Ινστιτούτο Μεσογειακών Σπουδών
Past and projected climate change impacts on rainfall erosivity: Advancing our knowledge for the eastern Mediterranean island of Crete0341-8162

Grillakis, M. G., Polykretis, C., & Alexakis, D. D. (2020). Past and projected climate change impacts on rainfall erosivity: Advancing our knowledge for the eastern Mediterranean island of Crete. Catena, 193 doi:10.1016/j.catena.2020.104625

Soil erosion constitutes an increasing thread for soil productivity and food security. Projected changes in Eastern Mediterranean rainfall regime show less but more intense rainfall events that are expected to affect the soil erosion processes. Research on the field has shown that the accurate estimation of rainfall erosivity dependents on the temporal resolution of rainfall data. Nonetheless, the scarcity of high frequency rainfall recordings, leads to the development of methodologies exploiting lower frequency data. This work aims to fill the gap of a rainfall erosivity formula that exploits the daily timescale rainfall data for the island of Crete at Eastern Mediterranean. An unprecedented daily and a sub-hourly rainfall station networks were used to calibrate and validate the formula. The calibrated formula is used along with the future climate projections, to estimate the potential future changes rainfall erosivity under three climate scenarios. Results for the future projections show moderate changes in the rainfall erosivity in the near future for all the assessed scenarios, with the Representative Concentration Pathway (RCP) 2.6 to project the largest change with increased erosivity. Even larger and of different direction are the changes projected for the far future and especially for the RCP2.6 and RCP8.5, with the former to show further increase while the latter a significant decrease in the rainfall erosivity. Attribution analysis shows that those changes are driven by the combination of the reduction in the number of the erosive events with a simultaneous increase in the events’ intensity in all cases, but of different magnitudes which define the final sign of change in the rainfall erosivity. Finally, this study provides evidence that rainfall erosivity in Crete is higher comparing to previous studies’ findings, yet, close to literature values that focus on the central and Eastern Mediterranean region.

doi:10.1016/j.catena.2020.104625