Hydrological extremes and feedbacks in the changing water cycle

Lead Research Organisation: University of Reading
Department Name: Walker Institute

Abstract

The prospect of significant climate change over the next decades means that society must urgently face up to the implications for the changing water cycle, in particular increasing risks from extreme floods and droughts. Guidance for policy-makers to support adaptation to these risks and to support mitigation strategies to combat climate change is urgently required. However, the ability of climate scientists and hydrologists to predict the possible magnitudes of floods and droughts, and the frequency with which they are expected to occur, is still limited. This is due largely to gaps in knowledge of how best to use available data and models; of particular concern is the limited ability of climate and hydrological models to produce realistic extremes and changing hydrological behaviour. For example, regional climate models produce data which often requires to be downscaled to finer resolutions, but questions arise about what properties of the downscaled data are critical and how the downscaling should be done. As another example, drought planning requires inter-annual and inter-regional rainfall and evaporation to be represented accurately, however there is little guidance about how this can best be achieved under future climate using available models. In addition, there are weaknesses in the simulation of hydrology (for example, groundwater storage, river flows and evaporation) which act as hurdles to development of next generation climate models; in particular models currently used to simulate feedbacks from the earth surface to the atmosphere neglect important hydrological processes. This proposal will produce the science and models needed to address these questions, integrating climate and hydrological science to take impact modelling beyond the current state of the art. Specifically, the proposal: 1. exploits current generation climate science and statistical methods to improve and enhance projections of potential change in hydrologically-relevant metrics over a time-scale of 10 to 60 years, in particular extremes of heavy precipitation and drought; 2. builds on the analysis of historical data to improve scientific understanding and develop innovative methods for the modelling of extremes and non-stationarity in the hydrological response to climate variability; 3. seeks to improve the representation of hydrological processes in land surface models, in particular, the enhanced modelling of surface and subsurface processes for simulation of land-atmosphere feedbacks.
 
Description The University of Reading contributed to Work Package 1 of the HyDef project. The research focused on improving the understanding of the hydrometeorological processes responsible for flooding in British river basins. The work showed that the 10 largest winter flood events since 1970 in a range of British river basins were connected to Atmospheric Rivers (ARs), narrow regions of enhanced water vapour transport across the mid-latitudes. When an AR makes landfall, large rainfall totals and flooding can result. As floods in Britain had a strong linkage with ARs, an algorithm was developed to identify ARs in atmospheric reanalyses. The algorithm uses criteria of the spatial and temporal extent of the vertically-integrated horizontal Water Vapour Transport for the detection of persistent ARs (lasting 18 hours or longer) in five atmospheric reanalysis products. The relationship between persistent ARs and winter floods was shown using winter peaks-over-threshold (POT) floods (with on average one flood peak per winter). In the nine study basins over the period 1980-2010 (31 years), the number of winter POT-1 floods associated with persistent ARs ranged from approximately 40 to 80 %. Furthermore the winter occurrence of ARs was found to have a significant negative dependence with the Scandinavian Pattern. Given the strong link between the ARs identified in the algorithm and the British winter floods, the algorithm was applied to the latest climate projections (Coupled Model Intercomparison Project Phase 5- CMIP5) to assess future AR activity near Great Britain and hence, their associated winter floods. Initial results suggest that the water vapour transport will increase in the future, which is likely to cause larger rainfall totals and in turn a risk of bigger winter floods. The results also suggest that the projected change in ARs is predominantly a thermodynamic response to warming resulting from anthropogenic radiative forcing
Exploitation Route The methodology, which can be used to assess changes flood frequency of the largest winter floods, will be of use to those involved in assessing flood risk and impacts. The work assesses future flood frequency in response to changes in the water cycle due to climate change. The work will have a broad international appeal to climate scientists, hydrologists and policy makers interested in the impacts of climate change on floods. The methodology employed has a wide utility for others looking for potential AR changes in other mid-latitude regions and provides a robust way of assessing the impacts of extreme precipitation on surface water flooding by considering the modelled outcomes from a range of climate models. The method for atmospheric river detection is being trialled by ECMWF to see if it leads to enhanced lead times for flood forecasting (Lavers et al., 2014, Nature Comms). The detection method is being explored further as part of a new NERC Industrial CASE PhD studentship.
Sectors Environment

