Severe storms in the Atlantic can cause a tsunami-like wave that funnels into the Firth of Clyde, and when this coincides with high tides it leads to severe coastal flooding, according to a study by mathematicians at the University of Strathclyde.
The researchers produced a computer simulation of storm surges in the sea level which have played a role in floods in recent years, including those during the hurricane which swept Scotland in December 2011.
The results are the fullest analysis so far of surge waves in the Clyde and could be used to forecast future flooding threats.
Professor Mike Heath, of Strathclyde's Department of Mathematics & Statistics, was a partner in the research. He said: "Storm surges are an abnormal increase of water levels in response to extreme weather. They have the capacity to cause damaging flooding in coastal areas, especially when they coincide with high spring tides.
"The location and geography of the Firth of Clyde make it an area with high flooding risk. In this research, we used a three-dimensional hydrodynamic model to simulate sea-level surges in the Clyde during storms; our findings suggest that the highest risk of flooding occurs when intense Atlantic storms travelling in a particular way around the northwest of Scotland coincide with high spring tides.
"The water level in the inner areas of the Clyde is also enhanced by a 'funnelling' effect, due to the narrowing of the estuary and sea lochs as the surge wave moves inland."
"The storms with the highest water levels usually followed a similar pattern, with intense low atmospheric pressure from the Atlantic moving quickly northwest off the west coast of Scotland."
The study examined three storm surge incidents in December 2011 – a particularly severe storm on the 8th-9th of the month, and others on 13th and 28th.
The research was carried out by Alessandro Sabatino, a Research Student in Strathclyde's Department of Mathematics & Statistics. It also involved researchers from Marine Scotland Science.
The research has been published in the journal Natural Hazards (doi: 10.1007/s11069-016-2506-7).