gis based method to analyse vulnerability of transportation infrastructure

Centre for Transport Studies GIS-based method to analyse vulnerability of transportation infrastructure

HAO YE

DR PANAGIOTIS ANGELOUDIS

PROFESSOR JOHN POLAK

IMPERIAL COLLEGE LONDON | DEPARTMENT OF CIVIL & ENVIRONMENTAL ENGINEERING | CENTRE FOR TRANSPORT STUDIES


Outline

Project Background

Infrastructure Vulnerability Analysis

Current Works and Progress

Future Work Plan


Project Background

Motivation: extreme events due to climate change, e.g. flooding, have caught the attention of insurance market, and there has been insufficient knowledge of potential damage risk due to inadequate capacity of current catastrophe models.

Open Access Catastrophe Model (OASIS), funded by European Climate-KIC and insurance sector, aims to develop open source catastrophe models to improve the climate change adaptation of critical infrastructure. These models will be adopted to assess the risk exposure of infrastructure and develop insurance business.

Damage Function

HazardFinancial Module

Asset Service

Insurance Price

OASIS project work flow chart


Vulnerability Model sub-project: explore the impact of climate change to transportation infrastructure networks, and develop models and software tools for predicting the quantitative impacts on the services provided by the networks.

The Role of CTS in OASIS

Transport Vulnerability Module

CTS


Network Interdependency

Transportation network – critical infrastructure supporting the movement of people and goods. It is also the primary conduit for rescue, recovery and reconstruction in disasters (Anna, 2011)

Infrastructure network interdependency, picture sourced from Huang et al, 2011


Cascading Effect

Flooding

As-planned status of network system Perturbed status

Cascading effect – unforeseen chain action, failure of a part of a system can trigger the failure of successive part due to component interaction


Transportation Infrastructure Network

Why the prediction of cascading effect for transportation network is more difficult than other networks?

• Multiple infrastructures interaction (e.g. roads, airport, seaport, railway, etc.)

• Massive network database (e.g. up to thousands of road links for a small area)

• Heterogeneity of network (e.g. the important degree of network units)

• The complex of traffic flow theory (e.g. the change of driver’s behaviour)

• The complex of traffic demand theory (e.g. the change of trip demand)

• And anything more ?…

IMPERIAL COLLEGE LONDON | DEPARTMENT OF CIVIL & ENVIRONMENTAL ENGINEERING | CENTRE FOR TRANSPORT

STUDIES

Our Efforts – Model development

Storm surge

Flooding

Rainfall

Hazard Infrastructure

Vulnerability Assessment

Hazard module

Catastrophe Vulnerability

Model

Catastrophe model analysis for transport infrastructure?

+ Infrastructure module + Vulnerability module


Current Work and Progress

Hazard Module• Explore the application of hydraulic models to generate high-precision raster-based

flooding hazard maps at Bogota in Columbia• Cooperate with Hydraulic Modelling Team at ICL

Infrastructure Module• Develop network representation for road topological infrastructure

• Develop rules for describing the property of traffic network/units, e.g. capacity of road links, the behaviour of traffic flow

• Data collection and potential cooperation with Transport Team at Bogota

Vulnerability Module• Develop mathematical models to describe the degradation of interdependent failure

(e.g. Input-Output Model, or other potential models in future)

• Work on the development of software for interdependent system design (Asty)

• GIS extensions for analysing interdependency network (Oasis)


Hazard Module

Adopt GIS to model temporal and spatial characteristics of extreme weather events e.g. the coverage of flooding

Model input: local weather data, Digital Elevation Model (DEM), Hydraulic model

model output: inundation depth, water velocity, angle of attack, etc.

Flooding Damage Functions: compute the physical damage based on the relationship between flooding parameters and infrastructure properties

An example of hydraulic watershed hazard maps (Data source: SSG-Surfer)


Infrastructure Module Transportation network representation

• Extracted vector data from Open Street Map (OSM)

Need to be simplified to suite computational demand• Junctions (nodes) and road segments (links)• Other Network simplification rules (e.g. directed road, road turns)

A simplified sample of network and Bogota transport network


Infrastructure Module – OD trip assignment

Distribute Origin-Destination (OD) trip data on simplified road network to implement trip prediction

Proximity assignment approach• be widely used by past studies, but might be potentially adapted

A result of OD assignment based on proximity approach

OD trip nodes

Infrastructure network node


Transport Model – Link Importance

The capability of road link is potential related to:• Link distance• Link free flow speed • Link capacity and capacity speed (Link capacity/speed relationship)

Identify the importance/reliability of each road link to weight the perturbation:• Travel time• Travel distance

Understand travel behaviour • When traffic decreases in a certain area, it logically will increase in another

area, how to identify such relationship?

Normal Traffic Flow

Perturbed Traffic Flow

Congested Traffic FlowPerturbed StatusNormal Status


Vulnerability Module – Input Output Model

Input- Output Infrastructure Model – is capable of studying the interdependency of component interaction• Application of input output model to transport infrastructure failure• Nodes: transportation junction or infrastructure components• Links: dependency among components

Software Implementation (Asty V1.0: developed by Dr Angeloudis Panagiotis) • Graphical software tool (C# based) to display the relationship of component

dependency• Static and dynamic modes to simulate component failure• Have potential to model various interacting systems

Junction 3

Junction 1

Road 1

Junction 2

Road 3

Road 4

Junction 4

Road 2


Vulnerability Module – Model Results

Operability/Failure variation, modelled results from Asty


OASIS Software Architecture DesignOASIS – A GIS-based software platform to design, analysis, model and visualise the cascading effect for interdependent infrastructure network, aimed at decision-makers, analysts and publics.

Hydraulic Model Hazard maps

Geospatial database

Transport network

Open-Street Map

Transport database Traffic data

ArcGIS/ QGIS

Models and Algorithms

Desktop GIS (to planners)

Web GIS (to public)OASISData Input


OASIS Implementation

Front-end GIS Visualisation• Open-source based SharpMap.Net (C# based component) • Tile maps (Google, Bing and Open Street), as well as ESRI shape files• Good interaction with many geospatial database, e.g. postgreSQL and Spatialite

Front-end GIS visualisation (under development)


OASIS Implementation

Open-source components based geospatial database • PostgreSQL + PostGIS (geospatial database management system)• PgRouting (routing and path algorithms)• Enable SQL enquire, spatial analysis of network-based database

Back-end GIS database support


Future Work Plan

Literature review and keep open-minded for other research models to implement vulnerability analysis e.g. agent-based model, neural networks model.

Continue to develop software platform by integrating Oasis and Asty, as well as other network analysis modules, in order to enhance current software functions

Explore mathematical models to identify the mechanism of road node/link failure and predict interdependent propagation to adjacent network components.

Explore mathematical rules of network behaviours and the relationship among travel demand, the change of link capacity and inoperability propagation.


[email protected]

Thank You!

gis based method to analyse vulnerability of transportation infrastructure

Technology

transport infrastructure

transport team

icl infrastructure module

hydraulic model model

network simplification

bogota vulnerability

massive network database

potential models