Landsliding is a collective term for physical processes that cause rock and soil to fail and move down slope. Landslides occur when steep slopes are destabilised by factors such as heavy rainfall, earthquakes, the removal of the base of the slope by natural processes (e.g., by rivers) or by the action of people causing material on the hillside to collapse. Many thousands of landslides occur globally each year, killing thousands of people (e.g., from 2004 and 2016; 55,997 people died in 4,862 separate landslide events) and significantly damaging infrastructure, disrupting economies and hindering international development. Despite extensive research, the ability to forecast when and where a landslide will occur remains a fundamental scientific challenge. This is partly because scientists had thought that the rate of landsliding in a certain area is constant from year to year, and that landslides would occur in similar places in those landscapes. If this were the case, then it would be straightforward to understand where and when landslides would most likely occur, i.e., they would be 'predictable'. Unfortunately, recent research shows that such assumptions are incorrect and in fact sudden extreme events such as storms and earthquakes will change the rates and patterns of landsliding. Being able to predict areas of elevated landslide risk thus remains an imperative frontier in hazard management. Earthquakes not only induce landslides because of ground deformation and shaking during the event, but also after an earthquake there are increased numbers of subsequent landslides over the next 1-10 years - this process has been termed "earthquake-preconditioning". This phenomenon poses an additional hazard and risk that is largely unrecognised and unquantified. Our recent ground-breaking research in Nepal suggests that there is a link between the strength of an earthquake and excess topography (areas in the landscape that are above a stable threshold slope) and subsequent landsliding. If this relationship is true in other parts of the world, we will have a highly innovative way of locating areas at higher risk. This project will address this critical research frontier through the study of recent events and computer modelling. Firstly, we will create new landslide catalogues before, during and after recent large earthquakes for six different regions, using high-resolution (<5m) satellite imagery. These high-resolution data allow us to accurately determine the long-term average rate of landslide occurrence in each region and confidently identify the size and duration of periods of increased landsliding following an earthquake. The regions and earthquakes selected span a range of climates, tectonic settings, and earthquake sizes to enable us to investigate the influence, and determine the relative importance that different control factors (e.g., rainfall, slope, topography, earthquake size) have at a global level, ensuring that the research outputs have wide applicability. These datasets will then be used in landslide susceptibility models at regional level to form outputs that can be used in hazard and risk mitigation by national/regional governments and agencies. Secondly, we will develop a new process-based computer model to investigate the mechanism of earthquake landscape damage and how this changes through time to cause observed patterns of landslides. Unlike empirical statistical models, process-based models explicitly simulate the drivers of landslide occurrence and can consider the impact of sudden and rapid environmental changes. The results of the model will be validated by the susceptibility maps, and the ability to model multiple earthquakes over 10s to 1000s of years will lead to new insights into the role of earthquake-induced and earthquake-preconditioned landslides in long-term landscape evolution, ultimately increasing the ability to accurately forecast the location of landslides across earthquake cycles.

The increased frequency of extreme weather events associated with climate change results in the increased risk of surface water (pluvial) flooding, posing a great threat to the integrity and function of critical urban infrastructure. During the winter of 2013/14 twelve major winter storms occurred resulting in more than 5,000 homes, businesses and infrastructure being flooded in southern England. Green infrastructure, in the form of Sustainable Urban Drainage Systems (SUDS), has been proposed as a potential measure that is likely to have a significant effect on flood risk in urban environments. However, despite their multifunctional benefits, SUDS often fail the feasibility criteria of Flood Risk Management (FRM) cost-benefit assessment. The Environment Agency (EA) highlighted a number of knowledge gaps concerning the cost and benefits of large-scale SUDS retrofitting schemes, in particular the data to remove uncertainties concerning the economic appraisal of innovative solutions. The scientific community and engineering consultants have also recognised the importance of utilising vegetation to enhance urban water management by delivering a range of essential services to towns and cities and supporting urban adaptation to climate change. The Climate-KIC funded Blue Green Dream (BGD) project gathered eminent partners to develop tools for assessing the interactions between urban water (blue) systems and vegetated (green) areas and hence maximise the multifunctional benefits of so-called Blue Green Solutions (including SUDS). Building on that research, this project will assign green infrastructure interventions as assets by progressing knowledge and understanding of the ability of Blue Green Solutions to provide cost-beneficial Flood Risk Management services. This will be achieved by brining together the expertise from three BGD project partners - Imperial College London, Deltares and AECOM, supported by the EA Water London Team. The Decoy Brook sub-catchment in London Borough of Barnet will be used as a case study for: a) mapping of Blue Green Solutions for infrastructure protection using the Adaptation Support Tool; b) improving the cost-benefit assessment of SUDS by quantifying multifunctional benefits of innovative Blue Green Solutions; and c) producing an advanced tool for full cost-benefit analysis of the proposed SUDS retrofitting scheme in compliance with the Flood Risk Management assessment. This will enable the EA to transparently and objectively assess Blue Green Solutions against the broad range of benefits. In addition, it will provide AECOM an example of a robust business case for utilising SUDS/Blue Green Solutions to protect infrastructure that addresses the reduction in the levels of uncertainty associated with the results from such analyses. Outputs from this project will be used to provide evidence to the Greater London Authority on the development of a pan London approach to delivering sustainable drainage systems. In addition, more accurate and robust valuing of SUDS and demonstrating the full return on each pound invested will enable EA's SUDS retrofit projects to compete on an equal footing for Flood and Coastal Erosion Risk Management Grant in Aid funding.

