One of the key inputs of a hydrologic budget is the potential evapotranspiration (PET), which represents the hypothetical upper limit to evapotranspirative water losses. However, different mathematical formulas proposed for defining PET often produce inconsistent results and challenge hydrological estimation. The objective of this study is to investigate the effects of the Priestley–Taylor (P–T), Hargreaves, and Penman–Monteith methods on daily streamflow simulation using the Soil and Water Assessment Tool (SWAT) for the southeastern United States. PET models are compared in terms of their sensitivity to the SWAT parameters and their ability to simulate daily streamflow over a five-year simulation period. The SWAT model forced by these three PET methods and by gauged climatic dataset showed more deficiency during low and peak flow estimates. Sensitive parameters vary in magnitudes with more skew and bias in saturated soil hydraulic conductivity and shallow aquifer properties. The results indicated that streamflow simulation using the P–T method performed well especially during extreme events’ simulation.
Article navigation
Research Article|July 04 2016
Assessing the sensitivity of SWAT physical parameters to potential evapotranspiration estimation methods over a coastal plain watershed in the southeastern United States
S. Zahra Samadi
S. Zahra Samadi
1Department of Civil and Environmental Engineering, University of South Carolina (USC), Columbia, SC 29208, USA
E-mail: samadi@cec.sc.edu
Search for other works by this author on:
Hydrology Research (2016) 48 (2): 395-415.
Article history
Received:
January 15 2016
Accepted:
May 11 2016
Citation
S. Zahra Samadi; Assessing the sensitivity of SWAT physical parameters to potential evapotranspiration estimation methods over a coastal plain watershed in the southeastern United States. Hydrology Research 1 April 2017; 48 (2): 395–415. doi: https://doi.org/10.2166/nh.2016.034
Download citation file:
×
Sign in
Don't already have an account? Register
You could not be signed in. Please check your email address / username and password and try again.