O risco ambiental em uma cidade pequena: análise da morfodinâmica atual e sua relação com as áreas de risco à enchentes, inundações e alagamentos na cidade de Capinópolis/MG

Abstract

The purpose of this study was to understand the relationship between current morphodynamics and flood risk areas, floods and floods, with the purpose of explaining them through the process of occupation of the relief and expansion of the urban network of Capinópolis / MG. These events are perceived from the moment in which the process of expansion of the urban mesh, represented by the agents producing the urban space, disregard the dynamic balance of the natural processes, allowing their rupture. Morphodynamics consists of the morphogenetic and pedogenetic dynamics acting on a geological time scale, breaking with the dynamic balance of natural processes creates a current morphodynamics, represented by the acceleration of the processes of relief sculpture and soil formation. Specific objectives were also listed, aiming at the steps that led to an understanding of the relationship between morphodynamics and environmental risks. Among the objectives, we highlight: a) to correlate the current morphodynamic processes, the dynamics of occupation of the relief and areas of environmental risk in Capinópolis / MG; b) identify areas of environmental risk, emphasizing events such as floods, floods and floods in the city of Capinópolis / MG; c) analyze the environmental risk areas from the current morphodynamic processes identified in the urban area of Capinópolis / MG. To reach them, a methodological roadmap was established, following systematized steps, among them it is possible to mention: 1) definition of the theme and area of study; 2) choice of interpretation method, 3) bibliographic survey; 4) fieldwork and photographic records; 5) elaboration of thematic maps; 6) production of profiles; 7) tabulation of rainfall data; 8) investigation of reports on events considered to be of environmental risk. The methodology allowed to reach the objectives, making it possible to see that the expansion of the urban network, representing an alteration in the morphodynamic processes, allowed the emergence of events such as floods, floods and floods, caused especially by the waterproofing of the relief surface and increase of the runoff. It is observed that floods and floods are restricted to the bottom of the valley where the Olaria Stream is located, an area most affected by the urban expansion process, which began around 1950. The Olaria Stream is a reflection of the activities promoted in most of the Brazilian cities, channeling it and occupying the unconsciously flooded floodplain became a major aggravating factor, allowing more frequent events such as floods and floods in the years 2017 and 2018. Already, floods are given less comprehensively in the city of Capinópolis / MG, restricting the areas where drainage of rainwater is unable to drain the flow of surface flow directed to them. It was observed the presence of floods in valley bottom areas and top areas, explained due to the process of occupation of relief forms and the absence of an efficient rainwater drainage system. The study emphasizes the importance of considering the geomorphological aspects in risk studies, the relief is not only the stage for the representation of the dynamics of society and nature, but also an agent that participates in the dynamics currently observed in cities. Based on a small city, Capinópolis / MG served to demonstrate that events considered at risk can be observed regardless of the scale of a city's size.