Mapeamento de suscetibilidade a movimentos de massas no município de Areia-PB.

Abstract

Disasters on Brazilian urban slopes are consequences of a set of geomorphometric weaknesses, enhanced by human action, which are responsible for substantial damage and losses. The identification of areas whose physical environment dynamics favor the instability of the soil mass is a subsidy for the planning and occupation of urban space. To achieve this, management units need reliable and optimized data for decision making. Given the conditions of the municipality of Areia, an area with a history of mass movements located in a mountainous region of the state of Paraiba, this study aimed to map the areas most susceptible to the occurrence of mass movements on slopes using a GIS-based model (Geographic Information System) and AHP (Analytic Hierarchy Process), both for the entire municipality and for a section of the urban center, as these are areas already occupied by the population. 8 mappable criteria were considered for the study, including elevations, slope, curvature in plan and profile, land use and cover, proximity to roads and proximity to rivers. After applying the GIS-AHP method, it was observed that the results were compatible with the data collection, previous studies carried out and historical records of the city. The criteria of Roads, Geology, Land Use and Cover and Slope were the most critical in this analysis, obtaining greater relative weights. In total, 57.5% of the urban area is in the highest susceptibility classes. It was also observed that 91.7% of the mass movement points mapped during fieldwork are in areas of greatest susceptibility. This study can be considered a potential instrument for managing land use and occupation for the municipality of Areia, as well as for cities with similar problems.