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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.

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Oxford flood experts contribute to government report on innovation and risk

Professor Edmund Penning-Rowsell and Paul Sayers co-authored a flooding case study in the Annual Report of the Government Chief Scientific Adviser 2014 ‘Innovation: Managing Risk, Not Avoiding It’.

The report of the Government Chief Scientific Adviser Mark Walport considers different perspectives on risk and innovation by the public, business and policy-makers. It aims to understand the bases upon which decisions are made about when and how to innovate.

The report states that “coastal and inland flooding remain high on the UK’s National Risk Register, with significant concerns around the three main sources of flooding: rivers, surface water and especially the sea”.

The high-level case study on flooding was written by Professor Edmund Penning-Rowsell (School of Geography and the Environment), Paul Sayers (Environmental Change Institute) and Andrew Watkinson (University of East Anglia). They discuss flood risk from three angles: the social perspective, the analysts’ perspective and the infrastructure planners’ perspective.

The report is available online and the flooding case study starts on page 101.

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Oxford researchers bridge the gap between flood risk science and management

Paul Sayers and Professor Jim Hall at the Environmental Change Institute have been awarded a grant from the Natural Environment Research Council (NERC) to capture current knowledge of methods for assessing flood risk and determining future infrastructure investments.

The past decade has seen significant developments in the approaches to assessing and managing flood risk, with both research and industry-led innovations. This has, however, led to a great number of methods that are difficult for practitioners and researchers to access and build upon. It is not always clear what best practice is, or how credible results are from different approaches.

The project ‘Flood risk: Building Infrastructure Resilience through better Understanding and Management choices ‘ (FoRUM) which is funded by NERC’s Environmental Risks to Infrastructure Innovation Projects call, will gather the current state-of-the-art knowledge on flood risk assessment and long-term investment planning.

The researchers will develop a common understanding of alternative methods and the uncertainties associated with each. This knowledge will be then be shared with stakeholders in the research, private and public sectors. Through the dialogue between researchers and stakeholders, FoRUM will establish the foundation for future advances in this field and collaboration between business and academia, ensuring that scientific developments have relevance to real-world needs.

The research team is led by Professor Jim Hall and Paul Sayers in the Environmental Change Institute at Oxford University with support from Professor Rob Nicholls (Southampton University) and Professor Edmund Penning-Rowsell (Oxford University). They are working closely with leading practitioners with an interest in flood risk and ability to make use of innovative science, including from the Environment Agency, Network Rail, Thames Water, JBA, CHM2HILL, AIR and HR Wallingford.

For further information, contact paul.sayers@ouce.ox.ac.uk

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Coping with the curse of freshwater variability

Oxford scientists say that institutions, infrastructure and information are the key ingredients for coping with freshwater variability and enabling economic growth, in an article published in Science.

The authors, which include Prof Jim Hall, Prof David Grey and Dr Simon Dadson, say that a key challenge to achieving water security is managing the risks posed by variable and unpredictable freshwater resources. Building resilience to these risks requires a transformation in the way investments are made.

Extreme events such as floods and droughts are hard to predict and future changes in variability are highly uncertain. The article highlights three dimensions of freshwater variability: change within the year (seasonal and monthly), year-to-year, and the unpredictable timing and intensity of extremes. When these three dimensions combine the situation is “most challenging – a wicked combination of hydrology that confronts the world’s poorest people,” say the authors.

The article warns that the inability to cope with variability can place serious burdens on society and the economy. Extreme events such as droughts and floods have ripple effects through the economy. For example, floods in Thailand in 2011 caused $43 billion in losses. Meanwhile in Ethiopia economic growth is 38% less that what would be expected based on average rainfall, due to the country’s complex hydrology.

Countries can do very little about their natural endowment of water: when and where it rains and how much water evaporates, infiltrates into the ground, and runs into rivers and lakes. However for those countries burdened with highly variable hydrology, investment in water management can help buy their way out of water insecurity.

The study’s analysis shows that countries that have achieved economic growth, despite high variability in freshwater resources, have invested heavily to reduce risk. In river basins with complex hydrology where there has been low investment, the economy suffers.

Countries along river basins with less variability are more wealthy, even though investments have sometimes been quite modest. Where the hydrology is highly variable, additional investment is needed to transition from water-insecure to secure, but this is least affordable and hardest to deliver in the poorest countries. Climate change may increase variability further, making water security an even more distant goal for countries already underequipped to cope.

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The authors highlight “the three ‘I’s” as essential for adapting to freshwater variability: institutions and good governance (such as river basin organisations, legal systems, and water pricing), infrastructure (such as water storage, wastewater treatment, groundwater wells) and information (including monitoring, forecast and warning systems, and modelling tools).

Crucially, coping with variability involves a combination of institutions, infrastructure and information – rarely will they generate their full benefits alone.

The article calls for a new approach to investing in water security. A broader and longer-term vision is needed that looks beyond individual projects to the sequence of investments that can create a pathway to water security. Context also matters when it comes to what combination and sequence of investments are needed.

This new approach will focus on risks, trade-offs and uncertainties to enable decision-makers to choose between alternative investment pathways and build a more water secure future.

This research stems from the work of a global Task Force on Water Security and Sustainable Growth, an initiative of the Global Water Partnership and OECD, co-chaired by Oxford University’s Professor Jim Hall and Professor David Grey.

Reference

Hall, J.W., Grey, D., Garrick, D., Fung, F., Brown, C., Dadson, S.J. and Sadoff, C.W. (2014) Coping with the curse of freshwater variability. Science, 346(6208): 429-430.

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Attributing extreme weather to climate change in real-time

Dr Friederike Otto examines the question of how extreme weather events might be linked to climate change in this blog entry for the Carbon Brief.

