Initiation of the Tungmen Debris Flow, Eastern Taiwan
Initiation of the Tungmen Debris Flow, Eastern Taiwan
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台湾东部东门泥石流的爆发
DOI：
10.2113/gseegeosci.v.4.459
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发表时间：
1999
影响因子：
0.9
通讯作者：
M. Lin
中科院分区：
文献类型：
--
作者：
Hongey Chen;R. Chen;M. Lin
1990年6月23日，台风奥菲利亚期间，一场大规模的泥石流造成至少39人死亡，覆盖了近半个村庄。没有采取任何预防措施。这种泥石流由岩石碎片、淤泥和粘土、树木和木材组成，它们在大约2小时内迅速流过一条又长又窄的沟壑，到达沟壑的尽头。本文通过对岩石结构面分布、地质形态变化和地质物质特征的研究，揭示了可能的危险因素，并确定了触发机制。结果表明，沟两侧岩体结构面发育明显。特别是，它们是形成沉积物质和造成危害的主要因素。这些沉积的物质被强降雨触发并移动到沟的下部。迅速扩大的泥石流对侧壁的侵蚀和破坏导致大量物质聚集在沟壑中。实验模拟结果表明，沟道底部的水压力比直接地表降水的水压力增加得更多。这种迅速增加的水压显然为泥石流的运动提供了相当大的动力。
A large-scale debris flow caused at least 39 deaths and covered nearly half a village during typhoon Ofelia on the 23rd of June, 1990. No precautions had been taken. This debris flow consisted of rock fragments, silt and clay, and tree and wood material that flowed quickly through a long, narrow gully to the end of the gully within approximately 2 hours. This paper investigates the distribution of rock discontinuities, geo-morphological changes, and geo-material characteristics to highlight the possible hazardous factors and to identify the triggering mechanism. These results demonstrated that the rock discontinuities were distinctly developed on both sides of the gully. In particular, they were a major factor in forming the deposited materials and creating the hazard. These deposited materials were triggered and moved to the lower part of the gully by high intensity rainfall. Erosion and undercutting of the sidewalls by a rapidly enlarging debris flow resulted in massive amounts of material converging in the gully. Experimental simulation shows that the water pressure in the gully deposits appeared to increase more from the channel bottom than from direct surface precipitation. This rapidly increasing water pressure evidently contributed a sizable dynamic force to initiate movement of the debris flow.