Análise da relação entre as ocorrências de inundações e precipitação na cidade de Manaus para o ano de 2014

Abstract

This work presents a study on the relationship between rainfall and number of floods in the city of Manaus-AM. In order to explore this relationship, flood records of the Civil Defense of Manaus were used for the period from 2010 to 2014. The rainfall variability over the city was analyzed through rainfall records of rain gauges distributed in five of the six zones that comprise the urban zone of Manaus for the year 2014. Pearson's correlation was used to validate the results. In general, it can be said that the stations SBMN, MAUÁ, BETA and EST followed the seasonal precipitation of the city of Manaus. On the other hand, the ALFA and SBEG stations presented different behavior. ALFA with low rainfall rates from April to October, and also in December. SBEG presented monthly accumulations superior to the climatology from March to December, mainly emphasizing the behavior of the rains during the dry period (jul-ago-set). This distinct behavior among the zones must have been caused by differences in land use, proximity to forested areas and influence of river breeze. With respect to flood cases, when monthly totals are analyzed for each year, greater records are observed during the rainy season and during the months of occurrence of Rio Negro maximum levels. The year of 2014 presented high values in the months of March (associated with accumulated precipitation in all zones), May and June, where the last two coincides with the months of occurrences of Rio Negro maximum levels. In relation to other years, the year 2011 presented the highest number of cases for the rainiest months (February and April) that may be associated with the increase of precipitation over the region due to a strong La Niña event occurring in the years 2010-2011 . The neighborhoods that stood out as the most susceptible to flood events were those of Jorge Teixeira (ZL), Terra Nova (ZN), Educandos (ZS), Tarumã (ZO), Alvorada (ZCO) and Flores (ZCS). The zones where the stations of MAUÁ, BETA and EST are located showed a strong correlation between precipitation and floods, when considering the monthly totals. Nevertheless, through the test of significance, only the BETA (ZN) station showed a correlation with a relatively strong degree. On the other hand, the results related to the daily correlation did not present significant values, presenting great dispersion in all the areas considered.