[1] Pontificia Univ Catolica Chile, Dept Ingn Hidraul & Ambiental, Santiago, Chile
[2] Colorado State Univ, Dept Civil & Environm Engn, Ft Collins, CO 80523 USA
[3] US EPA, Natl Risk Management Res Lab, Cincinnati, OH 45268 USA
[4] US Army Corps Engineers, Hydrol Engn Branch, Hydrol Sect, Omaha, NE 68102 USA