A consortium comprised of Mott MacDonald, EDF Energy, and Met Office in the United Kingdom produced a comprehensive series of technical volumes that helps engineers understand the risks and effects of natural hazards to infrastructure. Technical Director Sun Yan Evans of Mott MacDonald reports.
Weather disasters – such as extreme wind, flooding, and hail – bring damage and destruction to various types of infrastructure across the energy system. Stakeholders within the industry need to have a shared understanding of the risks and effects of those natural hazards to ensure the protection of people and infrastructure.
Each type of natural hazard carries potential to impact infrastructure, but there’s a wide spectrum of understanding surrounding each specific effect. For example, widely reported and researched coastal flooding and extreme rainfall are commonly known to have a large impact. Last March Cyclone Idai caused severe flooding in Mozambique and Malawi, death toll at 847 with hundreds more missing, and US$1 billion in infrastructure damage, according to the United Nations. On the other hand, space weather and marine biological fouling (the accumulation of microorganisms on wetted surfaces) also pose a risk, yet have not been subject to as much research. Therefore, their impacts are far less well-known.
This disparity of understanding triggered the need for research into the characterization of natural hazards, and a consistent organizational structure to discuss them in the industry. This consistency in terminology and methodology is vital for engineers who need to consider how to protect infrastructure against a variety of hazards, not just specific hazards that have been thoroughly researched in the past. For the first time, a consortium in the United Kingdom (UK) recently provided a set of technical volumes and case studies for the Energy Technologies Institute (ETI) to fill this gap, titled, “Enabling Resilient UK Energy Infrastructure: Natural Hazard Characterisation Technical Volumes and Case Studies.” The consortium includes the engineering consultancy Mott MacDonald, the UK’s largest producer of low-carbon electricity EDF Energy, and the UK’s national weather service Met Office. This consistency in language and terminology is vital for engineers who need to consider how to protect infrastructure against a variety of hazards, not just specific hazards thoroughly researched in the past.
Recent events and grave reminders
Recent events in the past few years provide a grave reminder of the impact of natural hazards on infrastructure. On 11th March 2011, an earthquake of magnitude 9.0 centered 130 kilometers (km) off the east coast of Japan triggered a 15-meter (m) tsunami, which struck the Fukushima nuclear plant. This disabled the plant’s power supply and cooling systems for three of the nuclear reactors, leading to a nuclear disaster. Tragically, the tsunami led to 19,000 deaths and caused significant damage to coastal ports and towns with over a million buildings destroyed in its path. Over 100,000 people were evacuated from areas close to the power plant to avoid deaths caused by radiation sickness.
The reactors were robust when initially hit by the earthquake, but were vulnerable to the tsunami that was triggered by the earthquake. This disaster highlighted not only the impact that individual hazards can have on infrastructure, but also how the combination of various natural hazards can lead to more severe impacts than if the same hazards had occurred separately. The Fukushima disaster led to a worldwide safety review of nuclear stations with new protection systems, safety equipment, and protocols instituted to prevent such severe consequences in the future.
In the UK, some of the most damaging natural hazard events in recent times have been caused by storms. A sequence of storms struck the UK in December 2013 leading to severe damage in multiple areas. Several hundred homes on the east coast of England required evacuation, while the Thames Barrier was closed to protect London. Extreme wind speeds across Scotland forced the closure of the rail network and left approximately 100,000 homes without power. A couple of years later in December 2015, Storm Desmond hit the northwest of the UK, leading to a new UK record of 341.4 millimeters (mm) of rainfall within a 24-hour period in Cumbria. The storm caused a wave of destruction, with several bridges being swept away and tens of thousands of houses left without power. This was swiftly followed by Storms Eva and Frank, which led to further intense flooding across the UK.
Climate change issues for millions
It is perhaps not a surprise that flooding is the second most serious natural hazard risk for the UK following the potential for a flu epidemic, with more than 5 million properties at risk in England alone. To put that into perspective, that is the equivalent to one in every six homes. More than 2.4 million properties are at risk of flooding from rivers or the sea. Within that figure, nearly half a million properties are at significant risk and 1 million are vulnerable to surface-water flooding, primarily due to insufficient draining capacities in urban areas.
An official report by the Environment Agency in the UK reveals that the winter floods of 2013 to 2014 caused damage in England and Wales costing around $1.7 billion (£1.3 billion). The cost of flooding will breach the $6.5 billion (£5 billion) mark, according to new Telegraph estimates. As well as affecting properties, flooding can damage national critical infrastructure such as electricity power supply, leading to a cascade failure in other sectors. Therefore, understanding the flood risk now and in the future, and building infrastructure with resilience to flooding, is critical to the sustainability of the UK and for society’s ability to continue daily life without disruption, economic damage, and environmental cost.
The risks associated with natural hazards have become heightened in recent years with the potential impacts of climate change on the environment. There are documented increases in global mean temperature from preindustrial times, due to increased human-induced emissions of greenhouse gases. There is a less clear picture for other hazards, such as intense rainfall and strong wind. However, developments in climate science are starting to open more research opportunities to study future changes for a variety of natural hazards. Two examples include:
- The Met Office is investigating the impacts of climate change and variability on earth and humans, including water resources, ecosystems, health, and energy.
