1. Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
2. Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
3. Central Midwest Water Science Center, U. S. Geological Survey, Urbana, IL, USA
4. U.S. Geological Survey, Columbia Environmental Science Center, Columbia, MO, USA