Comment on egusphere-2025-6014

Abstract. Soil moisture memory (SMM) defines the antecedent wetness states that modulate catchment responses to meteorological triggers, serving as a critical determinant of background hydraulic susceptibility. However, its multi-scale characteristics and environmental drivers remain poorly understood in complex terrain. This study characterizes SMM dynamics across daily-to-interannual scales using daily data (2003–2022) from three hazard-prone watersheds in southwestern China (Dali River, Anning River, and Jiangjia Ravine). By integrating Power Spectrum Analysis, Detrended Fluctuation Analysis (DFA-2), and a spatial attribution modeling framework, we identify a distinct scale-dependent transition in SMM persistence and its controls. Results revealed that while memory intensity generally weakened with scale, humid catchments exhibited a robust "inherent persistence" regime extending to multi-year scales. Crucially, feature importance analysis uncovered a structural transition at approximately the 5-year scale: atmospheric variables and vegetation dominated short-term variability, whereas soil properties and topography governed the system's long-term capacity to integrate low-frequency signals. Mechanistically, this marks a shift from event-driven hydraulic responses to background storage trends regulated by deep soil buffering. These findings provide a basis for distinguishing event-scale hydraulic preconditioning from long-term background susceptibility, offering a conceptual framework for incorporating operational persistence horizons into hierarchical hazard assessment strategies.