Impact of changing estuaries on offshore wind infrastructure: Identifying key environmental drivers

Project Description:

The full project title is: “Impact of changing estuaries on offshore wind infrastructure: identifying key environmental drivers for morphodynamics governing port access, in the context of current and future offshore wind requirements”.

To achieve climate goals, offshore wind is expected to grow fivefold in the next 7 years (50 GW ambition by 2030) with further continuance to provide UK net-zero by 2050. Essential to this growth is the development and expansion of ports and ensuring access through shipping fairway maintenance. Ports are essential to the whole lifecycle of offshore wind, from construction phase, ongoing operations and maintenance (O&M) to decommissioning activities. Despite their importance, there is a significant risk that port capacity will be insufficient to support the offshore wind build-out rates required to meet net-zero targets.

Ports are often built in highly morphodynamic coastal areas, such as the Humber estuary, since they are accessible by both the sea and upstream rivers, allowing for international ship access and supply of materials and national and international redistribution. Estuaries are the most dynamic landscapes on earth and are uniquely sensitive to slight changes in environmental drivers, e.g. sediment input, waves, currents and sea level rise. These coastal areas are therefore under significant pressure from climate change, with expected sea level rise and increased hydrological extremes, and from anthropogenic measures to decrease flood risk and maintain economic activity. A change in these environmental drivers will lead to changes in sediment dynamics, channel depth and bank erosion within, and just offshore of, the estuary. There is therefore a risk associated to ports and estuaries from climate change during operational lifespan of wind farms currently being constructed.

Understanding natural controls on port access is therefore critical to enable long-term logistical planning, managing and mitigating cost risks of the future offshore wind industry. With offshore wind developments planned through to 2030, and beyond, plus the operational lifespan of windfarms exceeding 25-years it is crucial that long term planning being undertaken now is appropriately constrained. Therefore, this project aims to investigate the environmental controls on estuaries, dictating port access, in the context of current and future offshore wind requirements.

The complex interaction between environmental drivers and internal processes, such as sediment characteristics and ecology, is poorly understood and requires knowledge on system scale morphodynamics. The relevant importance of these variables need to be identified in an overarching framework, since the impact of climate change and anthropogenic influences will vary significantly depending estuary characteristics and location.

For example, the impact of sea-level rise on estuary morphology is expected to depend on estuary size and the change in tidal amplitudes (Leuven et al., 2019). Change in river discharge and hydraulic extremes will depend on climatic changes in the catchment area. Sediment input from upstream and from marine sources will depend on sediment type, land use change and engineering structures (Cox et al., 2021).  

Training and skills

The PhD student will develop skills in: developing and running morphodynamic models, scripting and programming, processing and analysing large amounts of data, data visualisation, scientific writing and presenting work to varying audiences. Specific training can be provided (based on the student’s needs) in the numerical model used in this study (probably Delft3D), and in coding and programming for model development and data analyses.

References:

Cox, J. R., Dunn, F. E., Nienhuis, J. H., van der Perk, M., & Kleinhans, M. G. (2021). Climate change and human influences on sediment fluxes and the sediment budget of an urban delta: the example of the lower Rhine–Meuse delta distributary network. Anthropocene Coasts, 4(1), 251-280.

Leuven, J. R., Pierik, H. J., Vegt, M. V. D., Bouma, T. J., & Kleinhans, M. G. (2019). Sea-level-rise- induced threats depend on the size of tide-influenced estuaries worldwide. Nature climate change, 9(12), 986-992.