Location: Hydrology and Remote Sensing LaboratoryTitle: Effects of surface runoff and infiltration partition methods on hydrological modeling: A comparison of four schemes in two watersheds in the Northeastern US
|QI, J. - University Of Maryland
|LEE, S. - University Of Maryland
|ZHANG, X. - University Of Maryland
|YANG, Q. - University Of Maryland
Submitted to: Journal of Hydrology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/29/2019
Publication Date: 11/26/2019
Citation: Qi, J., Lee, S., Zhang, X., Yang, Q., McCarty, G.W., Moglen, G.E. 2019. Effects of surface runoff and infiltration partition methods on hydrological modeling: A comparison of four schemes in two watersheds in the Northeastern US. Journal of Hydrology. 581:124415. https://doi.org/10.1016/j.jhydrol.2019.124415.
Interpretive Summary: Modeling off-field movement of agricultural contaminants is important for understanding their fate in watersheds. The ratio of surface runoff to infiltration resulting from precipitation or snow melt is an important parameter in estimating overland transport of less soluble contaminants such as phosphorus, or leaching and subsurface movement of soluble contaminants such as nitrate. This study compared various surface runoff and infiltration partitioning methods using a Richards-equation-based SWAT model (RSWAT). A set of different models were tested to simulate the daily flow rate at the outlets of the Tuckahoe Creek watershed and Greensboro watershed of the Chesapeake Bay in Maryland. Of the models tested, analyses showed that the Daily Curve Number (DC)-RSWAT was the best performing model based on calibration and validation on the two watersheds. Generally, it was found that this model achieved more accurate flow simulation with reduced uncertainty. This improved SWAT model will permit better estimation of contaminant delivery by surface and subsurface mechanisms.
Technical Abstract: The ratio by which the precipitation/snowmelt is divided into surface and subsurface water is of primary importance to watershed scale hydrological modeling. The present study compared four different surface runoff and infiltration partition methods in the Richards-equation-based SWAT model (RSWAT), i.e., daily curve number method (DC-RSWAT), hourly curve number method (HC-RSWAT), Green-Ampt method (GA-RSWAT), and effective infiltration capacity method (EIC-RSWAT). These four versions of RSWAT and a daily-curve-number-based SWAT (DC-SWAT) were used to simulate daily flow rate (from 2001 to 2015) at the outlets of the Tuckahoe Creek Watershed (TCW) and Greensboro Watershed (GW) of the Chesapeake Bay in Maryland. Parameter sensitivity analysis, calibration, and prediction uncertainty analysis were conducted. The results indicate that surface runoff and infiltration partition methods have pronounced impacts on model performance. Comparative analysis showed that DC-RSWAT outperformed other versions of RSWAT for both calibration (from 2001 to2007) and validation (from 2008 to 2015) periods in the two test watersheds. In general, DC-RSWAT achieved more accurate deterministic flow simulation and reliable uncertainty estimation than other versions. As such, daily-curve-number method is recommended for surface runoff and infiltration partition in RSWAT for simulating stream flow.