Vulnerabilidade ambiental e risco a deslizamento na Bacia Hidrográfica do São Raimundo, em Manaus-Amazonas

Abstract

The São Raimundo Basin, located in the city of Manaus/AM, is one of the most densely populated hydrographic basins in Manaus, presenting a high number of mass movement occurrences. The use and occupation of these areas have been a recurrent problem, since portions of land with topography and morphology prone to natural disasters have been irregularly occupied, exposing the population to geological risks. The aim of this study is to analyze the degrees of environmental vulnerability and identify the risk sectors associated with mass movements.It is known that, historically, sites susceptible to geological risks are generally associated with the irregular occupation of drainage network margins, making them vulnerable to phenomena such as landslides. The methodology employed in the study is based on the identification of conditions and factors that make the analyzed hydrographic basin vulnerable, as well as the effects on its resident population, according to data published by the Brazilian Institute of Geography and Statistics (IBGE). Social, environmental, demographic, hydroclimatic, and geomorphological variables were taken into account, allowing for a comprehensive assessment of the situation. For the development of the study, the delimitation of the study area was carried out, along with the analysis of the historical use and occupation of these regions, and the acquisition and processing of secondary basin data. This enabled the elaboration of thematic maps, such as basin location, hypsometry, slope, land use and occupation, soil classes, in addition to housing data classified by IBGE (2022), including the distribution of “favelas and urban communities,” which can generally indicate aspects of the absence of basic sanitation services and adequate infrastructure. Risk sectors were defined and hierarchized between Very High (R4) and Low (R1), resulting in the Kernel map, which highlights areas of higher landslide risk concentration. From the data analyzed, it is understood that social inequality plays a fundamental role in understanding how natural disasters impact the most vulnerable populations, considering the territory’s response to its use over the decades. Therefore, landslides not only reveal the fragilities of the physical environment, but also expose social injustices and the need for environmental inclusion in urban planning.