URL http://www3.imperial.ac.uk/ewre/research/currentresearch/hydrology/changingwatercycles
 
Description The detection algorithm for integrated vapour transport has used been help improve the potential predictability of storm events leading to floods across northwest Europe. Water vapour transport was found to have a higher medium-range predictability compared with precipitation and its use could help extend the forecast horizon by 3 days. Lavers, D. A. et al. Extending medium-range predictability of extreme hydrological events in Europe. Nat. Commun. 5:5382 doi: 10.1038/ncomms6382 (2014).
First Year Of Impact 2014
Sector Environment
Impact Types Societal,Economic

 
Description H2020-EU.3.5.4. - Enabling the transition towards a green economy and society through eco-innovation to ECMWF includes work Atmospheric Rivers
Amount € 7,996,848 (EUR)
Funding ID 641811 
Organisation European Commission 
Sector Public
Country European Union (EU)
Start 10/2015 
End 09/2019
 
Description NERC Industrial CASE PhD studentship
Amount £85,000 (GBP)
Funding ID NE/P010040/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 09/2017 
End 08/2021
 
Description SINATRA: Susceptibility of catchments to INTense RAinfall and flooding (NE/K008595/1)
Amount £328,996 (GBP)
Funding ID NE/K008595/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 09/2013 
End 02/2017
 
Title Algorithm to detect atmospheric rivers 
Description An algorithm to detect atmospheric rivers has been derived based on the assessment of wind speed, atmospheric water vapour content, persistance and location. Full details are given in Lavers et al., (2012). References: Lavers, DA, Villarini G, Allan RP, Wood EF, Wade AJ. 2012. The detection of Atmospheric Rivers in Atmospheric Reanalyses and their links to British Winter Floods and the Large-Scale Climatic Circulation. Journal of Geophysical Research - Atmospheres. 117:D20106. doi:10.1029/2012JD018027 
Type Of Material Computer model/algorithm 
Year Produced 2012 
Provided To Others? Yes  
Impact The algorithm has been incorporated in a pilot study at the European Centre for Medium Range Weather Forecasts to extend lead times for flood prediction (Lavers et al., 2014). Lavers, DA, Pappenberger F, Zsoter E. 2014. Extending medium-range predictability of extreme hydrological events in Europe. Nature Communications. 5:5382. doi:10.1038/ncomms6382 The algorithm has been included in the Atmospheric River Tracking Method Intercomparison Project, ARTMIP (http://www.cgd.ucar.edu/projects/artmip/) 
 
Description 'Rivers' in air could boost flooding - BBC, 2013 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Article on BBC website - http://www.bbc.co.uk/news/science-environment-23455820
Year(s) Of Engagement Activity 2013
URL http://www.bbc.co.uk/news/science-environment-23455820
 
Description A hydroclimatological analysis of floods in Britain (AGU, 2011) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Lavers, D. A., Allan, R. P., Wood, E. F., Villarini, G., Brayshaw, D. J. and Wade, A. J. (2011). A hydroclimatological analysis of floods in Britain, AGU Fall Meeting, San Francisco (USA), December 2011, Oral Presentation.
Year(s) Of Engagement Activity 2011
 
Description Atmospheric rivers and winter flooding in the UK - Environment Agency Webinar 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A webinar given to the Environment Agency, hosted at EA, Horizon House, Bristol on the 09 December 2013
Year(s) Of Engagement Activity 2013
 
Description BBC Radio 4 interview for World at One, 20 Feb 2020 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Prof Andrew Wade was interviewed on the BBC's World at One programme on Thursday 20 February about Atmospheric Rivers, their relationship to UK winter flooding and how their occurence will change in the future given climate change. World at One has an average daily audience of 1.4 million listeners.
Year(s) Of Engagement Activity 2020
URL https://www.bbc.co.uk/programmes/b006qptc/episodes/player?page=2
 
Description Flooding in winter to get worse, scientists warn (Daily Telegraph, 2013) 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Article in The Daily Telegraph (http://www.telegraph.co.uk/topics/weather/10197566/Flooding-in-winter-to-get-worse-scientists-warn.html), published 24 July 2013.
Year(s) Of Engagement Activity 2013
URL http://www.telegraph.co.uk/topics/weather/10197566/Flooding-in-winter-to-get-worse-scientists-warn.h...
 
