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

TY - JOUR

T1 - Using lake sediment archives to improve understanding of flood magnitude and frequency

T2 - Recent extreme flooding in northwest UK

AU - Chiverrell, R.C.

AU - Sear, D. A.

AU - Warburton, J.

AU - Macdonald , N.

AU - Schillereff, D. N.

AU - Dearing, J.A.

AU - Croudace , I.W.

AU - Brown, J.

AU - Bradley, J.

PY - 2019/9/30

Y1 - 2019/9/30

N2 - We present the first quantitative reconstruction of palaeofloods using lake sediments for the UK and show that for a large catchment in NW England the cluster of devastating floods from 1990 to present is without precedent in this 558‐year palaeo‐record. Our approach augments conventional flood magnitude and frequency (FMF) analyses with continuous lake sedimentary data to provide a longer‐term perspective on flood magnitude recurrence probabilities. The 2009 flood, the largest in >558 years, had a recurrence interval larger (1:2,200 year) than revealed by conventional flood estimation using shorter duration gauged single station records (1:1,700 year). Flood‐rich periods are non‐stationary in their correlation with climate indices, but the 1990‐2018 cluster is associated with warmer Northern Hemisphere Temperatures and positive Atlantic Multidecadal Oscillation. Monitored records rarely capture the largest floods and our palaeoflood series shows, for this catchment, such omissions undermine evaluations of future risk. Our approach provides an exemplar of how to derive centennial palaeoflood reconstructions from lakes coupled well with their catchments around the world.

AB - We present the first quantitative reconstruction of palaeofloods using lake sediments for the UK and show that for a large catchment in NW England the cluster of devastating floods from 1990 to present is without precedent in this 558‐year palaeo‐record. Our approach augments conventional flood magnitude and frequency (FMF) analyses with continuous lake sedimentary data to provide a longer‐term perspective on flood magnitude recurrence probabilities. The 2009 flood, the largest in >558 years, had a recurrence interval larger (1:2,200 year) than revealed by conventional flood estimation using shorter duration gauged single station records (1:1,700 year). Flood‐rich periods are non‐stationary in their correlation with climate indices, but the 1990‐2018 cluster is associated with warmer Northern Hemisphere Temperatures and positive Atlantic Multidecadal Oscillation. Monitored records rarely capture the largest floods and our palaeoflood series shows, for this catchment, such omissions undermine evaluations of future risk. Our approach provides an exemplar of how to derive centennial palaeoflood reconstructions from lakes coupled well with their catchments around the world.

UR - http://www.scopus.com/inward/record.url?scp=85064202621&partnerID=8YFLogxK

U2 - 10.1002/esp.4650

DO - 10.1002/esp.4650

M3 - Article

SN - 0197-9337

VL - 44

SP - 2366

EP - 2376

JO - EARTH SURFACE PROCESSES AND LANDFORMS

JF - EARTH SURFACE PROCESSES AND LANDFORMS

IS - 12

ER -