SWAT Literature Database for Peer-Reviewed Journal Articles

Title:The relationship between land use and vulnerability to nitrogen and phosphorus pollution in an urban watershed 
Authors:Tasdighi, A., M. Arabi and D.L. Osmond 
Journal:Journal of Environmental Quality 
Volume (Issue):46(1) 
Article ID: 
URL (non-DOI journals): 
Broad Application Category:hydrologic only 
Primary Application Category:hydrologic assessment 
Secondary Application Category:none 
Watershed Description:4,367 km^2 Jordan Lake drainage area, located in north central North Carolina. 
Calibration Summary: 
Validation Summary: 
General Comments:SWAT served a relatively minor role in this study, being used to estimate streamflow at monitoring stations where measured streamflow data were not available. 
Abstract:Characterization of the vulnerability of water bodies to pollution from natural and anthropogenic sources requires understanding the relationship between land use and water quality. This study aims (i) to explore the influence of upstream land use on annual stream water concentrations and loads of total nitrogen (TN) and phosphorus (TP) and (ii) to characterize the vulnerability of water bodies to TN and TP pollution as a function of land use under varying climatic conditions. Multiple linear regression models were used across 23 stream locations within the Jordan Lake watershed in North Carolina between 1992 and 2012 to explore land use–water quality relationships. The percentage of urban land use and wastewater treatment plant capacity were the most important factors with strong (R2 > 0.7) and significant (p < 0.01) positive correlations with annual TN and TP concentrations and loads. Percent agricultural land was negatively correlated with TN in 18 out of 21 yr of the study period. Using analysis of covariance, significant (p < 0.01) differences were determined between models developed for urban land use with TN and TP loads based on annual precipitation. Using concentrations instead of loads resulted in a nonsignificant difference between models for average and wet years. Finally, a procedure was developed to characterize the vulnerability to TN and TP pollution, computed as the probability of exceeding the nutrient standard limits. Results indicated that the vulnerability to TN and TP was controlled primarily by urban land use, with higher values in dry years than normal and wet years.