基于综合雨量的秦巴山区降雨致灾概率模型研究

    Study on probability model for rainfall-induced hazards in Qinling-Daba Mountains Area based on comprehensive rainfall

    • 摘要: 降雨是诱发滑坡的主要因素,对降雨导致的地质灾害进行预警具有重要意义。基于秦巴山区气象站降雨监测数据与灾害记录,建立了降雨导致滑坡灾害发生的概率模型,即降雨致灾概率模型;基于不同预警等级对应的灾害点数量,对比了该模型与传统EE-D分级阈值模型在预警效率上的差异。结果表明:秦巴山区降雨导致滑坡灾害的概率呈S形曲面分布。对于低诱发性降雨条件,所提的概率模型预警效率与传统模型接近;对于高强诱发性降雨条件,概率模型具有更高的预警效率。此外,对于短持时高强度的降雨条件而言,传统模型相较于概率模型存在一定优势;而对于长持时的高诱发性降雨条件而言,概率模型相比于传统模型更具有优越性。其原因在于传统模型以致灾降雨的平均过程作为划分标准,对长持时降雨的致灾危险性存在低估;而概率模型则以灾害发生的频度作为划分标准,更契合灾害数量与严重性的增长趋势。所提的概率模型对严重地质灾害事件的预警效率更高,可提升地质灾害预警精度,降低预警成本。

       

      Abstract: Rainfall is recognized as a primary triggering factor for landslides, making early warning of rainfall-induced hazards is essential.Based on rainfall monitoring data from meteorological stations and disaster records in the Qinling-Daba Mountains Area, a probability model for rainfall-induced landslides was established.Subsequently, a comparison of the warning efficiency between the proposed model and the traditional EE-D (Early Effective Rainfall-Duration) graded threshold model was conducted, using the count of disaster sites corresponding to different warning levels as the evaluation metric.The results indicate that the probability of rainfall-induced landslides in the Qinling-Daba Mountains Area follows an S-shaped distribution surface.Under conditions of low rainfall inducement, the warning efficiency of the proposed probability model is comparable to that of the traditional model.However, under conditions of high-intensity rainfall inducement, the probability model demonstrates superior warning efficiency.Moreover, regarding short-duration, high-intensity rainfall, the traditional model holds a certain advantage over the probability model.When it comes to long-duration, high-induced rainfall conditions, however, the probability model shows greater superiority compared to the traditional model.This difference is attributed to their distinct delineation criteria.The traditional model uses the average process of disaster-triggering rainfall as its delineation criteria, which leads to an underestimation of the hazard risk associated with long-duration rainfall.In contrast, the probability model employs the frequency of disaster occurrence as its delineation criteria, making it more consistent with the increasing trend in quantity and severity of hazards.Consequently, the proposed probability model achieves higher warning efficiency for severe geological hazard events, thereby enhancing early warning accuracy and reducing associated costs.

       

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