SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Hydrologic modeling of an eastern Pennsylvania watershed with NEXRAD and rain gauge data 
Authors:Kalin, L. and M.H. Hantush 
Journal:Journal of Hydrologic Engineering 
Article ID: 
URL (non-DOI journals): 
Broad Application Category:hydrologic only 
Primary Application Category:climate data effects 
Secondary Application Category:hydrologic assessment 
Watershed Description:98.87 km^2 Pocono Creek (Pennsylvania) 
Calibration Summary:monthly base flow r2/NSE values (July 2002-May 2004): based on rain guage data=0.30/0.08, based on NEXRAD data=0.31/0.05; monthly surface runnoff r2/NSE values (July 2002-May 2004): based on rain gauge data=0.77/0.77, based on NEXRAD data=0.79/0.79; stream flow r2/NSE values (July 2002-May 2004): based on rain gauge data(daily)=0.74/0.74, based on rain gauge data(monthly)=0.85/0.83, based on NEXRAD data(daily)=0.74/0.73, based on NEXRAD data(monthly)=0.85/0.84 
Validation Summary:monthly base flow r2/NSE values (June 2004-April 2005): based on rain guage data=0.13/-0.26, based on NEXRAD data=0.06/-0.40; monthly surface runnoff r2/NSE values (June 2004-April 2005): based on rain gauge data=0.83/0.73, based on NEXRAD data=0.84/0.77; stream flow r2/NSE values (June 2004-April 2005): based on rain gauge data(daily)=0.70/0.64, based on rain gauge data(monthly)=0.81/0.66, based on NEXRAD data(daily)=0.66/0.62, based on NEXRAD data(monthly)=0.89/0.75 
General Comments: 
Abstract:This paper applies the Soil Water Assessment Tool (SWAT) to model the hydrology in the Pocono Creek watershed located in Monroe County, Pa. The calibrated model will be used in a subsequent study to examine the impact of population growth and rapid urbanization in the watershed on the base flow and peak runoff. Of particular interest in this paper is the exploration of potential use of Next Generation Weather Radar (NEXRAD) technology as an alternative source of precipitation data to the conventional surface rain gauges. NEXRAD estimated areal average precipitations are shown to compare well with the gauge measured ones at two climate stations in the study area. Investigation of the spatially distributed NEXRAD precipitation estimates revealed that average annual precipitation can vary spatially as much as 12% in the Pocono Creek watershed. The SWAT model is calibrated and validated for monthly stream flow, base flow, and surface runoff. Hydrographs generated from both gauge and NEXRAD driven model simulations compared well with observed flow hydrographs. Although little effort is spent on daily calibration, model simulations and observed flows were in good agreement at the daily scale as well. Almost similar model efficiency statistics, i.e., mass balance error (MBE), coefficient of determination (R2), and Nash-Sutcliffe efficiency (ENS), were obtained during the calibration period in the gauge and NEXRAD driven simulations. In the validation period, NEXRAD simulations generated higher model efficiencies at the monthly scale. On the other hand, simulations with gauge precipitations resulted in slightly better model efficiencies at the daily time scale. The spatial representation of precipitation did not contribute much to model performance when stream flow at the watershed outlet was the required output. However, the use of NEXRAD technology appears to offer a promising source of precipitation data in addition to currently existing surface gauge measurements. Discussions on new directions in radar-rainfall technology are provided.