Coal fire mapping from satellite thermal IR data – A case example in Jharia Coalfield, Jharkhand, India

Coal fire has been found to be a serious problem worldwide in coal mining processes. Coal fire burns valuable coal reserve and prevents access to proven reserve in the affected area. Moreover, it leads to severe environmental degradation of the region by an overall increase of the ambient atmospheric temperature, by the emission of obnoxious gases (e.g., SO2, NO, CO, CH4) along fissures and cracks and by causing land subsidence and collapse. Jharia Coalfield, Jharkhand, India, is known for being the exclusive storehouse of prime coking coal as well as for hosting the maximum number of known coal fires among all the coalfields in the country.In this paper, some of the important issues of coal fire mapping from satellite thermal IR data have been addressed in particular reference to Jharia Coalfield. Namely, these are: retrieval of true spectral radiance from raw digital data using scene-specific calibration coefficients of the detectors, thermal emissivity of surface materials to obtain kinetic temperature at each ground resolution cell of satellite data, field-based modelling of pixel-integrated temperature for differentiating surface and subsurface fire pixels in Landsat TM thermal IR data, identification of surface coal fire locations from reflected IR data and lateral propagation of coal fire.