Agricultural Ecology Program: Understanding sources and sinks of
nutrients and sediment in the upper Susquehanna River basin

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Models: Regional Nutrient Management (ReNuMa)

          ReNuMa is a large-watershed-scale model designed to allow planners and other stakeholders to explore scenarios for reducing N fluxes from the landscape. We have been funded by the US EPA STAR program and NOAA’s CHRP program to develop ReNuMa, a "descendent" of the GWLF model of Haith and Shoemaker (1987). This lumped parameter model has been an excellent predictor of freshwater discharge for the Hudson River and its tributaries on a fine temporal scale, and a good predictor of inputs of sediment and organic carbon on a monthly to seasonal time scale (Howarth et al. 1991; Swaney et al. 1996). GWLF has also been used to estimate nutrient loads into the Delaware River (Haith and Shoemaker 1987), the Tar-Pamlico estuary (Dodd and Tippett 1994), and the Choptank River drainage of Chesapeake Bay (Lee et al. 2000, 2001). However, the characterization of the N cycle within GWLF is excessively simple for our purposes. For example, it does not include denitrification, or within-soil, riparian-zone, and in-stream processes. Nor does it explicitly consider atmospheric inputs of N, even though these are the major nonpoint sources of N to many waters and watersheds in the northeastern US and elsewhere (Howarth et al. 1996, 2002b; NRC 2000; Boyer et al. 2002). In developing ReNuMa, we are adding modules to better capture biogeochemical complexity and the relationship between hydrology and nutrient sources and sinks in the landscape, as well as the effects of management practices on nutrient loads.

Genealogy of the GWLF family of models (modified from Swaney et al., in prep).

ERF 2003 Poster detailing ReNuMa

ASLO 2005 poster about ReNuMa applied to watersheds in the northeastern U.S.

Download ReNuMa1.0 spreadsheet software and auxiliary files (.zip format)

Download ReNuMa2.0 spreadsheet software and auxiliary files (.zip format)

Download ReNuMa2.1 spreadsheet software and auxiliary files (.zip format)

ReNuMa as applied to upper Susquehanna River watershed (Under Construction)

Support for development of ReNuMa has been provided by:

Current work is being supported by NOAA award NA05NOS478120 from the NOAA Center for Sponsored Coastal Ocean Research, Coastal Hypoxia Research Program, to D. Scavia, G. Helfand, R. Howarth, R. Alexander and D. Breitberg.

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