This study investigated potential inputs from the land area of the Isle or Arran that may impact coastal water quality around the island, identifying areas for further work to improve understanding about diffuse inputs from the land.
The research applied a modelling approach using the Sensitive Catchment Integrated Mapping Analysis Platform (SCIMAP) model, combined with the input of experts and external data sets, to produce predictive maps of in-stream fine sediment risk from catchment areas of Arran; fine sediment being modelled as a proxy measure for potential diffuse pollution inputs from the land. Local expert knowledge was used to explore and discuss the predicted model outputs and whether they fitted with what people had experienced in practice.
SCIMAP outputs predicted the north of the island and coastal zones in the south to be potentially higher risk areas, the likely reasons for this being identified as the erosion risk linked to the geology of the north and extreme elevation change along much of the coast in the south. The model predicted forestry to be of low risk, but this was contradicted by most of the experts consulted who stated that felling and other activities would contribute to fine sediment pollution. As such fine sediment pollution in areas of forestry operations was identified as something that would benefit from further investigation. Agricultural and peatland areas were also identified as being areas of potentially higher risk for in-stream fine sediment inputs and would also benefit from further work to better understand the actual inputs from catchments where these occur.
This study is the first time such an assessment of fine sediment risk across the entirety of the land area of Arran has been undertaken. It provides a informative starting point for further work on potential diffuse inputs from land to the sea area around the island and potential impacts of land activities on coastal water quality.
Last Updated on 8th October 2025