Evaluation of evapotranspirative covers for waste containment in arid and semiarid regions in the Southwestern USA

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doi: 10.2113/4.1.55
Authors:Scanlon, Bridget R.; Reedy, Robert C.; Keese, Kelley E.; Dwyer, Stephen F.
Author Affiliations:Primary:
University of Texas at Austin, Jackson School of Geosciences, Austin, TX, United States
Scandia National Laboratories, United States
Volume Title:Vadose Zone Journal
Source:Vadose Zone Journal, 4(1), p.55-71. Publisher: Soil Science Society of America, Madison, WI, United States. ISSN: 1539-1663
Publication Date:2005
Note:In English. Accessed on March 25, 2005. 37 refs.; illus., incl. 5 tables
Summary:Performance evaluation of evapotranspirative (ET) covers is critical for waste containment. The purpose of this study was to evaluate ET covers at sites in Texas and New Mexico representative of arid and semiarid regions in the southwestern USA using water balance monitoring during 4- and 5-yr periods and water balance simulations using short-term (1-5 yr) and long-term (25 yr) climate forcing. Estimated drainage at the Texas site was related to irrigation while measured drainage at the New Mexico site was restricted to the first 2 yr of the 5-yr monitoring period. Evapotranspirative covers work extremely well in these regions because of the dominance of summer precipitation (62-80%) that corresponds to periods of highest ET. Strong relationships between decreases in soil water storage and vegetation productivity at both sites underscore the importance of vegetation in controlling the water balance in these systems. Simulations of the Texas site indicate that drainage can occur in response to high precipitation near the end of the growing season, but such drainage can be eliminated with a capillary barrier. Inclusion of a capillary barrier increased available water storage by a factor of about 2.5 at both sites. The capillary barrier effect of drainage lysimeters can result in underestimation of drainage and overestimation of water storage relative to covers not underlain by capillary barriers. The data from this study indicate that a 1-m-thick ET cover underlain by a capillary barrier should be adequate to minimize drainage to ≤1 mm yr-1 in these arid and semiarid regions. Comprehensive monitoring integrated with modeling is required to assess total system performance to develop a predictive understanding of ET covers.
Subjects:Arid environment; Evapotranspiration; Experimental studies; Field studies; Hydrologic cycle; Numerical models; Quantitative analysis; Runoff; Semi-arid environment; Sensitivity analysis; Simulation; Site exploration; Terrestrial environment; Vegetation; Waste disposal; Water balance; Basin and Range Province; Bernalillo County New Mexico; Chihuahuan Desert; Hudspeth County Texas; New Mexico; North America; Southwestern U.S.; Texas; United States; West Texas; Kirtland Air Force Base
Coordinates:N310900 N310900 W1051600 W1051600
N345800 N345800 W1063200 W1063200
Record ID:2005062336
Copyright Information:GeoRef, Copyright 2018 American Geosciences Institute.
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