Mapping coal fires using Normalized Difference Coal Fire Index (NDCFI): case study at Khanh Hoa coal mine, Vietnam

L H Trinh,V N Nguyen

doi:10.17073/2500-0632-2021-4-233-240

Abstract

Khanh Hoa coal mine (Thai Nguyen province) is one of the largest coal mines in the north of Vietnam. For many years, this area suffered from underground fires at coal mine waste dumps, seriously affecting production activities and the environment. This paper presents the results of classification of underground fire areas at Khanh Hoa coal mine using Normalized Diference Coal Fire Index (NDCFI). 03 Landsat 8 OLI_TIRS images taken on December 2, 2013, December 10, 2016, and December 3, 2019 were used to calculate NDCFI index, and then classify the underground fire areas by thresholding method. In the study, the land surface temperature was also calculated from Landsat 8 thermal infrared bands data, and then compared with the results of underground coal fire classification at Khanh Hoa coal mine. The obtained results showed that the NDCFI index can be used effectively in detecting and monitoring underground fire areas at coal mines. The use of the NDCFI index also has many advantages due to its calculation simplicity and rapidness compared to other methods for classifying underground coal fire areas.

Highlights

Most types of coal have the ability to self-ignite under certain environmental conditions
These studies all showed that land surface temperatures in underground coal fire areas were much higher than in the surrounding area, even compared to urban areas characterized by impervious surfaces
Based on the analysis of the distribution of land surface temperatures calculated from Landsat satellite images, these studies enabled predicting fire locations, thereby providing information to help managers to promptly respond to underground fires at Khanh Hoa coal mines

Summary

Introduction

Most types of coal have the ability to self-ignite under certain environmental conditions (endogenous combustion). Most of these studies use land surface temperature calculated from the thermal infrared data from Landsat and Aster satellite images to monitor underground coal fires [6,7,8,9,10,11,12].

Results

Conclusion