Mean sea level around the UK has risen by approximately 1.5 mm per year on average from the start of the 20th century. This rate has increased to levels exceeding 3 mm per year for the period 1993-2019. The projections of sea level rise show that UK sea level will continue to rise well beyond 2100, even under scenarios where future temperature rise is stopped. For instance, under a low emissions scenario, the approximate projected ranges at 2300 are 0.5 - 2.2 m for London and Cardiff, and 0.0 - 1.7 m for Edinburgh and Belfast. Under a high emissions scenario, this increases to 1.4 - 4.3 m for London and Cardiff, and 0.7 - 3.6 m for Edinburgh and Belfast. Extreme sea level events are also expected to become more frequent in the future and occurring about 20 to 30 times more frequently by the year 2050. Around 148 million people are exposed to coastal flooding events worldwide, which will surge in the coming decades. Rising sea level will also have strong economic consequences. For instance, the investment required to protect London is expected to exceed 20 billion GBP. According to IPCC, unavoidable sea level rise will bring cascading and compounding impacts resulting in flooding and damages to coastal infrastructure that cascade into risks to livelihoods, settlements, health, well-being, food, and water security in the near to long-term. There are several known approaches to adapt to sea level rise (e.g., realignment, nature-based solutions, soft/hard defences). Although realignment, nature-based solutions and soft defences provide lower cost, sustainable and resilient solutions, there are cases where hard defence is unavoidable to: hold the line. Yet, they have the risk of increased exposure to climate risks in the long-term unless they are integrated into an adaptive plan, which strongly relies on understanding their response to future sea level rise and extreme events. The sea level rise, along with the increase of the extreme sea level events, will lead to increased frequency of wave overtopping at the seawalls. Wave overtopping will have significant impact on the interaction of the wall with the backfill soil, affecting the stability of the seawalls in the long-term. The extent to which the seawalls can be integrated as a part of the long-term climate change adaptation plans will depend substantially on their response to future sea level rise and extreme sea level events. To adapt the seawall design accordingly, the impact of wave overtopping on the overall stability of seawalls need to be evaluated in terms of modified backfill soil-seawall interaction due to (i) wetting-drying cycles and (ii) erosion. This first project will focus on the first aspect, unlocking the fundamental behaviour of backfill soil-seawall interaction to wetting-drying cycles due to wave overtopping. Considering the global nature of the problem, an international collaboration is of paramount importance to find a mutual solution with academics, stakeholders and industry partners. Thus, this project will be a first step to initiate international collaboration between Heriot Watt University (HWU) and Virginia Tech (VT), USA. The main benefits of this research work will be on (i) coastal population, (ii) UK economy and (iii) agricultural land and cultural values.

