Evaluation of risk associated with flooding in coastal plains of Aracaju - SE, Brazil

Abstract

The maintenance of the delicate balance of the coastal landscape, as evidenced by the complexity of its components, it's difficult, especially when considering the current arrangements for coastal grabbing. This situation has led to the emergence of several risk scenarios. Thus, this paper aims to assess the risks associated with flooding to the coastal plain of Aracaju/SE – Brazil, based on the application of a methodology supported on the variables hazard (hydrometeorological) and vulnerability (exposure to hazard). The methodological procedures consisted of assessing and measuring the hazard according to the probability of occurrence, magnitude and susceptibility; the vulnerability, based on an estimate of the density of drainage infrastructure and verification of anthropogenic derivations, which allow the analysis of the carrying capacity of the environment; and risk, by intertwining the indexes of hazard and vulnerability. The measurement of the indexes utilized revealed that about 70% of the coastal plain we have studied is associated with high levels of flooding risk. This scenario emerges where there is a greater natural susceptibility, or when there is high anthropic derivation of the landscape and a low capacity to support the rain drainage infrastructure, which is a fact that sharply alters the resilience of the environment and raises the risk levels. Thus, it is concluded that the risk has been systematically produced as there is a disorderly advance of occupation of naturally susceptible areas, combined with the continuous waterproofing of the soil and the absence of public policies for risk management.