Urban climatology
Introduction
Urban climate is understood as the weather conditions that urban areas have, in contrast to those that could occur in a rural area. Urbanization, in addition to other causes, exerts tremendous irreversible modifications (at least from an economic point of view) on the previous rural landscape, and that is why changes develop in the surrounding atmosphere.[1][2].
The constantly increasing world population is concentrated more and more in megalopolises such as: Bogotá, Buenos Aires, Mexico City, Lima, Los Angeles, New York, Beijing, Shanghai, São Paulo, Rio de Janeiro, Tokyo. Urban areas, which also have strong industrialization, experience strong changes in the properties of the surface soil. Natural surfaces such as meadows, forests, fields, become surfaces of stone, concrete, asphalt, metal, bricks, which primarily causes changes in atmospheric temperatures, rainfall and cloudiness.[3].
Temperature
An urban area develops significant warming compared to its rural (and possibly suburban) surroundings, particularly at night and in calm. As the population grows, there is a more or less proportional increase in temperatures (which are more welcome in winter than in summer). The United States Environmental Protection Agency states that: "on hot summer days, urban air can be 1 to 6°C warmer than suburban and rural areas." This is how the "urban heat island" effect phenomenon occurs.[4].
When the population exceeds a certain number of inhabitants (although this varies depending on the type of city and its level of development) the process expands, especially in developed countries, so more measures should be taken to mitigate the heat island effect, such as: afforestation and reforestation in block centers, in streets, squares and parks, both large and in small spaces; expand the "green space/inhabitant" relationship, a relationship that is rapidly deteriorating due to the increase in density and the decrease in space for housing and urban uses; creation of "articulated pavements" in order to create green microspaces between their joints; the promotion of "intelligent construction" of buildings (greater exterior-interior insulation, white colors to reflect sunlight, anti-sun screens), etc. However, it must be taken into account that all these measures depend on the location of the cities in terms of the general climate of the region: what is good in the intertropical zone may be inconvenient in a region with a very cold climate. And the opposite occurs with Dutch architecture, with narrow windows and very sloping roofs to drain rain and prevent the accumulation of snow, which is not appropriate in a place like Curacao, despite which said architecture was moved there, for historical-cultural reasons, almost without adapting to the warmer climate. Precisely, this architectural exoticism has become a tourist attraction for the Netherlands Antilles.