Measuring Mountaintop Removal Mining in Appalachia

SkyTruth, in partnership with Appalachian Voices, recently completed a project that documented the impact of Mountaintop Removal Mining for coal (MTR) over a 59 county area in Kentucky, West Virginia, Tennessee and Virginia. The goal of the project was to map the historical occurrence of mountaintop removal mining over a 30 year period, from 976 to 2005.

With this analysis, and some great database and Google Earth work by Appalachian Voices, we can tell you exactly which mountains in Appalachia have been - or are are being -destroyed to power your home or business (thought you might like to know...). The methodology involved several steps. The first step included a land cover classification for each decade that identified all the mining occurrences at that point in time. This digital spectral classification process was accomplished using a Landsat satellite image database totaling eight gigabytes of data. Classification required a two-step process where the spectral signatures of land cover types were identified (vegetation, soil, barren or rock, water, etc) and then, through a decision tree analysis, mined areas are classed.

The next step was to classify these mine areas as “MTR” and “Other Surface Mining.” The definition of MTR, as put forth by the U.S. Office of Surface Mining, Reclamation and Enforcement, guided the development of a reproducible, rules-based method to classify the mines. Using digital elevation data from the U.S. Geological Survey 1:100,000 series, the terrain parameters of ridge top, slope, and valleys were calculated. The MTR mines were identified by calculating the percentage of ridge top that comprised the mine’s total area. Simply put, MTR mines span over 320 acres and removed at least 40 acres of ridge top, or cover between 40 and 320 acres and contain at least 10 - 40 acres of ridge top within the mined area.

The historical record shows significant increases in MTR occurring in the last two decades: from 77,000 acres in 1985 to over 272,000 acres in 2005, a 250% increase. Also increased was the size of the individual mines, with some reaching over 15 square miles. In regards to ridge tops, over 2,700 ridges were impacted by mining.

MTR PROJECT - OVERVIEW OF RESULTS

Mountaintop Removal Mines

Total MTR Mined Area since 1976 = 445,792 Acres

Largest Single Mined Area = 10,410 Acres

Median Mined Area = 128 Acres

Average Mined Area = 406 Acres

Number of Mines > 1 mile² = 73

Ridge Tops

Number of Ridges Mined = 2,789

Total Acres of Impacted Ridges = 130,655 Acres

Average Ridge Length Mined = 1/2 Mile

Largest Ridge Removed = 504 Acres

Historical Analysis (Acres Directly Impacted by Mining)