Comparative analysis of HRU and grid-based SWAT models

Garett Pignotti, Hendrik Rathjens, Fnu Cibin Raj, Indrajeet Chaubey, Melba Crawford

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

A grid-based version of the Soil and Water Assessment Tool (SWAT) model, SWATgrid, was developed to perform simulations on a regularized grid with a modified routing algorithm to allow interaction between grid cells. However, SWATgrid remains largely untested with little understanding of the impact of user-defined grid cell size. Moreover, increases in computation time effectively preclude direct calibration of SWATgrid. To gain insight into defining appropriate strategies for future development and application of SWATgrid, this research considers the simulated differences between commonly-employed hydrologic response unit (HRU)-based and grid-based SWAT models and the implications of resolution on their simulation and calibrated parameter values for a Midwestern, agricultural watershed. Results indicate that: (1) the gridded approach underpredicted simulated streamflow between 5% and 50% relative to the baseline model, depending upon the input spatial resolution and routing algorithm implemented; (2) gridded models generally underpredicted total phosphorous and sediment loads while overpredicting nitrate load; and (3) ranges of values of optimized model parameters remained similar up to 90 m. Results from this analysis should help in defining future applications of the SWATgrid model and the effects of differing spatial resolution of the model input data.

Original languageEnglish (US)
Number of pages1
JournalWater (Switzerland)
Volume9
Issue number4
DOIs
StatePublished - Apr 11 2017

Fingerprint

Soil and Water Assessment Tool model
Soil
Soils
water
Water
Cell Size
Nitrates
Calibration
Routing algorithms
routing
Research
agricultural watersheds
spatial resolution
stream flow
simulation
calibration
nitrates
Grid Cells
analysis
soil and water assessment tool

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Geography, Planning and Development
  • Aquatic Science
  • Water Science and Technology

Cite this

Pignotti, Garett ; Rathjens, Hendrik ; Cibin Raj, Fnu ; Chaubey, Indrajeet ; Crawford, Melba. / Comparative analysis of HRU and grid-based SWAT models. In: Water (Switzerland). 2017 ; Vol. 9, No. 4.
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Comparative analysis of HRU and grid-based SWAT models. / Pignotti, Garett; Rathjens, Hendrik; Cibin Raj, Fnu; Chaubey, Indrajeet; Crawford, Melba.

In: Water (Switzerland), Vol. 9, No. 4, 11.04.2017.

Research output: Contribution to journalArticle

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