Your SlideShare is downloading. ×
Urban Monitoring Using NetKDE and VGI         Network Based Kernel Density Estimation on         Volunteered Geographic In...
Content •   Context •   (Network based) Kernel Density Estimation •   Background Case Studies     Barcelona, Ljubljana, Ge...
Context •   Problematic       – Fact         Spatial events location influenced by urban forms       – Principal need     ...
Network based Kernel Density Estimator                  KDE                                          NetKDE               ...
KDE vs. NetKDE                  KDE                                       NetKDE                    Source: Produit and La...
Case Studies 2009-2011                         Barcelona            Ljubljana            Geneva                Baghdad    ...
Barcelona Eco. Activities: Grid resolution variations (band. 500m)                                      H                 ...
Barcelona Eco. Activities: KDE vs. NetKDE (10m grid, 500m band.)                                      H                   ...
Ljubljana                                                                          GPS Bike:                              ...
Baghdad                                                                   Case Study                                      ...
Baghdad Case Study Data: Guardian database    Report ID                   Report                                          ...
Baghdad: Spatio-temporal multi-dimension analysis •   Events – Wikileaks-Guardian death casualties Baghdad 2004-2009      ...
Baghdad IED: NetKDE                   NetKDE 800m bandwidth                            NetKDE 1400m bandwidthNLB-TP-LG / p...
3D Spatio-temporal KDE* •   Proposed by Demsar and Virrantaus (2010)     based on space-time cube by Hägerstrand •   3D KD...
Baghdad IED explosions KDE                   January 2004 - December 2009 •   2,652 events - 1,030 km2 - 76 steps, 1500m K...
Conclusion •   NetKDE for spatio-temporal trends, hotspots, …      – Barcelona: playing with scale and model        How do...
Upcoming SlideShare
Loading in...5
×

Urban Monitoring Using NetKDE and VGI

485

Published on

Network Based Kernel Density Estimation on Volunteered Geographic Information Applied to Baghdad, Iraq

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
485
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "Urban Monitoring Using NetKDE and VGI"

  1. 1. Urban Monitoring Using NetKDE and VGI Network Based Kernel Density Estimation on Volunteered Geographic Information Applied to Baghdad, Iraq Nicolas Lachance-Bernard, Timothée Produit and Loïc Gasser Geographic Information Systems Laboratory Ecole polytechnique fédérale de Lausanne, Switzerland 7th VCT Virtual Cities and Territories Conference October 11th – 13th 2011, Lisbon, PortugalNLB-TP-LG / p.1 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  2. 2. Content • Context • (Network based) Kernel Density Estimation • Background Case Studies Barcelona, Ljubljana, Geneva, Baghdad • Baghdad Spatio-temporal multi-dimension analysis • Conclusion and Further researchNLB-TP-LG / p.2 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  3. 3. Context • Problematic – Fact Spatial events location influenced by urban forms – Principal need Adapting density estimation for graph constrained space – Goal Spatio-temporal monitoring of urban dynamics • Challenges 1. To use very large datasets 2. To decrease processing times compared to out-of-the-box GIS 3. To develop multi-scale approaches 4. To develop visualization methodsNLB-TP-LG / p.3 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  4. 4. Network based Kernel Density Estimator KDE NetKDE Source: Produit et Lachance-Bernard 2009, 2010NLB-TP-LG / p.4 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  5. 5. KDE vs. NetKDE KDE NetKDE Source: Produit and Lachance-Bernard, 2009/2010NLB-TP-LG / p.5 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  6. 6. Case Studies 2009-2011 Barcelona Ljubljana Geneva Baghdad (2009/2010) (May 2011) (June 2011) (June 2011) Network (Agency) 20 km2 (OSM) (Agency) (OSM) Segments 11,200 8,100 10,800 66,600 Events Eco. Activities Cyclist GPS Eco. Activities War records Locations 166,300 314,200 15,000 93,100 Class 1 1 12 16 + Weights Grid 200m 100m 100m 20m 200m 50m 50m 20m 10m - Gridpoints 160,000 310,000 22,600 - 360,000 Buildings - - 70,000 - Bandwidths [20m,6000m] [40m,1000m] [200m, 3000m] - KDE (Steps) (20m) (20m) (100m) Bandwidths [100m,1000m] 60m 100m 500m [200m, 3000m] NetKDE (Steps) (100m) 200m 400m (100m) Processing 9 computers 1 computer 1 computer 1 computer times 500h 18h + 77h 15h & 20h & KDE + NetKDE 5min/class 5min/classNLB-TP-LG / p.6 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  7. 7. Barcelona Eco. Activities: Grid resolution variations (band. 500m) H KDE grid 200m NetKDE grid: 200m L KDE grid 50m NetKDE grid: 50mNLB-TP-LG / p.7 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  8. 8. Barcelona Eco. Activities: KDE vs. NetKDE (10m grid, 500m band.) H KDE (ZOOM) NetKDE (ZOOM) L KDE NetKDENLB-TP-LG / p.8 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  9. 9. Ljubljana GPS Bike: NetKDE 20m grid Bandwidths A)60m B)100m C)200m D)400m *Deciles distributionNLB-TP-LG / p.9 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  10. 10. Baghdad Case Study DataNLB-TP-LG / p.10 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  11. 11. Baghdad Case Study Data: Guardian database Report ID Report InformationDate (dd.mm.yyyy) DescriptionNLB-TP-LG / p.11 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  12. 12. Baghdad: Spatio-temporal multi-dimension analysis • Events – Wikileaks-Guardian death casualties Baghdad 2004-2009 Coalition Iraqi Civilians Insurgents Forces Forces Attack 86 1,167 1,627 3,775 Direct Fire 482 4,270 4,766 6,807 Indirect Fire 192 284 2,087 1,040 IED Explosion 2,107 5,990 20,228 3,455 Murder 9 2,169 32,563 73 Total 93,157 events 2,876 13,880 61,251 15,150 • Network OpenStreetMap (66,648 segments) • Grid 200m resolution 22,644 gridpoints / 50m resolution 362,304 gridpointsNLB-TP-LG / p.12 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  13. 13. Baghdad IED: NetKDE NetKDE 800m bandwidth NetKDE 1400m bandwidthNLB-TP-LG / p.13 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  14. 14. 3D Spatio-temporal KDE* • Proposed by Demsar and Virrantaus (2010) based on space-time cube by Hägerstrand • 3D KDE function 3D Epanechnikov kernel function * Implemented by Loic Gasser, Timothée Produit and Nicolas Lachance-BernardNLB-TP-LG / p.14 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  15. 15. Baghdad IED explosions KDE January 2004 - December 2009 • 2,652 events - 1,030 km2 - 76 steps, 1500m KDE • 1 day equivalent to 10 meters Source: Loic Gasser, 2011NLB-TP-LG / p.15 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq
  16. 16. Conclusion • NetKDE for spatio-temporal trends, hotspots, … – Barcelona: playing with scale and model How does scale change vision? – Ljubljana: biking around the city Where are people most active? – Baghdad: learn/show using time, classification, weights When and how are event density patterns change? • Further work – Implementation of spatio-temporal NetKDE – Fixed time comparison (looking for concordances, differences) Fuzzy-set map comparison – Automated multi-scale multi-temporal geovizualisation “Connected-windows” views and annimated-mapsNLB-TP-LG / p.16 Urban monitoring using NetKDE and VGI: NetKDE, VGI applied to Baghdad, Iraq

×