Assessment and Mitigation of Dam-break Lahar Hazards from Mt Ruapehu Crater Lake Following the 1995-96 Eruptions
Assessment and Mitigation of Dam-break Lahar Hazards from Mt Ruapehu Crater Lake Following the 1995-96 Eruptions
复制标题
1995-96 年火山喷发后鲁阿佩胡山火山口湖溃坝泥流灾害的评估和缓解
DOI：
--
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
M. Webby
中科院分区：
文献类型：
--
作者：
G. Hancox;H. Keys;M. Webby
1995-96 年鲁阿佩胡山的喷发导致火山口区域发生重大变化，这对未来湖水重新注满时火山泥流的危害具有重要意义。现在，湖口区域覆盖着一层 7m 厚的火山灰（弱灰和火山渣），造成的情况与 1945 年火山喷发后的情况类似，当时火山喷发导致了 1953 年坦吉瓦伊火山喷发灾难，当时挡住湖泊的火山灰屏障倒塌。模拟流模型显示，在最坏的情况下，未来来自火山口湖的火山泥屏障崩塌（溃坝）火山泥流将在坦吉瓦铁路桥旺加胡河中增加 54-72%。预计流量将大于 1953 年的火山泥流，因为冰川退缩已经移除了火山口盆地冰川和冰隧道，从而限制了从湖口决口流出的流量。预计未来的一些火山泥流（-7%）将溢出到怀卡托溪、汤加里罗河和陶波湖。总体而言，火山泥流可能对桥梁、道路和电线造成比过去更大的破坏，并对受影响的流域和陶波湖造成重大环境破坏。经过公众咨询并考虑了一系列减轻鲁阿佩胡未来溃坝火山泥流危害的方案后，环境保护部建议建立声音警报系统以防止人员伤亡，并修建堤岸以防止洪水流入怀卡托溪和陶波湖。对火山口湖出口（汤加里罗国家公园的原始区域）的沟渠仅提供有限的支持，尽管该选择可以防止旺加胡河沿岸的基础设施受损，并防止人员伤亡。环境保护部长最近批准安装东鲁阿佩胡拉哈尔警报系统（ERLAS），并修建堤坝以防止洪水流入怀卡托溪。这些措施将减少鲁阿佩胡东侧火山泥浆对生命和环境污染的风险，包括未来火山喷发和溃坝产生的火山泥浆，但无法防止对基础设施可能造成的损害。
The 1995-96 eruptions of Mt Ruapehu caused significant changes to the crater area, which have important implications for the hazard from future lahars when the lake refills. A 7m thick layer of tephra (weak ash and scoria) now covers the lake outlet area, creating a situation similar to that after the 1945 eruptions, which led to the 1953 Tangiwai lahar disaster after collapse of a tephra barrier retaining the lake. Simulation flow modelling has shown that a future tephra barrier collapse (dam-break) lahar from Crater Lake will in the worst case be 54-72% larger in the Whangaehu River at the Tangiwai rail bridge. The flow is expected to be greater than the 1953 lahar because glacial recession has removed the Crater Basin Glacier and ice tunnel, which for that event restricted outflow from the breach at the lake outlet. Some of the future lahar (-7%) is expected to overflow into the Waikato Stream, Tongariro River, and Lake Taupo. Overall, the lahar could cause greater damage to bridges, roads, and power lines than has occurred in the past, and significant environmental damage in affected catchments and Lake Taupo. After public consultation and consideration of a range of options to mitigate hazards from a future dam-break lahar from Ruapehu, an acoustic warning system to prevent loss of life, and a bund to prevent overflow into Waikato Stream and Lake Taupo was recommended by the Department of Conservation. There was only limited support for a trench at the Crater Lake outlet (a pristine area of Tongariro National Park), although that option would prevent damage to infrastructure sites along the Whangaehu River, as well as prevent loss of life. The Minister of Conservation has recently approved installation of an Eastern Ruapehu Lahar Alarm System (ERLAS), and construction of a bund to prevent overflow into Waikato Stream. These measures will reduce risk to lives and environmental contamination from lahars on the east side of Ruapehu, including those generated by future eruptions and dam breaks, but they will not prevent possible damage to infrastructure.