Event Detection and Visualization of VGI

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1 Event Detection and Visualization of VGI Khatereh Polous Technical University Munich (TUM) Cartography Department

2 Background web 2.0 participatory platform colloquial readand-write functionality Individual users collaboratively generate the content

3 Background Text messaging, Social networks, Photos, Video, Blog entries

4 Background advances in locationaware devices web mapping technologies mobile cartography Contribution of none professional volunteers in providing and distributing geographic information

5 Background

6 Background Events and their patterns represent a higher level of knowledge Highly complex and irregular patterns still can be represented visually for further analysis Efficient planning and management of a complex system.

patterns still can be represented visually for further

7 Background

8 Objective To extract event related knowledge from OpenStreetMap Retrospective event refers to anomalous user activities, which happened at a time or within a specific period of time. User activity refers to number of contributors plus number of contributions

happened at a time or within a specific period of time.

9 Case Study 1 Stoppelmarkt in Vechta, Niedersachsen, Germany One of the oldest folk festival in Germany (since 1298). Once a year from Thursday to Tuesday in the week of 15 th August. Approximately 160,000 square meters

10 Case Study 2 Oktoberfest, in Munich, Bavaria, Germany One of the most famous events in Germany The largest world's folk festival. Mid-September until first week of October. Yearly more than 6 million people attend this fair and celebrate the Oktoberfest.

festival. Mid-September until first week of October.

11 Case Study 3 The earthquake and tsunami in Japan, 2011, one the most powerful earthquakes in the world The powerful tsunami waves traveled up to 10 km inland Extensive and severe damages to roads, railways and other infra-structures This event caused dramatically changes in the geometry of objects, which are important for a map.

Extensive and severe damages to roads, railways and other infra-structures This

12 Case Study 3 The earthquake and tsunami in Japan, 2011,

13 Results (Case Study 1) No detectible indications of unexpected increase in the amount of contributions. Slow changes in the number of contributions and contributors

14 Results (Case Study 1) Tag Mining: Information is only available in advanced editing modus

15 Results (Case Study 1) Tag Mining: Objects are constantly displayed on the map

16 Results (Case Study 1) Tag Mining for Maximilian s Pub: Exploring some relevant information about temporal characteristic of stands and the markets Edited at: 04. Aug Aug Aug Jan 12 Edited by: Duetzer Duetzer Duetzer Nolbelt San Version: In changeset: Comment: small changes amenity pub pub pub pub Tags: name Maximilian's Maximilian's Maximilian's Maximilian's opening_days to 16-Aug to 16-Aug-2011 Coordinates , , , ,

Jan 12 Edited by: Duetzer Duetzer Duetzer Nolbelt San Version: 1 2 3 4 In changeset: 8916581 8925849 8925909 10524834 Comment: -------------------

17 Results (Case Study 2) An upward trend in the number of contributions and contributors No easily detectible indications of unexpected increase in the amount of contributions.

18 Results (Case Study 2) An upward trend in the number of contributions and contributors The ratio between amount of contributions and the number of contributors decreases over time. New generation of OSM contributors is busy with enhancing and maintenance of OSM maps.

contributions and the number of contributors decreases over time.

19 Results (Case Study 2) Tag Mining: Tents not visible in the view layout of the map,

20 Results (Case Study 2) Tag Mining: The volunteers, identified the start, and end dates of the event, and have hidden the temporal tents

21 Results (Case Study 2) Tag Mining for Augustiner tent: Altering the hidden tag from yes to no Adapting the date after the event for next year Edited at: 27. Sep Sep Okt Nov Jan Sep Sep Nov 11 Edited by: mackerski mackerski mackerski sendelhorst spunsel chan mackerski swus Version: In changeset: Comment: hide update dates unhide unhide hide start_date Sep Sep Sep Sep Sep Sep Sep 12 end_date Okt Okt Okt Okt Okt Okt Okt 12 hidden yes yes no no yes name Augustiner Augustiner Augustiner Augustiner Augustiner Augustiner Augustiner Augustiner Tags: operator Augustiner Augustiner Augustiner Augustiner Augustiner Augustiner Augustiner Augustiner building beer_tent beer_tent beer_tent beer_tent seasonal_building beer_tent temp_building beer_tent beer_tent beer_tent note update update update update update update update The tents were created in September 2010 by Mackerski and have been updated regularly for the next year by different users

22 Results (Case Study 3) An obvious increase in the number of contributors and number of contributions over a very short space of time Change in the geometry and consequently the semantic information of affected objects

23 Results (Case Study 3) Edits in February 2011

24 Results (Case Study 3) Edits in March 2011

25 Conclusion Finding keys from Social events: OSM is not a tool which citizens would naturally turn to mark an event contributors do not treat this community in the same way that they contribute on user-friendly electronic exchange platforms such as Twitter, Facebook, or Flickr. Activity of contributors (Number of contributors plus Number of edits) for a specific period of time cannot be considered as an appropriate indicator for detecting social/temporary events.

26 Conclusion Finding keys from Social events: Size or popularity of an event does not have any significant effect on the possibility of event detection in OSM. OSM like other sharing platforms have the possibility to provide the semantic information for the mapped objects by tagging them. Overall there appears to be a lack of event detection and pattern recognition possibility form OSM community for the social and temporary event.

27 Conclusion OSM deficiencies for social event detection: Users do not have access to the embedded information (e.g. start and end date of events) Mapping of temporary objects for repetitive periodical events affect the quality of OSM for offline users Continuous maintenance is needed to update the map for each period. Many events are not manageable to be presented through hide and unhide mechanisms.

28 Thank You

OSM-CAT: A Java tool for OpenStreetMap Contributor Analysis. Peter Smith and Peter Mooney

OSM-CAT: A Java tool for OpenStreetMap Contributor Analysis Peter Smith and Peter Mooney Department of Computer Science, National University of Ireland Maynooth, Co. Kildare. Ireland Tel. +353-1-708 3847