Hydrogeochemical Modeling of Western Mountain Front Recharge, Upper Cienega Creek Sub-Basin, Pima County, Arizona
PublisherThe University of Arizona.
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AbstractUsing historical and current water quality data, the geochemical processes responsible for controlling the chemical evolution of groundwater in the Upper Cienega Creek Basin are characterized and modeled. Spatially, waters evolve from a calcium-bicarbonate type at the mountain front to a sodium-bicarbonate type in the central basin. Analyses for Cienega Creek perennial flows demonstrate a relatively high sodium concentration (greater than 1.71 mmol/l) characteristic of central basin groundwaters. Given the similar high sodium signature, it is assumed that surface and groundwaters evolve under the same geochemical controls while originating from the same mountain-front recharge sources. Mass balance modeling demonstrates that the chemical processes controlling water quality in the Upper Cienega Creek Basin are typical of alluvial basins in the Southwest (Robertson, 1991).