IMPRINTS Final Workshop

1. IMPRINTS Final Workshop Brussels, September 27, 2011 Marc Velasco – Researcher at CETaqua, Barcelona www.imprints-fp7.eu Flash Floods in a changing context: Importance of the impacts induced by a changing environment

2. Table of contents • Sub Project 5 • Review of current practices & past experiences • Futurescenarios • Futureriskassessment • Mitigation and adaptation • Conclusions

3. Sub project 5 FF & DF risk management and mitigation in changing environments • Review of current practices & past experiences • Creation of global change scenarios • Climate • Land-use • Forest fires • Development of a methodologies to assess the impacts future changes • Riskmapping • Rule-basedsystem • Provide guidelines for practitioners to design mitigation and adaptation measures

4. Review of current practices & past experiences • Prevention • Risk estimation • Land use regulations • Hydrometeorological forecasting systems • Integral analysis to plan protection infrastructures • Infrastructure inventory (maintenance) • Natural floodplains (water retention) • Historical FF and DF databases (learn from past) • Future changes (i.e. climate and land use) • Response • Coordination of organizations involved • Unit to monitor the post-crisis • Follow-up studies • Improve warningstransmission • Promote hydrometeorological systems • Continuous maintenance Compilation of FF & DF follow-up studies • Description of impacts • Improvements on the local risk management • Compilation of lessons learnt classified by • Prevention • Preparedness • Response • Dissemination and education • Dissemination and education • Exchange between experts • Diversify the mechanisms to disseminate • Risk culture: • sociological surveys • flood marks • hazard maps • … • Education programmes at schools • Preparedness • Review and update emergency plans (real effectiveness) • River bed maintenance • Evacuation maps • Training and plan evacuationsimulations

5. Creation of global changescenarios • Futureclimatescenarios • Extreme precipitationassessment • Futureland-use scenarios • Urbanland-use • Rural land-use • Futureforestfiresscenarios

6. Futureclimatescenarios Llobregat basin • Data used • Modelsvalidation • Temporal futuretrends • Futurespatialpatterns

7. Futureclimatescenarios Extreme precipitationassessment • Generalized Extreme Valuefunctions • Futurescenarios; periods of 30 years • High variability and uncertainty • GEV fitted to the annual maxima daily precipitation for the observations (1971-2000), the control (1971-2000) (dashed) and theclimatemodelsresults(1971-2100) (solid) showingtheminimum and maximumintensity in the Llobregat basin GEV fitted to the annual maxima daily precipitation for the control (1971-2000) and future periods simulated with SMC for the A2 scenario in the south Llobregat basin

8. Futureland-use scenarios Urbanland-use • Corinedatabase • JRC’s MOLAND model Urban land-use maps in the south Llobregat basin coming from Corine database (2000) and MOLAND A2 future scenario (2040)

9. Futureland-use scenarios Rural land-use • Eururalisproject data Llobregat 2030 A2 Llobregat 2030 B1 Llobregat 2030 B2 Llobregat 2000 Llobregat 2030 A1

10. Forestfiresscenarios Canadian DroughtCode • Dependson T and P • Validationwith actual forestfires • Dailycalculation of CDC > 400 Annual CDC computed on the Llobregat basin during the historical period. The highest value occurred in 1994 when the most significant forest fire occurred. Historicalandfuturescenarios of CDC on the Llobregat basin based on observationsand SMC climatescenarioA2 for threetimeperiods

11. Futureriskassessment Risk = Hazard x Exposure x Vulnerability Weighing function to update the hazard values for the future rainfall scenarios. Llobregat basin I – T relationship for a 24 h duration for the A2 SRES scenario, for the control period and the future scenario 2040. Low Llobregat basin, showing the flood plains for a 500 year return period event.

12. Futureriskassessment Risk = Hazard x Exposure x Vulnerability Vulnerability map for the A2 land use scenario for 2040. Urban land use in the Low Llobregat area: Urban land use from Corine 2000 (a); and A2 urban land use scenario for 2040 (b).

13. Futureriskassessment • Overlayingthethree variables and multiplyingtheweights Risk maps for the south Llobregat basin for the (a) current situation (2000), (b) future A2 – A2 scenario (2040) (c) and its difference

14. Rule based system • Forecasting system that allows to link real-time observed values with expected hazard in probabilistic terms • Simplification of a hydrological model with shorter lead times • Operational use: issue warnings • Considering high percentiles to represent extreme events • Governing variables for FF • Antecedent soil moisture • Forecasted rainfall

15. Rule based system • Anoia basin • Ocurrence • Moderate increase • Two exceptions • Intensity • Generalized increase • Even for the exceptions GP distribution fitted to the POT discharge values of the Anoia sub-basin for the control (1980-2009) and future periods for the A2 (left) and B1 (right) scenarios. Time series of the discharge values in the Anoia sub-basin.

16. Mitigation and adaptation • Importantchangesmayoccur, butuncertainties are high and difficulttoassess • Change of paradigmmust be done: • From «FightingagainstFloods» to «Living withfloods»

17. Mitigation and adaptation • Implementation of EC FloodsDirective and development of FRMP is crucial • Promotingcommunication and creating a risk culture • Implementing non-structuralmeasures, which are robust and win-win • Earlywarningsystems • SUDS • Local mitigationstrategies (involvingthepopulation) • Etc.

18. Conclusions • Climate projections strongly depend on models • Need for further research • Regionalized models are crucial • High variability and uncertainties • Present everywhere • Specially for extremes • Use results with care • Mitigation and adaptation • Implementation of EC Floods Directive is crucial • Change of paradigm is needed • Non-structural measures must be used

19. Marc Velasco mvelasco@cetaqua.comÀngels Cabello acabello@cetaqua.com http://imprints-fp7.eu/