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IWR Presents at the International SWAT Conference

GIS Specialist Glenn O’Neil presented at the 2015 International Soil & Water Assessment Tool Conference, October 12-16 at Purdue University, on Mapping Ground Water Recharge Rates in Southwest Michigan under Multiple Future Climate Simulations. The full abstract is available below.

This study used the Soil and Water Assessment Tool (SWAT) to map rates of ground water recharge under various projections of future climate in Southwest Michigan. The following five river basins were modeled with SWAT: the Kalamazoo, the Paw Paw, the headwaters of the St. Joseph (of Indiana and Michigan), the Thornapple, and Upper Dowagiac. Each model was developed using observed weather data from 1995 to 2010, which were originally interpolated to grid points by Maurer et al. (2002). To best simulate ground water hydrology within SWAT, the models were calibrated at multiple USGS stream gages to base flow conditions. The models were also adjusted to align with published rates of evapotranspiration, published estimates of base flow separation, irrigation rates reported to Michigan Department of Environmental Quality, and county-level crop yield estimates. The models were then run forward with future climate data organized and down-scaled by Hayhoe et al. (2013) to the grid points generated by Maurer et al. These climate projections included 10 different models, each under two to three different scenarios (A1B, A1fi, A2, B1). SWAT outputs projected overall increases in ground water recharge rates through the end of the century, mainly attributable to increases in precipitation within the different climate scenarios. However, recharge rates increased sharply towards the end of the century in climate scenarios in which CO2 is projected to be high (A1fi). These higher rates were attributable to decreases in projections of evapotranspiration, which were due to decreasing leaf conductance as CO2 levels rose.

For more information about the conference, click here.