Scientists at the James Hutton Institute have welcomed the announcement made by the Scottish Government of an action plan worth £235 million to protect 10,000 properties from flooding in Scotland.
However, research leader on Managing Catchments and Coasts at the Institute, Dr Marc Stutter, argues that a wider understanding of how catchments function is needed for well-planned and proportionate flood management whilst delivering multiple benefits.
"Approaches for flooding prevention and adaptation should be widespread across rural and urban areas. Simple designs, working with natural processes can be achieved cost-effectively and should be combined with bigger traditional schemes to give lasting resilience against climate extremes; neither should be considered alone, they are hugely complementary," Dr Stutter said.
Describing how the waters of the Dee caused devastation in Aberdeenshire and Aberdeen prior to New Year’s day, Dr Stutter commented: "The floods were triggered by a ‘perfect storm’ of three circumstances coinciding: moderate but intense rainfall from Storm Frank in the upper Dee, rain and rising temperature causing a pulse of mountain snowmelt, and importantly, already saturated soils. The ensuing flood wave that started at Braemar at 9 am and arrived at Aberdeen at 9 pm appears to have been the biggest in living memory. Our initial assessment shows that the rainfall following Storm Frank was even more extreme in parts of Aberdeenshire." The first week of 2016 showed 254 mm rainfall near Fettercairn and 165 mm at Tarland; amounts that had lead to further flooding.
Common to both has been the extreme soil wetness that has been unprecedented over recent years, Dr Stutter added. "Waterlogged soils quite simply mean that rainfall has nowhere to go, leading to the delivery of large volumes of water from all across the landscape. This water volume in the Dee surprised communities as to where flooding occurred when history suggested they were safe. The side effects of fast and energetic waters, in terms of valuable soil eroded and the resulting debris left on floodplain farmland, have also left long term damage. Inevitably these circumstances will coincide again to some degree. Hence, building in appropriate water holding capacity to our wider landscapes will counteract storage lost at times of high soil wetness and back up traditional approaches of flood defence. We are also developing observations of soil wetness for more dynamic future approaches for flood risk assessment."
Now that the waters are receding, Dr Stutter argues it is time to maintain the pressure for action right through the next year and think seriously about joined up actions to rethink our landscapes to deliver multiple benefits.
"Although the recent flooding has been extreme there are a range of actions we can take to help mitigate and adapt. Giving space for our rivers implies that floodplains be re-considered as active areas of natural rivers and not distinct and to be isolated from the channel. Floodplain farming should continue but should adapt practices for rapid provision of temporary water storage. Inevitably, dredging and flood banks protect locally but push problems on to those downstream. Hastening on the flow of water should be saved for our most critical urban areas, power and emergency services infrastructure.
"The long term message needs to be about slowing and holding water in landscapes, adapting and changing our practices in connected rural and urban systems. If one thing is apparent it’s that the climate brings extremes; we need to build resilience in our landscapes to counter these extremes and make the debate on flooding and water management more consistent and less like a seasonal deluge."