Vulnerabilidade social às secas na sub-bacia hidrográfica do rio Banabuiú, CE

Abstract

Natural disasters related to climate dynamics have been recorded since the early days of colonization of the semi-arid northeast of Brazil. The region's semi-arid climatic domain has a high degree of rainfall variability, which is potentially aggravated by climate change, resulting in extreme events such as prolonged droughts and flash floods, both of which result in significant damage and loss, including human life. In this context, the object of study of this dissertation is the Banabuiú River sub-basin, located in the semi-arid region of the state of Ceará. In view of this, the main objective of this research is to analyze the spatio-temporal distribution of natural disasters related to droughts and to identify the different levels of social vulnerability to drought in the municipalities that make up the Banabuiú River sub-basin. The methodology applied is structured in six stages, namely: 1) Literature review; 2) Collection of rainfall data from 1988 to 2023; 3) Collection of data on natural disasters in the historical series of the National Civil Defense Secretariat from 2003 to 2020; 4) Collection and processing of socio-demographic data; 5) Calculation of the social vulnerability index and; 6) Spatialization of vulnerability. The results show that this sub-basin has drier areas in the north, in the municipalities of Itatira and Madalena. While the areas in the Center/South, mainly in the municipalities of Pedra Branca, Senador Pompeu, Mombaça and Milhã, stand out with a higher concentration of rainfall during the period analyzed. The results showed that even at a local level, the Banabuiú River sub-basin shows significant variability in the spatial and temporal distribution of rainfall between municipalities. An analysis of the SE and ECP Recognition Orders showed that the Banabuiú River sub-basin is most affected by natural disasters caused by droughts. Of the 234 recognition orders issued, 208 were due to droughts. As for social vulnerability, there was a predominance of high social vulnerability. However, the municipality of Itatira stands out for having the highest levels of social vulnerability in the test basin. On the other hand, Limoeiro do Norte showed very low social vulnerability, with the best socio-economic conditions in the region. That said, the research is important because it can contribute to a more comprehensive understanding of the local climate, as well as providing support for the development of mitigation and adaptation strategies, aimed at minimizing the impacts caused by extreme weather events by reducing or amortizing the exposure of the resident population to such phenomena.