Dinâmica temporal dos índices de aridez e padronizado de vegetação na bacia hidrográfica do rio Pajeú, estado de Pernambuco

Abstract

Aridity is the characteristic of the climate that relates insufficient precipitation adequate to maintain a vegetation, where the degree of aridity of a certain region depends on the amount of water coming from the precipitation and the maximum possible loss of water through evaporation and transpiration, or evapotranspiration . The dryness index is widely used in the studies for the determination of dry areas and especially in the studies of the desertification process. The objective of this study was to obtain a representation of the spatial distribution of the aridity index and to quantify the anomalies as a standard deviation in relation to the mean in the Pajeú River watershed, one of the largest hydrographic basins in the territorial range of the state of Pernambuco, correlating with the standardized vegetation index (SVI), for the period from 2000 to 2015, aiming to have information that will help identify areas that are more susceptible to the occurrence of desertification, using a Geographic Information System. From the analysis of the period 2000 to 2015, critical periods were identified in the years 2012, 2013 and 2015, which presented the largest areas with negative anomalies, indicating low vegetation vigor and, consequently, severe droughts, impacting negatively.