Applying probability determination to refine landslide-triggering rainfall thresholds using an empirical "Antecedent Daily Rainfall Model"
Applying probability determination to refine landslide-triggering rainfall thresholds using an empirical "Antecedent Daily Rainfall Model"
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DOI：
10.1007/s000240050017
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发表时间：
2000-08-01
影响因子：
2
通讯作者：
Smith, P
中科院分区：
文献类型：
--
作者：
Glade, T;Crozier, M;Smith, P
在世界许多地区，降雨引发的山体滑坡是一种严重的灾害，也是一个重要的地貌过程。一些国家在不同的尺度上尝试调查触发条件，以便确定行为模式，并最终确定或计算引发滑坡的降雨阈值。这项研究是在新西兰北岛三个滑坡易发地区进行的。区域滑坡触发降雨阈值使用经验的“先行日降雨模型”计算。在CROZIER和EYLES（1980）首次引入的这个模型中，触发降雨条件由事件发生前一段时间的降雨（之前的降雨）和事件当天的降雨的组合来表示。一个基于物理的衰减系数是根据风暴水文的衰退行为为每个地区推导出来的，并被用来产生之前降雨的指数。采用统计技术来获得阈值，以最好地将与滑坡发生有关的降雨条件与不发生或给定发生概率的降雨条件区分开来。所得到的区域模式能够在降雨条件的基础上表示滑坡事件发生的概率。计算的阈值显示了给定景观对引发滑坡的降雨的易感性的区域差异。这些差异既与滑坡数据库有关，也与区域间现有物理条件的差异有关。
Rainfall-triggered landslides constitute a serious hazard and an important geomorphic process in many parts of the world. Attempts have been made at various scales in a number of countries to investigate triggering conditions in order to identify patterns in behaviour and, ultimately, to define or calculate landslide-triggering rainfall thresholds. This study was carried out in three landslide-prone regions in the North Island of New Zealand. Regional landslide-triggering rainfall thresholds were calculated using an empirical "Antecedent Daily Rainfall Model." In this model, first introduced by CROZIER and EYLES (1980), triggering rainfall conditions are represented by a combination of rainfall occurring in a period before the event (antecedent rainfall) and rainfall on the day of the event. A physically-based decay coefficient is derived for each region from the recessional behaviour of storm hydrographs and is used to produce an index for antecedent rainfall. Statistical techniques are employed to obtain the thresholds which best separate the rainfall conditions associated with landslide occurrence from those of non-occurrence or a given probability of occurrence.The resultant regional models are able to represent the probability of occurrence of landsliding events on the basis of rainfall conditions. The calculated thresholds show regional differences in susceptibility of a given landscape to landslide-triggering rainfall. These differences relate to both the landslide database and the difference of existing physical conditions between the regions.