A Spatial Analysis of Urban Space Albedo According to Urban Surfaces Color

The color of urban surfaces is a crucial physical factor that influences the urban microclimate. Dark-colored surfaces tend to absorb more solar radiation than light-colored ones, thereby intensifying the urban heat island (UHI) effect. In many cities today, the lack of color regulation in urban planning and the rapid pace of construction have led to the predominance of darker surfaces. Traditional methods for measuring urban albedo have often been limited by their high cost, time consumption, and small-scale applicability. This study introduces a Python program (version 3.10) to estimate urban surface albedo using street view imagery. The approach is based on identifying the dominant color of urban spaces, which serves as a proxy for surface reflectance. The estimated albedo values are derived by associating dominant colors with their corresponding reflectance properties. Applied to the Kowloon District in Hong Kong, a densely urbanized area with deep street canyons, the results show that the southern parts of Kowloon exhibit lower albedo values due to a higher concentration of dark-colored surfaces. This research highlights the potential of using color-based analysis as a scalable and cost-effective tool for assessing urban albedo, informing sustainable urban planning strategies aimed at mitigating UHI impacts.