Assessing Tidal Flood Risk in Ireland: Modelling, Mapping & Forecasting Coastal and Tidal Flood Risk for Irish APSFRs

Transcription

1 Assessing Tidal Flood Risk in Ireland: Modelling, Mapping & Forecasting Coastal and Tidal Flood Risk for Irish APSFRs Dr. John Martin C.Eng. OPW Flood Risk Assessment & Management Section, Ireland WG-F 17 Madrid, Wednesday, 21 st October 2015

2 Overview [1] History of Coastal Flooding in Ireland [2] ICPSS Mapping & PFRA [3] CFRAM Tide-plus-Surge Modelling & Mapping [4] CFRAM Wave-overtopping Modelling & Mapping [5] Irish Surge Forecasting Tool

3 History of Coastal Flooding in Ireland DUNDALK GALWAY DUBLIN LIMERICK CORK WATERFORD

4 History of Coastal Flooding in Ireland Cork, 1965 Dublin, November 2002 Cork and South Coast, October 2004 Dublin, Cork, Limerick, Galway, etc. Jan/Feb 2014

5 History of Coastal Flooding in Ireland Cork City, February 2014

6 History of Coastal Flooding in Ireland Limerick, February 2014

7 History of Coastal Flooding in Ireland Limerick, February 2014

8 History of Coastal Flooding in Ireland Dublin, January 2014 ( (c) Irish Times)

9 History of Coastal Flooding in Ireland Dublin, January 2014 ( (c) Irish Times)

10 ICPSS & PFRA ICPSS originally commissioned by the Department of Marine & Natural Resources as part of their coastal protection function and because the allocation of annual CP funding to local authorities required a more strategic approach. Phase 1 of the study, comprising a general overview of coastal protection in Ireland and internationally, commenced in 2003 with a draft report issued in October 2004

11 ICPSS & PFRA Following a review of the Phase 1 report it was decided to structure the subsequent elements of the project into a series of 9 primary work packages. Following transfer of responsibility for coastal flooding and coastal protection to OPW in January 2009 this project is now being managed by OPW.

12 ICPSS & PFRA - OUTPUTS Predicted Extreme Sea Levels for Combined Tide & Surge, 0.1%, 0.5% AEP Coastal Flood Hazard Extent Maps 0.1% AEP & 0.5% AEP Coastal Flood Hazard Depth Maps 0.5% AEP Coastal Erosion Hazard Maps, 2050 & 2030 Confidence Mapping for above Flood & Erosion Maps Future Scenario Coastal Flood Hazard Maps 0.5% AEP Reports Incorporating the above

13 ICPSS & PFRA

14 Coastal Flood Hazard Extent & Depth Maps Flood Hazard Extent Maps for 0.1% and 0.5% AEP events Flood Hazard Extent Maps for other AEP events Flood Hazard Depth Maps for 0.5% AEP events Flood Extent Map (Undefended, Current Scenario) Flood Depth Map (Undefended, Current Scenario)

15 ICPSS & PFRA

16 ICPSS & PFRA

17 ICPSS & PFRA One in three of Ireland's APSFRs are Coastal Flood Risk Areas (90/300)

18 Tide-plus-Surge Modelling/Mapping Carried out as part of the national Catchmentbased Flood Risk Assessment & Management (CFRAM) Programme Uses extreme tide-plus-surge water levels, and associated tide signals, to feed hydrodynamic modelling of inland tidal/coastal flood propagation

19 Tide-plus-Surge Modelling/Mapping

20 Wave-overtopping Modelling/Mapping

21 Wave-overtopping Modelling/Mapping For certain selected coastal and estuary reaches where wave overtopping of coastal flood defences (either manmade or natural) is considered to be a potentially significant flood risk Based on wave data, in the form of a joint probability analysis This data is in the form of tables including up to six combinations of predicted spectral significant wave heights ( Hmo ), mean wave periods ( Tm ) and extreme coastal water level.

22 Wave-overtopping Modelling/Mapping

23 Wave-overtopping Modelling/Mapping

24 Wave-overtopping Modelling/Mapping

25 Wave-overtopping Modelling/Mapping

26 Wave-overtopping Modelling/Mapping

27 Irish Storm Surge Forecasting Service

28 Irish Storm Surge Forecasting Service Development of Surge Prediction Model The ICPSS has developed storm surge prediction models and capability for the coast of Ireland (Irish Sea Tidal Surge Model, a Mike 21 flexible mesh model) Development of Coastal Flood Forecasting System OPW in conjunction with Met Éireann, is undertaking trials of a storm surge forecasting system with a view to evaluating and improving its capability. Irish Sea Tidal Surge Model

29 Irish Storm Surge Forecasting Service Available in the Autumn / Winter period (Sept. to April) Provides surge, astronomical tide and total water level time series prediction approximately 65 hours in advance Low resolution forecast at 15 locations around the coastline High resolution forecast in Galway Bay, Cork Harbour, Wexford Harbour and Dundalk Bay Forecasts are provided twice daily via a password protected project website Currently accessible to the OPW, coastal LAs, Irish Coast Guard, Met Éireann and the ESB Jan/Feb 2014 Excellent Accuracy

30 THANK YOU CFRAM.ie Dr. John Martin C.Eng. OPW Flood Risk Assessment & Management Section, Ireland WG-F 17 Madrid, Wednesday, 23 rd October 2015