The characterization and examination of geologic factors influencing the geomorphic development of playas within Fort Bliss, Texas and New Mexico

Yvette Marie Villegas, University of Texas at El Paso

Abstract

This study focuses on the delineation of playas at Fort Bliss, Texas and New Mexico, the relationship between the location of the playas and soil properties, and how these may be affected by military training activities. The Environmental Division at Fort Bliss, Texas and New Mexico conducts natural resource planning and management activities within the military installation. Some of the areas within the installation are unique and sensitive due to environmental concerns and cultural resources. These areas include but are not limited to, playas, which are at times used as designated areas where personnel and or equipment may be delivered by parachute or, in the case of certain items, by free drop (drop zones). To date, the geomorphic, edaphic, and ecological characteristics of these playas have not been identified or classified. The playas and drop zones are in the "heavy maneuver" classification with associated land use restrictions. The designation refers to areas where maneuver is unrestricted and can consist of all types of vehicles and equipment, including tracked vehicles for ground and air combat forces to train movements and tactics. During training activities, spills and maneuver damage to playas or streams have potential implications under the Clean Water Act (CWA). In order for the Installation to enforce the CWA, the playa areas need to be delineated. Due to the lack of scientific information, efforts to identify the U.S. Federal jurisdictional limits on areas of playas in the Southwest have been constrained. ^ This study delineates playas at Fort Bliss, Texas and New Mexico, and the relationship between the location of the playas and soil properties by utilizing remote sensing, Geographic Information Systems (GIS) and field work. Samples collected during field campaigns were analyzed to develop a database for each selected area. ^ Two study regions were selected, within the Hueco-Tularosa Basin. The first study region is located within Dona Ana Range-North Training Areas, along the southeast side of the Organ Mountains. The second region is located within McGregor Range, which is bordered by the Sacramento and Hueco Mountains on the east. Remote sensing analysis of satellite images was used to view the boundary of each playa and to characterize zonal changes of soil and vegetation. Five playas were identified within the Dona Ana Range study region and 12 were located in McGregor Range. All playas were selected for on-site data collection. At each playa 1 to 2 transects were laid out extending from the center of the playa to obtain soil and vegetation samples to characterize each playa. Analysis of soil samples included percent moisture, particle size, salinity, pH, and carbonate content. Eco-geomorphic zones were classified based on differences in soil and vegetation. Playa 1, Old Coe Lake had the highest percent of moisture content. The particle size analysis ranged from 2.7 to 53.7 microns (clay to silt/sand). The sediments are alkaline in nature with a pH ranging from 7.23 to 9.61. Salinity ranged from 1.1 to 4.17 dS/m. A total of eight different types of playas were identified. ^

Subject Area

Geology

Recommended Citation

Villegas, Yvette Marie, "The characterization and examination of geologic factors influencing the geomorphic development of playas within Fort Bliss, Texas and New Mexico" (2007). ETD Collection for University of Texas, El Paso. AAI1449735.
http://digitalcommons.utep.edu/dissertations/AAI1449735

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