El Nino-La Nina Implications on Flood Hazard Mitigation Phoenix, AZ Area

In a previous investigation, five maximum annual winter period daily depths of precipitation series from gaging stations on the U.S. Department of Energy's Nevada Test Site were examined from the viewpoint of the effects of El Nino - La Nina events on the series. This analysis demonstrated at the five precipitation gages considered, with periods of record ranging from 33 to 45 years, that there were actually two data series; one series associated with El Nino periods and a second series with La Nina events and neutral periods. That is, the precipitation data series contained a mixed population. This has critical implications from both the viewpoints of flood hazard identification and mitigation when rainfall-runoff modeling is used and environmental restoration. In this paper, annual maximum (winter and summer) depths of precipitation are analyzed for five long-term gaging stations in the Phoenix, AZ area.