Entrenchment and Widening of the Upper San Pedro River, Arizona

1980 Year Figure aerial photographs alluvial alluvial fans annual flood antecedent rainfall Arizona average daily discharge Babocomari River Bahre Betancourt and Turner cause of entrenchment channel enlargement channel widening Charleston cienegas climate Cochise Cooke and Reeves correlation cottonwood deposits downstream early eight weather stations entrenched channel f₁ Fairbank Fort Huachuca geomorphic geomorphology grazing Hastings and Turner Hereford bridge high-intensity rainfall Holocene inner valley inset June 15-October 15 large floods large runoff late Lewis Springs long-term average long-term pattern low-intensity rainfall mesquite occurred older floodplain Patagonia Pedro River valley postentrenchment alluvium pre-entrenchment alluvium pre-entrenchment terrace precipitation present probably rainfall and runoff rainfall intensity rate of channel riparian forest San Pedro River Santa Cruz River sediment shown in Figure shows stabilization stream entrenchment study area Tombstone trenchment tropical cyclones typical U.S. Geological Survey University of Arizona upper San Pedro upstream variation vegetation water table wet-season rainfall