Measurement
Green cover
Green cover is the share of an area showing living vegetation, usually derived from satellite imagery. It is quick to measure across a whole area, and it counts anything green, so it is read alongside ground checks that confirm what is growing.
Change in green cover over several years, measured in the same season each time, says considerably more than a single reading.
It is a screening indicator. It shows where to look, and a ground check confirms what is there.