Intense Rainfall Over the Region of Serra Do Mar - Brazil (PAP014918)

Código

PAP014918

Autores

Lígia Maria Nascimento de Araújo, Isela Vásquez, Daniel Medeiros Moreira, Mariana de Araujo Abdalad, Maria Letícia Rabelo Alves Patrus, Luciano Nobrega Rodrigues Xavier, Afonso Augusto Magalhaes de Araujo, NELSON FERREIRA FERNANDES, Humberto A. Barbosa, OTTO CORREA ROTUNNO FILHO

Tema

Land use and Floods, landslides and erosion

Resumo

Expressive amounts of rainfall may occur during the summer season along all the extension of the mountainous region known as Serra do Mar, which encompasses portions of four states in Brazil - Santa Catarina, Paraná, São Paulo and Rio de Janeiro -, causing landslides and floods. Inter-annual and intra-seasonal oscillations with significant variability in spatial location and range of coverage can be observed, when the phenomenon is analyzed at the appropriate scale. The hazards vary according to geomorphology and land use and the severity of the associated disasters increases with disordered urban occupation. In December 2013 an extremely heavy rainfall occurred over the states of Espírito Santo (ES) and Minas Gerais (MG), killing 45 people and leaving more than 10.000 homeless. These two states are near the region of Serra do Mar forming with it a wider region where the South Atlantic Convergence Zone (SACZ) episodically acts increasing significantly the amount of rainfall during spring and summer. The event of December 2013 resulted from the configuration of some SACZ episodes acting in a sequence over the same area, with little spatial variation from one to the following episode. In this work the frequency of the event is evaluated using data observed in different gages within the region and available Intensity-Duration-Frequency (IDF) curves from a study performed for the whole country in the 1950's. The rainfall amounts registered during the event by 64 available automatic gauging stations and observed at other 127 daily gauging stations are compared to Tropical Rainfall Measuring Mission (TRMM) data sensed over the affected area. The representativeness of the existing monitoring network was evaluated as the TRMM data were validated using time wavelet transform methodology and a multiresolution analysis (MRA).