Planet Imagery sheds light on Mine Expansions outside of Permit Boundaries

We were recently reviewing imagery of mine sites which experienced growth in 2017. We overlaid the mine permit boundaries that show where the government has legally granted companies permission to mine. We used our Landsat-based surface mining data to identify a set of candidate sites to examine more closely with higher-resolution Planet imagery through Planet’s Ambassadors Program. While looking at these sites, we noticed mining activity that seems to be occurring outside of permitted areas.

The Taywood West Mine as it appeared on a high-resolution Planetscope satellite image in July 2017. The mining permit boundary is shown in red; mining-disturbed land, based on SkyTruth’s analysis of lower-resolution Landsat 8 satellite imagery, is shown in orange and closely matches what we are able to see in this Planet image.  Apparent mining-related activity outside the permit area is highlighted in yellow.

The mine site continued to expand after July; the image below shows the extent of mining on October 19. More land outside the permit boundary appears to have been cleared since July 30.

The Taywood West Surface Mine is located in Mingo County, WV approximately 12 kilometers northeast of the town of Kermit and 76 kilometers southwest of the state capitol in Charleston.

The Taywood West Surface Mine (pictured above) caught our attention when we noticed evidence of mining activity, which fell outside the mine’s permit boundary. In the image, areas overlain in red show the extent of the mining permit; the bright areas of bare rock and soil on the image show where mining activity (cut and fill) activity has apparently occurred as of the date of the image (October 2017). Fifty-two acres of mining-disturbed land lie outside of the permitted area. According to permit data downloaded from the West Virginia Department of Environmental Protection (WVDEP), the permit for the Taywood West mine was issued to Southeastern Land, LLC in August 2005 and will expire in August 2020.

A 2004 study conducted in West Virginia showed a surprisingly high degree of mismatch between permit boundaries and actual mining, but we thought the situation had improved since then. Now we are not so sure, and we’re wondering how widespread this problem is. Accurate assessment of the location and amount of existing mine-damaged land is critical for forecasting the cumulative downstream impacts of mining in deciding whether to approve permit applications for new mining. And it’s critical for planning and executing the extensive reclamation work this region needs to recover from the negative impacts of coal mining. Whose job is it to make sure miners stay within the boundaries of their mining permit?

This map, created by SkyTruth (, shows the current boundaries of Bears Ears and Grand Staircase-Escalante National Monuments in green, and the proposed, reduced boundaries in red. Data was provided by The Wilderness Society and the Bureau of Land Management. Aerial images were provided by EcoFlight (

Our Shrinking National Monuments

The President announced sizeable reductions of several National Monuments earlier this week.  To help people see and understand the significance of this action, we produced an interactive map showing two of the most highly impacted Monuments, Bears Ears and Grand Staircase – Escalante, both in Utah.  Users of the map can zoom in and explore the places that the Trump administration wants to remove from protection.

Vigorous public opposition and lawsuits by companies such as Patagonia make it likely the fate of the monuments will be tied up in court for many months. In the meantime, our friends at EcoFlight tell us the reduced monuments are considered “de facto” until the courts decide the inevitable legal challenges.

Thanks to The Wilderness Society for providing the proposed new boundaries, based on maps that were leaked last week; and to EcoFlight for sharing geotagged photos from their many flyovers, to help us illustrate what’s in jeopardy.

This map, created by SkyTruth (, shows the current boundaries of Bears Ears and Grand Staircase-Escalante National Monuments in green, and the proposed, reduced boundaries in red. Data was provided by The Wilderness Society and the Bureau of Land Management. Aerial images were provided by EcoFlight (

This map shows the original boundaries of the Bears Ears and Grand Staircase – Escalante National Monuments in green, and the reduced boundaries announced by the President on December 4 in red. Click on the camera icons to see aerial photographs of those locations.  Data provided by The Wilderness Society and the US Bureau of Land Management. Aerial photographs provided by EcoFlight.

