Surface-water Hydrology, Groundwater Hydrology, Hydraulics, Irrigation Engineering, Environmental Quality and Water Resources. Principal research topics have encompassed: 1. Watershed modeling, 2. Erosion and Sediment Transport in Upland Watersheds, 3. Streamflow Forecasting, 4. Dam Break Analysis, 5. Entropy-Based Modeling, 6. Network Design, 7. Groundwater Modeling, and 8. Hydrologic Impacts of Climate Change.