Mapping the spatio-temporal distribution of solar radiation within street canyons of Boston using Google Street View panoramas and building height model

Abstract

Studying the solar radiation within street canyons would provide an important reference for increasing human thermal comfort and decreasing the potential health issues caused by too much exposure from sunlight. In this study, we used building height model and publicly accessible Google Street View panoramas to map the spatio-temporal distribution of solar radiation within street canyons of Boston, Massachusetts. Hemispherical images generated from Google Street View panoramas and building height model together with sun paths in summer and winter were used to estimate the spatio-temporal distribution of solar radiation within street canyons. Results show that street canyons in the downtown area have shorter sunshine duration and lower solar radiation to the ground compared with other regions of the study area in the whole year. The southwestern part of the study area with the abundance of vegetation canopies has relatively short direct sunshine duration and low solar radiation reaching the ground in summer, and relatively long direct sunshine duration and high solar radiation reaching the ground in winter. This study also shows that it is possible to estimate shading precisely within street canyons for a specific time and date at a specific location. Considering the public accessibility of Google Street View data in cities around the world, this study can be easily deployed in other cities. This study would give a great impetus to all studies relating the solar radiation at street level in future.