A fully integrated SWAT-MODFLOW hydrologic model

Authors: Guzman Jaimes, Jorge; Moriasi, Daniel; Gowda, Prasanna; Steiner, Jean; Arnold, Jeffrey; SRINIVASAN, RAGHAVAN - Texas A&M University; Starks, Patrick

Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 2/17/2012
Publication Date: N/A
Citation: N/A

Interpretive Summary: Abstract only.

Technical Abstract: The Soil and Water Assessment Tool (SWAT) and MODFLOW models are being used worldwide for managing surface and groundwater water resources. The SWAT models hydrological processes occurring at the surface including shallow aquifers, while MODFLOW simulate groundwater processes. However, neither SWAT nor MODFLOW can independently simulate the full extent of the hydrological cycle at the watershed scale. Further, spatially variable recharge inputs to MODFLOW are normally assumed constant and estimated as a percentage of rainfall, which is not always realistic. In this study, SWAT (v. 477) and MODFLOW-NWT were interfaced through routines that decoded simulated fluxes between SWAT hydrological units (HRU) and MODFLOW grids at user defined time steps. Also, new tools were developed using DELPHI to assist users to create SWAT-MODFLOW linking files and setup MODFLOW packages (i.e., NAM, BAS, DIS, RCH, UPW, NWT, and OC). The integrated model was evaluated with the Fort Cobb experimental watershed dataset for the period 2005-2010. Measured groundwater levels from the underlying Rush Spring aquifer and flow data at daily time-step from five gauge stations located within the watershed were used for this purpose. Calibration and validation results from this study will be presented and discussed.