Nevada Water Science Center


Evapotranspiration Studies in Nevada

Contact Information

Mike Moreo
Hydrologist
Phone: (702) 564-4625
Email:

 

Mailing Address
USGS
Nevada Water Science Center
160 N. Stephanie St.
Henderson, NV 89074

 

Nevada Water Science Center
Information

Home Page Surface Water Groundwater Water Quality Research Contact Us

 

 

Amargosa Flat Shallow

Site identification: 362934116153401

Study contact: Michael Moreo

ET Data

Annual ET reported (in inches): 5.31

Study period: 11/15/11 - 11/14/13

Days recorded: 867 from 7/26/11 to 12/09/13

 

Measurement method: Eddy covariance

Data: Download from NWISWeb

Graph of ET data

Location information

Latitude,
in decimal degrees
Longitude,
in decimal degrees
Altitude
36.4926 -116.2594 2323

 

Photo of ET site

 

ET Source Area

Very low density cover of saltgrass

 

Study Information

This report documents methodology and results of a study to evaluate groundwater discharge by evapotranspiration (GWET) in sparsely vegetated areas of Amargosa Desert and improve understanding of hydrologic-continuum processes controlling groundwater discharge. Evapotranspiration and GWET rates were computed and characterized at three sites over 2 years using a combination of micrometeorological, unsaturated zone, and stable-isotope measurements. One site (Amargosa Flat Shallow [AFS]) was in a sparse and isolated area of saltgrass (Distichlis spicata) where the depth to groundwater was 3.8 meters (m). The second site (Amargosa Flat Deep [AFD]) was in a sparse cover of predominantly shadscale (Atriplex confertifolia) where the depth to groundwater was 5.3 m. The third site (Amargosa Desert Research Site [ADRS]), selected as a control site where GWET is assumed to be zero, was located in sparse vegetation dominated by creosote bush (Larrea tridentata) where the depth to groundwater was 110 m.

Results indicated that capillary rise brought groundwater to within 0.9 m (at AFS) and 3 m (at AFD) of land surface, and that GWET rates were largely controlled by the slow but relatively persistent upward flow of water through the unsaturated zone in response to atmospheric-evaporative demands. Greater GWET at AFS (50 ± 20 millimeters per year [mm/yr]) than at AFD (16 ± 15 mm/yr) corresponded with its shallower depth to the capillary fringe and constantly higher soil-water content. The stable-isotope dataset for hydrogen (d2H) and oxygen (d18O) illustrated a broad range of plant-water-uptake scenarios. The AFS saltgrass and AFD shadscale responded to changing environmental conditions and their opportunistic water use included the time- and depth-variable uptake of unsaturated-zone water derived from a combination of groundwater and precipitation. These results can be used to estimate GWET in other areas of Amargosa Desert where hydrologic conditions are similar.

 

Study Publication: SIR 2017-5079

 

 

 

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Nevada Water Science Center Web Team
Page Last Modified: January 21, 2016 -->