Immediate geomorphological impact and fluvial system response to the Cumbria floods November 2009

2009年11月18日至20日，英格兰西北部坎布里亚郡遭遇了一场罕见的降水事件，降雨量达到了前所未有的372毫米。仅在11月19日至20日的24小时内，seathwathe的降雨量就达到了313毫米。这相当于一个月的降水量，创下了英国的新纪录。办公室，2009年，以前279毫米)。这次洪水是该地区有记录以来发生的最严重的事件，对大面积的人口和基础设施造成了重大影响，并造成了人员伤亡。由于其对整个系统的影响，2009年11月坎布里亚郡的洪水提供了一个无与伦比的机会，可以深入了解对大型集水区高地、低地部分极端洪水的控制和影响。本项目旨在研究德文特河的整个河流走廊，从源头，通过巴森韦特湖到低地农业/城市集水区，确定关键影响和联系。对极端事件期间的侵蚀和沉积进行量化至关重要，这样才能在制定有空间针对性的短期和长期管理战略时进行有效的危害管理。要做到这一点，必须在事件发生后立即收集现场数据，以确保完整记录事件的基本特征。我们的主要目标是对降水和洪水对德温特河走廊内沿源头到海岸的河流系统的直接地貌影响进行快速、结构化的实地调查；提供桥梁附近冲刷和沉积作用的快速地貌评估，以区分影响桥梁倒塌的因素，从而为未来的设计实践提供信息；确定有可能重新整理洪水沉积沉积物的地区；运送山坡沉积物和德文特河的侵蚀热点，以确定未来洪水事件的风险区域；与项目合作伙伴（环境局和LDNPA）以及当地利益相关者合作，指定受侵蚀和沉积“威胁”的集水区。

Between November 18th - 20th 2009 Cumbria, NW England was hit by an exceptional precipitation event producing an unprecedented total of 372 mm of rainfall. Over the 24 h period between November 19th-20th alone, 313 mm of rain fell at Seathwaithe. This was equivalent to a month's precipitation and set a new UK record (Met. Office, 2009, previously 279 mm). The flood was the biggest event recorded in this region and had major consequences for population and infrastructure over a large area, as well as involving loss of human life. Due to its system-wide impact, the November 2009 flooding in Cumbria presents an unparalleled opportunity to gain insight into the controls on, and impact of, an extreme flood within upland, lowland parts of a large catchment. This project aims to examine the whole river corridor of the river Derwent from the headwaters, through Bassenthwaite Lake to the Lowland agricultural/urban catchment identifying key impacts and linkages. Quantifying erosion and sedimentation during extreme events is crucial so that effective hazard management can be undertaken in the short term and long-term spatially targeted management strategies devised. To achieve this, field-data must be collected in the immediate aftermath of the event to ensure essential features of the event are fully documented. Our main objectives are to produce a rapid, structured field inventory of the immediate geomorphic impact of rainfall and flooding on fluvial systems within the River Derwent river corridor along a headwater to coast transect; provide a rapid geomorphic assessment of the role of scour and sedimentation in the vicinity of bridges to discriminate factors influencing bridge collapse and so inform future design practice; identify areas of risk for remobilisation of flood-deposited sediments; delivery of hillslope sediments and hotspots of erosion in the River Derwent to identify zones at risk from future flood events and; work with project partners (EA and LDNPA) and local stakeholders in designating catchment zones that are 'at risk' from erosion and sedimentation.