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ARS Home » Southeast Area » Tifton, Georgia » Southeast Watershed Research » Research » Publications at this Location » Publication #347818

Research Project: Enhancing Water Resources, Production Efficiency and Ecosystem Services in Gulf Atlantic Coastal Plain Agricultural Watersheds

Location: Southeast Watershed Research

Title: Comparative analysis of SWAT model with Coupled SWAT-MODFLOW model for Gibbs Farm Watershed in Georgia

Author
item Sangeetha, Kumar - Indian Institute Of Technology
item Narasimhan, Balaji - Indian Institute Of Technology
item Bosch, David - Dave
item Coffin, Alisa

Submitted to: Annual International SWAT Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/8/2017
Publication Date: 1/10/2018
Citation: Sangeetha, K., Narasimhan, B., Bosch, D.D., Coffin, A.W. 2018. Comparative analysis of SWAT model with Coupled SWAT-MODFLOW model for Gibbs Farm Watershed in Georgia. Annual International SWAT Conference. Pending Volume/Page.

Interpretive Summary:

Technical Abstract: In recent years, rapid world population growth has led to increased water demand. For efficient water resource management, a clear understanding of the linkages between the Surface Water (SW) and Ground Water (GW) is essential. The most commonly used watershed scale SW model is the Soil and Water Assessment Tool (SWAT) while the most commonly used GW model is the Modular Three-Dimensional Finite-Difference Groundwater Flow Model (MODFLOW). SWAT does not simulate the distribution and dynamics of GW levels and recharge rates . The major drawback of integrating SWAT with MODFLOW is the conversion from SWAT’s HRU's/sub-basins to grids for compatibility with MODFLOW. SWAT uses a one-dimensional empirical equation called Hooghoudt’s equation for simulating base flow contribution. Many studies have integrated the SWAT and MODFLOW models successfully for comprehensive assessment of (SW-GW) water resources. By integrating these two models, the spatial and temporal patterns of the interactions are better captured and assessed. This paper demonstrates the comparison of results of the SWAT model with the newly developed SWATMOD-Prep, graphical user interface, that couples a SWAT watershed model with a MODFLOW groundwater flow model. GW levels in the surficial aquifer and streamflow were examined and tested for a seven-year period at the University of Georgia Coastal Plain Experiment Station Gibbs Farm watershed (125 ha) near Tifton, Georgia. Spatial and temporal patterns of SW-GW interactions were studied throughout the watershed by comparing the results of the SWAT model with the coupled SWAT-MODFLOW model. Both the models were calibrated with observed values to replicate the responses of the SW and GW interactions in a reasonable way.