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John W Brakebill

Acting Director, Integrated Modeling and Prediction Division

Office of the Chief Operating Officer

Office Phone: 443-498-5557
Fax: 443-498-5510
ORCID: 0000-0001-9235-6810

UMBC Research Park
U.S. Geological Survey
5522 Research Park Drive
Baltimore , MD 21228

Supervisor: Stephen R Moulton II
This dataset includes all of the variables that were used in predictive models to estimate nitrogen and phosphorus fertilizer use from commercial fertilizer sales data at the catchment/county level for the Conterminous U.S. for the year 2012. The dataset includes model input at the catchment/county level. A companion USGS Scientific Investigations Report describes the methods and subsequent results of two models developed for estimating elemental nitrogen and phosphorus commercial fertilizer use on agricultural lands for the conterminous US at the catchment/county scale for the year 2012. A companion data release provides catchment-level estimates of nitrogen and phosphorus fertilizer use, for agricultural lands,...
This dataset contains catchment-level estimates of nitrogen and phosphorus fertilizer use, for agricultural lands, for the conterminous U.S., for 2012. An approach was developed to relate farm commercial fertilizer sales data from the Association of American Plant Food Control Officials (AAPFCO) to a set of explanatory variables using spatially-referenced modeling methods. Separate models for nitrogen and phosphorus are developed to estimate elemental fertilizer use on agricultural lands for the conterminous U.S. at the National Hydrography Dataset Plus version 2 (NHDPlusV2) catchment scale. The approach builds on earlier efforts that use Association of American Plant Food Control Officials (AAPFCO) data on fertilizer...
These data represent input and estimates from a medium-resolution (1:100,000 scale) NHDPlus SPAtially Referenced Regression on Watershed attributes (SPARROW) model for the Chesapeake Bay watershed (CBSS_v2). The model spatially correlates long-term mean annual suspended-sediment flux in 113 non-tidal streams to likely upland and stream-corridor sources, landscape factors affecting upland sediment transport and delivery to stream corridors, and fluvial and reservoir retention representing the early 2000 time period. The item COMID is a common related field between the data file and the spatial component (catchments) in NHDPlus version 1.0.
This data release contains mean-annual total nitrogen (TN) loads predicted by a SPARROW model for individual stream and shoreline reaches in the Chesapeake watershed as defined by NHDPlus, a 1:100,000 scale representation of stream hydrography built upon the National Hydrography Dataset (NHD) (Horizon Systems, 2010). Also included are the input variables required to execute the model, including landscape characteristics, nutrient inputs to land, and calibration data from water quality monitoring stations. Further details on model construction and results are described in Ator (2011,
The National Hydrography Dataset Plus, Version 2 (NHDPlusV2) is an attribute rich, digital hydrologic network for the Conterminous U.S. developed by the U.S. Environmental Protection Agency (EPA) and U.S. Geological Survey (USGS). SPAtially Referenced Regressions On Watershed attributes (SPARROW), is a process-based/statistical model that relies on a digital hydrologic network, like NHDPlusV2, in order to establish spatial relations between monitored contaminant loads, contaminant sources, and other watershed characteristics. The USGS National Water Quality Assessment (NAWQA) project adopted the medium-resolution NHDPlusV2 network as the primary framework supporting SPARROW modeling, and has become a unifying system...
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