1. Researcher, Dept. of Hydraulics and Sanitary Engineering, Univ. of São Paulo, P.O. Box 359, São Carlos, SP 13566-590, Brazil (corresponding author).
2. Professor, Dept. of Hydrology and Water Resources, Univ. of Arizona, Tucson, AZ 85721.
3. Research Associate Professor, Dept. of Hydrology and Water Resources, Univ. of Arizona, Tucson, AZ 85721.
4. Researcher, Dept. of Hydraulics and Sanitary Engineering, Univ. of São Paulo, P.O. Box 359, São Carlos, SP 13566-590, Brazil.
5. Professor, Dept. of Hydraulics and Sanitary Engineering, Univ. of São Paulo, P.O. Box 359, São Carlos, SP 13566-590, Brazil.
6. Planning Analyst, Colorado River Programs, Central Arizona Project, P.O. Box 43020, Phoenix, AZ 85080.