Comparison of two hydrological models on a Virginia Piedmont watershed

KINEROS and PSRM-QUAL:J two distributed parameter event-based hydrologic models, were applied to Foster Creek Watershed, Louisa County, Virginia. The simulations of the two models were conducted using published data and a ten year database from the Foster Creek Watershed, Louisa County, Virginia. Data management and analysis was supported through the use of PC-VirGIS, a DOS based GIS package developed by the Information Support Systems Laboratory, Virginia Tech.

The performance of the two models were based on the criteria established to compare the simulated and recorded peak discharge rates , total runoff volumes and time to peak. Goodness of fit criteria were based on graphic comparison relative error, model efficiency, linear regression, hypothesis testing and variance. Based on these measurements, the simulated results by both models were acceptable. KINEROS generally made better predictions of peak discharge rate and time to peak. Hydrograph shapes also generally matched the recorded sequence more closely. PSRM-QUAL simulated the total runoff volume slightly better than KINEROS.

The sensitivity of KINER OS and PSRM-QUAL to the model input parameters was evaluated. For KINEROS, peak discharge rate and runoff volume were very sensitive to changes in rainfall amount, saturated hydraulic conductivity and effective capillary drive. For PSRM-QUAL, peak discharge rate and total runoff volume were very sensitive to changes in SCS CN, initial abstraction coefficient and rainfall amount.