thumbnail

Field studies of borehole gamma-ray spectrometer methods for mineral exploration; a selected bibliography

Open-File Report 80-503
By:
https://doi.org/10.3133/ofr80503

Links

Abstract

A finite-difference digital model was developed to simulate the effects of a proposed well field on the water levels in existing wells in the Salt River Indian Reservation, which is in the southeastern part of Paradise Valley in central Arizona. The model area includes about 600 square miles in Paradise Valley and the adjoining Salt River Valley. In 1975 about 37,500 acre-feet of ground water was withdrawn for irrigation in the Salt River Indian Reservation. The proposed well field would withdraw as much as 45,000 acre-feet per year of additional irrigation water north of the Arizona Canal. The model was calibrated by using measured water-level declines for 1923-76 and simulated declines for 1946-75. The calibrated model was then used to predict water-level declines, based on projected amounts of pumpage, after 20 years of pumping. The rate of water-level decline would be an additional 2 to 6 feet per year in existing wells after 20 years of pumping in the proposed well field. The model was more sensitive to changes in pumpage distribution and in pumpage and recharge amounts than to changes in transmissivity and specific yield. (USGS)

Suggested Citation

Senftle, F.E., 1980, Field studies of borehole gamma-ray spectrometer methods for mineral exploration; a selected bibliography: U.S. Geological Survey Open-File Report 80-503, 44 p. ; 28 cm., https://doi.org/10.3133/ofr80503.

ISSN: 2331-1258 (online)

Publication type Report
Publication Subtype USGS Numbered Series
Title Field studies of borehole gamma-ray spectrometer methods for mineral exploration; a selected bibliography
Series title Open-File Report
Series number 80-503
DOI 10.3133/ofr80503
Year Published 1980
Language ENGLISH
Publisher U.S. Geological Survey],
Description 44 p. ; 28 cm.
Additional publication details