The impact of decanalization and restoration of fluvial systems in urban microclimate

case study of Ribeirão Arrudas, Belo Horizonte (MG)

Abstract

The city of Belo Horizonte has an expressive hydrographic network that has been lost in the urban landscape due to the constant efforts of the authorities to channel and cover the city's rivers over time. However, new trends in urban planning that integrate rivers to the landscape are gaining strength in the world. In this context, this study aimed to analyze the different impacts that the daylighting of a river can bring to the urban microclimate, using Ribeirão Arrudas as the object of the study. To establish a comparative scenario, two meteorological shelters were installed along its course, one in an area where the river is uncovered and close to its natural state and the other one in a channeled and covered area of it. With the collection of primary data from shelters plus official data from three meteorological stations operated by INMET, it was possible to observe that environments with uncovered aquatic surfaces and with vegetated margins have, on average, a lower temperature of about 2°C and a relative humidity almost 4% higher, in addition to a more intense ventilation. These variations, taken together, can more easily provide a condition of thermal comfort, which helps in the well-being state of the population of urban centers.