CHARACTERIZATION OF DAILY PRECIPITATION EXTREMES ON NORTHEASTERN BRAZIL - DOI 10.5216/bgg.v36i3.44557

Abstract

The intensification of climate change impacts made the extreme events more frequent. On Northeastern Brazil (NEB) these events are closely associated to drought or floods. In this work, the generalized extreme value (GEV) and Pareto (GPD) distributions were used with the objective to characterize the precipitation extremes on NEB and to assess the levels and return periods for 30, 50 and 100 years, based on the period of February to July from 1979 to 2011. The location and scale parameters results pointed that both distributions showed similar spatial patterns, the maximum precipitation located on the east coast of the NEB, on northern Maranhão and Ceará States; and a core in the extreme western region of Pernambuco State (influenced by topography of the Borborema and Araripe plateaus). The shape parameter showed that selected regions are set by Weibull negative and Beta distributions ( < 0) for GEV and GPD, respectively. The estimate of levels and return periods by GEV distribution showed that on Northern Maranhão State (central Bahia region) will occur at least one extreme precipitation event with equal or superior level to 160,9 mm/day (192,3 mm/day) in 30 years, and 182,1 mm/day (307,8 mm/day) on the next 100 years.

Keywords: borborema plateau, northern Maranhão State, GEV distribution.