Across North Carolina, excessive sediment and nutrient loading has contributed to the degradation of surface-water quality. To further understand the influence of human activities and natural processes on surface-water quality, the U.S. Geological Survey (USGS) developed the SPARROW (SPAtially Referenced Regressions On Watershed attributes) modeling framework to relate water-quality monitoring data to upstream nutrient and sediment sources and watershed characteristics. The model can be used to predict pollutant concentrations, loads, and yields in streams and these predictions are the basis for the North Carolina Water-Quality Model Mapper. The mapper can be used to evaluate alternative hypotheses about the relative importance of various pollutant sources.
Data collected at 235 water-quality monitoring stations throughout the state were used to inform the SPARROW model for North Carolina. The NC Water-Quality Model Mapper displays yields and source shares for sediment (using total suspended solids as a surrogate for sediment processes), total nitrogren, and total phosphorus. This work aims to support conservation efforts by assisting with the identification of watersheds with a maximum water-quality restoration potential.
Click the "Select Data" tab below to query water-quality model data. Click the "View Data" tab to view additional information. Click the User Guide button above for aditional instructions.
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| Channel Erosion: Scour | Sediment loss due to scour. |
|---|---|
| Channel Erosion: Incision | Erosion due to wearing of banks. |
| Land Disturbance | Sediment loss due to land use change between 2002 and 2012. |
| Development | Sediment from urban non-point runoff. |
| Cropland | Sediment loss from agronomic production. |
For complete descriptions of data sources, please visit the Data Download page.
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| Point Sources | Nitrogen in wastewater. |
|---|---|
| Atmospheric Deposition | Wet and dry deposition of nitrogen. |
| Swine Operations | Nitrogen loss associated with swine production. |
| Poultry Operations | Nitrogen associated with poultry production. |
| Development | Nitrogen from urban non-point runoff. |
| Farm Fertilizer | Nitrogen fertilizer applied to cropland. |
For complete descriptions of data sources, please visit the Data Download page.
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| Point Sources | Phosphorus in wastewater. |
|---|---|
| Natural P | Phosphorus associated with natural geology. |
| Poultry Operations | Phosphorus associated with poultry production. |
| Pasture | Phosphorus loss due to animal pasture and hay production. |
| Legacy Soil P | Phosphorus content of topsoil. |
| Farm Fertilizer | Phosphorus fertilizer applied to cropland. |
| Development | Phosphorus from non-point urban runoff |
| Channel Erosion: Scour | Phosphorus loss due to scour. |
For complete descriptions of data sources, please visit the Data Download page.
| HUC 8 Number | |
|---|---|
| HUC 8 Name | |
| Basin Name | |
| Area | |
| Total Sediment Yield | |
| Total Nitrogen Yield | |
| Total Phosphorus Yield |
