Spatiotemporal variability of vegetation due to drought dynamics (2012-2017): a case study of the Upper Paraiba River basin, Brazil

Vegetation indices have been widely used for monitoring the spatiotemporal variables of vegetation and characterizing droughts, primarily in semiarid regions. Drought is a multifaceted natural process that can lead to reduced water availability and can consequently have extensive effects on the socioeconomic, agricultural and development sectors of countries. This study aims to evaluate the spatial-temporal pattern of vegetation as a result of drought dynamics during the last major drought (2012-2017) in the Brazilian semiarid region. Satellite image products from the Moderate Resolution Imaging Spectroradiometer (MOD16, MOD11 and MOD15), standardized precipitation index, rainfall anomaly and vegetation indices were used to monitor and identify drought episodes. To relate vegetation with droughts, the vegetation supply water index was used. The results revealed a strong influence of droughts on vegetation behavior and a strong seasonal pattern of variables in the study area, primarily for land surface temperature, leaf area index and evapotranspiration. These results lead to the conclusion that, based on correlations between vegetation and droughts over a climatological period, it is possible to evaluate the relative roles of vegetation behavior for semiarid regions using MODIS products. Graphic abstract