1. Assistant Professor, Dept. of Water Resources and Environmental Management, Al-Balqa Applied Univ., Al-Salt 19117, Jordan.
2. Associate Professor, Civil, Construction and Environmental Engineering Dept., North Carolina State Univ., Raleigh, NC 27695 (corresponding author).
3. Chief Scientist for Water, United States Geological Survey, 12201 Sunrise Valley Dr., Reston, VA 20192-0002.