Geomorphic and sedimentary evolution of an extreme event: testing a sediment-based palaeoflood record

极端事件的地貌和沉积演化：测试基于沉积物的古洪水记录

• 批准号: NE/P000118/1
• 负责人: Richard Chiverrell
• 金额: $ 6.53万
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FP000118%2F1
• 关键词: Geomorphic; sedimentary; evolution; extreme; event

This project will use the December 2015 extreme flooding in Cumbria to critically test the integrity and responsiveness of our unique, long (>600 year) lake sedimentary records of flood magnitude and frequency by quantifying the initial sedimentary event, its' diagenetic evolution and the impacts of a sediment-rich post-flood catchment. The recent flooding, following previous extreme flood events in 2005 and 2009, has highlighted the inadequacies of flood magnitude / return-frequency models developed using recorded river flows (30-50 year), which are too short to address societal requirements for accurate measures of flood risk and to address questions regarding the role of climate forcing of recent events. Lake sedimentary archives developed by our research teams at Liverpool and Durham Universities provide the length of record necessary to address this research gap. This includes a sediment magnitude (event particle size) signature at Bassenthwaite that correlates well with river discharges (for 40 years) and identifies that the largest 3 floods in 600 years have occurred in the past decade. We have three specific aims:1. To establish the deep water sedimentary event signature for lakes with differing water retention times (21-350 days) and to use repeat sampling into the summer period of peak organic productivity in the lake to test the evolution of this and high magnitude events in the recent past (11/2009) into the palaeoflood record.2. To establish and monitor how post-flood conditioning of catchment-to-lake and within-lake processes modifies or augments the lake sediment flood signal for 2015 event.3. To improve confidence in our existing palaeoflood series by placing this recent extreme event in that longer term context, and to establish flood frequency models that use integrated sediment and river flow data.The proposed project will use the unique opportunity afforded by contrasting pre- and post-flood sedimentary records and fluxes to establish the sedimentary signature of one of NW England's most extreme floods; crucially to engender confidence in the use of our lake sediment records as genuine flood series, thus contributing to calls for enhanced flood records to accurately define flood risk in these and potentially wider UK and world river systems. Our team has existing sediment traps at Brotherswater and Buttermere, together with lake sediment surface gravity cores sampled before the flood (2012-2015) at key sites impacted by the recent events in the Eden catchment (Brotherswater and Ullswater (Glenridding)) and Cocker-Derwent catchment (Bassenthwaite and Buttermere). Our research methodology is designed to characterise the sediment signal (grain size, geochemistry, mass accumulation) of the flood deposits and repeat this sampling at 6 week intervals to establish the progression of the event into the palaeo-record. We will also monitor the post-flood sediment dynamics in the lake (monthly sediment trapping and continuous turbidity monitoring) and the catchment to quantify the supply of sediments from catchment slopes (6 weekly UAV drone surveys) through key nodes in the sediment cascade to the lake (source-to-sink). This will enable us to contrast the sedimentary characteristics (grain size, geochemistry) of the December 2015 flood with events in the longer palaeoflood record, and incorporate these data in our novel flood frequency modelling using combined sediment and river flow records.This provides an unparalleled opportunity to investigate directly recent flood sedimentation across a variety of lake environments. Uniquely, we have the opportunity to contrast the pre- and post-flood sedimentary records and place our developing long-term data on both flood magnitude and frequency on a robust footing, which will allow us at our stakeholder workshop to encourage national organisations, hydrologists and engineers to use these records with confidence in flood risk management.

