SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Assessment of surface water resources in the Big Sunflower River Watershed using coupled SWAT–MODFLOW model 
Authors:Gao F., G. Feng, M. Han, P. Dash, J. Jenkins and C. Liu 
Volume (Issue):11(3) 
Article ID:528 
URL (non-DOI journals): 
Broad Application Category:BMP review or conceptual approach 
Primary Application Category:model and/or data interface 
Secondary Application Category:hydrologic assessment 
Watershed Description:10,488 km^2 Big Sunflower River, located in northwest Mississippi, U.S. 
Calibration Summary: 
Validation Summary: 
General Comments: 
Abstract:The groundwater level in the Big Sunflower River Watershed (BSRW) in the U.S. has declined significantly in the past 30 years. Therefore, it is imperative to assess surface water resources (SWR) availability in BSRW to mitigate groundwater use for irrigation. This research applied the coupled Soil and Water Assessment Tool–Modular Groundwater Flow model (SWAT–MODFLOW) to assess SWR in BSRW. This study aimed at: (1) Assessing the reliability of SWAT–MODFLOW in BSRW, (2) analyzing temporal and spatial variations of SWR, and (3) assessing the potential availability of SWR in BSRW. Calibration and validation results showed that SWAT–MODFLOW can well simulate streamflow and groundwater levels in BSRW. Our results showed that BSRW had lower average monthly total stream resources (MSR = 8.8 × 107 m3) in growing seasons than in non-growing seasons (MSR = 11.0 × 107 m3), and monthly pond resources (MPR from 30,418 to 30,494 m3) varied less than stream resources. The proportion of sub-basins in BSRW with stream water resources greater than 700 mm was 21% in dry years (229 to 994 mm), while this increased to 35% in normal years (296 to 1141 mm) and 57% in wet years (554 to 991 mm). The Water Stress Index (WSI) ranged from 0.4 to 2.1, revealing that most of the sub-basins in BSRW have net SWR available for irrigation. Our results suggested that surface water resources might be supplementary irrigation sources to mitigate the water resources scarcity in this region. 
Keywords:surface water availability, stream, pond, Soil and Water Assessment Tool—Modular Groundwater Flow model, Big Sunflower River Watershed, Mississippi Delta