minor 
arings 
S. 
COLLECTION AND INTERPRETATION OF COLOR INFRARED AND 
THERMAL INFRARED IMAGERY OF LANDFILL COVERS 
Christopher Stohr 
Illinois State Geological Survey 
Champaign, IL USA 
Ross S. Lunetta 
United States Environmental Protection Agency 
Environmental Monitoring Systems Laboratory 
Las Vegas, Nevada USA 
Thomas D. Frank 
Department of Geography 
University of Illinois at Urbana-Champaign, USA 
ABSTRACT 
Earthen covers on a closed landfill are intended to prevent water from entering through the landfill cover and 
mixing with the wastes to produce methane and leachate. Landfill covers undergo changes in its local topography 
as waste volume changes in response to decomposition. The changes in local topography of the cover also changes 
drainage characteristics thereby causing some freely draining areas to impound water in depressions. 
Required monitoring of closed landfills is currently performed by sampling and testing of downgradient wells. 
This method can detect groundwater pollution only after it has already occurred. A proactive method can 
indicate potential problems, such as locations where large amounts of rainwater are infiltrating through the 
cover. 
Proactive monitoring of landfill covers by remote sensing methods is a promising supplement to passive 
monitoring by sampling wells. To test the method, color infrared photography and thermal infrared imagery were 
collected over three landfills in east central Illinois in June of 1991. Photography and post-sunset thermal 
infrared imagery were collected from fixed-wing airplane and helicopter platforms, respectively. The data were 
used to study the relationship of surface-drainage features to the infiltration of rainfall through landfill 
covers. 
Interpretation of stereoscopic aerial photography is used to identify depressions. Thermal infrared imagery 
is used to classify depressions into freely-infiltrating or moisture-retaining depressions, identify stressed 
vegetation, and erosion. Thermal infrared imagery also is used to investigate the relationship of freely- 
infiltrating depressions to the venting of gas through landfill covers. 
The project was funded by the Illinois State Geological Survey and the U. S. Environmental Protection Agency, 
Environmental Monitoring Systems Laboratory, Las Vegas through contract number EPA 2V-0259-NAEX. Additional 
support was provided by the Illinois Department of Corrections who provided a thermal infrared scanner, the 
Illinois Department of Transportation, Division of Aeronautics who provided a helicopter, and the University 
of Illinois Geographic Information Systems Laboratory. 
Key Words: Aerial Photography, Color Infrared, Thermal Infrared, Landfill Covers, Depressions, Remote Sensing. 
INTRODUCTION 
Per capita waste generation in the United States has The purpose of sanitary landfilling is to isolate 
risen to 180 million tons per year and is projected wastes from human society and the ecosystem: water, 
to reach 216 million tons in the year 2000 (O'Leary soil and air. If water mixes with the wastes, the 
and Walsh, 1991, p. 42-43). The increasing volumes wastes decompose producing methane, leachate and a 
generated have necessitated human society's atten- reduced volume of refuse (EMCON, 1980; Lu et al., 
tion in disposing of wastes. 1985, Christensen and Kjeldsen, 1989, p. 29-32, 
Bogner, et al., 1990). An increase in the amount of 
Sanitary landfilling is the prevailing method em- water mixing with the wastes will necessarily cause 
ployed in most industrialized countries ranging from an increase in the amount of leachate and methane 
30% to 95% of the total solid waste generated by generated by the decomposition. The production and 
weight (Cossu, 1989, p. 5-9). A sanitary landfill release of methane into the atmosphere and leachate 
is an excavation filled with wastes, covered daily into groundwater can be detrimental to the surround- 
by earth or geofabric, and finally closed by a thick ing ecosystem (Campbell, 1989). 
covering of compacted earth. Landfilling is and has 
been used for ultimate disposal of some hazardous Prevailing practice for evaluation of the effective- 
wastes in the United States and throughout the world ness of a landfill in isolating wastes from the 
(Frye, 1971; Schneider, 1975). Although consider- surrounding ecosystem is by means of monitoring 
able attention has focused on recycling of materi- wells, leachate collection systems, and personal 
als, the efficiency with which waste avoidance and field reconnaissance (Bagchi, 1989, Stohr, et al., 
recycling can reduce the amounts of solid waste is 1990). Groundwater, sampled from monitoring wells, 
finite. Sanitary landfilling remains part of an is analyzed for traces of chemicals found in leach- 
integrated approach to solid waste management, and ates from the wastes. If waste products are detect- 
is needed for that portion of the waste stream that ed, then leachate is known to have formed and dis- 
can not be recycled or incinerated. charged in the direction of the well, consequently 
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