Analysis of stable isotope ratios (δ18O and δ2H) in precipitation of the Verde River watershed, Arizona 2003 through 2014

Open-File Report 2016-1053
Prepared in cooperation with Yavapai County Water Advisory Committee and Arizona Department of Water Resources
By: , and 

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Abstract

Stable isotope delta values (δ18O and δ2H) of precipitation can vary with elevation, and quantification of the precipitation elevation gradient can be used to predict recharge elevation within a watershed. Precipitation samples were analyzed for stable isotope delta values between 2003 and 2014 from the Verde River watershed of north-central Arizona. Results indicate a significant decrease in summer isotopic values overtime at 3,100-, 4,100-, 6,100-, 7,100-, and 8,100-feet elevation. The updated local meteoric water line for the area is δ2H = 7.11 δ18O + 3.40. Equations to predict stable isotopic values based on elevation were updated from previous publications in Blasch and others (2006), Blasch and Bryson (2007), and Bryson and others (2007). New equations were separated for samples from the Camp Verde to Flagstaff transect and the Prescott to Chino Valley transect. For the Camp Verde to Flagstaff transect, the new equations for winter precipitation are δ18O = -0.0004z − 8.87 and δ2H = -0.0029z − 59.8 (where z represents elevation in feet) and the summer precipitation equations were not statistically significant. For the Prescott to Chino Valley transect, the new equations for summer precipitation are δ18O = -0.0005z − 3.22 and δ2H = -0.0022z − 27.9; the winter precipitation equations were not statistically significant and, notably, stable isotope values were similar across all elevations. Interpretation of elevation of recharge contributing to surface and groundwaters in the Verde River watershed using the updated equations for the Camp Verde to Flagstaff transect will give lower elevation values compared with interpretations presented in the previous studies. For waters in the Prescott and Chino Valley area, more information is needed to understand local controls on stable isotope values related to elevation.

Suggested Citation

Beisner, K.R., Paretti, N.V., and Tucci, R.S., 2016, Analysis of stable isotope ratios (δ18O and δ2H) in precipitation of the Verde River watershed, Arizona, 2003 through 2014: U.S. Geological Survey Open-File Report 2016–1053, 11 p., http://dx.doi.org/10.3133/ofr20161053.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Methodology
  • Results
  • Conclusions
  • References Cited
  • Appendix

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Analysis of stable isotope ratios (δ18O and δ2H) in precipitation of the Verde River watershed, Arizona 2003 through 2014
Series title Open-File Report
Series number 2016-1053
DOI 10.3133/ofr20161053
Year Published 2016
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Arizona Water Science Center
Description Report: iv, 9 p.; Stable Isotope Data
Country United States
State Arizona
Other Geospatial Verde River Watershed
Online Only (Y/N) Y
Additional Online Files (Y/N) Y