Coal Spontaneous Combustion Detection and Mapping

By Xiaomin Du

Coal spontaneous combustion (CSC) is a recurrent problem resulting in large loss of coal resources. These combustions also bring severe environmental impacts worldwide, including those impacts affecting Northern China. This research, conducted by Xiaomin Du, a visiting student at CGR from China University of Mining and Technology, investigates one of these critical areas affected by CSC in the Wuda coalfield, in Inner Mongolia, Northern China.

The estimation of coal resources losses and environmental degradation requires the detection of combustion events and the accurate estimation of the area affected by subsurface fire. Remote sensing and image processing are valuable tools when analyzing CSC, particularly when incorporating methods and techniques for surface temperature estimation and anomaly detection over large areas. This work employs these techniques and aims to:

  • Select and implement a land surface temperature (LST) estimation algorithm using Aster thermal infrared data
  • Propose a sub-pixel threshold model, based on Aster thermal infrared data and coal geological materials and characteristics (e.g. distribution of fire conducted fissures, laneway, and coal seam outcrops, thickness)
  • Map temperature anomalies in the Wuda coalfield during the last decade
  • Validate the coal fire zones delineated by this pixel-integrated threshold using historical field surveying maps and field campaigns
  • Understand the mechanism of coal fire propagation.

See below for temperature anomaly maps showing the area of study and period 2001 to 2011 (2004 and 2010 are not depicted due to data unavailability).

Temperature Anomalies

Temperature anomalies over the Wuda coalfield (Northern China) for years 2001 to 2011. Solid lines: coal seam outcrops; yellow areas: areas of temperature anomalies; red areas, areas of very high temperature, considered as burning areas; Purple areas, background.