Aerial Photography

Near infrared and thermal infrared aerial photography are useful tools for monitoring stressed vegetation and coal fires respectively. Near infrared photography can be used to detect decreases in water content within leaf cell structure, which indicate vegetative stress or death. In a joint effort, the BLM, the Southern Ute Indian Tribe, and gas operators collected near-infrared data over the Southern Ute Indian Portion of the western Hogback Monocline in September1996. These data showed strips of dead and stressed vegetation overlying the coal outcrop along known methane seeps. The study was so effective in defining the areas of methane seepage that another survey was flown in July 1999. Results are currently being evaluated. Periodically conducting near-infrared surveys in the future will greatly aid in assessing changes to vegetative health in the coal outcrop area. Thermal infrared aerial photography was also flown in July 1999. Thermal infrared is the radiant heat portion of the electromagnetic spectrum that lies between 3 and 14 micro-meters in wavelength. Anomalous heat patterns may indicate coalbed fires. Results of the July 1999 survey are currently being evaluated. Apparent hotspots from the survey must be verified on the ground. If this tool proves reliable, periodic surveys of thermal infrared photography could greatly aid in tracking known coal fire activity and detecting of new or resurgent coal fire occurrences.