Three-dimensional identification and assessment of compound droughts from a propagation perspective

作者：Zengkun Guo, Yang Yu, Lingxiao SUN, Chunlan Li, Jing He, Mingjie Chen, Yuting Gao, Ireneusz Malik, Małgorzata Wistuba, Ruide Yu · 发表于：CATENA · 年份：2026 · DOI：10.1016/j.catena.2026.109921 · 被引用次数：3 · 研究领域：Hydrology and Drought Analysis、Climate variability and models、Tree-ring climate responses

Global warming has increased the frequency of compound disaster events, posing significant threats to ecosystems. Among these, compound droughts are difficult to identify due to complex spatiotemporal interactions among different drought types. Most existing studies emphasize temporal overlaps, overlooking the spatiotemporal continuity of drought evolution. To address this limitation, we propose a dual spatiotemporal coupling framework. It first applies three-dimensional clustering to identify spatiotemporally continuous drought events within individual drought types and then performs event-level spatiotemporal coupling across drought types from a propagation perspective to identify compound drought events. Applied to a typical arid region in Northwest China from 1987 to 2020, the framework effectively identified multiple compound drought types and enabled systematic evaluation of their characteristics and compoundness (i.e. dependence) relative to single-type droughts. In addition, the variable importance in projection (VIP) method was employed to identify dominant hydrometeorological drivers. The result showed that the framework detected 32 meteorological–hydrological (MH), 33 meteorological–ecological (ME), 33 hydrological–ecological (HE), and 17 meteorological–hydrological–ecological (MHE) events. Notably, the identified compound drought events in the study area have exhibited a marked trend of increasing severity since the 2000s. In terms of compoundness, MH droughts exh...