Evaluating micrometeorological estimates of groundwater discharge from Great Basin desert playas
Groundwater availability studies in the arid southwestern United States traditionally have assumed that groundwater discharge by evapotranspiration (ETg) from desert playas is a significant component of the groundwater budget. However, desert playa ETg rates are poorly constrained by Bowen Ratio energy budget (BREB) and eddy-covariance (EC) micrometeorological measurement approaches. Best attempts by previous studies to constrain ETg from desert playas have resulted in ETg rates that are within the measurement error of micrometeorological approaches. This study uses numerical models to further constrain desert playa ETg rates that are within the measurement error of BREB and EC approaches, and to evaluate the effect of hydraulic properties and salinity-based groundwater-density contrasts on desert playa ETg rates. Numerical models simulated ETg rates from desert playas in Death Valley, California and Dixie Valley, Nevada. Results indicate that actual ETg rates from desert playas are significantly below the uncertainty thresholds of BREB- and EC-based micrometeorological measurements. Discharge from desert playas likely contributes less than 2 percent of total groundwater discharge from Dixie and Death Valleys, which suggests discharge from desert playas also is negligible in other basins. Simulation results also show that ETg from desert playas primarily is limited by differences in hydraulic properties between alluvial fan and playa sediments and, to a lesser extent, by salinity-based groundwater density contrasts.
Citation Information
Publication Year | 2018 |
---|---|
Title | Evaluating micrometeorological estimates of groundwater discharge from Great Basin desert playas |
DOI | 10.1111/gwat.12647 |
Authors | Tracie Jackson, Keith J. Halford, Philip M. Gardner, Amanda Garcia |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Ground Water |
Index ID | 70198730 |
Record Source | USGS Publications Warehouse |
USGS Organization | Nevada Water Science Center |
Related
Upper Midwest Water Science Center - Madison, WI, Office
1 Gifford Pinchot Drive
Madison, WI 53726
United States
Related
Upper Midwest Water Science Center - Madison, WI, Office
1 Gifford Pinchot Drive
Madison, WI 53726
United States