Using Non-authoritative Sources During Emergencies in Urban Areas - Computational Approaches for Urban Environments - page 335

Fig. 14.3 Crowdsourced assessments for the Civil Air Patrol data. Damage assessment:

red D high, yellow D medium, green D none

not require any crowdsourcing or automated assessment. Furthermore, it is shown
in Schnebele and Cervone ( 2013 ) that even a small number of properly located VGI
data can help improve flood assessment. Each location corresponding to a video
point was assigned a value of 10 (severe damage/flooding).
Photos (n D 25) which documented flooding within the study domain were
downloaded using the Google search engine and were also visually assessed by
the authors. The point locations were georeferenced to create a GIS layer of flooded
locations. Each point was assigned a value of 10 (severe damage/flooding).
Twitter, a popular social networking site, is often utilized by the public to
share information about their daily lives through micro-blogging. Arizona State
University's TweetTracker provided Twitter data for this project (Kumar et al. 2011 ).
Tweets generated in the New York City area extending from 40.92N to 40.54N
latitude and 73.75W to 74.13W longitude from October 26 to November 3, 2012
containing the word “flood” were used to provide a temporal framework.