ABSTRACT Debris flows are one of the most destructive mass‐movement processes. Previous studies have shown that debris‐flow occurrence may be related to antecedent higher temperatures or droughts, yet a comprehensive and objective regional understanding is still lacking. Here we integrated meteorological reanalysis with remotely‐sensed soil moisture products to investigate the hydrometeorological conditions preceding debris flows in Sichuan Province, Southwest China, during 2008–2018. Antecedent meteorological settings were classified into four characteristic patterns: “higher temperature with more rain”, “higher temperature with less rain”, “lower temperature with more rain”, and “lower temperature with less rain”. Approximately 80% of events occurred after anomalously high temperatures relative to climatology, highlighting a robust warming signal prior to debris‐flow initiation. Although spatial heterogeneity existed, most events were concentrated in the mountainous areas surrounding the western Sichuan Basin. Soil was predominantly wet before events (96.6%), while only a minority of events were preceded by drought. These drought‐related cases included both flash droughts (63%) and slowly‐evolving droughts (37%), also clustered in the western Sichuan Basin. The results demonstrate that antecedent high temperatures and droughts can both facilitate debris‐flow occurrence, and they provide new insights into how changing climate regimes may reshape debris‐flow hazards in mountain regions worldwide.
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