Description Hydrohazards: Processes, Diagnosis and Projection (AGU, 2012) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact David Lavers convened a session at the AGU Fall Meeting in 2012 titled "Hydrohazards: Processes, Diagnosis and Projection". This was co-convened with Upmanu Lall (Columbia University), David Hannah (University of Birmingham) and Amir AghaKouchak (UC Irvine).
Year(s) Of Engagement Activity 2012
 
Description Invited seminar at Centre for Ecology and Hydrology, Wallingford, UK (2013) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Seminar
Year(s) Of Engagement Activity 2013
 
Description Invited seminar at ECMWF, Reading, UK (2013) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The role of atmospheric rivers in extreme European precipitation
Year(s) Of Engagement Activity 2013
 
Description Invited seminar at ERSL, Boulder, CL, USA (2012) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact David Lavers gave an invited seminar at the Earth Systems Research Laboratory (ESRL) in Boulder, Colorado USA in May 2012 "Atmospheric Rivers and British Winter Floods".
Year(s) Of Engagement Activity 2012
 
Description Invited seminar at Loughborough University, UK (2013) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact Atmospheric Rivers and European / British extreme precipitation and floods
Year(s) Of Engagement Activity 2013
 
Description Invited seminar at University of Birmingham, UK. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact David Lavers gave an invited seminar at the University of Birmingham in October 2012 "Atmospheric Rivers and British Winter Floods".
Year(s) Of Engagement Activity 2011
 
Description Invited talk at Convex workshop (Reading, 2012) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact David Lavers gave an invited talk on Atmospheric Rivers at the Convex workshop on 'Extreme Rainfall' at the University of Reading, 17-18 April 2012.
Year(s) Of Engagement Activity 2012
 
Description Linking variations in large-scale climatic circulation and groundwater level in southern England A (AGU, 2012) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Lavers, D. A., Hannah, D. M. and Bradley, C. (2012). Linking variations in large-scale climatic circulation and groundwater level in southern England, AGU Fall Meeting, San Francisco (USA), December 2012, Poster.
Year(s) Of Engagement Activity 2012
 
Description Press release - Insitute of Physics 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact http://www.iop.org/news/13/jul/page_60651.html



Press release by Institute of Physics for paper published in Environmental Research Letters by Lavers DA et al. 2013.

Since the press release the paper has been downloaded over 13,000 times.
Year(s) Of Engagement Activity 2013
URL http://www.iop.org/news/13/jul/page_60651.html
 
Description Rivers in the sky cause UK's worst floods - Media (New Scientist) 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact An article on Atmospheric Rivers and flooding in Britain was published in New Scientist (12th November 2011) following the publication of Lavers et al., 2011.
Year(s) Of Engagement Activity 2011
 
Description Rivers of the skies drench Britain - Media (Sunday Times) 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact The Sunday Times (7th October 2012) ran an article based on the atmospheric rivers research (http://www.thesundaytimes.co.uk/sto/news/uk_news/Environment/article1142293.ece)
Year(s) Of Engagement Activity 2012
URL http://www.thesundaytimes.co.uk/sto/news/uk_news/Environment/article1142293.ece
 
Description The increasing risks of floods and droughts: what can the latest science tell us? (Walker Institute, 2013) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Richard Allan gave a key note presentation and David Lavers presented a poster on the work at the Walker Institute Stakeholder Engagment event, 'The increasing risks of floods and droughts: what can the latest science tell us?', Royal College of Physcians, London, 30 January 2013.
Year(s) Of Engagement Activity 2013