SILVA, A. P. L. M.; SILVA, Ana Paula Lima Marques da.
Résumé:
The research had a basic assumption, namely the fact that the growth
of the cities has been taking to great modifications of its structures, provoking its
pronounced heating, mainly due to asphalt's application and construction of
buildings with mirrored windows. Trying to study that situation in the state of
Paraiba, experiments with urban microclimate were driven in the winter periods
(July-August) and summer (December) of 1997 in the cities of Campina Grande
and Patos, objectifying to study the microclimate and the influence of the asphalt
surfaces, pavement and square, in the urban heating. So that, micrometeorological
stations were installed in the mentioned surfaces, equipped with
system of data's acquisition (micrologger 21X), that facilitated instantaneous
readings of global solar radiation, reflected radiation, radiation balance, flow of
heat, temperature and humidity of the air, temperature of the surface and speed of
the wind. Observations were also made with mobile transecto. Besides the
comparison among the parameters observed on the three studied areas, the
temperature of the air was also compared with that observed in the meteorological
station. The results showed that the asphalt surface is the hottest of the three
studied urban areas. In the city of Campina Grande, the temperature of the
asphalt reached hourly averages between 14 and 15 hours of 60,8°C and 47,5°C,
respectively, in the summer and winter, while in the city of Patos it arrived at
63,9°C and 55,5°C in the two mentioned periods. A fact that gets attention is that,
although the asphalt is the warmest surface, the temperature of the air on the
pavement street was larger than on the asphalt in the city of Patos, in the winter
and in the summer and, in Campina Grande, in the summer. That fact can be
associated to the great reflection of solar radiation by the pavement surface that,
although it contributes to liven up the temperature of the surface, provides more
radiation of short waves to be absorbed by the vapor of water in the adjacent
atmosphere. Observations with mobile transectos made in Patos, indicate that the
forest can contribute to reduce the temperature of the air in up to 1,8°C in asphalt
paved street and in 1,3°C in pavement street Last, the close made observations
to walls of several colors, they showed that on the sunny side of the street, the
temperature went 4,7°C superior on the average to that observed on the shaded
side and that the more dark it goes the color of to wall, larger heating this will
have.