Hemerobia da paisagem de Belém na Amazônia Oriental e estudo de impacto da urbanização no clima local

Abstract

Among the human activities that modify the surface coverage of natural landscapes, the urbanization process can be considered as one of the most serious forms of environmental anthropization. The impacts of urbanization are systemic in physical and ecological dimensions, with a direct effect being the change in local climate, particularly the increase in surface air temperature. In the present study, the concept of hemerobia (a term from landscape ecology that means “distance from nature”) is applied as a remote sensing technique to map the urbanization process in the municipality of Belém, the capital of the state of Pará in the region of Eastern Amazon. The results of mapping changes in land cover, comparing the years 1985 and 2021, revealed a significant increase in urbanization, which expanded by 17% at the expense of forest areas, which reduced by 11%. The urban area denoted by the areas of metahemerobia and polyhemerobia (classes with a medium and high degree of urban coverage) expanded to the neighborhoods and districts located in the center and north of the municipality and along the coastal strip of the islands of Outeiro and Mosqueiro. The results of the environmental mapping were integrated with statistical analyzes of air temperature data (point data from the meteorological station and CRU data at high spatial resolution), aiming to investigate the impacts of urbanization on seasonal patterns of maximum air temperature (TX) and minimum (TN). Trend analyzes showed significantly warmer climate patterns, with a notable indication of systematically higher TX and TN in the most densely urbanized areas compared to areas with preserved vegetation, with the increase in air temperature being more significant (statistically significant) during the dry season (July to November). An interesting result was found in the spatial maps of TX for the dry regime, with a climatological pattern similar to the classic heat island model with concentric isotherms that reach a maximum center over the more urbanized continental region of Belém and thermal decrease at the edges. The study highlights the urgent importance of government policies to mitigate the negative impacts of urbanization in the metropolitan area of Belém.