Mapeamento de risco de movimentos de massa em João Pessoa – PB através de uma metodologia quali-quantitativa de classificação de risco

Abstract

In the last decades, the occupation profile of Brazilian cities has changed significantly as a result of an accelerated urbanization process and population growth. However, this growth was not accompanied by the development of services and infrastructure compatible with this new reality, culminating in the appearance of irregular occupations on steep slopes and the banks of streams and rivers. The social and economic vulnerability of the population residing in these occupations and the fact that these regions of the territory are subject to the occurrence of natural and / or induced processes, means that these areas are called risk areas. Among the main processes to which risk areas are subject, mass movements were the ones that showed the greatest increase in the number of records in recent decades. In view of this scenario, the Law Nº 12.608/2012 was created in 2012, which instituted the national registry of municipalities with areas susceptible to the occurrence of landslides and floods, which must prepare a mapping of these areas. The municipality of João Pessoa, in Paraíba, is one of the municipalities registered by the Federal Government. Since 2013, the Geological Survey of Brazil of the Mineral Resources Research Company (CPRM / SGB) has mapped the high and very high risk sectors in the municipality, through the application of a qualitative risk classification methodology, which is based on field observations and depends on the experience and judgment of who performs the mapping. In order to assist municipal management bodies in the identification and monitoring of these areas, the present work sought to validate a qualitative and quantitative methodology risk classification for the municipality of João Pessoa and the creation of a database on the areas mapped in a Geographic Information System (GIS). Comparing the risk ratings obtained with those attributed by CPRM / SGB, there was a difference of 56.2%. Thus, some modifications in the weights attributed to two analyzed parameters were proposed, resulting in a difference of 27.1% between the risk classifications compared.