Impromptu crisis mapping to prioritize emergency response

To visualize post-emergency damage, a crisis-mapping system uses readily available semantic annotators, a machine-learning classifier to analyze relevant tweets, and interactive maps to rank extracted situational information. The system was validated against data from two recent disasters in Italy

Crisis Mapping during Natural Disasters via Text Analysis of Social Media Messages

Recent disasters demonstrated the central role of social media during emergencies thus motivating the exploitation of such data for crisis mapping. We propose a crisis mapping system that addresses limitations of current state-of-the-art approaches by analyzing the textual content of disaster reports from a twofold perspective. A damage detection component employs a SVM classifier to detect mentions of damage among emergency reports. A novel geoparsing technique is proposed and used to perform message geolocation. We report on a case study to show how the information extracted through damage detection and message geolocation can be combined to produce accurate crisis maps. Our crisis maps clearly detect both highly and lightly damaged areas, thus opening up the possibility to prioritize rescue efforts where they are most needed

How Do People Describe Locations During a Natural Disaster: An Analysis of Tweets from Hurricane Harvey

Social media platforms, such as Twitter, have been increasingly used by people during natural disasters to share information and request for help. Hurricane Harvey was a category 4 hurricane that devastated Houston, Texas, USA in August 2017 and caused catastrophic flooding in the Houston metropolitan area. Hurricane Harvey also witnessed the widespread use of social media by the general public in response to this major disaster, and geographic locations are key information pieces described in many of the social media messages. A geoparsing system, or a geoparser, can be utilized to automatically extract and locate the described locations, which can help first responders reach the people in need. While a number of geoparsers have already been developed, it is unclear how effective they are in recognizing and geo-locating the locations described by people during natural disasters. To fill this gap, this work seeks to understand how people describe locations during a natural disaster by analyzing a sample of tweets posted during Hurricane Harvey. We then identify the limitations of existing geoparsers in processing these tweets, and discuss possible approaches to overcoming these limitations

A Process Evaluation of Intelligence Gathering Using Social Media for Emergency Management Organizations in California

When responding to an emergency, correct and timely information is often the difference between a successful response and a potential disaster. The information that emergency managers in California receive from the public often dictates how agencies respond to emergencies. The emergence of social media has presented several benefits to emergency managers regarding intelligence gathering during the emergency response process. Simultaneously, the emergence of social media has raised several concerns for the stakeholders involved. One major issue involves inaccurate information circulating on social media platforms during ongoing disasters. If emergency managers cannot discern incorrect information from correct information, disaster response may be less effective. Rumors and misinformation tend to circulate before, during, and after emergencies. Although incorrect information circulating on social media cannot be stopped in totality, emergency managers can use cutting-edge technology and strategies to discern and counteract false information. New technologies and intelligence gathering tools can be used as a source of intelligence to relay lifesaving information to the public. Past negative examples of inaccurate information on social media influencing stakeholder decision-making raise the focus of this research: How can emergency management agencies in California leverage the flow of valid information on social media during crisis conditions

Geocoding location expressions in Twitter messages: A preference learning method

Resolving location expressions in text to the correct physical location, also known as geocoding or grounding, is complicated by the fact that so many places around the world share the same name. Correct resolution is made even more difficult when there is little context to determine which place is intended, as in a 140-character Twitter message, or when location cues from different sources conflict, as may be the case among different metadata fields of a Twitter message. We used supervised machine learning to weigh the different fields of the Twitter message and the features of a world gazetteer to create a model that will prefer the correct gazetteer candidate to resolve the extracted expression. We evaluated our model using the F1 measure and compared it to similar algorithms. Our method achieved results higher than state-of-the-art competitors