Estimating discharge of shallow groundwater by transpiration from greasewood in the Northern Great Basin

Water Resources Research
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Abstract

Evapotranspiration from bare soil and phreatophytes is a principal mechanism of groundwater discharge in arid and semiarid regions of the midwestern and western United States including the Great Basin. The imbalance between independent estimates of groundwater recharge from precipitation and of groundwater discharge based on estimates of groundwater evapotranspiration leads to large uncertainties in groundwater budgets. Few studies have addressed this problem. Energy budget micrometeorological field studies were conducted in a stand of sparse-canopy greasewood growing in an area of shallow groundwater in the western Great Basin during the summer of 1989. The data were used to calculate above-canopy fluxes of sensible and latent heat using the energy budget-Bowen ratio method. The calculated energy budget fluxes were used, with soil surface and plant canopy temperature measurements, to calibrate and apply a two-component, energy-combination model that partitions the energy and heat fluxes between bare soil and the canopy. This permitted the separation of evaporation from the soil and transpiration from greasewood. The calibrated model was used to estimate daily transpiration of groundwater by greasewood growing in an area with a depth to water of about 2 m. The daily rate of groundwater discharge by transpiration during July and August was estimated to be 2.4 mm. A period of 100 days for groundwater discharge at this rate was assumed to estimate an annual discharge of groundwater of 24 cm at the study site.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Estimating discharge of shallow groundwater by transpiration from greasewood in the Northern Great Basin
Series title Water Resources Research
DOI 10.1029/93WR00930
Volume 29
Issue 8
Year Published 1993
Language English
Publisher American Geophysical Union
Description 8 p.
First page 2771
Last page 2778
Country United States
Other Geospatial Great Basin