urban dynamics monitoring: innovative density and centrality indicators of economic activities

NLB / 06.05.10 / p.1 Urban Dynamics Monitoring: Network Based Density Indicator

Urban Dynamics Monitoring: Innovative Density and Centrality Indicators of Economic Activities

Nicolas Lachance-Bernard Geographic Information Systems LaboratoryEcole polytechnique fédérale de Lausanne (EPFL)

COST Action TU0602 - Land Management and Urban Dynamics Under Shift of Contexts, 6th May 2010, Kaunas, Lithuania


Plan

• Urban transformations, indicators and monitoring

• Integrated monitoring and assessment system

• Network based kernel density evaluation (NetKDE)

• Proof-of-concept: Barcelona

• Current projects


Urban Transformations and Indicators

1. Urban planning

2. Urban monitoring


Monitoring what?

• Land use changes• Emitted number of development/construction permits• Apartment's turn-over rates (owner, leaser)• Completed construction projects• Economic activities• Empty lots and apartments• Socioeconomics (job, household)• Accessibilities and mobilities• …

Presenter

Presentation Notes

Example: solar panel policies in Switzerland … linked to a particular neighborhood, city, region?


Project : Centrality and density indicator

• Goals

– To create a density indicator that will respect network constraints

– To complete a proof-of-concept on Barcelona


Theory

• Kernel Density Estimator (KDE)– Operates in euclidean space– Weights events by their radial distances from grid centroid

• Network based Kernel Density Estimator (NetKDE)– Operates in a network constrained space– Weights events by the distance from grid centroid measured along

this network


Indicators : KDE vs. NetKDE

KDE NetKDE


Project's Process and Data


Proof-of-concept: Barcelona

Raw data 2002(Agencia de Ecologia Urbana)

• Economic activities166,311 entities

• Grid10m, 92.65km2

1,890,000 cellules• Graphe routier

11,222 segments

Treatments

• 926,000 grid points• 400m bandwith

(network and euclidean distance)• Duration: 33 hours

Intel(R) Core(TM)2 Quad CPU Q950 @ 3.00GHz 8GB of RAM


KDE of activities (bandwith: 400m)

*dot could represents supperposed activitiesNetKDE of activities (spt: 400m)

Results for ponctual data (activities)


Global Betweeness KDE of segments

(bandwith:400m)

*input: segment’s centroid

Global Betweeness NetKDE of segments

(spt:400m)

Results for linear data (segments)


Betweeness KDE/NetKDE of segments


Current Projects

• NetKDE vs. KDE: Barcelona– Grid 10m, 20m, 50m, 100m, 200m– Bandwith 100m, 200m, 400m, 500m

• Segment centralities vs. Activity densities (NetKDE): Barcelona, Roma, Bologna, Glasgow, Geneva– Grid 10m – Bandwith 100m, 200m, 500m

• Over time series (real monitoring)… Bologna?• Outside Europe… Montréal Metropolitan Area and Delhi?


References

• Produit, T., Lachance-Bernard, N., Strano, E., Porta, S., Joost, S., A network based kernel density estimator applied to Barcelona economic activities. The International Conference on ComputationalScience and its Applications - Japan (ICCSA), Part I, LNCS 6016, Springer-Verlag Berlin Heidelberg, 32-45 (2010)

• Porta, S., Latora, V., Wang, F., Strano, E., Cardillo, A., Scellato, S., Iacoviello, V., Messora, R., Street centrality and densities of retail and services in Bologna, Italy. Environment and Planning B: Planning and Design 36, 450–465 (2009)

• Porta, S., Crucitti, P., Latora, V., The network analysis of urban streets: a primal approach. Environment and Planning B: Planning and Design 33, 705–725 (2006)

urban dynamics monitoring: innovative density and centrality indicators of economic activities

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