Socio-spatialvulnerability to droughts and floods in the Piracuruca river hydrographic sub-basin (Ceará-Piauí/Brazil)

Abstract

Studies aimed at understanding socio-spatial vulnerability, with the hydrographic basin as a spatial cutout, are important to subsidize the prognosis and planning in face of the occurrence of droughts and floods.. Thus, we aimed to analyze the socio-spatial vulnerability of the Piracuruca River Hydrographic sub-basin to the occurrence of droughts and floods. The sub-basin is located between the states of Ceará and Piauí, drains an area of 7,704 sq. km and is heterogeneous, both from a biophysical and socioeconomic point of view. The multivariate statistical model, Factor Analysis (FA), and the Principal Component Analysis (PCA) estimation method were applied to the study, both considering the use of variables - demographic, infrastructure, basic sanitation, natural, economic and social population - considering the 296 (two hundred and ninety-six) census sectors of the 2010 demographic census. It is noteworthy that from this method / model and integration of the elements Criticity (characteristics and behavior of the population) and Support Capacity (infrastructure), it was possible to construct the Socio-spatial Vulnerability Index (SSVI) of the Piracuruca River Sub-basin. Thus, the variables used to know the Criticity indicated that in 87 (29.4%) sectors of the Sub-basin the upper class predomiates. In turn, it was inferred through the Support Capacity that 137 (46.3%) sectors of the Sub-basin are in the very upper class. However, the SSVI indicated the predominance of the lower class, which is distributed by 172 (58.1%) sectors of the sub-basin surveyed. However, investment is needed to improve socioeconomic indicators and reduce Criticism and maintain Support Capacity.

Keywords:
Natural Disasters; Factor Analysis; Principal Component Analysis; Criticity; Support Capacity