Integrated Numerical Modeling of Spatial and Time-Variant Hydrologic Response in Subsurface Drained Watersheds
Field-scale studies showed that the subsurface module could provide good predictions with accurate descriptions of soil hydraulic properties, climatic data and drainage parameters. Simulated results at the field scale also indicated that the subsurface model was highly sensitive to estimates of evapotranspiration during the summer. Hydraulic parameters obtained from calibration studies failed to simulate post-rainfall event recessions. Drain flow simulations that included macropore flow resulted in higher magnitudes of response and better agreement with observed data, compared to simulations that considered sorptive flow alone. Simulations also showed that drain responses were in better agreement with observed flows during low rainfall, as compared to high rainfall. Results from the application of the integrated model to the Upper Little Vermilion River Watershed showed that the integrated modeling framework underestimated stream flows, indicating the importance of contributions from surface runoff and ditch drainage.
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign