SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Modelling nitrate reduction strategies from diffuse sources in the Po River Basin 
Authors:Malagó, A., F. Bouraoui, M. Pastori and E. Gelati 
Volume (Issue):11(5) 
Article ID: 
URL (non-DOI journals): 
Broad Application Category:hydrologic and pollutant 
Primary Application Category:nitrogen cycling/loss and transport 
Secondary Application Category:crop, forest and/or vegetation growth/yield and/or parameters 
Watershed Description:74,500 km^2 Po River, which is the largest river system in Italy. The river has a stream length of 652 km, and the drainage area includes 141 tributaries, 450 lakes and a delta area of 380 km^2. The basin covers seven Italian regions, and includes part of the Canton Ticino in Switzerland. Climate is influenced by orographic effects: it is typically alpine in the mountain zone, continental-warm in the flat basin area and Mediterranean on the coast. 
Calibration Summary:The calibration of SWAT was performed following a cascade modelling approach starting from crop yield, then streamflow and finally nitrate concentration 
Validation Summary: 
General Comments: 
Abstract:Water contamination caused by the presence of excessive amounts of nitrate can be catastrophic for aquatic ecosystems and human health. Due to these high risks, a great deal of emphasis has been placed on finding effective measures to reduce nitrate concentrations in rivers and aquifers. In this study, we used the SWAT model based on grid-cells of 5 minutes of resolution for assessing the processes involved in nitrate loads generation and transport into aquifers and rivers and for providing basin management strategies of nitrate reduction. We applied the model in the Po River Basin (Italy), one of the most densely populated and highly agriculturally exploited area in the Mediterranean basin. The model was successfully calibrated and validated in eight monitoring stations along the Po River for the period 2000–2012. Simulated monthly streamflow and nitrate concentrations were in good agreement with observations, obtaining values of bias around 25% in both calibration and validation. Among the tested scenarios of nitrogen reduction from agricultural sources, red clover cover crop after corn, coupled with a targeted reduction of mineral fertilizers and the limitation of nitrogen manure leads to a reduction of nitrate leaching and nitrogen emissions of around 37%. 
Keywords:Diffuse sources; SWAT; Po River Basin; nitrate reduction; scenario analysis; agriculture management practices