NatureScot Research Report 1228 - Anticipating and mitigating projected climate-driven increases in extreme drought in Scotland, 2021-2040
This study shows that a clear increase in extreme drought risk in Scotland is likely in the imminent future. Using modelled temperature and precipitation data and a drought index, changes in extreme drought were calculated for the near future (2021-2040) in comparison to a baseline period (1981-2001). The results showed increases in both the number and length of extreme drought events in the near future. These changes were then mapped to highlight areas and seasons with the greatest projected change, enabling identification of 'hotspot' areas that may be at most risk. These results can be used to direct mitigation and management actions to these areas, enabling pre-emption of drought damage and facilitating improved resilience to extreme weather events.
This resport concludes with the following main findings:
- Increases in extreme drought are likely throughout the country; extreme drought increases were projected in all cells on a 12km grid across Scotland;
- Extreme droughts are likely to become more common; the number of extreme drought events was projected to increase from an average of one event every 20 years in the baseline period, to one event every 3 years in the near future (2021-2040);
- Extreme droughts are likely to be longer; typical drought events were projected to be up to 2-3 months longer than during the baseline period, with an average of 11 extra drought months per decade;
- Increases are likely to be felt most in autumn, with increases of up to 9.5 months across all autumns in the next 20 years, while spring showed the lowest increases of up to 5.5 months;
- Increases are likely to be highest in the east, particularly in the Borders, Grampian, Caithness, Orkney, and Shetland, while the increases along the west coast and in the Western Isles were projected to be lower;
- These increases are likely to interact with other climate-driven changes and anthropogenic pressures, creating feedback loops that can negatively impact built and ecological environments.