Download - 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
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Plan
• Urban transformations, indicators and monitoring
• Integrated monitoring and assessment system
• Network based kernel density evaluation (NetKDE)
• Proof-of-concept: Barcelona
• Current projects
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Urban Transformations and Indicators
1. Urban planning
2. Urban monitoring
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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• …
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Project : Centrality and density indicator
• Goals
– To create a density indicator that will respect network constraints
– To complete a proof-of-concept on Barcelona
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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
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Indicators : KDE vs. NetKDE
KDE NetKDE
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Indicators : KDE vs. NetKDE
KDE NetKDE
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Project's Process and Data
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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
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KDE of activities (bandwith: 400m)
*dot could represents supperposed activitiesNetKDE of activities (spt: 400m)
Results for ponctual data (activities)
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Global Betweeness KDE of segments
(bandwith:400m)
*input: segment’s centroid
Global Betweeness NetKDE of segments
(spt:400m)
Results for linear data (segments)
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Betweeness KDE/NetKDE of segments
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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?
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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)