Modelo metodológico para avaliação regional da vulnerabilidade costeira: aplicação na Costa Atlântica Paraense, Amazônia Oriental, Brasil

Abstract

Coastal vulnerability is one of the main challenges within the scope of global environmental changes, especially in systems of high dynamics and complexity, as is the case with the Atlantic coast of the Pará Amazon. The constant erosive processes, the rise of the mean sea level, and the occupation in coastal zones have expanded the exposure of communities and ecosystems, which requires approaches that are capable of understanding vulnerability beyond its physical dimension. Thus, one tangentially reaches the problem residing in the limitation of “traditional” models of coastal vulnerability assessment, which, in their majority, are operated in a fragmented way, prioritizing physical exposure or socioeconomic indicators in a dissociated manner, without the incorporation of coastal containment capacity. In this way, the objective of this thesis is to compose the development of an integrated approach for the analysis of coastal vulnerability in the Pará Amazon, being grounded in the articulation between physical exposure and containment capacity, operationalized by means of the creation of a Coastal Vulnerability Index (CVI). The methodological structure was conceived from the integration between the Physical Vulnerability Index (PVI) and the Coastal Containment Index (CCI), using multicriteria modeling based on AHP, associated with techniques of geoprocessing and remote sensing. The analysis was conducted at regional scale, encompassing approximately 553 km of coastal zone, segmented into seven sectors on the Atlantic coast of Pará. The results evidence that coastal vulnerability presents a predominance of the classes of vulnerability: ‘low’ (48.01%; 12,744.54 ha) and ‘moderate’ (32.11%; 8,523.63 ha), followed by ‘high’ (19.57%; 5,197.14 ha), while the class ‘very low’ presents residual expression (0.31%) and there is no occurrence of areas classified as of ‘very high’ vulnerability (0%). The spatialized pattern denotes that the absence of extreme levels of vulnerability is directly associated with the action of natural systems, such as mangroves, and with the presence of institutional instruments of territorial ordering. The main contribution of this thesis resides in the proposition of a conceptual understanding of coastal vulnerability as a result of the interaction between physical exposure and containment capacity, displacing the analysis from a unidimensional perspective to a systemic and integrated approach. Thus, this proposal configures itself as a pertinent methodological and conceptual advancement, by allowing the spatialization of vulnerability from the integration between environmental processes and territorial organization, in which vulnerability, in the coastal Pará Amazon, is also institutionally produced. The implications of the study are relevant both in the scientific scope and in the applied one, by providing subsidies for planning and for the integrated management of the coastal zone, as well as by reinforcing the necessity of incorporation of ecosystem services and of governance instruments in the reduction of vulnerability, highlighting the necessity of expansion of coastal zoning models, incorporating in an integrated way the onshore and offshore components. Finally, this research corroborates with future perspectives of expansion of studies in view of the incorporation of the socioeconomic dimension, the use of high-resolution multispectral technologies, and the application of the model in other contexts inserted in the ITCZ, contributing to the advancement of knowledge about coastal vulnerability at local, regional, and global scale.