Permeable (fast draining) infrastructure will reduce the impact from climate change and urbanisation related flooding, which has a projected annual global cost of £500bn by 2030. Flooding is expected to cost the UK economy £27bn annually by 2080, without investment in flood resilient infrastructure. Along with the 2020 government plan for green infrastructure development, it is timely to invest in flood resilient permeable infrastructure. An extreme example of flood-affected infrastructure are airport pavements, impacted by stormwater and ice/snow build-up causing aircraft skidding. Skidding accounts for nearly half of all post 1990 major global commercial air crashes. In 2017 a Heathrow snow event grounded over 50,000 passengers and required a hurried £10m purchase of de-icing equipment. The current methods for preventing ice/snow build-up damage the environment, aircraft components and runway surfaces, increasing infrastructure maintenance costs. Airport operators, seeking to address these concerns, have expressed a strong desire to use permeable concrete technology to keep infrastructure clear. Permeable concrete pavements are one of the most promising mitigation strategies to prevent surface flooding, they rapidly drain stormwater through otherwise impermeable infrastructure. Conventional permeable pavements are, however, prone to clogging, due to debris trapped within the pore network, blocking the pavement and reducing its drainage capacity. The frequent required maintenance degrades performance and service life and is difficult to perform in an active airport. Most importantly, conventional permeable pavements have insufficient strength, making them unsuited for airports. There is an urgent need for a new system that can reliably keep airports clear of standing water and ice/snow. I recently developed next generation clogging resistant permeable pavement (CRP) of uniform pore structure to address infrastructure flooding. It has improved strength (twice as strong >50 MPa) and higher permeability (ten times more) than conventional systems of equal porosity, yet does not clog despite exposure to stormwater sediments. This Fellowship will significantly reengineer my novel pavement to develop the first permeable pavement, with sufficient strength and resilience, for the extreme airport case, while also applicable to less extreme highway, railway and novel green wall scenarios. These step-change advancements will be achieved by steel reinforcement, used in permeable pavements for the first time. The structural performance, material integrity, skid resistance, long-term durability and hydrological (drainage) properties will be assessed for airport suitability and improved if required. This project will be the first to investigate conductive (direct contact) and convective (transmission through air) heat transfer through permeable pavements used in high-value heavy load-bearing infrastructure. I will use heat extracted from the ground (ground source energy system, GSES) in these new pavements to melt the deposited ice/snow and drain away the excess water. Conventional pavements can be heated by conduction only, whereas CRP can be heated through both conduction and convection (via the pores) as the novel pore structure also allows for natural convection. This Fellowship will, through extensive laboratory experimentation, computer modelling and the permanent large-scale deployment at Inverness Airport (spanning across multiple technology readiness levels (1-7), a measure of technology maturity), develop climate change resilient infrastructure materials that can be used to deliver a sustainable built environment resistant to flooding, ice/snow build-up and the harmful heat island effect. To achieve this ambitious goal, I will address significant structural, material, thermal and hydrological challenges with wide reaching economic, environmental and societal benefits to the construction and transportation sector.

The built environment is estimated to account for around 50% of all carbon emissions. About 10% of global GDP is generated by the construction industry, which creates and maintains our built environment. Recent success in reducing operational energy consumption and the introduction of strict targets for near-zero energy buildings mean that the embodied energy will soon approach 100% of total energy consumption. The importance of this fundamental shift in focus is highlighted by the analysis of recently constructed steel and concrete buildings, in which it was demonstrated that embodied energy wastage in the order of 50% is common. Inefficient over-design of buildings and infrastructure must be tackled to minimise embodied energy demand and to meet future energy efficiency targets. The UK Government has set out its ambition to achieve 50% lower emissions, 33% lower costs, and 50% faster delivery in construction by 2025. These ambitious targets must be met at the same time as the global construction market is expected to grow in value by over 70%. Achieving growth and minimising embodied energy will require a step change in procurement, design and construction that puts embodied energy at the centre of a holistic whole-life cycle design process. The global population is expected to grow to 9.7billion by 2050, with 67% of us living in cities. China alone will add 350 million people to its urban population by 2030. Yet Europe's and Japan's population will both be smaller in 2060 than they are today, and the total population of China is expected to fall by 400million between 2030 and 2100. Depopulation of cities will occur alongside reductions in total populations for some countries. This presents a complex problem for the design of the built environment in which buildings and infrastructure constructed today are expected to be in use for 60-120 years: providing structures that are resilient, healthy, and productive in the medium term, but demountable and potentially reusable in the long term. The targeted feasibility studies of this proposal will be vital in ensuring that this can be achieved. We have identified a series of areas where feasibility studies are essential to define research needs to enable significant energy savings in the construction industry before 2025. We will identify a series of 'low-hanging fruit' research areas, in priority order, for embodied energy savings, and work with our industrial partners to develop feasible pathways to implementation in the construction industry.