Hydrologic effects of cottonwood trees on a shallow aquifer containing trichloroethene

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Authors:Eberts, Sandra M.; Schalk, Charles W.; Vose, James; Harvey, Gregory J.
Author Affiliations:Primary:
U. S. Geological Survey, Columbus, OH, United States
U. S. Forest Service, United States
U. S. Air Force, ASC/ENVR, United States
Volume Title:Geological Society of America, 2000 annual meeting
Source:Abstracts with Programs - Geological Society of America, 32(7), p.127; Geological Society of America, 2000 annual meeting, Reno, NV, Nov. 9-18, 2000. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0016-7592
Publication Date:2000
Note:In English
Summary:In April 1996, a field demonstration was begun to evaluate hydrologic, geochemical and biologic effects of cottonwood trees planted over a trichloroethene-contaminated shallow aquifer (<12 feet below land surface) at the Naval Air Station, Fort Worth, Texas. Site-specific data on climate, transpiration, tree roots, soil moisture, ground-water levels, and aquifer properties were collected or estimated to assess the hydrologic effects. The climate, transpiration, tree root, and soil-moisture data were used for parameterization and validation of the hydrologic model PROSPER, which was used to simulate evapotranspiration for a 12-year period and to determine the trees' uptake of contaminated water from the saturated zone (aquifer). Maximum simulated annual evapotranspiration from the combined unsaturated and saturated zones is 48 cm for year 12 and beyond; maximum predicted annual uptake from the saturated zone is 28 cm for year 12 and beyond. The ground-water flow model MODFLOW was used to simulate the effects of this estimated transpiration on ground-water flow in the aquifer. Simulated drawdown at the water table near the center of the stand of trees is approximately 9 cm for 1998; measured drawdown for the same period is approximately 10 cm. Maximum simulated drawdown at the water table (year 12 maximum transpiration estimates) is just over 25 cm. The model results indicate that the trees are able to hydraulically influence the movement of the contaminated ground water at the site. In their current configuration, however, the trees will not be able to create a cone of depression large enough to completely hydraulically control the migration of the contaminated ground water.
Subjects:Angiospermae; Aquifers; Bioremediation; Chlorinated hydrocarbons; Climate; Controls; Drawdown; Effects; Evaluation; Evapotranspiration; Geochemistry; Ground water; Halogenated hydrocarbons; Hydrology; Levels; Models; Moisture; Movement; Organic compounds; Plantae; Pollutants; Pollution; Properties; Remediation; Saturated zone; Shallow aquifers; Simulation; Soils; Spermatophyta; Trees; Trichloroethylene; Unsaturated zone; Water table; Tarrant County Texas; Texas; United States; Fort Worth Naval Air Station; Populus; Populus deltoides; PROSPER
Coordinates:N323000 N330000 W0970500 W0973700
Record ID:2002059096
Copyright Information:GeoRef, Copyright 2018 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
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