The question of how extreme weather events might be linked to climate change is a key one.

It’s particularly important because in many regions, extreme weather like heatwaves, floods and droughts cause more damage than other, more predictable consequences of climate change, such as sea-level rise.

Scientists know that an increase in average temperature as the climate changes will lead to an increase in the number or magnitude of some extreme events, while others will get less likely.

But the chaotic nature of weather means it’s generally impossible to say, for any particular event, that it only happened because of climate change.

Read more on the Carbon Brief website

Dr Friederike Otto is a research fellow in the ECI Global Climate Science Programme at the Uiversity of Oxford and scientific coordinator of climateprediction.net.

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Report identifies the ‘most vulnerable’ to climate-related disasters

Extreme weather events leave populations with not enough food both in the short- and the long-term, says a new report by the Environmental Change Institute that examines the impacts of climate-related diasters on food security. The authors conclude that better governance could have lessened the impact on the poorest and most vulnerable, and affected populations have been let down by the authorities in past disasters.

The report, commissioned by the charity Oxfam, tracks the effects on four countries: Russia which experienced a heatwave in 2010; flood-hit Pakistan the same year; East Africa during the drought of 2010-2011; and the Philippines after Typhoon Haiyan in 2013. The researchers conclude that the authorities in each of the countries studied were unprepared for extreme weather events, and citizens suffered even more than they needed to.

The report, ‘A Sign of Things to Come?’, says that during the floods in Pakistan ‘coercive landlords’ took advantage of smallholders and people affected by the floods. Overall, the flooding is estimated to have led to an 80% rise in wheat and rice prices in 2010.

The drought-affected people of East Africa did not receive international or domestic aid for six months, partly due to the risks posed by armed groups. Food prices reached record levels in several markets that included the cost of wheat in Ethiopia, maize in Kenya and red sorghum grain in Somalia, says the report. It notes that children under five accounted for over half of all deaths in Somalia.

On a global level, the report warns that climate change is expected to increase the intensity and frequency of heatwaves and floods. It says although there is no scientific evidence to show a specific weather event would not have happened without climate change, scientists can estimate whether it increases the risk of an event. It finds that the Russian heat wave and the East African drought were more likely because of climate change, but there is not yet the evidence to say that climate change played a part in the floods in Pakistan or Typhoon Haiyan.

One of the lead authors Dr John Ingram said: “Weather has always affected food security, particularly for many of the world’s poorest people. Perhaps we think of farmers or fishermen first, but extreme weather will affect many more people in other ways too. While direct measures such as emergency preparedness and the strengthening of response-related institutions is helpful, this study has identified the need for a wider cultural shift to ensure the poorest and most vulnerable are properly protected. This goes beyond mere technical improvements to equipment or redirected funding and gets to the very heart of what ‘climate justice’ should be about.”

Reference

Coghlan, C., Muzammil, M., Ingram, J., Vervoort, J., Otto, F. and James, R. (2014) A sign of things to come? Examining four major climate-related disasters, 2010-2013 and their impacts on food security. Oxfam Research Reports, Oxford. Oxfam.

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Managing coasts under threat from climate change and sea-level rise

Coastal regions under threat from climate change and sea-level rise need to tackle the more immediate threats of human-led and other non-climatic changes, according to a team of international scientists.

The team of 27 scientists from five continents reviewed 24 years of Intergovernmental Panel on Climate Change (IPCC) assessments. They focused on climate change and sea-level rise impacts in the coastal zone, and examined ways of how to better manage and cope with climate change. The research team was led by Dr Sally Brown at the University of Southampton and included Andres Payo at the Environmental Change Institute, Oxford University.

They found that to better understand climate change and its impacts, scientists need to adopt an integrated approach into how coasts are changing. This involves recognising other causes of change, such as population growth, economic development and changes in biodiversity. Dr Brown emphasised that: “Over the last two and half decades, our scientific understanding of climate change and sea-level rise, and how it will affect coastal zones has greatly increased. We now recognise that we need to analyse all parts of our human and natural environments to understand how climate change will affect the world.”

The scientists also acknowledged that long-term adaptation to climate change can greatly reduce impacts, but further research and evaluation is required to realise the potential of adaptation. “Many parts of the coast can, with forward planning, adapt to sea-level rise, but we need to better understand environments that will struggle to adapt, such as developing countries with large low-lying river deltas sensitive to salinisation, or coral reefs and particularly small, remote islands or poorer communities,” said Dr Brown.

For example, in the Maldives, many small, remote low-lying islands are at risk from climate change and will struggle to adapt. But around the densely populated capital city and airport, adaptation has already occurred as land claim is a common practice in order to relive population pressure. Sea-level rise has already been considered into newly claimed land. Thus in decades to come, potential climate change impacts, such as flooding, will be reduced for this island, benefiting both the local population and economy.

Dr Jochen Hinkel from Global Climate Forum in Germany, who is a co-author of this paper and a Lead Author of the coastal chapter for the 2014 IPCC Assessment Report added: “The IPCC has done a great job in bringing together knowledge on climate change, sea-level rise and is potential impacts but now needs to complement this work with a solution-oriented perspective focusing on overcoming barriers to adaptation, mobilising resources, empowering people and discovering opportunities for strengthening coastal resilience in the context of both climate change as well as existing coastal challenges and other issues.”

This new research, published as a commentary in Nature Climate Change, will help in the understanding of the impacts of climate change and how to reduce impacts via adaptation. Its multi-disciplinary approach could be useful if future IPCC assessment reports are commissioned.

Reference

Brown, S. et al. (2014). Shifting perspectives on coastal impacts and adaptation. Nature Climate Change, 4: 752–755. DOI: 10.1038/nclimate2344

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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.

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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.

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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

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