Perious surface fraction threshold and quantil -based optimization: a new framework for heating in urban areas with high density

The urban heat islands considerably make thermal complaints, energy consumption and public health risks in dense urban cores with limited green areas. While landscape optimization is a recognized damage reduction strategy, practical and quantifiable approaches for highly urbanized areas remain scarce. In this study, the city is reconverted as a continuous mosaic of intertwined gray (built) and Greens (vegetated) rooms. We apply a frame “Down Scale-Classify-Attribute” to analyze urban functional zones on a gray-to-green continuum. We concentrated on Beijing's fifth ring road area and analyzed 11 landscape metrics in socio -economic function zones with perverse surface fraction (PSF) (0–1 at intervals of 0.05). The results identified PSF = 0.5 as a critical threshold, which distinguishes two thermal regulatory regimes. Under this value, building patterns (e.g. coverage ratio, height, sky view factor) dominate the temperature regulation. In these low-PSF zones (