Control of structural lineaments on the distribution of hazardous coal fire zones in Jharia Coalfield, Eastern India
摘要
This study investigates the relationship between the natural fire hazard zones and the spatial distribution of the tectonic structures in the Jharia Coalfield. Digital Elevation Model (DEM) was used to generate positive and negative hill-shade images. The produced images were used to automatically extract and map the lineaments. Structural fieldwork was conducted to provide ground-truth data and investigate the nature of lineaments. The fieldwork indicates that the lineament features are normal faults and fractures. Directional analysis using DEM indicates that the predominant sets of lineaments are oriented NW–SE and NNW-SSE. These trends are parallel or sub-parallel to the face cleat orientation observed in the field. The less dominant sets using the DEM are oriented E-W and WNW-ESE and are parallel or sub-parallel to the butt cleat orientations. Most of the high lineament-density clusters observed through the DEM are in the east and northeast part of the Jharia Coalfield. Overlaying the extracted lineaments from this study onto previously mapped hazard zones shows that fire-affected areas occur near regions of high lineament density in the Barakar Formation. Fire zones tend to align with lineaments, appearing along their traces, at intersection points, or near their tips. The migration of the fire zones is predicted to be along the lineament in the Barakar Formation and laterally in the dip direction within the Barakar beds due to the sustained air influx through the overlying lineaments. Moreover, field analysis reveals a progressive decrease in lineament density from the older Talchir Formation to the younger Raniganj Formation.