The dynamics of spatio-temporal droughts in Northeast Brazil

Abstract

Droughts are complex spatiotemporal phenomena that challenge effective monitoring and response. This study introduces a novel analytical framework that simplifies drought characterization. Building on three-dimensional (3D) drought analysis, we introduce three new evolution metrics - Growth Curve, State Curve, and Dynamic Curve. This framework allows clear assessment of drought evolution through its expansion, persistence, and contraction phases. Applied to Northeast Brazil, a semi-arid region with recurrent severe droughts, the method identified four main typologies of drought progression. Most droughts in the region exhibit a characteristic pattern of rapid expansion, long persistence, and abrupt contraction, reflecting a typical signature of regional climate variability. Recognizing such recurrent evolution patterns provides decision-makers with an evidence-based understanding of how droughts tend to evolve, supporting more timely and region-specific management actions. The proposed framework thus bridges the gap between scientific drought analysis and practical preparedness planning, breaking the complexity dilemma of scientific information that is hard to apply in operational applications. Its flexible structure can be adapted to other drought indices and regions, offering a transferable tool to strengthen proactive drought governance worldwide.