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Derna, Wadi Derna

The September 2023 dam collapse and flood.

168.6 hectares changed — new vegetation · Before: 1 Jun 2023 – 31 Aug 2023 · After: 15 Sep 2023 – 30 Nov 2023 · 32.760, 22.640

BEFORE 2023-08

AFTER 2023-11

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168.6 haarea changed

74areas flagged

3,612 haarea examined

2satellites used

What changed, by type

132.9 haNew vegetation

32.9 haVegetation cleared

2.8 haNew construction / earthworks

Land changes in both directions at once. SCOPE reports every type it measured, not only the one that makes the better headline.

What SCOPE found

New vegetation — 30.8 ha
3.4 km south-east · between 28 Aug 2023 and 12 Oct 2023 · 92% sure

Vegetation cleared — 19.6 ha
2.3 km south-west · between 28 Aug 2023 and 12 Oct 2023 · 98% sure

New vegetation — 13.5 ha
2.9 km south-east · between 28 Aug 2023 and 12 Oct 2023 · 91% sure

New vegetation — 5.4 ha
2.8 km south-west · between 28 Aug 2023 and 12 Oct 2023 · 91% sure

New vegetation — 5.3 ha
0.9 km south-east · between 28 Aug 2023 and 12 Oct 2023 · 93% sure

How sure is this?

The strongest area (#1) has 92% confidence. It appears in 6 of 6 later clear images, so it is not a one-day artefact. Radar confirmed some of these areas; the others rest on optical and seasonal evidence. Compared with the same season in earlier years, this is clearly unusual. Confidence measures how strong the evidence for real surface change is; it does not identify the cause or who did it.

How it was measured

SCOPE used Sentinel-2 optical imagery at 10 m, cloud-masked and combined over each period, Sentinel-1 radar as an independent check , and the same season in earlier years so normal seasonal change is not reported as real change. The analysis took 15 seconds.

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