The geography of risk and vulnerability to heat in urban spaces in the tropical zone: the case of the city of Cuiabá in Mato Grosso, Brazil

Author(s)

Aristóteles Teobaldo Neto

• Document type: Doctoral Thesis
• Press: Presidente Prudente. 2019-04-02.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências e Tecnologia. Presidente Prudente
• Defense date: 2019-02-22
• Advisor: Margarete Cristiane de Costa Trindade Amorim

Abstract

The society that lives in urban spaces in the Earth’s tropical zone is subject to a greater propensity of exposure to high temperatures. It constitutes a risk which may range from a reduction in the quality of life to more serious health issues. The geographic analysis of any phenomenon with natural origin embodies a specific complexity in the tropical zone as most countries in this zone are marked by deep social inequalities which imply easing or worsening of the risk according to the social group someone belongs to. Therefore, it has been established as the main goal of this thesis, to investigate the dimension of the risk according to the heat exposure in tropical urban areas during the warmest season of the year, with the urban area of Cuiabá (Mato Grosso), which is one of the warmest in Brazil, being the case study. To achieve such goal, it was necessary to: identify and explain the processes that produce the different levels of risk and vulnerability in the urban space; analyse the danger represented by heat exposure through the study of the Urban Heat Island (UHI) and the household microclimate; elaborate a social vulnerability index for the urban areas; analyse and explain how the social vulnerability constrains (increases/reduces) the danger according to heat exposure. The methodology was based on the application of statistical techniques, geoprocessing, field work and the use of first-source and second-source databases where the use of data from the 2010 Census (from the Brazilian Geographic and Statistical Institute (IBGE)) played a very important role in the elaboration of the Social Vulnerability Index (SVI). The diagnostic of the danger related to heat exposure has allowed to reach some conclusions on the formation of “very strong” Urban Heat Islands that expose 70% of the urban population to high levels of Heat-Exposure- related Danger Index (HEDI). Yet, the SVI map revealed the importance of the social characteristics in determining the heat vulnerability, showing that 42,3% of the population live in high social vulnerability sectors, determined as such mainly because of variables related to low income, black/mixed-race skin colour and educational deficit. The used methodology has primarily shown the viability of the space-temporal evaluation of the social vulnerability in all Brazilian territory starting from the census sector. Secondarily, it has been shown to be possible to integrate the study of risks related to various hazards, such as: floods and flooding processes, landslides, hurricanes and others. The combination of the Social (SVI) and Climatic Dimension (HEDI) Indexes resulted in the Heat Vulnerability Index (HVI) map. The 21% of the population in the best HVI sectors, though located in the areas of most heat exposure, had those effects sharply reduced (or nulled) due to the good social indicators. On the other hand, the sectors with the worst HVIs show low heat exposure index (HEDI) because they are located by urban streams in the urban fringes where the temperatures are lower. The obtained results at the mesoclimate scale refutes the hypothesis that the areas of greater social vulnerability coincide with the warmest ones. Notwithstanding, the results obtained at the microclimate scale confirms such hypothesis. In substandard dwellings located in high HVI sectors, the measured temperatures indoors were higher than those outdoors in 85% of the readings. The measures taken against the heat were not efficient, resulting in insomnia, irritability, tiredness, fatigue, headache, low blood pressure and respiratory problems. It was concluded that heat vulnerability, though being considered as a climate-related risk/hazard, is determined by social-originated factors. (AU)

• FAPESP's process: 16/03599-9 - Urban Climate in Cuiabá / MT: The dimension of risk in areas of high socio-spatial vulnerability
• Grantee: Aristoteles Teobaldo Neto
• Support Opportunities: Scholarships in Brazil - Doctorate