Spatial-temporal dynamics of the Caatinga vegetation cover by remote sensing in municipality of the Brazilian semi-arid

Abstract

The aim of this study was to monitor and evaluate the Caatinga vegetation cover in a municipality from the Brazilian semi-arid through of the spatial-temporal distribution of vegetation indexes by remote sensing. The study was developed using six satellite images which covers the municipality of Iguatu, Ceará. Thematic maps of the SAVI and LAI vegetation indexes were developed and evaluated by descriptive statistics and according to their spatial-temporal variability. Maps of the SAVI and LAI showed high heterogeneity in the spatial-temporal distribution pattern, classified as medium variability (CV = 35 to 57%) and high variability (CV = 63 to 104%), respectively. The indexes provided answers as to the land uses behavior pattern, highlighting conditions of changes in the Caatinga vegetation. In general, the SAVI and LAI indexes showed a low condition of the vegetal biomass over time, a typical spatial-temporal dynamics characteristic in the dry season of the semi-arid. The vegetation indexes detected a remarkable sensitivity of the Caatinga vegetation to the presence and/or absence of rainfall, owing a high resilience capacity in response to intense rainfall. The semi-arid region becomes more vulnerable due to the intensification of drought events.