Impact of Quaternary megafloods on erosion of the Tsangpo River gorge, southeastern Tibet

第四纪特大洪水对藏东南雅鲁藏布江峡谷侵蚀的影响

• 批准号: 1349279
• 负责人: Katharine Huntington
• 金额: $ 22.4万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-15 至 2018-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1349279&HistoricalAwards=false
• 关键词: Impact; Quaternary; megafloods; erosion; Tsangpo

The last decade has seen a resurgence of debate over the role of extreme events such as earthquakes, landslides and floods in long-term erosion and landscape evolution. Yet progress in this area is fundamentally limited by the difficulty of observing extreme events on human timescales and linking them to million-year average erosion rate measurements. This project helps bridge the gap by combining field, laboratory and computer modeling approaches to investigate the first direct evidence of the legacy of prehistoric megafloods in one of the most rapidly eroding natural landscapes on Earth, southeastern Tibet. This project will integrate glacial lake deposit chronologies, field observations and dating of flood deposits, provenance data for sediments deposited in different magnitude flows, and computer simulations of flood events to (1) model flood hydraulics, landslide triggering, slackwater sediment deposition and flood hazard; (2) relate flood conditions to erosion processes and evaluate the extent to which megafloods focus erosion in the gorge; and (3) begin to constrain the timing and frequency of megaflood events to better understand their relationship to climate and impact on long-term erosion. Ultimately, this novel approach of chemically "fingerprinting" flood sands (using zircon U-Pb ages) to investigate erosion processes will improve our understanding of possible feedbacks between river incision and rock uplift, Tibetan plateau margin evolution, and links between climate and erosion on glacial-interglacial timescales. The modeling study will benefit society by evaluating flood hazard associated with hydropower dam development in the region. The project involves collaborations among the University of Washington, US Geological Survey, and a disaster management agency in India. Graduate and undergraduate research students will be trained in field, laboratory, and computer modeling methods. To promote K-12 STEM education in minority-serving high schools, the researchers and students will work with a teacher to develop a lesson and activity on floods and megaflood erosion for the University of Washington outreach program, Rocking Out. Additionally, research findings will be disseminated broadly through University of Washington's outreach and high school programs, Indian disaster management personnel, university courses, conferences and publications. This project is jointly supported by the Geomorphology and Land Use Dynamics and International Science and Engineering programs.

在过去的十年中，人们就长期侵蚀和景观演变中的地震，滑坡和洪水等极端事件的作用进行了辩论。然而，这一领域的进展从根本上受到观察到人类时标的极端事件并将其与百万年平均侵蚀率测量联系起来的困难。该项目通过结合田地，实验室和计算机建模方法来帮助弥合差距，以调查在地球上地球上最迅速侵蚀的自然景观之一，这是西藏东南部最快速侵蚀的自然景观之一。 该项目将整合冰川湖沉积的时间顺序，现场观察和洪水沉积物的日期，沉积在不同幅度流中的沉积物的出处数据，以及对洪水事件的计算机模拟，以（1）模拟洪水液压，山水滑坡触发，松弛的水沉积物沉积和洪水危害； （2）将洪水条件与侵蚀过程联系起来，并评估峡谷中大型富集的重点侵蚀的程度； （3）开始限制大型事件的时机和频率，以更好地了解它们与气候和对长期侵蚀的影响。 最终，这种新型的“指纹”洪水（使用锆石U-PB年龄）来研究侵蚀过程的新方法将提高我们对河流切口和岩石隆起之间可能反馈的理解，藏族高原边缘的演变，以及在冰川相互作用时段的气候和侵蚀之间的联系。 该模型研究将通过评估与该地区水力发电大坝开发相关的洪水危害来使社会受益。 该项目涉及华盛顿大学，美国地质调查局和印度灾难管理机构之间的合作。 研究生和本科研究的学生将接受现场，实验室和计算机建模方法的培训。为了促进在少数族裔服务的高中的K-12 STEM教育，研究人员和学生将与老师合作，​​为华盛顿大学外展计划开展课程和活动，以消除洪水和大型侵蚀。 此外，研究结果将通过华盛顿大学的宣传和高中计划，印度灾难管理人员，大学课程，会议和出版物进行广泛传播。 该项目由地貌和土地使用动态以及国际科学与工程计划共同支持。