Mapping flood risk its role in improving flood resilience in England

Transcription

1 Mapping flood risk its role in improving flood resilience in England Catherine Wright Director of Digital and Skills Flood and Coastal Risk Management Environment Agency 6 October 2017

2 The Environment Agency

3 A moment to reflect 2017 so far

4 Significant flood events / /16

5 Floods of Summer 2007

6 Our roles in flood and coastal risk management (FCRM)

7 Flood and Water Management Act FCRM roles and responsibilities in England Risk Management Authority Strategic Level Operational Level Environment Agency National Strategy, reporting and general supervision Main Rivers, Sea (flooding and erosion) Lead Local Flood Authority District Council or IDB Local Strategy, Flood Risk Management Plans and investigations Input to national and local strategies RFCCs Surface run-off, Groundwater, Coastal erosion Ordinary watercourses, Sea, Coastal erosion (with EA consent) Water and sewerage companies Input to national and local strategies, lead on company drainage strategies Flooding from surface water and foul or combined sewer systems Arrangements underpinned by duties to cooperate and share data, ability to delegate functions, and scope for Ministerial directions

8 National Flood Risk Assessment

9 Properties at risk of flooding

10 2.5 billion of Defra capital grant invested in the 6 years

11 Forecasting & warning is enabled by technology developments.

12 Flood incident management

13 How we use modelling in our work Testing options for scheme design including optimum options for climate change Prioritisation and design of all flood risk management activities Government investment planning Flood forecasting for asset operation and issue of flood warnings Public awareness and decision-making including insurance and homebuying Spatial planning Local and national emergency planning including resilience of infrastructure Supporting growth through data re-use

14 The mapping and modelling process CEH Flood Estimation Handbook

15 Local detailed models The shape of the land Survey data Hydrological model How much water Where the water will go Hydraulic model Model Outputs

16 Survey data 16

17 National modelling Looks at risk of flooding Used for prioritising and comparing across the country Asses expected economic damages High level data Approximations Uncalibrated Flood extents only (no depth)

18 Local detailed models Over 65% of the total floodplain currently covered by local detailed modelling Over 60% of properties in the floodplain covered by local detailed modelling Over 2000 models 18

19 Model scenarios Range of probabilities e.g. 1 in 5, 20, 75, 100 (based on local need) Climate Change Defended and undefended Breach

20 Forecast led, response driven 109 counties 4 sources of flooding 5 day forecasts 2180 daily forecasts

21 Real time modelling Flood forecasting models 3600 communities at flood risk Flood Forecasts at 2500 locations Wide range of models Rainfall/Runoff 4 types Routing 2 types 1d hydro-dynamic 2 types 2d hydro-dynamic only used offline Distributed grid to grid

22 Forecast led, response driven

23 Flood mapping Visualising model outputs

24 Situational awareness and data capture Incident Management Portal

25 Open Data enabling growth

26 The National Flood Resilience Review Pilot for innovative flood defence and urban development in core cities Flood risk communication Improving the resilience of local infrastructure Surface water flooding Rolling programme of longterm modelling improvements Long term (post 2021) strategy

27 Future Modelling Developments Depth full range Hazard risk to life Climate change Depth below certain threshold Flood probability - depth greater than 300mm Flood duration

28 Communicating flood risk what we have learned Public surveys Ipsos MORI % of people at risk believe it Am I at risk? 54% of them say they are not at risk When? What can I do? What are you doing? Sciencewise 2015 Use simple risk language Maps not the best way Focus on impacts and action

29 Sciencewise: public communication and engagement on risk

30

31 Digital services Am I at risk? Live Flood Warnings Flood Information Service (FIS) River and sea levels 5 day flood risk Long Term Flood Risk Information Flood Map for Planning

32 Public Flood Information Service

33 Meaningful flood risk communications Raising awareness Facilitate needs Community involvement All have a role to play

34 Growing risk

35 Flood Strategy A strategy for a flood resilient England Resistance and resilience Role of natural flood risk management Future investment

36 International working MoU with Rijkswaterstaat MoU with US Army Corps of Engineers Tri-lateral co-operation: Levee Safety Partnership European Networks Coastal engineering and science: KRING Coastal Policy: North Sea Coastal Managers Levee group under I-COLD European Dam Safety Regulators Implementing the flood directive: Working Group F Global networks Storm surge barriers: I-STORM Dams: CEATI & I-COLD Targeting specific conferences MoU with Australian Bureau of Meteorology

37 FCRM expenditure ( millions) FCRM expenditure (%GDP) International comparison FCRM expenditure FCRM Expenditure as % of GDP England France Netherlands 0,20% 0,18% 0,16% 0,14% 0,12% 0,10% 0,08% 0,06% 0,04% 0,02% 0,00% England is noted for: Flood forecasting, warning and emergency A holistic approach to FCRM - from prevention through defence and mitigation to emergency planning, response and recovery Our economic approach to FCRM

38 Flood Risk is a mosaic

39 Thank you & questions Catherine Wright Director of Digital and Skills

40 Additional Information

41 Reviews, legislation & strategy Pitt Review 2007 Flood Risk Regulations 2009 and European Flood Directive Flood and Water Management Act 2010 Flood and Coastal Erosion Risk Management Strategy for England 2011 National Flood Resilience Review 2016

42 Developing our infrastructure

43 43

44 Hydrological model 44

45 Hydraulic modelling Inflow Hydrographs Sections Inflow Hydrographs Reservoirs Downstream Boundary 45

46 Calibration and verification Comparing predicted levels to observed data Model parameters are adjusted Re-run for design flows

47 Calculating confidence in our models We describe confidence with a star rating which implies suitability at a spatial scale: 1 star (National to county) 2 stars (County to town) 3 stars (Town to street) 4 stars (Street to parcels of land) 5 stars (Property) Most local detailed models are 3* or 4*

48 Every flood is different 48