1. Department of Electrical and Computer Engineering, University of Missouri–Columbia, Columbia, MO 65211, USA.
2. Desert Research Institute, University and Community College System of Nevada, Reno, NV 89512, USA.
3. Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ 85721, USA.
4. Department of Geography, University of Sheffield, Sheffield S10 2TN, UK.