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

FormationArea (ha)zLocation
Mangrove8,906.35.597.6288, -12.4805
Mangrove8,082.15.537.7557, -12.6145
Mangrove7,771.15.517.6908, -12.4923
Mangrove6,254.15.397.7449, -12.5480
Mangrove5,532.55.337.9074, -12.8941
Mangrove4,492.25.217.8597, -12.4751
Mangrove3,928.25.147.5496, -12.5883
Mangrove3,824.45.127.5795, -12.5733
Mangrove3,418.25.067.6051, -12.8094
Mangrove3,333.15.058.1141, -12.8778

Most irregular outlines

Shape index (perimeter ÷ circle perimeter): high values suggest jagged or sliver-like edges

FormationArea (ha)Shape idxLocation
Mangrove8,082.1015.27.7557, -12.6145
Mangrove1,449.0014.37.5666, -12.8756
Mangrove588.8713.27.0457, -11.6187
Mangrove4,492.1612.77.8597, -12.4751
Mangrove2,872.8610.97.6075, -12.6580
Mangrove589.6210.07.4270, -12.3731
Mangrove3,064.9210.08.2127, -12.9651
Mangrove328.8010.08.1346, -12.6591
Mangrove1,947.119.67.8519, -12.7928
Mangrove1,434.479.48.2672, -12.9619
Mangrove5,532.479.37.9074, -12.8941
Mangrove8,906.259.17.6288, -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.
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