effective interventions were planned to efficiently reduce soil erosion. The optimization algorithm is based on a simple sediment transport model and it minimizes the necessary area of interventions. In accordance with the critical source area concept, it was shown that intervention with better management practices on properly selected, a few percent of the total area is sufficient to reach a significant reduction in soil loss, reservoir siltation and consequently an improvement in water quality.