Measure the total extent of natural areas in the city with at least one of the following:

● An officially adopted sustainable management plan that encourages integrated pest management while reducing or eliminating:
○ fertilisers
○ pesticides (including rodenticides)
○ motorised mowing and other motorised tool use
● An active co-management programme with local community groups
● Stewardship by local indigenous group(s)

Complete Singapore Index indicator 19.
https://www.nparks.gov.sg/biodiversity/urban-biodiversity/the-singapore-index-on-cities-biodiversity

Protected Area Management Effectiveness (PAME) methodologies may alternately be used.
https://www.protectedplanet.net/en/thematic-areas/protected-areas-management-effectiveness-pame?tab=Methoodologies