Research by Duke University in the US has found that Central Appalachia became 60% flatter due to mountaintop coal mining.
The mining process involves blasting of bedrock in order to obtain coal seams below the surface, with excess rock then dumped in nearby valleys, creating valley fills.
By comparing digitised topographic maps in southern West Virginia before and after mining, the study examined the regional impact of mountaintop mines on landscape topography.
The researcher found that the mines and valley fills could ranges anywhere from 10m to 200m deep.
It also ascertained how the changes might influence the quality of water.
Lead author on the study Matthew Ross said: "There hasn’t been a large-scale assessment of just the simple full topographic impact of mountaintop mining, which occupies more than 10% of the land in the region we studied.
"It is locally large and more wide-ranging than other forms of mining."
After performing mining, the average slope of the land across the region dropped by more than 10%.
Ross joined forces with Duke University’s Data+ programme to develop a web-based visualisation tool in collaboration with Aaron Berdanier, Tess Harper, and Molly Rosenstein.
Using the tool, users will be able to toggle between pre and post-mining topographic maps in each watershed of the study.
Duke University professor of biology Emily Bernhardt said: "We tend to measure the impact of human activity based on the area it affects on a map, but mountaintop mining is penetrating much more deeply into the earth than other land use in the region like forestry, agriculture or urbanisation.
"The depth of these impacts is changing the way the geology, water, and vegetation interact in fundamental ways that are likely to persist far longer than other forms of land use."
The data revealed that there exists a correlation between the total volume of displaced rock and the concentration of certain pollutants, such as selenium, downstream, Ross added.
Image: The hillside slope of West Virginia’s Headwaters Twentymile Creek watershed pre and post-mining, calculated from elevation maps. Photo: courtesy of Matthew Ross, Duke University.