Fragilidade ambiental da bacia hidrográfica do córrego São José em Ituiutaba - MG

Abstract

Problems of hydrological origin, such as floods, inundation and overflow, are environmental impacts commonly observed in urban environments, these problems can be caused by several factors, the main one being the poor ordering of the urbanization process. This research had as main goal to analyze the environmental fragility of the São José Stream Basin in Ituiutaba-MG. To this end, the rainfall variability between 1989 and 2018 was analyzed using data from meteorological stations closest to the study area, with a focus on the occurrence of extreme rainfall, relating them to the record of occurrences carried out by the Military Fire Brigade of the city, an analysis of the basin's morphometric parameters was also carried out, as well as its potential and emerging weaknesses. It was found that an average of 12 episodes of extreme precipitation occur in the study area, these being, in general, concentrated between the months of October and March, a period in which the occurrences recorded by the Fire Department were also concentrated. The indices and coefficients found in the morphometric analysis point to a low natural tendency of the basin to floods and inundation, a result corroborated by the study of its potential fragility, which indicated a predominance of areas of low fragility, except for a small part in the low course which presented high fragility (10.3%) and very high (2.4%). The emerging fragility, in turn, showed a significantly greater fragility, being the places where there is urban occupation, basically all showing high or very high fragility, representing 39.2 and 14.5% of the total area respectively. The avenues Minas Gerais and José João Dib are, according to the report of occurrences of the Fire Brigade and the news carried by the local media, the points of the basin where they present more problems related to precipitations, being observed in the first, in occasions of intense rain, concentrated runoff events, and in the second, flooding. Both caused due to the inefficiency of the drainage system and intense waterproofing of the soil.