Analysis of the direct solar radiation in the streets of Barcelona, based on the relation between its morphology and vegetation

Abstract

The use of vegetation as a protection against solar radiation and as a generator of thermal comfort in outdoor areas is not something new and it has been used throughout history, many times in the right way and many others in the wrong way, obtaining results that are not always the desired ones. The objective of this study is the quantification of direct solar radiation on the horizontal plane of an urban canyon, taking into account its relation between its morphology and the urban vegetation present in the canyon. The methodology used consists in several stages: firstly, the selection of the areas of study (in the city of Barcelona); secondly, a survey of the tree species present; thirdly, three-dimensional models were made in order to run simulations to analyse; as the fourth stage, on-site measurements are made in order to compare the simulation’s results, obtaining as main conclusion that the factor that has greater weight in regard to the incidence or not of direct solar radiation on the horizontal plane of the urban canyon, is its morphology (aspect ratio (H/W), which goes hand in hand with the sky view factor (SVF)), being possible to modify the incidence of direct radiation through the correct use of  urban vegetation. The originality of this study, lies in taking into consideration multiple factors that affect the incidence of direct solar radiation on the horizontal plane of any urban canyon (orientation, ratio aspect and SVF), along with the use of urban vegetation.