Remote Sensing
Minimum mapping unit
The smallest area that a land-cover map will record as a distinct polygon, setting a floor on what counts as change.
The minimum mapping unit decides whether a half-hectare clearing exists in the dataset. Areas below the threshold are merged into neighbours and effectively disappear from the accounting.
Choosing it is a trade-off between noise and sensitivity. A large unit suppresses false positives but misses small-scale encroachment, which is often exactly how degradation proceeds.
Frequently asked questions
Why does it matter for carbon claims?
Because omissions below the threshold accumulate silently and are systematically in one direction.
Is there a standard value?
No. It is set by the programme and must be disclosed with the results.