Alterações da temperatura em ambientes externos de favela e desconforto térmico

Edelci Nunes Da Silva,Helena Ribeiro

doi:10.1590/s0034-89102006000500016

Abstract

To study aspects of the microclimate in a shantytown (favela), in order to understand the influence of the land occupation pattern on its climatic parameters. The study was carried out in a shantytown located in the southwestern region of the city of São Paulo, Brazil, between February 19 and July 31, 2003, i.e. covering the whole autumn and parts of the summer and winter. The air temperatures were measured every hour on a microclimate scale, at four points within this densely populated shantytown and, as a control, on a tree-lined street nearby. In the summer, the average hourly temperatures in the shantytown were between 18.5 degrees C and 29.5 degrees C but, away from it, they were 2 degrees C to 3 degrees C lower at the hottest times of the day. In the autumn, the temperatures ranged from 15.5 degrees C to 25.5 degrees C and in the winter, 13.5 degrees C to 25.5 degrees C. The chilliest time in the shantytown was before dawn in the autumn and at 7 a.m. in the winter. The temperature variation was greater inside the shantytown than outside of it. The temperatures were within the comfort range for around 50% of the time. Temperatures below the lower limit (18 degrees C) were more frequent than those above the upper limit (24 degrees C). Temperatures above the upper limit were more frequent in the shantytown than outside of it. The land occupation is a temperature differentiation factor. In the shantytown, the temperatures were higher during the daytime (by up to 3 degrees C) and lower at nighttime (by 1 degrees C on average). The shantytown environment accentuated the temperature extremes, while the temperatures in the control street were milder.

Highlights

São Paulo is one of the biggest cities in the world, with many problems relating to the absence of housing policies
The temperatures were higher during the daytime and lower at nighttime
The data relating to air temperatures are presented

Summary

Introduction

São Paulo is one of the biggest cities in the world, with many problems relating to the absence of housing policies. Shantytown areas have been growing in number and extent since 1970. During the 1990s, while the population of the municipality grew by 0.9% per year, the population in the shantytowns grew by 3.84% per year, to reach 8.5% of the city’s population in 2000.*. The shantytowns predominantly consist of houses built using concrete and bricks, with concrete roof slabs or asbestos roofing. The installation of infrastructure (asphalt, water and electricity) and the masonry construction of the houses themselves have not been reflected in widespread improvements in the livability conditions. The absence of vegetation, high density and impermeabilization of the construction lots – with irregular and very narrow streets – expose the resident population to risks that are not always visible. There are reductions in gains or increases in losses of heat by means of certain control mechanisms.[1,3,7]

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Conclusion