Eventos de chuva extrema associados a sistemas atmosféricos de escala sinótica e escala local no Estado do Ceará

Abstract

This research aimed to discover the frequency of extreme rainfall events, associated with synoptic scale weather systems and local scale acting on the state of Ceará, in the period 2000 to 2010 this period, it was observed that the years 2004 and 2009 was the year with the highest number of cases of extreme rainfall in Ceará. The synoptic analysis showed that the main weather systems that acted in Ceará were the ITCZ, LI, MCCs, CV and VCANs. In this period, it was observed that even in unfavorable conditions of the Atlantic Ocean (positive dipole) the ITCZ oscillated between Ecuador and northern NEB, favoring the formation of LI systems and MCCs on Ceará. The rain gauge stations with higher thresholds of heavy rain for the period January to December 2000 to 2010, were observed in the regions of the North Coast (Tour Cross), Jaguaribana region (post Fortescue), Central Region Hinterland/Inhamuns (post Tarrafas) and Cariri (post Granjeiro). Between the months of the rainy season from 2000 to 2010, it was found that the rainfall stations most affected by heavy rainfall events are located in the regions of Central Hinterland/Inhamuns, North Coast, Cariri Jaguaribana and Ibiapaba. The rainy season of 2009, was the hardest hit by heavy rain events, with 40 events in the North Coast, 48 in the Coast of Pecém, in Ibiapaba 41, 38 and 46 in Jaguaribana region in Central Hinterland/Inhamun. The methodology was based on classification thresholds to determine the rainfall intensity as well as the classification of intensity and frequency of extreme rainfall events and identification of weather systems associated with these events. The state of Ceará, in every year over the study period was hit by heavy rainfall events, regardless of the rainy season be rainy, very rainy or dry. These events are linked to climate dynamics, but on the other hand, poor socioeconomic conditions, the degree of degradation of natural systems amplifying the vulnerability, the use by the population of vulnerable natural areas devoid of means to cope with the negative manifestations of heavy rainfall events, contribute to enhance the performances of the consequences of extreme events.