Relation of geometry, vegetation and thermal comfort around buildings in urban settings, the case of hot arid regions

In the cities of the arid regions, sun and light are the most crucial dimensions and the most important ones in the assessment of the quality of environment in urban external spaces. They can generate, depending on their magnitude, a momentary embarrassment or a daily permanent stress, likely to condition the relations of the man with his entourage. The inhabitant of these cities and these spaces develops a whole arsenal of behaviours to adapt to it. They go from the simple embarrassment to social isolation. The daily practice of urban space is inevitably disturbed. The public streets and places are among the features in which the quality of environment and comfort have come to deterioration. This degradation is due mainly to a discontinuity in the use of these spaces: the hours of frequentation correspond to the freshest hours of the day, with the result that during the long summer period, which spreads out from May to October, the majority of these spaces witness a drastically reduced frequentation.