Climatic Variability and Flood Frequency of the Santa Cruz River, Pima County, Arizona.

摘要

Past estimates of the 100-year flood for the Santa Cruz River at Tucson, Arizona, range from 572 to 2,780 cubic meters per second. Am apparent increase in flood magnitude during the past two decades raises concern that the annual flood series is nonstationary in time. The apparent increase is accompanied by more annual floods occurring in fall and winter and fewer in summer. The greater mixture of storm types that produce annual flood peaks is caused by a higher frequency of meridional flow in the upper-air circulation and increased variance of ocean-atmosphere conditions in the tropical Pacific Ocean.