Post on 25-Dec-2015
transcript
Coastal vulnerability assessments for England and Wales:
the National Coastal Erosion Risk Mapping Project (NCERM)
Coastal Groups
Key drivers for better assessment:
Shoreline Management Plans and spatial planning (1995 ongoing): 100 year horizons
‘Making Space for Water’ Government Strategy (2005): adaptation and public awareness
Environment Agency ‘strategic overview of all flood and coastal risk management (2008): gaps in national assessment
National Coastal Erosion Risk Mapping
Web-based tool to complement Environment Agency Flood Map‘Comparison Report’ to highlight differences with Shoreline Management PlansHigh level statistics for local authorities
A staged approach
Stage 1 – FD2324 RACE R&D Project [April 2006]
Stage 2 – Inception Phase [July 2006]
Stage 3 – Create Baseline Position (Software and Data) [June 2007]
Stage 4 – First National Runs [December 2007]
Stage 5 – Local Validation [2009-2010]
Stage 6 – Finalise Data [current]
Stage 7 – National Coastal Erosion Risk Mapping tool [September 2011]
Coastal Groups
Risk Assessment of Coastal Erosion (RACE) Defra project FD2324
Source: techniques for assessing unconstrained erosion and defence failure
Pathway: brings these together to establish probability within confidence bands
Receptor: analysis of socio-economic/ecological consequences
Risk Assessment of Coastal Erosion (RACE) Defra project FD2324
Judgement
Probabilistic Models
Variety of outputs, but these are only as good as the data validation and resolution
Risk Assessment of Coastal Erosion (RACE) Defra project FD2324
Robust and consistent approach;
Designed for high spatial resolution, but able to aggregate local results to inform high level assessments;
Addresses 20, 50 and 100 year horizons;
Limited to erosion but complements tools used for flood risk assessment in England and Wales;
Assesses erosion of backshore landform but may be developed further to incorporate foreshore impacts
Risk assessment combines hazard and impacts;
Risk Assessment of Coastal Erosion (RACE) Defra project FD2324
Can be reviewed in the context of SMPs to accommodate effects of adaptive responses;Inputs can range from qualitative assessments to probabilistic models and a range of assumptions/scenarios can be tested;Considers climate change through sensitivity testingAssesses uncertainties such as erosion ‘catch up’ after defence failure.Hierarchy of analytical methods allows proportionality of assessment according to risk, scale and data availability;
Stage 2: Inception and consultation
End-User ConsultationInitial best estimate of erosion rates
Editing and review at local level
Developing a web-based interface for testing
Coastal Groups
Stage 3: Create baseline position
Spatial DataOS MasterMapAerial Photography (EA Twerton)
Recession DataFuturecoast
Defence DataNational Flood & Coastal Defence DatabaseBespoke LA Data
Key Statistics produced6,256km of coastline (England and Wales)
• 2,900km (46%) at risk from erosion• 2,354km undefended• 546km defended
Coastal Groups
Stage 4: First national runs
First National Coastal Erosion ‘Maps’ using two scenarios
• No Defences• No Active Intervention
National Data LimitationsDefence Data
• 39% defended coastline could not produce any results
Recession Data• Futurecoast was a high-level study
Spatial Data• National aerial photography dataset out of
date
Coastal Groups
Stage 5: local validation
Local Validation #2Validate initial coastline position
Validate defence data
Validate recession information
Re-run RACE Model
View indicative results
Provide feedback
Coastal Groups
Stage 5 cont’d: local validation tool
Stage 6: Final validationTo ensure local authority officers are satisfied with the accuracy of final outputsFacilitated by local authority ‘champions’ and Environment Agency regional project leads
Final outputs will be released from September 2011, starting with two ‘pilot Shoreline Management Plan areas in the NE and south.
Coastal Groups
How do we show the risk from erosion?PROFESSIONAL PRODUCTS:
2 scenarios within the GISNo Active Intervention ‘baseline’ scenarioSMP2 policies factored in
Erosion predictions for 3 epochs:0 – 20 years20 – 50 years50 – 100 years
3 confidence bands for each epoch5%50%95%
Coastal Groups
PUBLIC-FACING INFORMATION:
1 scenario displayedSMP2 policies factored in
Erosion predictions for 1 epoch:0 – 20 years
Upper and lower percentile confidence limits quoted as a range
5%95%
Fundamental disagreement
Zoomed out is more representative of the level of confidence in the data
The professionals recommend..... What the public want.....
Zoomed in the only thing they felt was useful. They’re not interested in regional abstractions, but want to know about their house.
Coastal Groups
Coastal Groups
Complex information
Epochs
Range of erosion rates / confidence bands
ScenariosUnrealistic impression of certainty
Doesn’t reflect what really happens
Interactive web tool chosen instead…
Concerns about existing presentation
NOTE: dummy data only. This is a test example for presentation purposes only and is likely to change prior to publication
NOTE: dummy data only. This is a test example for presentation purposes only and is likely to change prior to publication
“We are improving our understanding of coastal erosion using local knowledge and the best available science, and raising awareness now, so that we can all adapt together to our changing coast…”
Coastal Groups