Rainfall control of debris-flow triggering in the Réal Torrent, Southern French Prealps
Rainfall control of debris-flow triggering in the Réal Torrent, Southern French Prealps
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法国南部阿尔卑斯山雷阿尔托伦特地区降雨对泥石流的控制
DOI：
10.1016/j.geomorph.2016.04.004
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发表时间：
2017
期刊：
影响因子：
3.9
通讯作者：
D. Laigle
中科院分区：
文献类型：
--
作者：
C. Bel;F. Liébault;O. Navratil;N. Eckert;H. Bellot;Firmin Fontaine;D. Laigle
本文研究了在法国南部平原一个非常活跃的泥石流集水区Réal Torrent由于降雨强迫而导致的泥石流的发生。这项研究得到了三个高频监测站四年的流量响应和降雨事件记录的支持，这些监测站配备了地震检波器、流量传感器、数码相机和雨量计，每隔5分钟测量一次降雨量。使用了经典的降雨强度-持续时间(ID)阈值方法，特别强调了对降雨事件的客观识别，以及对超过ID阈值观测到的水流响应的区分。结果表明，用于识别降雨事件的参数显著影响ID阈值，并可能解释文献中报告的阈值变异性的部分原因。尤其是关于两个不同降雨事件之间的最小降雨中断持续时间(MDRI)的情况。在Réal Torrent，3 hMDRI似乎代表了当地的降雨状况。通过对三个站点的比较以及对泥石流试验性集水区数据的汇编，还观察到流域面积的阈值有系统地增加。用Logistic回归分离超过ID阈值的水流响应，结果表明，最好的预测因子是5分钟最大降雨强度、前48小时降雨量、降雨量和冬季结束以来经过的天数(作为泥沙供应的替代指标)。这强调了只有使用高时间分辨率降雨记录才能检测到的短强降雨序列所起的关键作用。它还突出了前置条件和泥沙供应的季节性波动的重大影响。
This paper investigates the occurrence of debris flow due to rainfall forcing in the Réal Torrent, a very active debris flow-prone catchment in the Southern French Prealps. The study is supported by a 4-year record of flow responses and rainfall events, from three high-frequency monitoring stations equipped with geophones, flow stage sensors, digital cameras, and rain gauges measuring rainfall at 5-min intervals. The classic method of rainfall intensity–duration (ID) threshold was used, and a specific emphasis was placed on the objective identification of rainfall events, as well as on the discrimination of flow responses observed above theIDthreshold. The results show that parameters used to identify rainfall events significantly affect theIDthreshold and are likely to explain part of the threshold variability reported in the literature. This is especially the case regarding the minimum duration of rain interruption (MDRI) between two distinct rainfall events. In the Réal Torrent, a 3-hMDRIappears to be representative of the local rainfall regime. A systematic increase in theIDthreshold with drainage area was also observed from the comparison of the three stations, as well as from the compilation of data from experimental debris-flow catchments. A logistic regression used to separate flow responses above theIDthreshold, revealed that the best predictors are the 5-min maximum rainfall intensity, the 48-h antecedent rainfall, the rainfall amount and the number of days elapsed since the end of winter (used as a proxy of sediment supply). This emphasizes the critical role played by short intense rainfall sequences that are only detectable using high time-resolution rainfall records. It also highlights the significant influence of antecedent conditions and the seasonal fluctuations of sediment supply.
影响因子：
5.2
作者：
F. Imaizumi;R. Sidle;S. Tsuchiya;O. Ohsaka
通讯作者：
F. Imaizumi;R. Sidle;S. Tsuchiya;O. Ohsaka