Runoff as a conditionality for floods in Belo Horizonte, MG: case study of sub-basin Córrego do Leitão, basin of the Ribeirão Arrudas

Floods, rising of river flow, flooding and runoff in the city of Belo Horizonte are frequent. There are numerous factors that cause floods in urban areas such as the intensity of runoff, topography, geology and soil sealing. Over the last years the city has suffered dramatically with the occurrence of disasters related to floods. Floods are triggered by intense runoff as the city is located in a region of hilly, undulating and with great impermeable areas. Recently two deaths occurred due to flooding caused by sudden runoff. This article aims to employ methods to evaluate the susceptibility to formation of runoff in urban area. The study area was the basin of Leitao creek, belonging to the basin of Arrudas river, Belo Horizonte, in Minas Gerais. The method used was Analysis of Multicriteria that allowed the preparation of the map of susceptibility to formation of runoff. Analyzing the final map has been observed that areas that were less susceptible to the formation of runoff in most cases coincided with green areas. Places of greater susceptibility, with greater concavity, slope and impermeable, were correlated with more frequent flooding.The maps of areas of flood risk when analyzed separately, did not show the causes of the process, only locate the flooded areas. Therefore, the maps of susceptibility to the formation of runoff help to understand the phenomena of floods and allow better planning of interventions that aims to reduce flooding by reducing your triggers.