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ARS Home » Plains Area » El Reno, Oklahoma » Grazinglands Research Laboratory » Agroclimate and Natural Resources Research » Research » Publications at this Location » Publication #290257

Research Project: AGRICULTURAL LAND MANAGEMENT TO OPTIMIZE PRODUCTIVITY AND NATURAL RESOURCE CONSERVATION AT FARM AND WATERSHED SCALES

Location: Agroclimate and Natural Resources Research

Title: A model integration framework for linking SWAT and MODFLOW

Author
item Guzman Jaimes, Jorge
item Moriasi, Daniel
item Gowda, Prasanna
item Steiner, Jean
item Arnold, Jeffrey
item Srinivasan, Raghavan - Texas A&M University
item Starks, Patrick - Pat

Submitted to: Journal of Environmental Modeling and Software
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/31/2015
Publication Date: 8/15/2015
Citation: Guzman Jaimes, J.A., Moriasi, D.N., Gowda, P., Steiner, J.L., Arnold, J.G., Srinivasan, R., Starks, P.J. 2015. A model integration framework for linking SWAT and MODFLOW. Journal of Environmental Modeling and Software. 73:103-116.

Interpretive Summary: Water movement and the associated transport of pollutants following rainfall events are driven by surface and subsurface processes. Therefore, it is important to develop models that can simulate the full extent of these processes. In this study, the Soil and Water Assessment Tool (SWAT) and the Modular Three-Dimensional Finite-Difference Groundwater Flow (MODFLOW) models simulating the surface and subsurface processes, respectively, were integrated. A modeling framework was developed in order to assist users with model setup, parameterization, and integration. This was accomplished by developing a series of new computer programs to enable interaction between the SWAT and MODFLOW models. The integrated model framework was tested using data from the Fort Cobb Reservoir Experimental Watershed located in southwestern Oklahoma. The developed modeling framework enables MODFLOW to simulate distributed daily infiltration and well extraction volumes estimated by the SWAT model. Errors in daily groundwater levels at three USGS monitoring wells were lower than 1% on average. This model integration is expected to improve simulation of distributed surface and subsurface water interaction thereby providing a platform for a more detailed simulation of the movement of pollutants and the impacts of human activity on surface and groundwater.

Technical Abstract: Hydrological response and transport phenomena are driven by atmospheric, surface and subsurface processes. These complex processes occur at different spatiotemporal scales requiring comprehensive modeling to assess the impact of anthropogenic activity on hydrology and fate and transport of chemical contaminants and nutrient. In this paper, the Soil and Water Assessment Tool (SWAT) and the Modular Three-Dimensional Finite-Difference Groundwater Flow (MODFLOW) models were integrated and coupled to better represent distributed surface-subsurface water interaction. Due to the differences in the models’ physical discretization and representation, a modeling framework was developed allowing model setup, parameterization, and integration. A series of new routines were incorporated in the SWAT model to dynamically interact with MODFLOW and a SWAT-MODFLOW project builder application, SWATmf, was developed. Using the coupled model, the surface-subsurface interactions were simulated at daily time-step (Oct-2010 to Aug-2012) to estimate groundwater levels in the Fort Cobb Reservoir Experimental Watershed located in southwestern Oklahoma. Additionally, the modeling framework was used to setup the stream network, reservoir and well extraction model features simulated by MODFLOW. The developed modeling framework enables MODFLOW to simulate distributed daily infiltration and well extraction volumes estimated by the SWAT model. Errors in daily groundwater levels at three USGS monitoring wells were lower than 1% on average ranging between -0.8 m to 4.4. m. A better hydrogeological characterization and parameterization of the aquifer is needed to properly represent the groundwater surface in the extent of the watershed. This modeling framework is expected to improve simulation of distributed surface and subsurface interactions of flow fluxes thus providing a platform for more detailed fate and transport phenomena simulation and a comprehensive approach to assess more realistically anthropogenic impacts on aquifers and streams.