1 Infrastructure-threatening heavy precipitation in the Mediterranean region under climate change conditions MedCLIVAR Athens September 2016 Katrin Nissen and Uwe Ulbrich Institute of Meteorology Freie Universität Berlin www.rain-project.eu This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 608166. The contents of this presentation are the author's views. The European Union is not liable for any use that may be made of the information contained therein.

Heavy Precipitation The RAIN Project Risk Analysis of Infrastructure Networks in response to extreme weather Heavy Precipitation

Which thresholds are relevant? Regulations for drainage systems Stakeholder inteviews 50-100 mm/day 20-30 mm/hour 2, 5,10, 50, 100 year return period 10-year return values amount intensity

Example for impacts High Amounts High Intensities Greece, October 2015 Small-scale convective event Berlin August 2013 Diario de Mallorca Greece, October 2015 Andravida:135 mm/ 24 hours Spain, Mallorca, October 2013 Galilea: 65mm/35min

Data Present day: Climate change: E-OBS gridded observational ERA-Int downscaled by EURO-CORDEX regional models Climate change: EURO-CORDEX 0.11° (~12 km) Scenario RCP 8.5 DRIVING GCM RCA4 RACMO22E CCLM4-8-17 HIRHAM5 WRF331F MPI-ESM day, 3 hour   day EC-EARTH HADGEM2  day, 3 hour  day CM5A-MR CM5 daily: 13 simulations 3-hourly: 7 simulations

Thresholds 10-year return value (present day) Obs/Reana Multi-model ensemble mean mm/day mm/3hours 24-hour (high amounts) 3-hour (high intensities)

Identification of events Identification of areas in which the 10-year return value is exceeded Tracking in time and space Information on: Duration Size Severity (duration,size and amount) Example: August 2002 5 days 185000 km2 Severity 99th percentile Aug 9 Aug 10 Aug 11 Aug 12 Aug 13 [mm]

Climate change signal 8 high amounts high intensities (1, 2 or 3 day 10-year return value exceeded) high intensities (3-hour 10-year return value exceeded) Difference in number of events between 1971-2000 and RCP8.5 scenario 2071-2100

Climate change signal

Climate change signal annual cycle high amounts high intensities

Climate change signal size high amounts high intensities

Conclusions high amounts decrease (summer) increase increase (summer) (winter) number of events increase size Iberia Italy Greece East Med high intensities increase (winter) increase (winter) increase (winter) decrease (winter) number of events increase increase increase increase size Iberia Italy Greece East Med Risk of infrastructure failures due to heavy precipitation is predicted to increase in many Mediterranean regions. A decrease is found for the Eastern Mediterranean and Africa.

Report: http://rain-project.eu/about/deliverables/ Data: https://data.4tu.nl/repository/collection: ab70dbf9-ac4f-40a7-9859-9552d38fdccd