URBANIZATION EFFECTS ON MANAUS MICROCLIMATE

Abstract:

Urban growth, related to urbanization and consequent land use and land cover changes, can directly modify the Surface Energy Balance (SEB), generating changes in the atmosphere that can vary from local to regional scales. Trying to understand these effects, the main objective of this work is to study the influence of urbanization on the local microclimate of the city of Manaus through numerical simulations using three different scenarios of urban area growth. These scenarios consider a representation of the anthropogenic energy fluxes and physical characteristics of the urban area of Manaus, with a scenario related to urban characteristics in 2008, 1973 and a future scenario considering that the physical area of Manaus will be duplicated as well as anthropogenic fluxes. A first analysis of the results showed that the model has an excellent skill in representing the diurnal cycle of temperature and humidity in urban area. It was observed that the presence of the urban area modifies significantly the SEB, generating a thermal gradient between the city adjacent regions, favoring the formation and intensification of local atmospheric circulations. The growth of the urban area of Manaus had a direct influence on the SEB, where it was observed that with increase in its area there is an increase in temperature, a decrease in moisture and water vapor, as well as significant changes in the flow at low levels (Figure 1) and the structure and characteristic of ABL on the urban region. Was also observed that the flow at low levels, related with breeze circulations, has greater intensity mainly due to the intensification of the thermal gradient. In the general context of the results it was observed that the process of urbanization and the consequently increased of anthropogenic heat fluxes is directly related to changes in local microclimate. It is emphasized so that public policies that aim an organized growth of urban areas and the comfort of the population are necessary for the effects of climate change are not potentiated by existing local microclimate effects related to the process of urbanization.