ABSTRACT The spontaneous combustion of coal gangue hills is accompanied by the release of toxic gases and the infiltration of metal elements, posing a serious threat to the global ecological environment. The current temperature monitoring methods for coal gangue hills have certain limitations, hence advanced and timely temperature monitoring is crucial for the management of coal gangue hills. This paper takes Guojiahe coal gangue hill as an example, thousands of visible light and thermal infrared images are obtained by using an unmanned aerial vehicle, and the 3-D model of the surface temperature of the gangue hill is established with Gaussian kernel technique and Random Sampling Consensus Method (RANSAC). Furthermore, the high-temperature zone in the gangue hill is measured by handheld thermocouples. The results indicate that high-temperature areas are distributed in a circular pattern and mostly concentrated on the slope surface and the boundary line between the slope and the bench. The thermal images can reflect the temperature inside the gangue hill by comparing the results of thermocouple temperature measurement and UAV detection. Further, it is analyzed that the air leakage cracks formed on the slope of the gangue hill provide a channel for the combination of coal gangue and oxygen, accelerating the heat accumulation, and the three-field coupling mechanism of coal gangue spontaneous combustion is proposed. This study can provide technical and methodological support for the prevention and control of spontaneous combustion in coal gangue hills.
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