Ten Years of Land Opened
If we could look down at the mining areas once a year for ten years, what would we see?
To answer that, I traced the footprint of 124 coal mining permits across South Sumatra, one year at a time, from 2016 to 2025. Every patch of open ground was delineated by hand on 30 m Harmonized Landsat and Sentinel imagery, then cross-checked against 3 m imagery and base maps. Overlapping polygons were removed first, so no hectare is ever counted twice. 2015 was dropped because the imagery that year was too cloudy to read.
The result is an annual, wall-to-wall record of two things that are usually reported separately: how much land was opened, and how much actually grew back.
What the record shows
- Open land grew 3.6×, from 6,291 ha in 2016 to 22,373 ha in 2025.
- 29,178 ha were opened at least once over the decade; 6,805 ha (23%) are now vegetated again.
- Between 2017 and 2025, 25,589 ha were opened against 9,363 ha recovered, a ratio of 1 : 2.7. In nine consecutive years, recovery never exceeded clearing.
- 2,464 ha have stayed bare for the entire ten years, and a third of the currently open land has been open for five years or more.
- 41% of land open in 2025 sits within 1 km of housing, and 77 of the 124 permits have a main river within 500 m of their boundary.
Where recovery did happen, it holds up: NDVI on recovered ground climbs steadily for four to five years, then settles near 0.74, well above the 0.33 threshold for healthy cover. That measures greenness, not species composition, which is a limit worth stating out loud in any rehabilitation report.
The same method was then run over a single open-cut mine as a case study, with an animated pit outline and a recovery map for each year, to show that the workflow travels between sites.
I built the findings into a self-contained interactive deck: animated maps, a year-by-year opened-versus-recovered chart, a cumulative disturbance and recovery footprint, duration histograms, NDVI recovery curves, and proximity analysis for schools, villages, places of worship, and rivers. Every figure traces back to the table it came from.