We’ll add more photos and info to this map as we get it.  View the map here, and please share this link with interested friends:

Update on Our Efforts to Map Surface Mining in Appalachia

Some time has passed since we’ve written about our work mapping surface mining in central Appalachia, but rest assured, we’re still actively monitoring this devastating practice. Our mining work to date has focused on mapping the locations of these operations.

Researchers, some of whom are using our data, are beginning to draw troubling connections between coal mining and the health of people living in communities near those operations. We are working to refine our mapping processes and enable new types of analysis to help understand the environmental and public health consequences of mountaintop removal mining.

The process we used to create our annual maps of surface mining from 1985-2015, relies on the use of a Normalized Difference Vegetation Index (NDVI). NDVI essentially measures a ratio of reflected red and near-infrared light and is particularly useful for detecting changes in vegetation. When areas within the scope of our study experience a change from forest to bare earth, this registers as mineland. The analysis is available here:

This NDVI image shows the Hobet 21 Coal Mine in West Virginia. Vegetated areas are visualized in white, while bare earth is seen as dark grey or black.

We are working with Dr. Matt Ross, an ecosystem scientist from the University of North Carolina at Chapel Hill, to improve our mining identification algorithm, and add the capacity to evaluate how landscapes affected by surface mining recover over time. This algorithm is an integral step in assessing the efficacy of the reclamation efforts undertaken by mine operators. We expect our mapping will allow researchers to conduct more robust studies on the long-term environmental and health impacts of surface mining, which in turn will help mining-impacted communities hold industry and government accountable for repairing the damage done to Appalachian landscapes, ecosystems and public health. We also hope the work will stimulate government investment as coal mining declines throughout the region, enabling a just transition to a new economy.

The following slider compares one of the new indexes we are incorporating into our work, a Normalized Difference Moisture Index (NDWI), with NDVI at the Hobet 21 Coal Mine. NDWI measures the relative amounts of moisture present in landscapes, densely vegetated areas have high NDMI values, while sparsely vegetated areas or bare earth have lower values. By incorporating new indices we are gaining a better understanding of how the land is affected by these operations. It is worth noting, therefore, the low amount of moisture present across the mine, even in those areas which appear to be recovering in the NDVI.

Coal mining in Black Thunder coal mine, WY from 1985 (in green) to 2015 (in red) overlain on 2015 aerial survey photography (NAIP).

Examining Mining Operations in the Powder River Basin Using Google Earth Engine

When you hear of coal production in America, what comes to mind? Perhaps you imagine a rugged man with a miner’s lamp on his helmet descending into a tunnel several hundred feet below the ground. Or maybe you picture giant machines removing topsoil and bedrock from a forested West Virginia mountain. But what if I told you most of the coal produced in America is mined from the arid grasslands of Wyoming and Montana?

According to the 2017 Federal Coal Program, “85% of production occurs in the arid region of Wyoming and Montana known as the Powder River Basin”. The Gillette coalfield in Wyoming contains the largest deposits of low-sulfur sub-bituminous coal. The area is flat, and the coal seams are very thick and close to the surface, making it much easier (and cheaper) to extract from open-pit mines, compared to the cost and effort of removing Appalachian mountaintops.

Mountaintop removal mining (MTR) is reshaping the Appalachian landscape. In the spring of 2016, Duke University and SkyTruth created a Google Earth Engine script to process satellite imagery and derive an accurate, annually updated map and GIS dataset of MTR operations across Appalachia. Google Earth Engine is a cloud-based geospatial processing platform with access to satellite imagery archives. For this work, we used Landsat imagery from 1985 to 2015. A band ratio was used on the imagery to identify active mining operations and to discriminate bare surfaces from vegetated land. A normalized difference vegetation index (NDVI) is a ratio of the red band to the infrared band. We chose this band ratio because vegetation will use red light but reflect infrared, while bare rock and soil strongly reflect both. The script determines an NDVI threshold based on testing the results against thousands of manually classified control points randomly scattered throughout the project area. If the NDVI value of a given pixel falls below the automatically determined threshold, it is classified as active mining.

