Evaluation of alternative cover systems using GIS
Julie Coonrod, John Stormont, and Lisa Vantassell
University of New Mexico, Department of Civil Engineering, Albuquerque, NM, United States
Geographic Information Systems (GIS) can be used to determine and display the depths of native soil covers required for waste containment sites. Readily available data for the State of New Mexico are used in a GIS environment to determine the required depth of two separate cover systems. The depth of an evapotranspirative (ET) soil cover is determined using the available water capacity of the soil and the amount of dormant precipitation. The thickness of a capillary barrier cover system is determined using unsaturated hydraulic parameters, the amount of dormant precipitation, and an iterative numerical model. A difference map showing the savings using a capillary barrier instead of an ET cover is then created. The use of a capillary barrier in areas with fine-grained soils can decrease the necessary soil cover thickness by 90 cm of soil. The computed cover thickness compare well with those determined using Hydrologic Evaluation of Landfill Performance (HELP) (Schroeder et al., 1994), a model commonly used in New Mexico to determine if alternative cover systems can meet the required performance criteria.
This record provided courtesy of AGI/GeoRef.
