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Stopping floods on the cheap: A success story from Yorkshire

A team of researchers led by Professor Sarah Whatmore at the School of Geography and the Environment ran a pilot project in Pickering, North Yorkshire to study the effectiveness of a new methodology for flood management decision making.

The outcome was much more than academic, and the town is safer for it.

The research was funded by the Economic and Social Research Council, the Natural Environmental Research Council and the Biotechnology and Biosciences Research Council.

Prize-winning article on Changing Conceptions of Rights to Water

Congratulations to Dr Bettina Lange at the Centre for Socio-Legal Studies who has been awarded the Annual Richard Macrory Prize for the Best Article in the Journal of Environmental Law.

The article “Changing Conceptions of Rights to Water?—An Eco-Socio-Legal Perspective” investigates the meaning of a ‘right’ to water, focussing on water use for agricultural production.

The authors explore how the concept of private property rights to water relates to the idea of water stewardship, which obliges stakeholders to protect water resources for the benefit of the wider public.

The article highlights changes to environmental regulation in the UK in recent years where there has been a greater emphasis on water stewardship aimed at tackling the risks of water scarcity. For example, water abstractions have been further regulated through the Water Act 2003 and the draft Water Bill (now the Water Act 2014).

The authors conducted research on how farmers in England think about their right to access and use water and how this understanding is changing in light of developments in UK water regulation. They develop a eco-socio-legal perspective for understanding how conceptions of rights to water are generated.

The article is now available for free online here

Global experts discuss drought risk

A symposium was held in Oxford on 22 September, bringing together global experts on the causes and impacts of droughts. The speakers shared experience and expertise from Australia, America, Europe and the UK, providing interdisciplinary insights into the climatic and socio-economic factors that contribute to drought.

“If you do what you’ve always done, you’ll get what you’ve always got!” said Professor Donald Wilhite, University of Nebraska, stressing the need to change the way droughts are managed. Although drought is a normal part of climate variability, unprepared governments and vulnerable societies often react to droughts with shock and alarm. Professor Wilhite proposed that droughts can act as a window of opportunity to change from post-impact crisis response to a pre-impact drought risk management approach. The cost of preparedness action against drought is insignificant when compared to the cost of inaction, he said.

The speakers at the symposium are members of the International Advisory Board of the Oxford-led MaRIUS project on drought and water scarcity in the UK. Oxford University’s Professor Jim Hall presented the project which was launched earlier this year and adopts a risk-based approach to understanding droughts and water scarcity; analyses the impacts on people, the environment and the economy; and will develop methods to support decision-making and improve drought risk management.

Dr Henny van Lanen from Wageningen University in the Netherlands said that there is medium confidence that droughts will intensify in the 21st Century in some areas and during some seasons in southern and central Europe, central North America, Central America and Mexico, northeast Brazil and southern Africa. Elsewhere in the world inconsistencies in models make it difficult to draw any firm conclusions. The ability of scientists to identify future drought trends is constrained by available data, various definitions of droughts, different ways to quantify or identify a drought, and the inability of models to include all the factors that influence a drought.

Climate change poses a challenge to water planners, as drought risks in the future may be greater than in the past. Professor Casey Brown, University of Massachusetts, argued that the best approach to address these uncertainties is to focus on understanding the project and its vulnerabilities to climate change. By identifying the key climate variables to which the system is sensitive and the magnitude of climate changes that cause unacceptable outcomes, a water planner can incorporate the desired or acceptable level of resilience into the project.

Drawing on research in the Shale Hills / Susquehanna wetland catchments in northeastern United States, Professor Christopher Duffy from Penn State University presented a methodology for assessing the vulnerability of wetlands to climate change and droughts. Early results show that upland catchments are the most vulnerable based on depth to groundwater which acts as a buffer during periods of low rainfall.

Professor Lucia De Stefano stressed that stakeholder input is essential for understanding vulnerability and response to drought. Her research in Spain and on a pan-European scale found that there are inconsistencies in drought perceptions across scales and that improving communication could benefit drought management and address mismatches between policy objectives and implemented measures.

Dr Narendra Kumar Tuteja from the Australian Bureau of Meteorology shared experiences from Australia, a country that has faced around eight major drought events in the last century, with the Millennium drought (1997-2009) radically influencing national water reform. He talked about the need for water availability forecasts at a range of time scales for operational water planning and management, and the challenges in generating these. He underscored the importance of continued and extensive consultation with stakeholders and users in order to deliver useful research, data or tools.

Safe enough? Proportionate climate change adaptation in London’s water supply system

London faces increased risk of water shortages in the future due to climate change and population growth if no actions are taken to increase supply or reduce demand, according to a new study led by Edoardo Borgomeo and Jim Hall at the Environmental Change Institute. The research presents a new methodology for water managers to incorporate climate change uncertainties into water resources planning.

Water resources managers have significant experience in planning and operating their systems in the face of hydrological and weather variability. The reality of climate change, however, poses new challenges for water resources managers. Whilst the precise impacts of climate change for temperature, precipitation and water availability remain uncertain, water managers still need to take into account these uncertainties in their water plans. In the UK water companies are now legally obliged to evaluate the impacts of climate-related risks on their systems.

To help water managers address this challenge, this study develops a methodology for incorporating climate change related uncertainties in water resources planning. The methodology uses a risk-based metric to compare different water management options on the basis of their ability to reduce risks of water shortages under continuously changing climate conditions.

This methodology responds to the need in the UK and worldwide for a way of identifying water management investments which are proportionate to the risks the water systems are facing. Supply-side and demand-side management strategies can be compared based on how cost-effective they are at reducing risks to acceptable levels.

The risk-based methodology was applied to the London water supply area to characterise the most important uncertainties and identify water management options that are capable of reducing the harmful impacts of climate change. Results from the study demonstrate that without further supply or demand interventions, the combined effects of climate change and population growth are projected to increase the risk of water shortages in the future in London.

This research, led by Edoardo Borgomeo and Jim Hall, was carried out in partnership with Thames Water and the Environment Agency. The study contributes to the ongoing discussion in the UK water sector on whether the current approach to water resources planning should change for the next round of water resources management plans in 2019.

Reference

Borgomeo, E., Hall, J.W., Fung, F., Watts, G., Colquhoun, K. and Lambert, C. (2014) Risk-based water resources planning: Incorporating probabilistic nonstationary climate uncertainties. Water Resources Research. DOI: 10.1002/2014WR015558

Unravelling the history of droughts in the UK

Oxford Univeristy is a partner in a cross-disciplinary research project on historic droughts and water scarcity funded by the UK Natural Environment Research Council’s programme on ‘UK Droughts and Water Scarcity’.

The project, led by the Centre for Ecology and Hydrology, will characterise and quantify the hydrometeorological, environmental, agricultural, policy and resource management, and social and cultural history of droughts and water scarcity in the UK since the late 19th century.

The research aims to identify interactions between natural and social systems in the production and management of droughts over the historic record. A major research outcome will be the first droughts inventory for the UK – an evidence base that will provide a common reference for policy makers, regulators, water supply companies, and UK business.

Drs Bettina Lange and Chris Decker, based at the Centre for Socio-Legal Studies, Oxford University, will analyse the history of regulating water scarcity and its economic impacts in the UK, drawing on case studies of key historic droughts.

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Long-term investment in flood and coastal risk management – scoping future approaches

Working in association with CH2M HILL, Paul Sayers, Senior Visiting Fellow at the School of Geography and the Environment, and Professor Jim Hall, Director of the Environmental Change Institute, have recently been appointed to explore the next generation of methods to support the Environment Agency’s national long-term investment strategy.

The long-term investment strategy for flood and coastal risk management provides the basis for the Agency’s bid to Defra for funding and currently combines a national risk analysis (using an evolution of a method developed by Jim and Paul (Hall et al., 2003) and an exploration of investment needs under alternative climate and management futures.

Reference

Hall, J.H., Dawson, R.J., Sayers, P.B., Rosu, C., Chatterton, J.B. and Deakin, R. (2003) A methodology for national-scale flood risk assessment. Water and Maritime Engineering, 156(3): 235-247.

Citizen science project finds global warming makes very wet winters ‘a bit more likely’

An Oxford University citizen science project to assess the effects of global warming has reported a small but statistically significant increase in the probability of extremely wet winters in southern England.

Following preliminary assessments from the Met Office, Oxford University researchers undertook the first scientific experiment to analyse whether the risk of extreme rainfall has changed due to climate change after the winter deluge between December 2013 and February 2014. Total rainfall in Oxford over the three months was the highest ever recorded by the University’s Radcliffe Observatory since it set up 200 years ago.

Scientists used the spare capacity on volunteers’ home computers to compare tens of thousands of simulations of possible weather in our present-day climate with tens of thousands of simulations of a hypothetical world without the influence of past greenhouse gas emissions in the atmosphere using the same climate model. Comparing numbers of extremely wet winters between these two groups provides estimates of the influence of climate change on the UK weather. They found a 1-in-100-year winter rainfall event (ie. 1% risk of extreme rainfall in the winter of any given year) is now estimated to be a 1-in-80 year event (i.e. 1.25% risk of extreme rainfall in any given winter) so the risk of a very wet winter has increased by around 25%.

The researchers say this change is statistically significant thanks to the number of computer simulations they were able to run– over 33,000 computer models run in the experiment. However, the researchers say that while their finding is statistically robust the result depends on how man-made climate change is represented in the experiment. They used different climate models to estimate the pattern of global warming which provided a range of possible changes in risk. In several cases, the models gave no change or even a reduction in risk, but overall the simulations showed a small increase in the likelihood of extremely wet winters in the south of England.

The experiment for the weather@home project, based at the University’s School of Geography and the Environment, started in March 2014. The winter deluge affected large parts of south England and Wales and as a consequence, large areas were flooded, some more than once during the three-month period. This led to a good deal of public debate, which at one point involved Prime Minister David Cameron, about whether the extreme rainfall and resulting floods could be linked to climate change.

Researcher Dr Friederike Otto, from the weather@home project based in the University’s School of Geography and the Environment, said: “It will never be possible to say that any specific flood was caused by human-induced climate change. We have shown, however, that the odds of getting an extremely wet winter are changing due to man-made climate change. Past greenhouse gas emissions and other forms of pollution have ‘loaded the weather dice’ so the probability of the south of England experiencing extremely wet winters again has slightly increased.”

She added: “Total winter rainfall, although useful as a benchmark, is not the direct cause of flood damage, so we are working with collaborators, such as the Centre for Ecology and Hydrology, to explore the implications of our results for river flows, flooding and ultimately property damage.”

Anyone who wants to join the project or volunteer spare time on their home computer should visit the weather@home website.

Graphs displaying the results of the weather@home project can be viewed here.

Watch Professor Myles Allen speaking about these results at a press conference at the EGU General Assembly [Myles speaks at 23 minutes into the video].

Read coverage of this story in the Guardian, the BBC and on the University of Oxford news site.

Vulnerable substations serving millions still at risk from flooding

An article in the Independent online highlights the significant threat UK power supplies face from flooding, with comment from Professor Jim Hall.

The National Grid has revealed that seven of the country’s biggest electricity substations could be affected by flooding, putting up to 1.1 million households at risk of losing power.

Jim Hall, Professor of Climate and Environmental Risks at the University of Oxford, said: “The 2007 floods were a wake-up call in terms of vulnerability and some very significant steps have been taken since then.

“But we are not there yet and in a changing climate we need to make sure that we are able to deal with past hazards and the increasing risks we face in the future.”

Read the full article in The Independent online

From flood science to flood policy – highly commended paper award

The paper ‘From flood science to flood policy: the Foresight Future Flooding project seven years on’ published in foresight has been selected by the journal’s Editorial Team as a Highly Commended Paper of 2013.

The paper, authored by Oxford’s Edmund Penning-Rowsell and Jim Hall, assesses the impact of the Foresight Future Flooding (FFF) project, both nationally and internationally. The FFF project researched flood risk in the UK to the year 2100 for central government, using scenarios and a national risk assessment model backed by qualitative analysis from panels of some 45 senior scientists.

View all award winners and download the full paper

Calculating the risks of coastal flooding and cliff erosion

Scientists at the University of Oxford are developing a computer model that will forecast the environmental risks to Britain’s coastline for decades ahead. This will be of immense value to local authority planning departments.

Happisburgh Beach, Norfolk, UK. Photo credit

Happisburgh Beach, Norfolk, UK. Photo credit

Calculating the risks of coastal flooding and cliff erosion has become ever more important as the UK’s weather patterns change and sea levels rise. The capability to do that depends upon having reliable data. Developing such data and creating a model for forecasting has been the work of scientists such as Professor Jim Hall and Dr Andres Payo at Oxford University’s Environmental Change Institute.

Around 35% of the UK’s coastline is vulnerable to flooding or erosion. Some areas are especially susceptible such as the East Coast. Research in Norfolk and Suffolk by Professor Hall and other scientists has shown how coastal areas respond to the forces of nature over years, decades and centuries.

By measuring the changes in coastal formation and recording how these changes occur – e.g. by sedimentary movement, wave height, wave direction etc, – the scientists have been able to construct a simulation model of the whole process of coastal change. Much of this process is self-regulating, e.g. rocky cliffs erode to form beaches below. More dramatic are those instances where soft cliff erosion leads to a build up of new headlands miles down the coast.

The current coastal model – created by Hall and colleagues – focuses on cliffs and beaches, but the newer, more advanced model will include estuaries, tidal inlets, sand dunes, spits and sandbanks. The East Anglian coast, which has long been the subject of Professor Hall’s research, has many examples of these. Meanwhile Hall’s colleagues in Manchester are looking at the coastal impact of offshore energy devices.

“The new insights of potential coastal change being delivered by the iCoast Consortium could bring about a step change in our understanding and management of the coast” said Owen Tarrant, Principal Scientist at the Environment Agency. “Only by understanding the full picture of the effects of both natural change and the influence of human activity over the long-term and large scale will we be able to manage flood and erosions risk sustainably.”

This research by Hall and his colleagues has applications far beyond East Anglia. In the UK the coastal model is being used by the Environment Agency and local authorities, when assessing long- term plans for coastal and offshore development. Beyond the UK New Zealand has shown interest. Other countries are likely to follow.

Funded by: Natural Environment Research Council

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