Data are from 1,000 river and stream sites across the conterminous US where consistent biological, chemical, physical and watershed data were gathered. The sites were selected using a probability survey design so that the results provide inferences to all perennial flowing waters in the lower 48 states. This dataset is associated with the following publication: Omernik, J., S. Paulsen , M. Weber , and G. Griffith. Regional patterns of total nitrogen concentrations in the National Rivers and Streams Assessment. JOURNAL OF SOIL AND WATER CONSERVATION. Soil and Water Conservation Society, 71(3): 167-181, (2016).

This tabular data set represents the mean rate of nitrogen from fertilizer and manure applied on agricultural land in 1997 compiled for two spatial components of the NHDPlus version 2 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data for mean rate of nitrogen from fertilizer and manure applied on agricultural land in 1997 was produced by Ruddy and others, (USGS, 2006). Units are kilogram per square kilometer. Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values are computed using two methods, 1) divergence-routed and 2) total cumulative drainage area. Both approaches use a modified routing database to navigate the NHDPlus reach network to aggregate (accumulate) the metrics derived from the reach catchment scale. (Schwarz and Wieczorek, 2018).

This tabular data set represents the mean rate of nitrogen from fertilizer and manure applied on agricultural land in 1997 compiled for two spatial components of the NHDPlus version 2 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data for mean rate of nitrogen from fertilizer and manure applied on agricultural land in 1997 was produced by Ruddy and others, (USGS, 2006). Units are kilogram per square kilometer. Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values are computed using two methods, 1) divergence-routed and 2) total cumulative drainage area. Both approaches use a modified routing database to navigate the NHDPlus reach network to aggregate (accumulate) the metrics derived from the reach catchment scale. (Schwarz and Wieczorek, 2018).

This tabular data set represents the mean rate of nitrogen from fertilizer and manure applied on agricultural land in 1997 compiled for two spatial components of the NHDPlus version 2 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data for mean rate of nitrogen from fertilizer and manure applied on agricultural land in 1997 was produced by Ruddy and others, (USGS, 2006). Units are kilogram per square kilometer. Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values are computed using two methods, 1) divergence-routed and 2) total cumulative drainage area. Both approaches use a modified routing database to navigate the NHDPlus reach network to aggregate (accumulate) the metrics derived from the reach catchment scale. (Schwarz and Wieczorek, 2018).

Data include watershed N export from approximately 25 Willamette River basin tributaries, including information about nitrogen inputs to the watersheds. Data used for the following paper: Compton, J.E., Goodwin, K.E., Sobota, D.J. and Lin, J., 2019. Seasonal Disconnect Between Streamflow and Retention Shapes Riverine Nitrogen Export in the Willamette River Basin, Oregon. Ecosystems, pp.1-17. https://doi.org/10.1007/s10021-019-00383-9. This dataset is associated with the following publication: Compton, J., K. Goodwin, D. Sobota, and J. Lin. Seasonal disconnect between streamflow and retention shapes riverine nitrogen export in the Willamette River Basin, Oregon. ECOSYSTEMS. Springer, New York, NY, USA, 23: 1-17, (2020).

This dataset represents estimated surface water TN flux within individual, local NHDPlusV2 catchments and upstream, contributing watersheds. Measured as kg N/km2.

This dataset represents estimated surface water TN load within individual, local NHDPlusV2 catchments and upstream, contributing watersheds. Measured as kg Nitrogen.

This dataset represents Nitrogen from rock weathering (kg/ km2) within AOI

This dataset represents the application of nitrogen within individual, local NHDPlusV2 catchments and upstream, contributing watersheds based data published in EPA EnviroAtlas. Attributes were calculated for every local NHDPlusV2 catchment and accumulated to provide watershed-level metrics. These data are based on county-scale estimates of N in the form of fertilizer, manure, or cultivated biological nitrogen fixation. The rasters used for this analysis were prepared for EnviroAtlas published datasets on agricultural nitrogen inputs. Links to data in each raster can be found in Data Sources below. The nitrogen characteristics (kg N/ha/yr) were summarized to produce local catchment-level and watershed-level metrics as a continuous data type.

This dataset represents the density of nitrogen surplus as kg N / yr, excluding biological N Fixation, within individual, local NHDPlusV2 catchments and upstream, contributing watersheds.