As precipitações extremas na microbacia do Rio Potengi (área urbana de Riachuelo): uma análise das causas e consequências do processo de inundação

Abstract

Urban floods, resulting from intense rainfall, in highly anthropized areas have become increasingly frequent and in the Potengi micro basin, which covers the municipal seat of Riachuelo/RN, a precipitation was observed on January 3, 2022, of which it was noticed a distinct behavior of the river that cuts the county headquarters at this moment. Through a systemic analysis of the components of the micro basin, the following question was considered for the forwarding of this research: Does the flood event identified in the county headquarters of Riachuelo come from the way in which the use and occupation of the soil occurred in the micro basin that covers the seat, associated with physical-environmental characteristics of the area? From this question, the general objective was to understand the flood event of the Potengi watershed in the municipal seat of Riachuelo, on January 3, 2022, from socio-environmental aspects. The theoretical foundation was based on a discussion about the (geo)systemic analysis of precipitation elements and basin morphometry and their influence on flood episodes. In the methodological procedures, bibliographic research was used to support the concepts cited, as well as knowledge of methods and techniques of analysis in basins, data survey and cartographic material; later, the characterization of the precipitation event on January 3rd was carried out and the morphometry in the watershed was evaluated; next, there was an analysis of the use and occupation of the Permanent Preservation Area; and the field work with interviews and identification of the environmental conditions of the waterways in loco. As a result, it was verified that it was an extreme precipitation for the place, with a return time of 5 years, and this fact correlated with the current territorial planning of the town that did not consider the natural features of the area, were substantial elements for the occurrence of the flood. In this way, the research concluded that, mainly with regard to the use and occupation of the soil, it did not respect the environmental conditions, and the drainage infrastructure does not support expressive volumes, so the municipal headquarters is exposed to new flood events.