Modelling the potential impact of climate change on a shallow coastal aquifer in northern Scotland

The potential impact of climate change on a freshwater wetland in a coastal dune system at St. Fergus, north-east Scotland, was assessed using hydrogeological modelling techniques. A range of climate change scenarios were input into a numerical model (MODFLOW) that had been calibrated for the site using contemporary field data. The combination of parameter and hydrogeological uncertainty in models, together with uncertainty over likely site-specific climate change in the future, dictates that such modelling studies are often inconclusive. Nevertheless, a range of scenarios was forecast which indicates that future average recharge and flooding of the wetland is likely to fall within the range of interannual variation observed at the site, regardless of whether recharge increases or decreases. It is therefore likely that any resulting ecological impacts will be limited and reflect subtle hydrological changes that will affect different species in different ways. The utility of such a modelling approach is in providing environmental managers with a range of likely scenarios that can be incorporated into future management plans and policies to maximize flexibility of response.