Coasts provide us with a wide variety of vital resources and services. They support our fisheries and tourism industries, and play an important role in the cycles that affect the climate and environment. They have also historically served as our links to other parts of the globe, allowing us to trade and interact with those previously beyond our reach, which has shaped our societies into those we live in today. It is no surprise, then, that over a third of the human population live close to the sea – the majority of the world’s cities are located on the coast, despite coastal regions only constituting 4% of global land cover.
The coastline is dynamic and ever-changing. It is governed and shaped by a wide range of physical processes and forces. Therefore, while these areas provide great support to a nation’s society and economy, there are great risks associated with coastal development that should be considered heavily during investment and planning. Modelling is a significant method of visualising the processes at play in the coastal environment. Dr Andres Payo of the British Geological Survey is currently working on developing such models and tools to help stakeholders anticipate coastal change so that they can make informed decisions during development and allow us to continue using the vital resources the coasts provide in a sustainable manner.Energetic environments
Energy levels can vary widely at different parts of the coast, from relatively calm beaches enclosed in bays to rocky cliffs exposed to the harsh conditions of the open sea. It is this energy that moulds the landscape – coasts facing high levels of energy endure high levels of erosion from powerful waves, while low-energy coasts experience low-power waves and thus face little erosion. Landforms such as wave-cut platforms and headlands are common on high-energy coasts, forming through wave action and the geology of the area. Cliffs are rarely uniform in terms of their geology, typically constituting layers of different types of rock that erode with varying levels of ease. Softer types of rock may be eaten away by wave action, leaving protrusions of harder rock extending into the sea.
The numerous processes that shape the land of the coastal environment take place at a range of time-scales that ultimately change the morphology of the coastline at different rates. Waves and tides move sediment instantaneously, while large-scale morphological change may not be notable for decades or centuries. Despite their dynamic and ever-changing nature, humans have settled near coasts for millennia owing to the resources and services they provide, including the easy transport of goods across the seas and the bountiful produce that supports millions of people worldwide. However, settlement in the coastal zone is not without risk. Erosion, coastal flooding, and harsh weather conditions are often endured by those living in these areas. Therefore, sustainably managing and responding to these factors is vital if we are to continue our coastal development.Coastal protection
Responses to protect human settlements from such difficult conditions can exacerbate the problems such responses were implemented to solve or move them elsewhere. For example, “hard” methods of stabilising eroding coasts, such as the deployment of jetties or seawalls, affect sedimentation processes and wave energy, respectively. The implementation of a jetty to protect a harbour from erosion may cause sand to build up at the end of the jetty and ultimately accumulate in the harbour if it is not dredged, which can be a costly process. Similarly, seawalls are often built to protect structures from rising sea levels. However, wave energy often builds behind the wall resulting in larger, more forceful waves that defeat the wall’s purpose. It is, therefore, vital that we find methods of preserving our coastal communities and reduce the risks of coastal development, which typically increase as city expansion continues, without impacting natural geomorphological processes. In these cases, nature should not be fought. Attempting to prevent the onset of coastal change will incur increasing costs throughout the future; it makes sense to work with natural processes rather than against them.
The development of infrastructure is at risk of becoming locked into unsustainable pathways that do not consider the dynamic nature of the environment. Developers and stakeholders are likely to focus on protecting and maintaining their existing assets, which hinders expansion into more sustainable methods. Therefore, they will face the ever-increasing cost of continually responding to the extreme events that are expected to occur as the climate changes, instead of developing a resilient community that can adapt to the challenges of the future environment. This has already been observed in the use of “hard” approaches to erosion, which are short-term and, as stated above, are likely to delay or relocate the problems they were implemented to solve. These methods are expensive to implement and maintain, which, along with the environmental issues they contribute to, render them unsustainable in the long-term. There is a need to implement sustainable coastal management practices and develop adaptable and resilient communities that will be able to respond to the changing planet in an environmentally friendly manner. To do this, it is important to predict how long-term processes might affect and geomorphologically change coastal systems in the future by employing models that simulate and predict this.
Modelling the future
Models are extremely useful tools for examining processes and systems which occur over large spatial and temporal scales that we cannot directly observe. They can be used to simulate future scenarios and ultimately inform decision makers and stakeholders during investment, planning and construction; models are vital for sustainable development. Dr Payo’s work focuses on coastal system models which simulate and predict processes such as waves, tides, hydraulics and sediment conservation. He uses these models to inform investors of likely geomorphological change over the upcoming decades so that it may be considered during the development of coastal infrastructure.
Combining different types of modelling approaches may be a more prudent method of forecasting system-wide coastal change which is vital for informing developers exploring sustainable development and intervention strategies. Dr Payo’s modelling tool, CoastalME, can simulate the geomorphological change of a coastline over several decades while considering interactions between different landforms and human activity. This work is fundamental if we are to continue sustainably using the resources that coastal environments offer us without damaging and hindering natural processes.
- Payo, A. (2017). Section 5.6.3 Modelling Geomorphic systems: Coastal. In: Cook, S.J., Clarke, L.E. & Nield, J.M. (Eds.) Geomorphological Techniques (Online Edition). British Society for Geomorphology, London. ISSN: 2047-0371
- Becker P, Payo A (2013) Changing the Paradigm: A Requisite for Safe and Sustainable Coastal Societies. J. Geogr. Nat. Disast. S1: 002 doi:10.4172/2167-0587.S1-002
- Payo A, Becker P, Otto A, Vervoot J, Kingsborough A (2016) Experimental Lock-In: Characterizing Avoidable Maladaptation in Infrastructure Systems. J. Infrastruct. Syst 22(1): 02515001-4 doi:10.1061/(ASCE)IS.1943-555X.0000268
Dr Payo’s area of expertise lies in modelling geomorphic coastal change.
- Dr Michael A. Ellis, British Geological Survey
- Dr David Favis-Mortlock, Oxford University
- Prof Jim W. Hall, Oxford University
- Dr Mark Dickson, Auckland University, NZ
- Prof Ian Townend, Southampton University
- Dr Martin Hurst, Glasgow University
- Dr Andrew Barkwith, British Geological Survey
- Prof Nobuhisa Kobayahsi, Delaware University, USA
- Prof Fengyan Shi, Delaware University
Dr Andres Payo is a Coastal Geomorphologist at the British Geological Survey and specialises in quantitative geomorphology applied to coastal protection against flooding and coastal erosion at decadal and longer time scales. Using the systems of systems approach, he is interested in the use of long-term analytical capacity to avoid maladaptation of long-lived infrastructure systems.
Dr Andres Payo
British Geological Survey
Environmental Science Centre