Mapping the yearly extent of surface coal mining in Central Appalachia using Landsat and Google Earth Engine

Abstract

Surface mining for coal has taken place in the Central Appalachian region of the United States for well over a century, with a notable increase since the 1970s. Researchers have quantified the ecosystem and health impacts stemming from mining, relying in part on a geospatial dataset defining surface mining’s extent at a decadal interval. This dataset, however, does not deliver the temporal resolution necessary to support research that could establish causal links between mining activity and environmental or public health and safety outcomes, nor has it been updated since 2005. Here we use Google Earth Engine and Landsat imagery to map the yearly extent of surface coal mining in Central Appalachia from 1985 through 2015, making our processing models and output data publicly available. We find that 2,900 km2 of land has been newly mined over this 31-year period. Adding this more-recent mining to surface mines constructed prior to 1985, we calculate a cumulative mining footprint of 5,900 km2. Over the study period, correlating active mine area with historical surface mine coal production shows that each metric ton of coal is associated with 12 m2 of actively mined land. Our automated, open-source model can be regularly updated as new surface mining occurs in the region and can be refined to capture mining reclamation activity into the future. We freely and openly offer the data for use in a range of environmental, health, and economic studies; moreover, we demonstrate the capability of using tools like Earth Engine to analyze years of remotely sensed imagery over spatially large areas to quantify land use change.

Global Changes in Urban Vegetation Cover

“…Two additional calculated bands based on the normalised difference vegetation index (NDVI) were also added for classification. NDVI is a commonly-used index of the greenness of a pixel [50], and the "greenest pixel" in a temporal stack has been previously been used in compositing [49,51]. To avoid the risk of outlier NDVI values influencing the composite [48], we extracted the 75 th percentile of NDVI over the period as an indicator of overall greenness during the growing season.…”

Pyrite Oxidation Drives Exceptionally High Weathering Rates and Geologic CO2 Release in Mountaintop‐Mined Landscapes

“…Mountaintop removal coal mining with valley fills as practiced in Central Appalachia is a particularly extreme form of surface mining, excavating ridges as deep as 200 m and burying adjacent valleys and streams beneath many meters of highly heterogeneous fractured bedrock (Greer et al, 2017) and coal residues (Ross et al, 2016). These impacts are extensive (Drummond & Loveland, 2010;Townsend et al, 2009), covering more than 5,900 km 2 in central Appalachia (Pericak et al, 2018).…”

Excess Nitrate Export in Mountaintop Removal Coal Mining Watersheds

“…Regression lines are also shown for mean (solid black line), maximum (dotted grey), and minimum (dotted orange). Active mining % and cumulative mining % is derived from yearly mining estimates from LANDSAT imagery (Pericak et al, ). Nitrate and SO 4 2− data are from public data sets available through the Water Quality Portal and the State of West Virginia.…”

“…Premining and postmining digital elevation models were used to delineate watersheds, calculate watershed area postmining, and estimate valley fill volumes (see Ross et al, for methods). Peak mining years and percent of watershed mined were assessed using a yearly mining extent data set (Pericak et al, ). We monitored stream stage at ten‐minute intervals and developed rating curves to generate continuous streamflow records (see Nippgen et al, , for details).…”

“…Regression lines are also shown for mean (solid black line), maximum (dotted grey), and minimum (dotted orange). Active mining % and cumulative mining % is derived from yearly mining estimates from LANDSAT imagery (Pericak et al, 2018…”