DEM generation methods and applications in revealing of topographic changes caused by coal mining activities

Abstract

Digital elevation model (DEM) is indispensable for many applications in earth sciences, and there are many kinds of DEM generation methods, such as interpolation between contour lines from topographic maps, stereoscopy from aerial photographs or satellite images, and interferometry from Synthetic Aperture Radar (SAR) data. Due to long years of coal mining activities, topographic changes have happened to Fushun city, northeastern China. In this study, different DEM generation methods of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) stereoscopy, ERS tandem Interferometry Synthetic Aperture Radar (InSAR), and Shuttle Radar Topography Mission (SRTM) InSAR were discussed. Multi-temporal and multi-source DEM data, with different spatial resolutions of 15 m, 40 m and 90 m respectively, were combined to study the topographic changes in the past 10 years caused by open coal mining activities in western Fushun city. ERS InSAR DEM and SRTM DEM data are free of weather conditions, but ASTER DEM quality may be affected by cloud coverage in some local areas. Results from multi-source of DEM data, i.e. ERS InSAR, SRTM and ASTER DEM, show that obvious topographic changes associated with coal mining activities have occurred in Fushun area. The depth of the famous West Open Coal Mine is increasing in the past 10 years, and the maximum depth change is 140 m between 1996 and 2006. Meanwhile, the elevation of three waste rocks piling fields increased more than 10 m due to the coal mining activities.