This was a project done with a Master’s student from Biological and Agricultural Engineering, (Yu Liu).

Full Document: Hydrological Water Quality for the Upper South River Watershed

Abstract

Water quality is a very complex thing to model, and is dependent on several different parameters, including hydraulic and soils properties, and land use and management. The Upper South River watershed is located in Black River watershed, in Central North Carolina. The water quality of the watershed is simulated using ArcSWAT model from the period Jan. 1, 1988 to Dec. 31, 2010. SAS 9.1 and ArcGIS 9.3 are used to analyze the relationship of hydrologic response and containment transport. Agricultural land use is largely responsible for having high levels of ground water nitrate, organic nitrogen, and sediment and soluble phosphorus in the water.  Surface water runoff is well correlated with soil hydraulic group, but total sediment movement is associated with management, with soils having high slopes under agricultural conditions having more erosion then well forested areas. Organic N moves in the sediment along with P to surface water under high erosion, and groundwater nitrate was a function of the overall percolation level and soil water content. The agricultural watersheds have higher release of sediment and soluble P, as well as nitrate entering the water system when compared to their forested counterparts.

This is the surface runoff and the average sediment yield for each of the subbasins in the Upper Cape Fear Watershed

Sediment yield is well correlated with Organic Nitrogen delivered to waterways.

Nitrate moves into groundwater based on the soil hydrological grouping.

These are the Phosphorus levels that come from each watershed.

Key Findings

• SWAT is a useful tool in modeling contaminant transport, sediment load, river flow,  and nitrogen and phosphorus transport and transformation.
•  Surface water runoff is well correlated with soil hydraulic group, but total sediment movement is associated with management, with soils having high slopes under agricultural conditions having more erosion then well forested areas.
• Organic N moves in the sediment along with P to surface water under high erosion, and groundwater nitrate was a function of the overall percolation level and soil water content.
• The agricultural watersheds have higher release of sediment and soluble P, as well as nitrate entering the water system when compared to their forested counterparts.