An analysis of the effects of retiring irrigation pumpage in the San Pedro riparian national conservation area, Cochise county, Arizona
Affiliation
Department of Hydrology & Water Resources, The University of ArizonaArizona Research Laboratory for Riparian Studies
Issue Date
2000Keywords
Water-supply -- Arizona -- San Pedro Riparian National Conservation Area.Irrigation farming -- San Pedro River Valley (Mexico and Ariz.)
Groundwater -- San Pedro River Valley (Mexico and Ariz.)
Riparian areas -- San Pedro River (Mexico and Ariz.)
Groundwater.
Irrigation farming.
Riparian areas.
Water-supply.
Metadata
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Copyright © Arizona Board of RegentsCollection Information
This title from the Hydrology & Water Resources Technical Reports collection is made available by the Department of Hydrology & Atmospheric Sciences and the University Libraries, University of Arizona. If you have questions about titles in this collection, please contact repository@u.library.arizona.edu.Abstract
A seasonal groundwater model was developed to simulate fluxes and head distributions with periodic boundary conditions within the San Pedro Riparian National Conservation Area (SPRNCA) in southeastern Arizona. This model incorporated a seasonal approach for the period 1940-1995. Two years were used to simulate streamflow, 1990 and 1995. The model, as currently calibrated, does not accurately reproduce observed baseflow conditions in the San Pedro River and simulates an exaggerated effect of retiring irrigation within the SPRNCA. The model simulated increased baseflows while the observed baseflows declined at the USGS Charleston stream gage, though increases in baseflow contributions between Hereford Bridge and Lewis Springs have been reported. The original (Corell, et al., 1996) model and the seasonal transient model suffer from over- estimation of discharge from the floodplain aquifer to the San Pedro river, as well as errors in the seasonal transient model's simulation of riparian ET, and seasonal variations in stream conductance. These problems precluded the seasonal transient model from replicating the observed baseflows in the San Pedro river at the Charleston bridge, however, the results of the simulation are thought to be qualitatively indicative of changes in the flow system resulting from the retirement of irrigated agriculture in the San Pedro Riparian National Conservation Area. Possible sources for this problem include replacement of irrigation stresses by the expansion of cones of depression more distant from the river, overestimation of mountain front recharge, poor baseflow estimates and evapotransipration calculations from the stream gages at Charleston and Palominas, and the effects of a recently discovered silt -clay body that may dampen the speed of the rivers response to changes in stress. Additional efforts to re- calibrate the model, taking these areas into account, should provide better simulated baseflow values of the observed data.Series/Report no.
Technical Reports on Hydrology and Water Resources, No. 00-010Sponsors
This project was funded by, and this report prepared for the Bureau of Land Management. We are very grateful to many individuals whose support was invaluable to the completion of this project. Stan Leake, of the USGS, Frank Putman of the ADWR, Steve Correll, of Hydrosystem, Inc., and many of Dr. Sorooshian's research group at the University of Arizona.Collections
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