Vulnerabilities

In cold regions, soil frost is a key indicator of urban flooding. The frozen soil inhibits infiltration of rain or snowmelt, increasing the risk of urban flooding. The most severe urban flood events in Reykjavík in the past were associated with the co-action of rain, snow, and soil frost (1).

Trends in soil frost formation and the impacts on urban flood risk under climate change were assessed for Reykjavík over the last 70 years (1994-2018). The assessment, based on observations and model results, shows that the rise in air temperatures and liquid precipitation in winter due to climate change has resulted in a significant reduction in frost depth over the last 70 years. However, soil frost is not becoming a less relevant driver for urban flooding. The timing of maximum frost depth has also shifted, and this moment now coincides with the largest events of rain-on-snow and snowmelt in the months of January–March. Urban flood risk, therefore, seems to be increasing despite the reduction in frost depth (2).

References

The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Iceland.

1. Andradóttir et al. (2021), in: Zaqout et al. (2023)
2. Zaqout et al. (2023)