Atlas · Sierra Leone / Knowledge Base
KNOWLEDGE BASE

How to read a hot-spot map

What “statistically significant cluster” means.

Intermediate 1 min read hot spotsspatial statisticsmaps

A hot spot is a grid cell with much more mangrove than chance would suggest given its neighbours; a cold spot has much less. Atlas uses the Getis-Ord Gi* statistic and shows cells at 95% and 99% confidence.

A positive global Moran's I means similar values sit close together (clustering); near zero means a random pattern; negative means a checkerboard.

Limits. Results depend on the grid size (0.05° ≈ 5.5 km) and neighbour definition (queen contiguity). Edge cells have fewer neighbours.

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