Abstract

The U.S. Bureau of Mines (USBM) has conducted research on the application of remote sensing techniques to subsidence over abandoned coal mines and to inventorying and characterization of noncoal abandoned mine lands. Subsidence over abandoned coal mines can occur over long periods and can adversely impact more recent residential or commercial surface development. Most subsidence-risk assessments incorporate depth of mining, overburden type, and mining methods but generally do not include geologic structures unless faults have been mapped previously in the mined area. Remote sensing, primarily lineament analysis of images and photos, can provide information on less obvious geologic structures (e.g., faults and fractures) that influence subsidence, thereby allowing refinement of subsidence-risk assessment.

Inventorying and characterization of abandoned mine lands have become major interests within the Federal government because of the potential for many of these old mines to degrade the surrounding lands and waters with such effluents as acid drainage and heavy metals. This does not occur at all sites or in all mining districts. However, the scope and locations of actual problems are poorly known, thereby leading to widely varying estimates of number of sites and degree of degradation from past mining. Both the USBM and the U.S. Geological Survey have been investigating this matter. Spectral analysis using remote sensing data provides a means 1) of discriminating mined from unmined areas, 2) of inventorying wastes in a consistent and relatively rapid manner over large areas of the United States, and 3) of developing a basic characterization of mine sites, based on mineralogy, that can help prioritize sites for field examination and chemical characterization.