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