Análise de alagamentos urbanos a partir de veículos aéreos não-tripulados: um estudo de caso em Pau dos Ferros/RN

Abstract

Brazilian cities, given the rapid urban expansion and the lack of infrastructure in terms of sanitation services, are highly susceptible to the occurrence of environmental disasters, especially floods and flooding. Thus, this work aimed to develop a method for analyzing urban flooding based on high spatial resolution Digital Elevation Models (DEM) through the photogrammetric processing of Unmanned Aerial Vehicle (UAV) images, associated with strategic survey in GNSS. For this purpose, bibliographic and cartographic research was carried out. An aerophotogrammetric survey was carried out, enabling the verification of image quality and alignment; the production of three digital surface models (MDS), one being simplified, unchanged and corrected; and the production of an orthomosaic. Remote sensing was also used, enabling a delimitation of the drainage network, micro-basins, topographic depressions and flood simulation. Thus, 7 topographic depressions were identified and two drainage galleries were modeled. In these depressions, the misallocation of existing drainage instruments or even their inexistence was found, impacting no potential for accumulation of rainwater in its entirety. In other cases, the accumulated rainwater only flows to other locations after a depth of 30 cm. Finally, there is a need for correction in digital elevation models so that they represent more faithfully the flow of rainwater, as well as the potential for accumulation of topographic depressions.