Effects of urban geometry on thermal environment in 2D street canyons: A scaled experimental study

The Future of Climate-Resilient and Climate-Neutral City in the Temperate Climate Zone

“…The canyon geometry dynamically influences its thermal behavior during the day and throughout the year [ 227 , 256 , 257 , 258 , 259 , 260 ], and changes in canyon depth have better mitigation potential for the nocturnal UHI [ 121 , 188 ]. Wide canyons are characterized by a rapid LST increase in the morning, and because of the greater heated surface area, they reach higher maximum temperatures earlier [ 227 , 261 , 262 ]. At night, their thermal response is better than the high canyons.…”

Influence of Changes in Meteorological Observational Environment on Urbanization Bias in Surface Air Temperature: A Review

“…The anthropogenic heat flux is closely related to changes in the built-up area around stations (Yang X. et al, 2019;Yang et al, 2020a;Chen G. et al, 2021;Zhang et al, 2021) and can reliably reflect the effects of both anthropogenic emissions and changes in land use related to the latent heat flux and the sensible heat flux. A characterization system of the MOE (the surface thermal environment class and the anthropogenic heat flux) centered on the thermal environment around a station has been developed based on remote sensing images and geographical information systems technology (Shi et al, 2015;Yang X. et al, 2019;Yang et al, 2020a,b;Zhang et al, 2021).…”

“…Another approach is numerical modeling, in which numerical simulations are used to study the impact of changes in the MOE caused by urbanization on the meteorological observational elements (Zhang et al, 2002(Zhang et al, , 2016Liu and Zhou, 2007;Yang et al, 2016;Chen, 2021;Chen G. et al, 2021;Yu et al, 2021). The simulations include physical equations and the laws of atmospheric radiation related to energy and mass and therefore explain the changes in terms of the mechanism of influence.…”

“…The impact of urban sprawl on the MOE is not only reflected horizontally, but also vertically as an important part of the spatial structure (Figure 5). Indexes such as the sky visual factor (SVF), the block height to width ratio (BHWR), the floor area ratio (FAR), and Vegetation volume to building volume (VV2BV) are often used to depict vertical morphology within cities (Figure 5), which are expected to provide scientific assessments for the MOE changes and their effects on urban thermal environments (Chen G. et al, 2021;Chen X. et al, 2021). In detail, the SVF is the ratio of the area of sky visible at a fixed point on the surface to the total visible area (Oke et al, 1991) and the BHWR is defined as the ratio between the average building height within a street canyon and the width of the canyon (Oke, 1988).…”

“…In detail, the SVF is the ratio of the area of sky visible at a fixed point on the surface to the total visible area (Oke et al, 1991) and the BHWR is defined as the ratio between the average building height within a street canyon and the width of the canyon (Oke, 1988). FAR and SVF are two important parameters for characterizing the geometry, density and heat balance of urban areas, in addition to generating and controlling the heat island effect (Svensson, 2004;Chen et al, 2020;Chen G. et al, 2021). The BHWR and VV2BV are two important indicators for characterizing the microscopic three-dimensional morphology and play key roles in radiation balance and outdoor thermal environment studies (Shashua and Hoffman, 2000;Chen, 2021).…”