Water-Resources Investigations Report 03-4254

Estimated Ground-Water Discharge by Evapotranspiration from Death Valley,
California, 1997-2001

By Guy A. DeMeo, Randell J. Laczniak, Robert A. Boyd, J. LaRue Smith, and Walter E. Nylund

Report availability: Portable Document Format (PDF).

CONTENTS

Abstract

Introduction

Purpose and Scope

Previous Investigations

Acknowledgments

Description and Setting

• Climate
• Vegetation
• Hydrology

Evapotranspiration Units

Evapotranspiration Rates

Site Selection and Instrumentation

Energy-Budget Methods

• Bowen Ratio Method
• Eddy Correlation Method

Micrometeorological Data

Daily and Annual Evapotranspiration

• Comparison of Bowen Ratio and Eddy Correlation Methods

Estimates of Annual Evapotranspiration

Estimates of Annual Ground-Water Discharge

Limitations

Summary

References Cited

FIGURES

1. Map showing Death Valley ground-water flow system, California and Nevada
2. Map showing location of valley floor and other major physiographic features of Death Valley
3. Graphs showing temporal modified soil-adjusted vegetation indices (MSAVI) clusters of signatures used to delineate vegetation in Death Valley
4. Map showing distribution of evapotranspiration units and location of instrumented sites in Death Valley
5. Photographs of evapotranspiration sites at (A) salt-encrusted playa, (B) bare-soil playa, (C) pickleweed, (D) Eagle Borax, (E) Mesquite Flat, and (F) Mesquite Flat mixed grasses, Death Valley, California, August 1998-October 2001
6. Schematic of typical micrometeorological data-collection site for computation of evapotranspiration by (A) Bowen ratio method and (B) eddy correlation method, Death Valley, California, 1997-2001
7. Schematic showing components of the surface-energy budget
8. Graphs showing 20-minute averaged micrometeorological data collected from the Mesquite Flat mixed-grasses site, Death Valley, California, July 29-August 2, 2000
9. Graph showing examples of (A) energy-budget fluxes and (B) daily evapotranspiration computed with micrometeorological data collected from the Mesquite Flat mixed-grasses site, Death Valley, California, July 29-August 5, 2000
10. Graph showing example of daily evapotranspiration and smoothed fit for data collected at the Mesquite Flat mixed-grasses site, Death Valley, California, July 2000-October 2001
11. Graph showing comparison of (A) measured annual precipitation and (B) calculated daily evapotranspiration from micrometeorological data-collection sites, Death Valley, California, 1997-2001
12. Correlation plot of daily evapotranspiration of Bowen ratio method and eddy correlation method, at Mesquite Flat mixed-grasses site, Death Valley, California, July 2000-October 2001
13. Graph showing comparison of (A) annual precipitation and (B) daily evapotranspiration at the salt-encrusted playa micrometeorological data-collection site, Death Valley, California, January 1999-July 2001
14. Photograph of salt-crystal deposits on a rain gage following the evaporation of surface flooding near the salt-encrusted playa micrometeorological data-collection site, Death Valley, California, April 2001
15. Graph showing relation of vegetation density and ground-water evapotranspiration for vegetated evapotranspiration units, Death Valley, California, August 1997-October 2001

TABLES

1. Evapotranspiration units determined from temporal analysis of modified soil-adjusted vegetation indices (MSAVI), Death Valley, California
2. Location, depth of peizometer, and period of data collection for instrumented sites used to collect micrometeorological data, Death Valley, California, 1997-2001
3. Rates of annual evapotranspiration, measured precipitation, and annual ground-water evapotranspiration at data-collection sites in Death Valley, California, 1997-2001
4. Annual ground-water discharge rate and total annual ground-water discharge for evapotranspiration units, Death Valley, California, 1997-2001

Return to WRIR 03-4254 or the Abstract.

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