Eventos de precipitação extrema associados às inundações na área urbana de Bragança/PA

Abstract

The study of urban climate has a great importance in regard to the understanding of the human-nature relationship and the interaction between the local climate and the city. This expectation motivated this study on the Urban Climate in the city of Bragança, Pará State, a city that has undergone urban impacts from the rains that cause floods and flooding that hit several areas of the city, especially along the course from the Cereja stream, that is cutting the urban mesh. The Floods are one of the most serious problems which affects the cities when there is an occurrence of extreme precipitation events, generating impacts that affect the daily routine of the people. In this way, the choice for the study of meteoric impact of the channel, the third channel among the subsystems of the Urban Climate System (SCU), it is justified by the study of floods and flooding that happened in the city and the need to understanding the environmental conditions that originate. In this context, this study aimed to analyze the urban climate and extreme expectation events associated with the occurrence of floods and flooding in the urban area of Bragança. Therewith, we analyzed the occurrence of floods in Cereja stream and flooding in Bragança in 2004-2013 period; It was analyzed the variability of precipitation in urban areas from January to May, in 2014; we identified the atmospheric systems linked to extreme expectation events in the urban area of the city; however, the balance of participation of climate systems during the Amazon winter 2014 and it was made a map of climate risk in areas of extreme rainfall situations with sight to urban land use planning in the city. Therefore, the research was based on the SCU theory developed by Monteiro (1976). In the historic flood (2004-2013) were found 32 extreme events, that only 07 were classified as episodes of relevance for this study due to the impact of records in the urban area. The weather data analyzed was collected of the Weather Station Conventional of Tracuateua city (EMT) and Automatic Weather Station of Bragança (EMB) that belongs to INMET and a network of 07 rain gauges installed in the urban area of the city in 2014 which allowed a development of variability maps precipitation during the Amazon winter. Were also it was developed participation swing charts of atmospheric systems with satellite images from GOES 13 aid provided by INPE and Letters daily Synoptic of 00h and 12h provided by the Navy of Brazil. With the results, it was observed that the ZCIT has increased the participation in the occurrence of extreme events and urban impacts, and it was noted that there is a great variability of expectation in the study of the area, up to 161 mm between the northnortheast sector (Rainier) and the South-southwest sector (less rain). Finally we prepared a risk map as a tool for urban land in use planning, considering the local climate variable.