Rainfall pattern and erosion potential in the physiographic regions of the state of Pernambuco, Brazil

Características e potencial erosivo das chuvas para as zonas fisiográficas do estado de Pernambuco

ABSTRACT

The objective of the present study was to characterize the spatial and temporal (2000-2015) rainfall pattern variability and erosive potential in the different physiographic regions of the state of Pernambuco, Brazil. Rainfall data series (3 to 12 years) from 25 weather stations of the state were analyzed. Erosive rainfall events (more than 10 mm depth) were considered to evaluate the annual erosivity index, monthly erosivity index (EI₃₀), rainfall erosivity factor (R), and rainfall pattern. The inverse distance weighting (IDW) - inverse of the square of the distance - was used to create spatial interpolation and develop maps. The rainfall data from the weather stations showed average annual rainfall of 827 mm and average erosivity of 4,784 MJ mm ha^-1 h^-1. The Metropolitan region of Pernambuco presented the highest rainfall erosivity index, with annual average of 9,704 MJ mm ha^-1 h^-1; and the Sertão do São Francisco region had the lowest, with annual average of 4,902 MJ mm ha^-1 h^-1. The state of Pernambuco presented advanced (42%), intermediate (38%), and delayed (20%) rainfall patterns.

Key words:
erosivity; mapping; rainfall characterization; precipitation