BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//pretalx//talks.osgeo.org//foss4g-2026//talk//DBAG8B
BEGIN:VTIMEZONE
TZID:JST
BEGIN:STANDARD
DTSTART:20000101T000000
RRULE:FREQ=YEARLY;BYMONTH=1
TZNAME:JST
TZOFFSETFROM:+0900
TZOFFSETTO:+0900
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
UID:pretalx-foss4g-2026-DBAG8B@talks.osgeo.org
DTSTART;TZID=JST:20260901T170000
DTEND;TZID=JST:20260901T173000
DESCRIPTION:Background\n\nUrban parks provide essential ecosystem services 
 and recreational opportunities that contribute to physical health\, mental
  well-being\, and social interaction in dense metropolitan areas. Evidence
 -based park planning requires accurate and fine-grained measurements of vi
 sitor numbers\, spatial distribution patterns\, and movement trajectories.
  Conventional data collection approaches—such as manual observation\, su
 rveys\, and GPS tracking experiments—are labor-intensive\, costly\, and 
 difficult to implement continuously at scale. Although commercial mobility
  datasets derived from smartphones provide large-scale behavioral informat
 ion\, they are typically proprietary and financially restrictive. Meanwhil
 e\, geotagged social media data have been widely used to estimate recreati
 onal visitation\; however\, these data are often sparse and insufficient f
 or capturing microscale spatio-temporal and trajectory-level behavior patt
 erns.\n\nWith the proliferation of Web 2.0 and volunteered geographic info
 rmation (VGI)\, volunteered street view imagery (VSVI) platforms such as M
 apillary offer a novel open-data source with global coverage. Unlike tradi
 tional social media posts that consist of isolated image points\, VSVI dat
 a are organized into sequential\, geotagged photo trajectories\, inherentl
 y embedding movement information. This structural advantage suggests poten
 tial for behavioral analysis at fine spatial and temporal resolutions. Nev
 ertheless\, VSVI contributions are generated by self-selected individuals 
 and often dominated by a small number of highly active users. Consequently
 \, it remains unclear whether VSVI contribution behavior reflects general 
 park-use behavior or primarily captures the habits of specific contributor
 s. Furthermore\, given the spatial heterogeneity of VSVI contributions and
  the potential role of data volume in improving data quality\, we hypothes
 ize that the statistical validity of such data depends on contribution vol
 ume.\n\nMethods\n\nThis study empirically evaluates whether VSVI can serve
  as a reliable proxy for park-use behavior and investigates whether its ef
 fectiveness increases with higher levels of contribution. The analysis was
  conducted in 49 metropolitan parks located in Tokyo’s 23 wards\, one of
  Japan’s major hotspots of Mapillary activity. Three dimensions of park-
 use behavior were examined: (1) estimation of park visitor counts\, (2) sp
 atio-temporal distribution patterns\, and (3) travel-path characteristics.
  Two reference datasets were employed. First\, official annual park visito
 r counts (2019) published by the Tokyo Metropolitan Government were used t
 o validate visitation estimation. Second\, commercial Real People Flow Dat
 a (May 2023) provided anonymized GPS trajectories from approximately 869\,
 840 users (about 6% of Tokyo’s population)\, generating around 65 millio
 n records per day. After preprocessing—restricting to walking trips with
 in park boundaries and correcting for temporal gaps and cross-park traject
 ories—523\,057 PeopleFlow trajectories were retained for analysis. VSVI 
 metadata were collected from Mapillary (2014–March 2024)\, yielding 242\
 ,534 cleaned image points organized into 2\,007 sequences contributed by 4
 5 users within park areas.\n\nResults\n\nTo assess visitation estimation c
 apacity\, Spearman’s rank correlation analyses were conducted between of
 ficial visitor counts and four VSVI contribution indicators: number of ima
 ge points\, number of sequences\, number of photo-user-days (PUD)\, and nu
 mber of creators. When considering all parks collectively\, none of the in
 dicators showed statistically significant correlations with official visit
 or counts. However\, when parks were grouped based on mean PUD into low- a
 nd high-contribution categories\, moderate and statistically significant c
 orrelations emerged in the high-PUD group for PUD and number of creators (
 p < 0.05)\, whereas low-PUD parks showed no significant relationships. The
 se results indicate that VSVI data may not universally estimate visitation
  levels but can approximate visitor counts in parks with sufficiently dens
 e contribution activity.\n\nSpatio-temporal distribution patterns were com
 pared at a 20 m × 20 m grid resolution using three indicators derived fro
 m both datasets: point counts\, dwell time per trip\, and average speed. W
 hen pooling all parks\, statistically significant but weak positive correl
 ations were observed between VSVI and PeopleFlow data for all indicators (
 p < 0.001). However\, park-specific analyses revealed substantial heteroge
 neity. The proportion of parks exhibiting significant positive correlation
 s was markedly higher in the high-PUD group\, particularly for spatial ind
 icators such as point density and dwell time. Improvements for average spe
 ed were comparatively moderate. These findings suggest that increased cont
 ribution volume mitigates individual behavioral bias and enhances represen
 tativeness at the aggregated spatial level.\n\nTravel-path characteristics
  were further compared at the park level\, including temporal features (st
 art time\, end time\, duration)\, standardized movement range features (tr
 avel distance\, standard deviation ellipse (SDE) area\, and SDE perimeter 
 normalized by park area)\, and behavioral features (average speed and devi
 ation rate). Strong and highly significant correlations were identified fo
 r standardized travel distance\, SDE perimeter\, and SDE area\, indicating
  a high degree of consistency between VSVI-derived trajectories and refere
 nce mobility data in terms of movement range characteristics. Average spee
 d showed moderate positive correlations. In contrast\, temporal features e
 xhibited no significant relationships\, suggesting fundamental differences
  between photo-sharing behavior and general recreational timing patterns. 
 Group-specific analyses indicated that correlations were generally stronge
 r in parks with a higher number of VSVI trips\, particularly for movement 
 range indicators\, although variability remained across parks and metrics.
 \n\nConclusions and implications\n\nOverall\, the results demonstrate that
  VSVI can serve as a meaningful proxy for selected aspects of park-use beh
 avior\, especially spatial distribution and movement range characteristics
 . However\, its reliability is strongly conditioned by contribution volume
 . Parks with higher contribution density—often scenic or tourism-oriente
 d sites—show substantially stronger alignment with commercial mobility d
 ata. Low-contribution parks exhibit weaker or inconsistent relationships\,
  underscoring the importance of sufficient data accumulation in VGI-based 
 behavioral inference. For the FOSS4G community\, this study demonstrates h
 ow crowdsourced open street-level imagery can complement proprietary mobil
 ity datasets in large-scale urban behavioral analysis. By empirically exam
 ining the relationship between contribution volume and analytical validity
 \, the study contributes to ongoing discussions on data-quality growth\, r
 epresentativeness\, and the practical integration of open geospatial data 
 into reproducible urban analytics workflows. While limitations related to 
 GPS accuracy\, timestamp uncertainty\, and contextual heterogeneity remain
 \, the results highlight the potential of open\, crowd-sourced street-leve
 l imagery as a scalable complement to traditional data sources in spatial 
 planning and geospatial research.
DTSTAMP:20260717T234906Z
LOCATION:Cosmos1
SUMMARY:Capturing park-use behavior patterns using volunteered street view 
 imagery: Does the likelihood increase with the volume of contributions? - 
 Xinrui Zheng
URL:https://talks.osgeo.org/foss4g-2026/talk/DBAG8B/
END:VEVENT
END:VCALENDAR
