Sky view factor （SVF）

The sky view factor （SVF） is an indicator used to measure the level of enclosure of street canyons, which has been widely applied and has become a standard metric employed by urban designers. Because SVF relates to the amount of direct solar radiation reaching the ground, it holds direct implications on the thermal comfort of citizens. As a parameter of urban geometry, the sky view factor （SVF） indicates how much sky is obstructed by buildings and tree canopies. The SVF also represents the ratio between radiation received by a planar ground and that from the entire sky hemisphere’s input radiation. When the sky is totally obstructed, the SVF is 0, while the SVF is 1 when there is no obstruction. SVF has been used as an indicator of the shading level, which is jointly caused by both block building sand street trees.

Edited and translated by ZhangYifei