Advances in Geosciences www.adv-geosci.net 1680-7340 1680-7359 5 Proceedings of the 8th Workshop for Large Scale Hydrological Modelling - Oppurg 2004 2005 10.5194/adgeo-5-13-2005 http://www.adv-geosci.net/5/13/2005/ http://www.adv-geosci.net/5/13/2005/adgeo-5-13-2005.html http://www.adv-geosci.net/5/13/2005/adgeo-5-13-2005.pdf 13 17 2005-12-16 Integrated analysis of water quality in a mesoscale lowland basin A. Habeck V. Krysanova F. Hattermann Potsdam Institute for Climate Impact Research (PIK), Telegrafenberg, 14473 Potsdam, Germany This article describes a modelling study on nitrogen transport from diffuse sources in the Nuthe catchment, representing a typical lowland region in the north-eastern Germany. Building on a hydrological validation performed in advance using the ecohydrological model SWIM, the nitrogen flows were simulated over a 20-year period (1981-2000). The relatively good quality of the input data, particularly for the years from 1993 to 2000, enabled the nitrogen flows to be reproduced sufficiently well, although modelling nutrient flows is always associated with a great deal of uncertainty. Subsequently, scenario calculations were carried out in order to investigate how nitrogen transport from the catchment could be further reduced. The selected scenario results with the greatest reduction of nitrogen washoff will briefly be presented in the paper.