FLOODS DUE TO EXTREME PRECIPITATION EVENTS IN THE BRAZILIAN SEMIARID
Geotechnologies, GNSS, UAV, Northeast Brazil
The unrestrained and disorderly growth coupled with the rural exodus process that began in the 19th century in Brazil, has caused the expansion rate of its cities to be faster than that of the implementation of basic urban infrastructures. Experiencing this problem, Pau dos Ferros/RN presents in its extension several places vulnerable to flooding that affect not only the marginal areas of the city, but also the central neighborhoods where a large part of the commercial movement of its homonymous micro-region develops. Based on this, the present research aims to analyze the occurrence of flooding in a spatial area located between the neighborhoods Centro, São Geraldo and São Benedito using methods of hydrological analysis of geoprocessing. Data acquisition was performed using an Unmanned Aerial Vehicle (UAV). The collected images were treated by means of Digital Image Processing (DIP), where the orthophotomosaic, Digital Elevation Models and Digital Surface Model were produced. Through these products, the flow and presence of topographic depressions of the studied spatial profile were analyzed, in which it was verified that before going to the Apodi river, the rainwater is conducted to the study space whose flooding problems occur with precipitation accumulated above 40 mm/day. In addition, there was an insufficient number of urban drainage devices and, in some cases, their obstruction, revealing poor public management regarding the components of environmental sanitation.