- King’s College in London is conducting research on natural hazards and climate change, to improve the understanding of natural hazards, and to reduce disaster risk and loss through knowledge-based actions.
The impact of climate change is likely to drive alterations in the way that energy is used. Climate change is also expected to influence the frequency and intensity of natural hazards, which could affect energy production and distribution. Major shifts in the UK energy system are expected to occur soon, with preexisting energy infrastructure reaching end of life. Future infrastructure design is being driven by economics, innovation, and social acceptability. This unavoidable transition in the energy industry means that it is crucial to have a shared understanding of the risks and impacts climate change can have on natural hazards. The UK’s National Planning Policy Framework attempts to address this issue. The framework explains how the planning system should help to minimize vulnerability and provide resilience against the impacts of climate change by making an allowance for climate change in flood-risk assessments.
Meanwhile, Sir Michael Pitt was appointed by the UK Secretary of State for the Environment, Food and Rural Affairs to write a review looking at lessons learned from the widespread flooding in 2007. Extensive recommendations were made on how to prevent new buildings in flood risk areas and how to increase the resilience of existing buildings in floodplains. The report also brought essential services to the forefront, with several recommendations for government and infrastructure operators to work together on increasing resilience of those assets. The government’s response to the review led to the Flood and Water Management Act, which became law in April 2010.
Changes in UK energy system by 2050
Looking to the future, it is essential that the UK energy system changes – not only to become more resilient, but also to deliver decarbonization and efficiency improvements. Indeed, it is expected that the country’s existing energy infrastructure will be completely overhauled or replaced by 2050 as it continues to evolve, taking advantage of new technologies and innovations that could provide cleaner and green energy solutions. This will likely create a greater reliance on system integration and computing technology. As it evolves, it is crucial that the UK’s energy infrastructure meets future needs with adequate resilience to the impact of nature hazards.
It is necessary to consider the details regarding the UK’s long list of specific natural hazard threats. This step is important. The ETI-commissioned research ensured that the documents provide information about the most relevant natural hazards that could affect UK infrastructure. The process of characterizing natural hazards can help to address the vulnerability of the energy system by being used within safety analysis and the operation of different infrastructure. More specifically, it can be focused on the initial planning, design, and build of infrastructure, as well as adaptation over time to account for new hazards and the effects of climate change.
During the initial planning, design, and build of any infrastructure it is important to charac- terize the impact that natural hazards may have on safety and operations. It is necessary to decide on the level of protection against natural hazards and whether there are any hazards that can be screened out for being either very unlikely to occur or very unlikely to impact upon the infrastructure under consideration. A rigorous characterization of natural hazards ensures that these decisions are robust and provide the appropriate level of protection.
This will depend on the asset, its vulnerability to the natural hazard, and the rarity of the natural hazard under consideration. The potential for future adaptation also needs to be taken into account should the magnitude of the natural hazard frequency alter, as well as the joint probability of different hazards, such as increasing sea levels leading to a higher probability of coastal flooding.
It is also important to consider how to appropriately characterize various hazards. It is crucial to understand how to use sources of environmental data that are now available for this purpose. This cannot be done properly without an appreciation of state-of-the-art methodologies that are currently available.
The 11 types of natural hazard characterizations presented in the technical documents and case studies in the ETI-commissioned research are applicable to water, energy, transportation, and communication infrastructure. The information presented in the series of technical documents is going to be extremely valuable to the future design and construction of rail and water infrastructure, including water intake structures and treatment plants.
The technical volumes are further supported by five case studies that illustrate how the approaches outlined in the technical volumes can be used to characterize a specific set of natural hazards at a site, to better understand the risk.
The case studies observe several different locations around the UK, such as offshore, onshore coastal, and inland river. For example, the Trawsfynydd, Wales study represents an inland case. This ETI case study applies the hazard characterization techniques outlined in technical volume 2 (extreme high and low air temperature), volume 7 (seismic, volcanic, and geological hazards), and volume 12 (hazard combinations).
Natural hazard characterization is not only important for new-build infrastructure projects. Existing energy infrastructure assets also require approaches for natural hazard characterization to ensure that they are prepared for any weather disasters that may strike. However, this poses a slightly different challenge as many of these projects were built using earlier techniques for characterizing natural hazards that have since been supplanted. Many of this existing infrastructure did not take climate change or hazard combinations into consideration when first implemented. As such, the process of periodic safety review is especially important.
For example, coastal power stations that use seawater in a once-through cooling water system can also suffer from biofouling within the system. If untreated, this will impede water flow and drastically reduce the efficiency of heat transfer condensers. However, the semienclosed nature of these systems allows the water itself to be dosed with anti-fouling chemicals. This is currently an effective solution, which generally keeps the issue within manageable levels. However, future changes in environmental permitting of chemical discharges could make the current solution ineffective due to new, alien, or invasive biofouling species that may be more resistant to even the current treatment.
The UK energy infrastructure – as it transitions to a low-carbon, efficient, and integrated system – needs to maintain resiliency central to its development. Understanding, characterizing, and mitigating the impacts of natural hazards are more important than ever to enable resilient UK energy infrastructure fit for the future.