Rainfall induced debris flows in pyroclastic deposits, Campania (southern Italy)
Rainfall induced debris flows in pyroclastic deposits, Campania (southern Italy)
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DOI：
10.1016/j.enggeo.2004.06.014
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发表时间：
2004-11
影响因子：
7.4
通讯作者：
F. Fiorillo;Raymond C. Wilson
中科院分区：
文献类型：
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作者：
F. Fiorillo;Raymond C. Wilson
采用经验和物理相结合的水文模型分析了坎帕尼亚西部降雨和泥石流发生的历史数据，以考察降雨和泥石流事件之间的相关性。汇编了坎帕尼亚西部近几十年记录的主要风暴的降雨量数据，包括位于滑坡地区的几个雨量计的每日系列数据，以及一些主要风暴的每小时降雨量数据。提出了一种两阶段的方法。在第一阶段，土壤水分水平被模拟为降水和蒸散之间的水文平衡，在每日尺度上，使用Thornthwaite[Geoggraph]的方法。Rev.38(1948)55]。第二阶段与强降雨产生的多余水分积累有关，从而导致正孔压的发展。这些相互作用在每小时的时间尺度上由Wilson和Wiezoreck[Env.英语。地球科学，1(1995)11]。结合逐时降雨量记录，使用了LB模式来比较不同风暴的水文影响。滞留雨水的临界水平由泥石流活动的时间确定，这与有记录的风暴事件有关。提出了坎帕尼亚西部泥石流引发的新的降雨强度-持续时间阈值。这些阈值与单个雨量计有关，并假定以前满足田间容量条件。新的门槛略高于之前作者绘制的门槛，但被认为更准确，因此需要更少的保守性。
A combination of empirical and physically based hydrological models has been used to analyze historical data on rainfall and debris-flow occurrence in western Campania, to examine the correlation between rainfall and debris-flow events. Rainfall data from major storms recorded in recent decades in western Campania were compiled, including daily series from several rain gauges located inside landslide areas, supplemented by hourly rainfall data from some of the principal storms. A two-phase approach is proposed. During phase 1, soil moisture levels have been modelled as the hydrological balance between precipitation and evapotranspiration, on a daily scale, using the method of Thornthwaite [Geograph. Rev. 38 (1948) 55]. Phase 2 is related to the accumulation of surplus moisture from intense rainfall, leading to the development of positive pore pressures. These interactions take place on an hourly time scale by the “leaky barrel” (LB) model described by Wilson and Wiezoreck [Env. Eng. Geoscience, 1 (1995) 11]. In combination with hourly rainfall records, the LB model has been used to compare hydrological effects of different storms. The critical level of retained rain water has been fixed by the timing of debris-flow activity, related to recorded storm events. New rainfall intensity–duration thresholds for debris-flow initiation in western Campania are proposed. These thresholds are related to individual rain gauge and assume a previously satisfied field capacity condition. The new thresholds are somewhat higher than those plotted by previous authors, but are thought to be more accurate and thus need less conservatism.