Mapeamento e diagnóstico de suscetibilidade a movimentos de massa na região de brejo do cruz, Paraíba

Abstract

Mass movements occur in the landscape, often caused by biological activity or physical processes resulting from climatic conditions and the action of gravitational forces on the Earth's surface. The present research aimed to elaborate mapping and diagnosis of susceptibility to the movements of falling blocks in the residual massifs of the Brejo do Cruz region, in Paraíba, considering the risks associated with the occurrence of mass movements in the granitic reliefs of the accentuated declivity, it was considered the importance of making the diagnosis and classification of mass movements also in the reliefs of semi-arid climate. For this, techniques of geoprocessing and multicriteria analysis were used based on the hierarchical analytical process method - (AHP), as well as bibliographic research in dissertations, magazine articles (national and international), and in works that deal with the investigated problem. Base maps of the analyzed variables were made and the map of susceptibility to mass movements, which showed three degrees of susceptibility to the investigated processes, 55.9% of the area was classified as of low susceptibility; 36.4% corresponded to areas with moderate susceptibility and 7.6% corresponded to areas with high susceptibility to processes. It was found that in the areas classified as highly susceptible, they coincide with the granitic massifs with sharp declivity (> 45%), where the relief is steep and strong steep, the index of dissection of the relief showed strong and very strong percentages and occur in the terrain. high altitudes. Concerning the mapping and diagnosis of the processes, it was observed that the results of the synthesis of these maps are directly correlated with the types of movement that occur in these areas, which corroborates the relevance of the conditioning factors in the triggering of the processes. Thus, the results of the interpolation of the maps by the multicriteria analysis method were satisfactory, since they corroborate the investigated hypotheses, which was demonstrated by the correlation of the results with the areas where movement is proven to occur and the consistency ratio presented consistent results for the analysis. multicriteria of morphometric variables.