该项目将利用2015年12月的坎布里亚郡极端洪水来批判性地测试我们独特的，漫长（> 600年）湖泊沉积记录的洪水幅度和频率记录的完整性和响应能力，通过量化最初的沉积事件，其成岩性进化和影响富含沉积物的水流域。最近发生的洪水是在2005年和2009年以前的极端洪水事件之后，强调了使用记录的河流（30 - 50年）开发的洪水幅度 /返回频率模型的不足，这太短了，无法满足社会要求，无法准确地衡量。洪水风险并解决有关气候强迫最近事件的作用的问题。我们的研究团队在利物浦和达勒姆大学开发的湖泊沉积档案提供了解决这一差距所需的记录。这包括Bassenthwaite的沉积物幅度（事件粒度）签名，该标志与河流排放良好（40年），并确定了600年来最大的3次洪水发生在过去十年中。我们有三个具体的目标：1。为了建立深水沉积事件签名，以供湖泊不同的湖泊（21-350天）（21-350天），并在湖中使用重复采样到夏季的有机生产力夏季，以测试最近在最近的事件的演变过去（11/2009）进入古罗德唱片2。为了建立和监视流域对湖泊和湖内过程的洪水条件如何修改或增加2015年湖沉积物洪水信号。3。通过将最近的极端事件放置在长期的环境中，并建立使用集成沉积物和河流流数据的洪水频率模型，以提高对我们现有的古富尔德系列的信心。拟议的项目将利用与前后相比的独特机会 - 鲜花沉积记录和通量，以建立西北英格兰最极端洪水之一的沉积物签名；至关重要的是，对使用我们的湖泊沉积物记录作为真正的洪水系列的信心，从而促进了呼吁增强的洪水记录，以准确地确定这些更广泛的英国和世界河流系统的洪水风险。我们的团队在Brotherswater和Buttermere有现有的沉积物陷阱，以及在洪水（2012-2015）在伊甸园集水区（Brotherswater和Ullswater（Glenridding））和Cocker-cocker-cocker-cocker-cocker-cocker-cocker-cocker-cocker-- Derwent集水区（Bassenthwaite和Buttermere）。我们的研究方法旨在表征洪水沉积物的沉积物信号（晶粒尺寸，地球化学，质量积累），并以6周的间隔重复此抽样，以确定事件的进展为古录制。我们还将监视湖中液化后的沉积物动力学（每月沉积物捕获和连续的浊度监测）和流域，以量化来自集水坡度（6周每周无人机无人机调查）的沉积物的供应，该沉积物通过沉积物级联的关键节点到湖（来源到渠道）。这将使我们能够对比2015年12月洪水的沉积特性（晶粒尺寸，地球化学）与较长古古德记录中的事件，并使用组合的沉积物和河流流记录将这些数据纳入我们的新型洪水频率建模中。有机会调查最近在各种湖泊环境中直接洪水沉积的机会。独特的是，我们有机会对比洪水前和洪水后的沉积记录，并将开发的有关洪水幅度和频率的长期数据放在稳健的基础上，这将使我们在利益相关者研讨会上鼓励国家组织，水文学家，水文学家，工程师对洪水风险管理充满信心地使用这些记录。

项目成果

Quantifying system disturbance and recovery from historical mining-derived metal contamination at Brotherswater, northwest England

量化英格兰西北部兄弟沃特历史采矿金属污染的系统扰动和恢复

• DOI: 10.1007/s10933-016-9907-1
• 发表时间: 2016
• 期刊: Journal of Paleolimnology
• 影响因子: 2.1
• 作者: Schillereff D

Convergent human and climate forcing of late-Holocene flooding in Northwest England

英格兰西北部全新世晚期洪水的汇聚人类和气候强迫

• DOI: 10.1016/j.gloplacha.2019.102998
• 发表时间: 2019
• 期刊: Global and Planetary Change
• 影响因子: 3.9
• 作者: Schillereff D

The transport and mass balance of fallout radionuclides in Brotherswater, Cumbria (UK)

• DOI: 10.1007/s10933-019-00095-z
• 发表时间: 2019-12-01
• 期刊: JOURNAL OF PALEOLIMNOLOGY
• 影响因子: 2.1
• 作者: Appleby, P. G.;Semertzidou, P.;Warburton, J.
• 通讯作者: Warburton, J.

Using lake sediment archives to improve understanding of flood magnitude and frequency: Recent extreme flooding in northwest UK

• DOI: 10.1002/esp.4650
• 发表时间: 2019-06
• 期刊: Earth Surface Processes and Landforms
• 影响因子: 3.3
• 作者: R. Chiverrell;D. Sear;J. Warburton;N. Macdonald;D. Schillereff;J. Dearing;I. Croudace;J. Brown;J. Bradley

Long-term stability of records of fallout radionuclides in the sediments of Brotherswater, Cumbria (UK)

英国坎布里亚郡 Brotherswater 沉积物中放射性核素沉降物记录的长期稳定性

• DOI: 10.1007/s10933-018-0055-7
• 发表时间: 2018
• 期刊: Journal of Paleolimnology
• 影响因子: 2.1
• 作者: Semertzidou P