MODELING NITROGEN DYNAMICS IN THE TIOUGHNIOGA RIVER, NEW YORK

Elevated nutrient concentrations such as nitrogen have led to serious problems of surface water eutrophication and groundwater contamination in many places around the world. Chesapeake Bay has been the subject of intensive research on eutrophication and nutrient input reductions. Tioughnioga River, the headwater to the Susquehanna River and Chesapeake Bay, plays an important role in controlling the transport of nutrients downstream. In this study, an integrated catchment nitrogen model (INCA-N) is used to simulate in-stream nitrate concentrations in the headwater of Tioughnioga River which begins as two branches with contrasting land use characteristics. The model is calibrated using the weekly nitrate concentrations at the mouths of two branches and monthly nitrate concentrations from multiple locations along the two branches from 2012 to 2014 and 2016. Preliminary modeling results suggest the main drive of the in-stream nitrate concentrations is the agricultural practices. The model is also sensitive to hydrological controls such as precipitation. Projected climate change effects in the Tioughnioga River using the INCA-N model will be explored in future studies.