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Lowell F. W. Duell

Publications and source records attributed to Lowell F. W. Duell.

3 recordsLinked to original sources

Design and implementation of evapotranspiration measuring equipment for Owens Valley, California

As part of a plant survivability and ground water study in Owens Valley, California, semipermanent installations are used to measure continuous range‐land evapotranspiration in the valley's phreatophyte community. A proposed mobile installation also has been designed. The semipermanent micrometeoro‐logical station collects continuous data for solution of the Bowen ratio/energy budget equation and the Penman combination equation. Three sites were chosen for this type of installation to provide a representative sampling of Owens Valley. The proposed mobile aerodynamic installation should be capable of calculating evapotranspiration by the eddy correlation method. This instrumentation will be used throughout the valley for short periods of time (up to five days). Many problems with equipment operation, calibration and design have been identified and resolved by means of improved calibration techniques, systematic error‐removal techniques, reduced cycle times, modified equipment design and proper observer training. The collected evapotranspiration data will be instrumental in developing a one‐dimensional evapotranspiration flux algorithm for a model of valleywide ground water flow.

California↗

Ground-water data for San Nicolas Island, California, 1989-90

In an effort to gain geohydrologic knowledge and to increase the availability of ground water to the U.S. Navy on San Nicolas Island, nine test wells were drilled by the U.S. Geological Survey in 1989 and one production well was drilled by the U.S. Navy in 1990. One of the nine test wells was dry, five produced less than 10 gallons of water per day, two produced between 20 and 30 gallons per day, and one produced 400 gallons per day. The production well produced about 900 gallons per day. Water samples were collected from eight wells during 1989-90 and analyzed for concentrations of major dissolved inorganic ions and nutrients. Five of the sampled wells were constructed in 1989, one was constructed in 1990, and two were constructed prior to 1989. Data from the study are presented in tables and graphs. Included are geophysical, lithologic, and well-construction data and results obtained from well-pumping tests and from the chemical analysis of water from selected wells.

California↗

Estimates of evapotranspiration in alkaline scrub and meadow communities of Owens Valley, California, using the Bowen-ratio, eddy-correlation, and penman-combination methods

In Owens Valley, evapotranspiration (ET) is one of the largest components of outflow in the hydrologic budget and the least understood. ET estimates for December 1983 through October 1985 were made for seven representative locations selected on the basis of geohydrology and the characteristics of phreatophytic alkaline scrub and meadow communities. The Bowen-ratio, eddy-correlation, and Penman-combination methods were used to estimate ET. The results of the analyses appear satisfactory when compared with other estimates of ET. Results by the eddy-correlation method are for a direct and a residual latent-heat flux that is based on sensible-heat flux and energy-budget measurements. Penman-combination potential-ET estimates were determined to be unusable because they overestimated actual ET. Modification of the psychrometer constant of this method to account for differences between heat-diffusion resistance and vapor-diffusion resistance permitted actual ET to be estimated. The methods described in this report may be used for studies in similar semiarid and arid rangeland areas in the Western United States. Meteorological data for three field sites are included in the appendix of this report. Simple linear regression analysis indicates that ET estimates are correlated to air temperature, vapor-density deficit, and net radiation. Estimates of annual ET range from 301 millimeters at a low-density scrub site to 1,137 millimeters at a high-density meadow site. The monthly percentage of annual ET was determined to be similar for all sites studied.

Water Supply Paper↗