Part of my summer internship was devoted to adapting this process for mining operations in the Powder River Basin. The first step in applying this script was to create a mask. Its purpose is to mask out everything that could be misclassified as mining because it’s a bare surface, like lakes, streams, roads, railroads, urban areas, etc. This data was collected from US Census TIGER shapefiles and merged to generate a raster mask. However, unlike Appalachian MTR operations, Powder River Basin coal mining is also surrounded by natural gas and oil drilling sites. To mask out these fracking pads, well permits were downloaded from the Wyoming Oil & Gas Conservation Commission, then added to the mask. Variables such as coal mining permits, and county boundaries (Converse and Campbell) were added for Wyoming.  

The vastly different climate proved difficult in this adaptation. While Appalachia is mostly mountainous deciduous forest, the high plains of eastern Wyoming are flat and semi-arid. There are naturally many small barren areas or badlands in this region that mimic mining operations, at least from the satellite’s perspective. My solution was to filter the results by eliminating any area classified as active mining that was less than 300,000 square meters (m2) in size. This threshold was determined during some post-process editing, where I examined all of the areas classified as mining that fell outside the boundaries of mining permits, and the largest was 300,000 m2. The resulting output only retained the larger vectors located within the permits and can be seen below.

Coal mining in Black Thunder coal mine, WY from 1985 (in green) to 2015 (in red) overlain on 2015 aerial survey photography (NAIP).

Coal mining in Black Thunder coal mine, WY from 1985 (in green) to 2015 (in red) overlain on 2015 aerial survey photography (NAIP).  

As you can see, this approach yields reliable results. I’m confident the methodology we demonstrated in Appalachia can work for coal mining out West. It is worth experimenting with changing the NDVI threshold to see if we can come up with a better tradeoff between identifying the active mining areas, and misclassifying badlands and other non-mining barren areas.  


Infrastructure Drives Development in the Brazilian Amazon: Highway –> Hydroelectric Plant –> Gold Mine

Big changes are happening in the Brazilian Amazon along a stretch of the Xingu River known as the Volta Grande (Big Bend), where it takes a detour to the south before turning back north to flow into the Amazon River. The region has experienced rapid growth and deforestation following the construction of the Trans-Amazonian Highway (BR 230 ) in 1972, as this pair of images illustrates:

1988:  Satellite imagery showing the Volta Grande region along the Xingu River in Brazil’s Para state. Tendrils of deforestation reveal settlement reaching out into the rainforest along the Trans-Amazonian Highway, built in 1972. Site of the future Belo Monte hydroelectric project is marked for reference. Compare with 2016 image below of the same area.


2016:  The same area as shown above in 1988. Considerable deforestation has occurred in the 18-year interval.

Small-scale gold mining has also occurred in this area over the past few decades, peaking in the 1980s. But now a major hydroelectric project, that became operational in 2015 and is still under construction, may be paving the way for a multinational mining company, Belo Sun of Canada, to propose a massive open-pit gold-mining operation.  Some local residents, already negatively impacted by the hydro project, are wary of the gold mining proposal: “I have seen mining companies elsewhere, they take all the wealth and leave craters. We have to think about it ten times over before accepting their projects.”

The mining operation is temporarily on hold, so there’s nothing yet to see.  But Google Earth does have high-resolution satellite imagery showing the construction of the hydroelectric project that may be a key part of the business plan for this mining project.

2014: High-resolution panchromatic (black and white) satellite imagery of the Belo Monte hydroelectric project under construction on Brazil’s Xingu River. Project became operational in 2015. Compare with 2010 image below of the same area.


2010: High-resolution satellite imagery showing the site of the future Belo Monte hydroelectric project. Compare with 2016 image above of same area.

As we can see from the detail below, showing a line of trucks at work on the dam in 2014, this is a huge project. And the development sequence illustrated so clearly in this area shows that one big project begets another — from highway, to hydro, to mine.

Detail from 2014 satellite imagery showing trucks at work on part of the Belo Monte hydroelectric project.

The influx of people that results is inexorably transforming the Amazon rainforest.

Into… Ohio?