HIMMELI - Heuristic three-level Instrument combining urban

Morphology, Mobility, service Environments and Locational Information

Morphologically structured agent based

simulation model of urban retail system

Sanna Iltanen Tampere University of Technology, Finland

COST TU1002 WG Meeting Edinburgh 13.10.2011

MODEL PRINCIPLE

The holistic model of the urban retail system which utilises the

accessibility measures in multiple ways

The model combines approaches of urban morphology, spatial

interaction modeling and agent based modeling techniques

MODELretail services

households

transportation system

EVOLUTION OF RETAIL SERVICES

Model structure:

INPUT OUTPUT

Network city theory

Model framework Dupuy ’s triple layered network

Households

Retail Units / Types(Daily/Specilaty)

Road Network

THEORETICAL FRAMEWORK

THEORETICAL FRAMEWORK

Gabriel Dupuy’s three level network theory defines the overall

framework for the model

The urban morphological methodologies is exploited to define the

retail unit typologies and in handling the infrastructural networks

The interaction principles in the model are derived from the tradition

of spatial interaction modeling

Agent based modeling enables the observation of spatial self-

organization of retail units based on local interactions

The bottom up approach allows also the observation of emergent

phenomena and relates the model to the complex system theory

Input dataIn

itia

lisa

tion

Ph

ase

Sim

ula

tion

Ph

ase

MODEL FLOWCHART

Get network data & calculate travel cost matrix

Get retail unit typology & locations

Get household typology & locations

Calculate Accessibilities

Calculate utilities for households

Update retail unit accounts

Remove unprofitable retail units

Create new retail units

simulation cycles

ACCESSIBILITY IN THE MODEL

ACCESSIBILITY FUNCTIONS

Acc R-Raccessibility from retail unit to all

other retail units

Acc Hh-Raccessibility from household

location to retail unit affects to utility

Acc networkAccessibility as a network property

affects on locations of new retail units

1. Agent level

2. Production & consumption level

3. Infrastructural level

Simulation Phase

TRAVEL COST MATRIX

INDICATORS

At current stage the focus is on roadnetwork

mean depth of road centre line network (or integration)

travel cost in terms of distance (meters)

travel cost in terms of time (minutes)

The travelcost matrix (of discrete space) enables combination of several

accessibility levels (e.g. road network based, public transportation based,

walkability based).

INPUT

census data of households (grid format database, three income brackets)

register database of companies (classification based onNACE Rev.2)

road network database or general travel cost matrix

Scenario 1 Scenario 2 Scenario N…

OUTPUT

dynamics: the spatial self-organization of retail system

temporal behavior of the system: stable / periodic / chaotic / complex

USEFULNESS IN PRACTICE

The model increases understanding of the feedback loops and

cumulative influence of boundary conditions related to infrastructure,

mobility and service typologies

The model allows observation of possible development paths of the

system as one of the attributes is changed

Possible phase transitions in spatial distribution of (retail) services

can be anticipated

THANK YOU!