Defining coastal storms

Dr Mitchell Harley (right) supervising a beach surveyWRL’s Dr Mitchell Harley is an expert in coastal storms. Predicting last years east coast low that destroyed houses at Collaroy eight days before it hit, he was also one of the first to document the damage as it was occurring.

Recently Mitch has contributed to a new book (“Coastal Storms: Processes and Impacts”, edited by Paolo Ciavola and Giovanni Coco) that includes a chapter covering the issue of defining what is classified as a ‘coastal storm’. 

Give us a general overview of what we can find in the book:

“The book is aimed at the undergraduate student level and provides a first-of-its-kind detailed overview of the processes and impacts related to coastal storms. It consists of 13 chapters addressing various aspects of coastal storms, from the detailed hydrodynamics and sediment transport that occurs during coastal storm conditions, coastal storm impacts in coastal environments such as coral reefs, tidal flats, barrier islands and cliffed coastlines, numerical modelling of coastal storms as well as state-of-the-art techniques to manage and minimise coastal storm risk. Some 30 researchers contributed to the book from research institutions in Europe, the USA as well as Australia.”

Coastal Storms: Processes and ImpactsWhat was your contribution to the book?

“My contribution was to write the first chapter on defining exactly what a coastal storm is – and hence lay the platform for the remainder of the book. It turns out that when investigating definitions of coastal storms I found out that no single broad definition previously existed – and in fact the term was often misused. So my role was to specifically articulate what it means when we refer to a coastal storm, to encompass both the most impressive examples of severe tropical cyclones striking the coast, as well as the less-dramatic coastal storms such as small wind waves breaking on extremely sheltered coastlines.”

What got you interested in studying coastal storms?

“I have always been interested in the dynamic nature of the environment that surrounds us and coastal storms are one of the most extreme examples of that. My grandma used to live on the beachfront at Narrabeen in the early 1970s and she still remembers to this day the fear of the whole building shaking during the 1974 storms, as wave after wave progressively stripped the sand from underneath the building. Until last year, it was difficult to imagine storms of such destructive capability occurring on our coastline, as most days the beach is relatively wide and waves break far offshore. What last year’s east coast low really brought home was that it only takes a couple of days for the beach to go from a healthy state with lots of sand on it, to houses almost falling in the water. It also highlighted that there is plenty more work to be done if we are to manage the coast in a sustainable way – and that’s what keeps me interested.”

What are your research goals?

“Ultimately my research goals are to see the latest knowledge about coastal storms and management of coastal storm risk being translated into practical outcomes for society. Often in the field of coastal engineering the solutions are there, but, for one reason or another, the societal or political willpower is not. At the WRL we have been particularly keen on communicating and sharing our research with the public, in the hope that people can learn more about and appreciate the dynamic nature of the coast. We now have a website ( that allows anybody to browse our latest beach measurements as soon as we come back from the field, which I think is a great initiative.”

What advice would you give to prospective civil or environmental engineers interested in coastal engineering?

“Be passionate about the things that interest you and surround yourself with people that inspire you. These days with social media platforms like Twitter and Facebook, at a single mouse click you can get direct access to leading coastal researchers from all around the world and find out what they are up to. Every day I am amazed and inspired by what creative solutions people are coming up with and I try to learn from them in some way. Plus the wonderful thing about the coast is that it is in a constant state of change, so you are always learning something new.”