Interactive Maps for Managing Asset Flood Risk Across ManchesterAnneka Lowis BSc, MSc - JBA Consulting
Dr Barry Hankin BSc, FCIWEM, C.WEM - JBA Consulting Dr Tariq M Ziad, BSc, MSc, PhD, CEng, MICE – MCCEsther Goodship BSc, MRes, C.WEM, CSci, CEnv, MCIWEM - MCC
• Section 21 of the Flood and Water Management Act 2010
• Lead Local Flood Authority (LLFA) duty to establish and maintain
– A register of structures that are likely to have a significant effect on flood risk
– A record of information about each of those structures or features, including information about ownership and state of repair
Background
• Create a Flood Risk Asset Register
– Location and type of asset and watercourse
– Details on asset condition to be populated by LLFA
• Enable the LLFA to prioritise maintenance
– Quantify properties and infrastructure at risk
– Spatially differentiate and visualise flood risk
– Provide an understanding of the relative risks from asset blockage across the city
Aims
InteractiveMaps
Flood Hazard Grids
Methodology
ImpactAnalysis
Asset Register
Existing Records• Spreadsheet• Paper records• GIS layers
Records Combined• Duplicates consolidated• Location and Type recorded• Unique ID
Asset Register• 960 assets• 463 assessed for flood risk
Intersecting GIS Layers
• Roads• Railways, Metro• Watercourse
Creation of Asset Register
0
2
4
6
8
10
12
14
16
0 2 4 6 8 10 12
Time (hrs)
Flow
m3 /s
Q5
Q30
Q100
Q200
Q1000
• 463 assets• 5 return periods
Hydrology
• Depth• Hazar
d• Velocit
y
Flood Grids• 6945 (463 * 5 * 3)• GIS format
JFLOW+• Rapid 2D overland flood model• 100% blocked scenario• Unblocked or partial blockage
scenarios in future work
Flood Modelling
Receptors• National Receptor Dataset (NRD)• Residential• Non Residential Ground
Floor• Key Infrastructure• Roads, Railways, Metrolink • Detailed Count
• Damages• Lengths
Metrics
Frism• JBA’s ArcGIS based impact
analysis software• Batch consequence analysis• Flood metrics calculated for each
asset and return period modelled
Damages• NRD property type• Depth within property
footprint• MCM depth damage curve• Floor area
Impact Analysis
Impact Analysis• Results for 463 assets• Hazard data• Receptor data
Excel spreadsheet• Asset details• Hydrology• Metric information• Ranked
Impact Analysis
Geodatabase
• Feature Class per scenario
• Feature per asset• Attribute per Metric
Challenge
• Clearly present asset blockage data
– 463 independent assets
– Flood Hazard grids
– Impact analysis
• Viewable to non technical users without GIS software
Solution
• Suite of interactive PDFs
– Individual asset report containing flood maps and impact analysis tables
– Overview maps summarising information at the ward level
– Interlinked PDFs
• Viewable to non technical users without GIS software
Interactive Maps
Map Package
• Multipage PDF• Depth, Hazard, Velocity• 5 return periods
Data• Asset
information• Flood grids• Receptors• Impact analysis
Automated Mapping• Data driven pages
(ArcGIS)• Python scripting• One map package
per asset modelled(463)
Asset Map Package
Data• Asset
information• Flood grids• Receptors• Impact analysis
Data• Asset information• Flood grids• Receptors• Impact analysis
Data• Asset information• Flood grids• Receptors• Impact analysis
Data• Asset information• Flood grids• Receptors• Impact analysis
Asset Map Package
Overview Map
• Coloured by number of assets
Interactive Maps• Easy to navigate• Drill down detail
Linked to Ward Map
Linked to
Asset
package
Interactive Overview Maps
Ward Map
• Spatial relationship
• Coloured by impact
• Appreciation of risk for each asset
13
Map Animation
• Benefit calculations– Unblocked or partial blockage modelling
– Annual Average damages
– Benefit of culvert maintenance
• Increase interactivity of individual PDFs
– Dropdowns to allow users to switch between depth, hazard and velocity grids
• Advantages: Reduce file sizes
• Disadvantages: Increasing complexity
Further Work
16
Map Animation
• GIS techniques have been used to visualise local flood risk from bridge and culvert assets– GIS automation and python scripting has streamlined the process of
generating interactive risk maps from large quantities of data
– Repeatable operation
• Maps viewable by those without GIS software
– Easy to disseminate and print
– Provides an understanding of the relative flood risk from asset blockage around the City
– Allows asset maintenance to be prioritised
Conclusions and Outcomes
• Creation of Manchester City Council’s Flood Risk Asset Register
• Satisfies their requirements under the Flood and Water Management Act 2010
– Asset location
– Understanding of asset risk
– Visualisation of local flood risk
– Prioritisation for flood risk management and maintenance
– Accessible outputs
Conclusions and Outcomes