Análise da precipitação e eventos extremos em região semiárida

o caso da sub-bacia hidrográfica do Rio Figueiredo, Ceará - Brasil

Abstract

The precipitation is essential for better understanding of the natural cycle of water. The extreme natural events that more impact on human activities in our country are climate. Some cities have presented critical situations related to flood during heavy rain concentrated episodes. This study analyzed the variability of rainfall in the watershed Figuereido focused on extreme precipitation events in the period 1979-2014. Data were used daily precipitation of 5 stations obtained from the database of the National Water Agency (ANA), being organized and treated for the determination of Time of Return, to detect the frequency and spatial differences and generation of map. The intense events greater precipitation occurred in the months of January to may. The results indicated the occurrence of 30 episodes daily rainfall intensities equal and over 100 mm in 1979 to 2014 period within the watershed. The analysis of the results obtained for the basin under study revealed increased number of intense precipitation episodes, as they only occur with greater frequency and intensity in years of El Niño.