Proposta metodológica de gestão dos espaços-riscos de inundações urbana em Mossoró-RN

Abstract

This research is within the topic of risk associated with urban floods in a semiarid northeast Brazilian city. The aim of the research is the study of climate dynamics – hydrological (droughts and floods) in situations of emergency and a state of emergency. The research focuses on the methodology of delimitation of urban floods considering the weather and its economic and social impacts on the lives of the affected population. The concepts discussed are: hazard, risk, disaster, catastrophe, vulnerability and extreme events. The methodology used is based on review of existing documentation, database and fieldwork, analysis and interpretation of urban evolution and climatic dynamics and delimitation of flood risky spaces in Mossoró with the following timeframes: urban data (1970-2010), climatic (1970-2013), Mossoró civil defense (1983-2013). The risk management approach in discussion is related to risk mapping, prevention, monitoring, alert and response. Within the analyzed series, 18 events were found, among them 16 were declared as situation of emergency and 2 as state of emergency. This research explores a methodology that enables the definition of flooding areas in the urban core of Mossoró andpeople at risk through the census tracts. The methodology showed that the use of ASTERGDEM images with the resolution of 30 meters is an interesting approach for definition of flooding areas, given that, with the use of Qgis 2.8 and Arcgis 10.1 there is a possibility of application of filters to reduce noise from the images as well as smoothing the contours. Two regions were found, the first with the maximum flood at an altitude of 15 meters and the lowest between 7 and 13 meters. The intersection and delimitation with census tracts shows that 67 census tracts are daily affected, with 35.775 people living in the first region (up to 15metres) and 8.364 people are in the second region (7-13 metres), the sectors with the largest number of people at risk are: Barrocas 10.708 people, Belo Horizonte 6.353, Alto da Conceição 5.306, Paredões 5.187, Ilha de Santa Luzia, Lagoa do Mato 2.015, Pintos 1.436., Bom Jardim 1.430 e Alto de São Manoel 1.153. As a result a contingency plan was proposed considering the most affected neighborhoods. The appreciation of the risky areas, as an expression of the potential hazards, promotes fitness and ensures resources and means for the protection and relief, also favors health and social support (quantitatively and qualitatively) in dangerous areas.