b'11Targeting Riparian Buffer Strips at Field Scale in the Upper Bann CatchmentAnderson A1, Goslee S2, Adams R1, Veith T2 and Doody DG11Agri-Food & Bioscience Institute, Northern Ireland2USDA Agricultural Research Service, USA3The Pennsylvania State University, USA Riparian buffer strips (RBSs) are one of the most widely implemented mitigation measures for addressing nutrient loss in overland flow from agricultural soils. However, there are significant uncertainties in the effectiveness of RBSs due to the impact of inter alia terrain, land use, soil type and hydrological connectivity on their ability to mitigate nutrient loss in overland flow.This study evaluates the effectiveness of four RBS designs: 2m wide grass, 10m wide grass,2m wide trees, and 10m wide trees, in different topographic and soil scenarios. Basins were first characterised within the Upper Bann catchment (250km2) in Northern Ireland using flowcontributing area and average slope data extracted from a 5m Digital Elevation model to create basin specific topographic profiles. Soil drainage characteristics were then attributed to the riparian agricultural fields using The Ordinance Survey Map of Northern Ireland (OSNI). Using both the topographic profiles and soil characteristics, fields were then grouped into typologies through cluster analysis in R. The RBS designs were then evaluated for each site typology using the Riparian Ecosystem Management Model (REMM) to estimate the change in pollutant loading for each scenario. This approach enabled not only the evaluation of the RBS but also how their effectiveness varies among site specific characteristics in the Upper Bann. We conclude that topography and soil characteristics are of greater importance on nutrient reduction than buffer strip width, and can be used to direct the placement of RBS templates in the landscape. Greater site specific targeting of RBSs in the landscape is required in order to maximise pollutantreduction.55'