Post-earthquake debris flows pose significant hazards in mountainous regions following large seismic events. Evaluating the thresholds for predicting the occurrence of these flows is crucial. However, the absenting of comparison for different predicting methods hampers progress in improving and updating predictions for debris flows. In this study, based on on-site measurements of post-earthquake debris flows in an active catchment during the first year following the 2022 Luding Ms6.8 earthquake, 30 debris-flow events were identified and observed. We established and compared three distinct methods—namely, the meteorological approach, the hydro-meteorological approach, and the critical discharge approach for predicting the occurrence of post-earthquake debris flows. Additionally, we introduced a factor called absolute energy to improve the accuracy of the traditional meteorological approach. Absolute energy is defined as the sum of squared values within a time series. Our findings indicate that the hydro-meteorological model outperforms others in predicting post-earthquake debris flows, whereas the meteorological approaches especially the intensity–duration (I–D) thresholds exhibit suboptimal performance. Furthermore, the updated meteorological model incorporating absolute energy demonstrates improved predictive capability compared to traditional meteorological approaches like intensity–duration (I–D) thresholds. We argue that this comparative analysis will aid in selecting the suitable method for predicting post-earthquake debris flows.

中文翻译：

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评估预测震后泥石流的阈值：气象、水文气象和临界排放方法的比较


地震后泥石流在大型地震事件后对山区构成重大危害。评估用于预测这些流发生的阈值至关重要。然而，缺乏对不同预测方法的比较阻碍了改进和更新泥石流预测的进展。本研究基于对 2022 年泸定 Ms6.8 地震后第一年活跃集水区震后泥石流的现场测量，确定并观测了 30 起泥石流事件。我们建立并比较了三种不同的方法，即气象方法、水文气象方法和临界排放方法，用于预测震后泥石流的发生。此外，我们还引入了一个称为绝对能量的因子，以提高传统气象方法的准确性。绝对能量定义为时间序列中数值的平方和。我们的研究结果表明，水文气象模型在预测震后泥石流方面优于其他模型，而气象方法，尤其是强度-持续时间 （I-D） 阈值表现出次优性能。此外，与传统气象方法（如强度-持续时间 （I-D） 阈值）相比，包含绝对能量的更新气象模型显示出更高的预测能力。我们认为，这种比较分析将有助于选择合适的方法来预测震后泥石流。