Urban Green Space Analysis

NDVI compares how strongly a surface reflects near-infrared versus red light. Healthy vegetation reflects a lot of near-infrared and absorbs red, so it scores high, while water, bare soil, and built surfaces score low or negative. The result is a continuous per-pixel greenness index that captures all photosynthetic vegetation — including street trees and gardens — making it a fast, scalable proxy for green cover, though it cannot tell apart a lawn from a forest of equal greenness.

Total or per-capita green area can be high while most of it sits in a few large parks far from where people live. Accessibility measures weight each green space by how easily residents can reach it along the network, so they reveal whether green space is actually usable in daily life. This is what exposes green deserts — dense neighbourhoods with little reachable green space — that area totals hide, and it is central to equity analysis.

It is a simple green-space standard proposed by Cecil Konijnendijk: every home should have a view of at least three trees, every neighbourhood should have at least thirty percent tree-canopy cover, and every resident should live within three hundred metres of a park or green space. It bundles the view, canopy, and proximity dimensions into auditable targets, giving planners and communities a clear, communicable benchmark to design and check green-space provision against.