Zhouqu, China, disaster - data capture, modelling and preliminary geohazard assessment

中国舟曲，灾害 - 数据采集、建模和初步地质灾害评估

• 批准号: NE/I016236/1
• 负责人: Peter Hobbs
• 金额: $ 1.3万
• 依托单位: British Geological Survey
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI016236%2F1
• 关键词: Zhouqu; China; disaster; data; capture

At 1am on Sunday the 8th of August a large flow slide took place in Zhouqu, a county town in SW Gansu Province, China. Current information suggests that the trigger was a rainfall event delivering a reported 97mm in less than 40 minutes (annual precipitation averages from 400 to 900mm). Antecedent rainfall may also have played a role. The devastating event caused the deaths of more than 1000 people (1,144 as of Friday 13th of August in Zhouqu alone with at least 600 people still missing). In the wider region, mudslides and debris flows continue to affect the local population with further fatalities in Longnan (south and downstream of Zhouqu) and Tianshui (to the northeast). The region is characterised by a seismically active mountainous terrain, an extension zone of the Tibetan uplift, and was affected by the Wenchuan earthquake (12/5/2008) that generated and re-activated a large number of landslides. At Zhouqu, the local erosion base is formed by the Bailong River at about 1300m asl. The surrounding peaks reach heights of about 3500 to 3750m. The catchment where the sediments originate is approximately 20km2 and is characterised by very steep slopes. Vegetation cover is sparse with only a small remnant of upland forest cover remaining. Following the disaster a lively debate has sprung up apportioning blame to deforestation, hydropower development and mining in the area. In order to learn lessons from this kind of events, instead of speculation, a scientific approach is required to collect data, verify their robustness and make impartial observations and develop reliable process models that will be essential to develop appropriate mitigation strategies for the future. The site was visited in November 2009 by Dijkstra and Gibson and discussions were held with the government of Zhouqu about the risk posed by large landslides in the area. It is vitally important to collect data soon. As with all landslide events, an understanding of local geological structure, drainage, morphology and geotechnical parameters are essential in building a robust model of landsliding (e.g. Geertsma et al. 2006). The key characteristics of landslides and landslide dams in this region are often removed rapidly by the very instability that causes them. It is inherently difficult to map out the potential for landslides to transfer into catastrophic viscous flows with complex and transient mechanical and rheological interactions. However, this is an essential component in any reliable assessment of the risks. These sort of assessments are rare because of the scarcity of events available for this type of research. When these occur we must make the most of it. Mostly, our understanding of these processes is derived from small-scale laboratory experiments, requiring upscaling that may affect the relevance of the observations. In this case, a unique field laboratory is waiting to be explored to gain a better understanding of the risks posed by geohazards to the population in this region.

8月8日（周日）凌晨1点，中国甘肃省舟曲县发生特大泥石流。目前的信息表明，触发因素是在不到40分钟的时间内降雨量达到97毫米（年平均降水量为400至900毫米）。之前的降雨可能也起到了一定作用。这场毁灭性的事件造成1000多人死亡（截至8月13日星期五，仅舟曲就有1144人死亡，至少有600人失踪）。在更广泛的地区，泥石流和泥石流继续影响着当地居民，陇南（舟曲南部和下游）和天水（舟曲东北部）的死亡人数进一步增加。舟曲地区的局部侵蚀基地由白龙江在海拔约1300m处形成。周围山峰的高度约为3500至3750m。沉积物产生的集水区面积约为20平方公里，其特点是坡度非常陡。植被覆盖稀疏，仅剩少量高地森林覆盖。灾难发生后，一场激烈的辩论如雨后春笋般出现，将责任归咎于该地区的森林砍伐、水电开发和采矿。为了从这类事件中吸取教训，而不是进行猜测，需要采取科学的方法来收集数据，核实数据的稳健性，进行公正的观察，并建立可靠的过程模型，这些模型对于为未来制定适当的缓解战略至关重要。Dijkstra和Gibson于2009年11月访问了该地区，并与舟曲政府讨论了该地区大型山体滑坡带来的风险。尽快收集数据是至关重要的。与所有滑坡事件一样，对当地地质结构、排水、形态和岩土参数的了解对于建立可靠的滑坡模型至关重要（例如Geertsma等人，2006年）。该地区山体滑坡和滑坡坝的主要特征往往由于造成它们的不稳定性而迅速消失。从本质上讲，很难描绘出滑坡转变为具有复杂和瞬态力学和流变相互作用的灾难性粘性流动的可能性。然而，这是任何可靠的风险评估的重要组成部分。这种类型的评估是罕见的，因为这类研究缺乏可用的事件。当这些发生时，我们必须充分利用它。大多数情况下，我们对这些过程的理解来自小规模的实验室实验，需要扩大规模，这可能会影响观察结果的相关性。在这种情况下，一个独特的实地实验室正在等待探索，以便更好地了解地质灾害对该地区人口构成的风险。

项目成果

Geomorphic controls and debris flows - the 2010 Zhouqu disaster, China

• 发表时间: 2012-06
• 作者: T. Dijkstra;J. Chandler;R. Wackrow;Xing-min Meng;D. ma;A. Gibson;M. Whitworth;C. Foster;Kyung-Min Lee;P. Hobbs;H. Reeves;J. Wasowski