Atlas · Sierra Leone
/
Signals & Anomalies
INTELLIGENCE
Signals & anomalies
Statistical checks that flag polygons and patterns that look unusual. They are prompts for review, not errors: an unusual polygon can be a real feature.
Polygons < 0.01 ha
0
0.0% of all polygons
Polygons < 0.001 ha
0
Likely slivers (≈ 10 m²)
Geometries repaired
55,235
Invalid shapes fixed on import
Effective mesh size
2,890.8 ha
Largest patch 5.9% of area
Largest-size outliers
z-score of ln(area): how many standard deviations above typical
| Formation | Area (ha) | z | Location |
|---|---|---|---|
| Mangrove | 8,906.3 | 5.59 | 7.6288, -12.4805 |
| Mangrove | 8,082.1 | 5.53 | 7.7557, -12.6145 |
| Mangrove | 7,771.1 | 5.51 | 7.6908, -12.4923 |
| Mangrove | 6,254.1 | 5.39 | 7.7449, -12.5480 |
| Mangrove | 5,532.5 | 5.33 | 7.9074, -12.8941 |
| Mangrove | 4,492.2 | 5.21 | 7.8597, -12.4751 |
| Mangrove | 3,928.2 | 5.14 | 7.5496, -12.5883 |
| Mangrove | 3,824.4 | 5.12 | 7.5795, -12.5733 |
| Mangrove | 3,418.2 | 5.06 | 7.6051, -12.8094 |
| Mangrove | 3,333.1 | 5.05 | 8.1141, -12.8778 |
Most irregular outlines
Shape index (perimeter ÷ circle perimeter): high values suggest jagged or sliver-like edges
| Formation | Area (ha) | Shape idx | Location |
|---|---|---|---|
| Mangrove | 8,082.10 | 15.2 | 7.7557, -12.6145 |
| Mangrove | 1,449.00 | 14.3 | 7.5666, -12.8756 |
| Mangrove | 588.87 | 13.2 | 7.0457, -11.6187 |
| Mangrove | 4,492.16 | 12.7 | 7.8597, -12.4751 |
| Mangrove | 2,872.86 | 10.9 | 7.6075, -12.6580 |
| Mangrove | 589.62 | 10.0 | 7.4270, -12.3731 |
| Mangrove | 3,064.92 | 10.0 | 8.2127, -12.9651 |
| Mangrove | 328.80 | 10.0 | 8.1346, -12.6591 |
| Mangrove | 1,947.11 | 9.6 | 7.8519, -12.7928 |
| Mangrove | 1,434.47 | 9.4 | 8.2672, -12.9619 |
| Mangrove | 5,532.47 | 9.3 | 7.9074, -12.8941 |
| Mangrove | 8,906.25 | 9.1 | 7.6288, -12.4805 |
How to use this page. Check flagged polygons against recent satellite imagery. Remove genuine mapping artefacts in the next source update; keep real features. Atlas never edits the source data silently.