title: Identification of phosphorus emission hotspots in agricultural catchments.
abstract: An enhanced transport-based management approach is presented, which is able to support cost-effective water quality management with respect to diffuse phosphorus pollution. Suspended solids and particulate phosphorus emissions and their transport were modeled in two hilly agricultural watersheds (Wulka River in Austria and Zala River in Hungary) with an improved version of the catchment-scale PhosFate model. Source and transmission areas were ranked by an optimization method in order to provide a priority list of the areas of economically efficient (optimal) management alternatives. The model was calibrated and validated at different gauges and for various years. The spatial distribution of the emissions shows that approximately one third of the catchment area is responsible for the majority of the emissions. However, only a few percent of the source areas can transport fluxes to the catchment outlet. These effective source areas, together with the main transmission areas are potential candidates for improved management practices. In accordance with the critical area concept, it was shown that intervention with better management practices on a properly selected small proportion of the total area (1-3%) is sufficient to reach a remarkable improvement in water quality. If soil nutrient management is also considered in addition to water quality, intervention on 4-12% of the catchment areas can fulfill both aspects.
authors: Research Center for Water Quality Management, Institute for Water Quality, Resource and Waste Management, Vienna University of Technology, Karlsplatz 13/226, A-1040 Vienna, Austria. akovacs@iwag.tuwien.ac.at
authors: Adam
authors: A
authors: Kovacs
authors: Mark
authors: M
authors: Honti
authors: Matthias
authors: M
authors: Zessner
authors: Alexander
authors: A
authors: Eder
authors: Adrienne
authors: A
authors: Clement
authors: Günter
authors: G
authors: Blöschl
mesh_terms: D000383:Agriculture; D004784:Environmental Monitoring; D006814:Hungary; D008962:Models, Theoretical; D010758:Phosphorus / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus