=Paper= {{Paper |id=Vol-1268/paper15 |storemode=property |title=Comprehensive Wikipedia monitoring for global and realtime natural disaster detection |pdfUrl=https://ceur-ws.org/Vol-1268/paper15.pdf |volume=Vol-1268 |dblpUrl=https://dblp.org/rec/conf/semweb/Steiner14 }} ==Comprehensive Wikipedia monitoring for global and realtime natural disaster detection== https://ceur-ws.org/Vol-1268/paper15.pdf
              Comprehensive Wikipedia Monitoring for Global
                 and Realtime Natural Disaster Detection

                                                  Thomas Steiner

                              Google Germany GmbH, Hamburg, Germany and
                     CNRS, Université de Lyon, LIRIS – UMR5205, Université Lyon 1, France
                                tsteiner@{liris.cnrs.fr, google.com}




                      Abstract. Natural disasters are harmful events resulting from natural
                      processes of the Earth. Examples of natural disasters include tsunamis,
                      volcanic eruptions, earthquakes, floods, droughts, and other geologic pro-
                      cesses. If they affect populated areas, natural disasters can cause eco-
                      nomic damage, injuries, or even losses of lives. It is thus desirable that
                      natural disasters be detected as early as possible and potentially affected
                      persons be notified via emergency alerts. By their pure nature, natural
                      disasters are global phenomena that people refer to by different names,
                      for example, the 2014 typhoon Rammasun 1 is known as typhoon Glenda
                      in the Philippines. In this paper, we present our ongoing early-stage
                      research on a realtime Wikipedia-based monitoring system for the de-
                      tection of natural disasters around the globe. The long-term objective is
                      to make data about natural disasters detected by this system available
                      through public alerts following the Common Alerting Protocol (CAP).

                      Keywords: Natural disaster detection, crisis response, Wikipedia



              1     Introduction

              1.1     Natural Disaster Detection and Response: A Global Challenge

              According to a study [4] published by the International Monetary Funds (IMF)
              in 2012, about 700 natural disasters were registered worldwide between 2010 and
              2012, affecting more than 450 million people. According to the study, “[d]amages
              have risen from an estimated US$20 billion on average per year in the 1990s to
              about US$100 billion per year during 2000–10.” The authors expect this upward
              trend to continue “as a result of the rising concentration of people living in areas
              more exposed to natural disasters, and climate change.” In consequence, public
              emergency alerting systems become more and more crucial in the future.
                  National agencies like the Federal Emergency Management Agency (FEMA)2
              in the United States of America or the Bundesamt für Bevölkerungsschutz und
               1
                   Rammasun: http://en.wikipedia.org/wiki/Typhoon_Rammasun_(2014)
               2
                   FEMA: http://www.fema.gov/




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              2       Comprehensive Wikipedia Monitoring for Natural Disaster Detection

              Katastrophenhilfe (BBK,3 “Federal Office of Civil Protection and Disaster As-
              sistance”) in Germany work to ensure the safety of the population on a na-
              tional level, combining and providing relevant tasks and information in a single
              place. The United Nations Office for the Coordination of Humanitarian Affairs
              (OCHA)4 is a United Nations (UN) body formed to strengthen the UN’s re-
              sponse to complex emergencies and natural disasters. The Global Disaster Alert
              and Coordination System (GDACS)5 is “a cooperation framework between the
              United Nations, the European Commission, and disaster managers worldwide
              to improve alerts, information exchange, and coordination in the first phase af-
              ter major sudden-onset disasters.” Global companies like Facebook,6 Airbnb,7
              or Google8 have dedicated crisis response teams that work on making critical
              emergency information accessible in times of disaster. As can be seen from the
              (incomprehensive) list above, natural disaster detection and response is a prob-
              lem tackled on national, international, and global levels; both from the public
              and private sectors. To facilitate collaboration, a common protocol is essential.


              1.2    The Common Alerting Protocol

              The Common Alerting Protocol (CAP) [10] is an XML-based general data format
              for exchanging public warnings and emergencies between alerting technologies.
              CAP allows a warning message to be consistently disseminated simultaneously
              over many warning systems to many applications. The protocol increases warning
              effectiveness and simplifies the task of activating a warning for officials. CAP
              also provides the capability to include multimedia data, such as photos, maps,
              or videos. Alerts can be geographically targeted to a defined warning area. An
              exemplary flood warning CAP feed stemming from GDACS is shown in Listing 1.


              1.3    Contributions, Hypotheses, and Research Questions

              In this paper, we present first results of our ongoing early-stage research on
              a realtime comprehensive Wikipedia-based monitoring system for the detection
              of natural disasters around the globe. We are steered by the following hypotheses.

              H1 Content about natural disasters gets added to Wikipedia in a timely fashion.
              H2 Natural disasters being geographically constrained, textual and multimedia
                 content about them gets added to local, i.e., non-English Wikipedias as well.
              H3 Link structure dynamics of Wikipedia provide for a meaningful way to detect
                 future natural disasters, i.e., disasters unknown at system creation time.

               3
                 BBK: http://www.bbk.bund.de/
               4
                 OCHA: http://www.unocha.org/
               5
                 GDACS: http://www.gdacs.org/
               6
                 Facebook Disaster Relief: https://www.facebook.com/DisasterRelief
               7
                 Airbnb Disaster Response: https://www.airbnb.com/disaster-response
               8
                 Google Crisis Response: https://www.google.org/crisisresponse/




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                       Comprehensive Wikipedia Monitoring for Natural Disaster Detection                  3

              These hypotheses lead us to the following research questions.

              Q1 How timely and accurate for the purpose of natural disaster detection is
                 content from Wikipedia compared to authoritative sources mentioned above?
              Q2 Does the disambiguated nature of Wikipedia surpass keyword-based natural
                 disaster detection approaches, e.g., via online social networks or search logs?


              2    Related Work
              Digitally crowdsourced data for disaster detection and response has gained mo-
              mentum in recent years, as the Internet has proven resilient in times of crises,
              compared to other infrastructure. Ryan Falor, Crisis Response Product Manager



              
              
                GDACS_FL_4159_1
                info@gdacs.org
                2014-07-14T23:59:59-00:00
                Actual
                Alert
                Public
                4159
                
                  GeoFlood
                  PastModerate
                  Unknown
                  Global Disaster Alert and Coordination System
                  
                  http://www.gdacs.org/reports.aspx?eventype=FL&eventid=4159
                  eventid4159
                  currentepisodeid1
                  glide
                  version1
                  fromdate
                      Wed, 21 May 2014 22:00:00 GMT
                  todate
                      Mon, 14 Jul 2014 21:59:59 GMT
                  eventtypeFL
                  alertlevelGreen
                  alerttypeautomatic
                  link
                      http://www.gdacs.org/report.aspx?eventtype=FL&eventid=4159
                  
                  countryBrazil
                  eventname
                  severityMagnitude 7.44
                  population0 killed and 0 displaced
                  
                  vulnerability
                  sourceidDFO
                  iso3
                  hazardcomponents
                      FL,dead=0,displaced=0,main_cause=Heavy Rain,severity=2,sqkm=256564.57
                      
                  datemodified
                      Mon, 01 Jan 0001 00:00:00 GMT
                  Polygon,,100
                
              

              Listing 1. Common Alerting Protocol feed via the Global Disaster Alert and
              Coordination System (http://www.gdacs.org/xml/gdacs_cap.xml, 2014-07-16)




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              4       Comprehensive Wikipedia Monitoring for Natural Disaster Detection

              at Google in 2011, remarks in [2] that “a substantial [ . . . ] proportion of searches
              are directly related to the crises; and people continue to search and access infor-
              mation online even while traffic and search levels drop temporarily during and
              immediately following the crises.” In the following, we provide a non-exhaustive
              list of related work on digitally crowdsourced natural disaster detection and
              response. Sakaki et al. consider in [7] each user of the online social network-
              ing (OSN) site Twitter9 a sensor for the purpose of earthquake detection in
              Japan. Goodchild et al. show in [3] how crowdsourced geodata from Wikipedia
              and Wikimapia,10 “a multilingual open-content collaborative map,” can help
              complete authoritative data about natural disasters. In [1], Abel et al. describe
              a crisis monitoring system that extracts relevant content about known disasters
              from Twitter. Liu et al. examine in [6] common patterns and norms of natu-
              ral disaster coverage on the photo sharing site Flickr.11 We have developed [9]
              a monitoring system that detects news events from concurrent Wikipedia edits
              and auto-generates related multimedia galleries based on content from various
              OSN sites and Wikimedia Commons.12 Finally, Lin and Mishne examine realtime
              search query churn on Twitter [5] including in the context of natural disasters.


              3     Proposed Methodology

              3.1    Leveraging Wikipedia Link Structure

              Wikipedia is an international online encyclopedia currently available in 287 lan-
              guages.13 (i) Articles in one language are interlinked with versions of the same
              article in other languages, e.g., the article “Natural disaster” on the English
              Wikipedia         (http://en.wikipedia.org/wiki/Natural_disaster)
              links to 74 versions of this article in other languages.14 (ii) Each article can
              have redirects, i.e., alternative URLs that point to the article. For the English
              “Natural disaster” article, there are eight redirects,15 e.g., “Natural Hazard”
              (synonym), “Examples of natural disaster” (refinement), or “Natural disasters”
              (plural). (iii) For each article, the list of back links that link to the current ar-
              ticle is available, i.e., inbound links other than redirects. The article “Natural
              disaster” has more than 500 articles that link to it.16 Likewise, the list of out-
               9
                 Twitter: https://twitter.com/
              10
                 Wikimapia: http://wikimapia.org/
              11
                 Flickr: https://www.flickr.com/
              12
                 Wikimedia Commons: https://commons.wikimedia.org/
              13
                 All Wikipedias: http://meta.wikimedia.org/wiki/List_of_Wikipedias
              14
                 Article language links: http://en.wikipedia.org/w/api.php?action=
                 query&prop=langlinks&lllimit=max&titles=Natural_disaster
              15
                 Article redirects: http://en.wikipedia.org/w/api.php?action=query&
                 list=backlinks&blfilterredir=redirects&bllimit=max&bltitle=
                 Natural_disaster
              16
                 Article inbound links: http://en.wikipedia.org/w/api.php?action=
                 query&list=backlinks&bllimit=max&blnamespace=0&bltitle=
                 Natural_disaster




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                      Comprehensive Wikipedia Monitoring for Natural Disaster Detection            5

              bound links, i.e., other articles that the current article links to, is available.17 By
              combining an article’s in- and outbound links, we determine the set of mutual
              links, i.e., the set of articles that the current article links to (outbound links)
              and at the same time receives links from (inbound links).

              3.2    Identification of Wikipedia Articles for Monitoring
              Starting with the well-curated English seed article “Natural disaster”, we pro-
              grammatically follow each of the therein contained links of type “Main arti-
              cle:”, which leads to an exhaustive list of English articles of concrete types
              of natural disasters, e.g., “Tsunami” (http://en.wikipedia.org/wiki/
              Tsunami), “Flood” (http://en.wikipedia.org/wiki/Flood), “Earth-
              quake” (http://en.wikipedia.org/wiki/Earthquake), etc. In total, we
              obtain links to 20 English articles about different types of natural disasters.18
              For each of these English natural disasters articles, we obtain all versions of
              each article in different languages [step (i) above], and of the resulting list of
              international articles in turn all their redirect URLs [step (ii) above]. The inter-
              mediate result is a complete list of all (currently 1,270) articles in all Wikipedia
              languages and all their redirects that have any type of natural disaster as their
              subject. We call this list the “natural disasters list” and make it publicly avail-
              able in different formats (.txt, .tsv, and .json), where the JSON version
              is the most flexible and recommended one.19 Finally, we obtain for each of the
              1,270 articles in the “natural disasters list” all their back links, i.e., their in-
              bound links [step (iii) above], which serves to detect instances of natural disas-
              ters unknown at system creation time. For example, the article “Typhoon Ram-
              masun (2014)” (http://en.wikipedia.org/wiki/Typhoon_Rammasun_
              (2014))—which, as a concrete instance of a natural disaster of type tropical
              cyclone, is not contained in our “natural disasters list”—links back to “Tropical
              cyclone” (http://en.wikipedia.org/wiki/Tropical_cyclone), so we
              can identify “Typhoon Rammasun (2014)” as related to tropical cyclones (but
              not necessarily identify as a tropical cyclone), even if at the system’s creation
              time the typhoon did not exist yet. Analog to the inbound links, we obtain
              all outbound links of all articles in the “natural disasters list”, e.g., “Tropi-
              cal cyclone” has an outbound link to “2014 Pacific typhoon season” (http://
              en.wikipedia.org/wiki/2014_Pacific_typhoon_season), which also
              17
                 Article outbound links: http://en.wikipedia.org/w/api.php?action=
                 query&prop=links&plnamespace=0&format=json&pllimit=max&titles=
                 Natural_disaster
              18
                 “Avalanche”, “Blizzard”, “Cyclone”, “Drought”, “Earthquake”, “Epidemic”, “Ex-
                 tratropical cyclone”, “Flood”, “Gamma-ray burst”, “Hail”, “Heat wave”, “Impact
                 event”, “Limnic eruption”, “Meteorological disaster”, “Solar flare”, “Tornado”,
                 “Tropical cyclone”, “Tsunami”, “Volcanic eruption”, “Wildfire”
              19
                 “Natural      disasters    list”:  https://github.com/tomayac/postdoc/
                 blob/master/papers/comprehensive-wikipedia-monitoring-for-
                 global-and-realtime-natural-disaster-detection/data/natural-
                 disasters-list.json




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              6        Comprehensive Wikipedia Monitoring for Natural Disaster Detection

              happens to be an inbound link of “Tropical cyclone”, so we have detected a mu-
              tual, circular link structure. Figure 1 shows the example in its entirety, starting
              from the seed level, to the disaster type level, to the in-/outbound link level.
              The end result is a large list called the “monitoring list” of all articles in all
              Wikipedia languages that are somehow—via a redirect, inbound, or outbound
              link (or resulting mutual link)—related to any of the articles in the “natural dis-
              asters list”. We make a snapshot of this dynamic “monitoring list” available for
              reference,20 but note that it will be out-of-date soon and should be regenerated
              on a regular basis. The current version holds 141,001 different articles.


                        Legend:
                           seed level                               en:Natural    (seed article)
                           disaster type level                       disaster
                            in-/outbound link level
                            English German
                                                      (redirect)                      (mutual link)
                                                      en:Tropical en:Tropical        en:2014 Pacific
                           de:Pazifische                storm                        typhoon season
                                                                   cyclone
                         Taifunsaison 2014
                         (inbound link)           de:Tropischer
                                                   Wirbelsturm                       en:Disaster
                                                                                    preparedness
                                          (language link)        en:Typhoon            (outbound link)
                                                               Rammasun (2014)
                                                                   (inbound link)


              Fig. 1. Extracted Wikipedia link structure starting from seed article “Natural disaster”




              3.3     Monitoring Process
              In the past, we have worked on a Server-Sent Events (SSE) API [8] capable of
              monitoring realtime editing activity on all language versions of Wikipedia. This
              API allows us to easily analyze Wikipedia edits by reacting on events fired by
              the API. Whenever an edit event occurs, we check if it is for one of the articles
              on our “monitoring list”. We keep track of the historic one-day-window editing
              activity for each article on the “monitoring list” including their versions in other
              languages, and, upon a sudden spike of editing activity, trigger an alert about
              a potential new instance of a natural disaster type that the spiking article is an
              inbound or outbound link of (or both). To illustrate this, if, e.g., the German
              article “Pazifische Taifunsaison 2014” including all of its language links is spiking,
              20
                   “Monitoring list”: https://github.com/tomayac/postdoc/blob/master/
                   papers/comprehensive-wikipedia-monitoring-for-global-and-
                   realtime-natural-disaster-detection/data/monitoring-list.json




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                      Comprehensive Wikipedia Monitoring for Natural Disaster Detection         7

              we can infer that this is related to a natural disaster of type “Tropical cyclone”
              due to the detected mutual link structure mentioned earlier (Figure 1).
                  In order to detect spikes, we apply exponential smoothing to the last n edit
              intervals (we require n ≥ 5) that occurred in the past 24 hours with a smoothing
              factor α = 0.5. The therefore required edit events are retrieved programmatically
              via the Wikipedia API.21 As a spike occurs when an edit interval gets “short
              enough” compared to historic editing activity, we report a spike whenever the
              latest edit interval is shorter than half a standard deviation 0.5 × σ.
                  A subset of all Wikipedia articles are geo-referenced,22 so when we detect
              a spiking article, we try to obtain geo coordinates for the article itself (e.g.,
              “Pazifische Taifunsaison 2014”) or any of its language links that—as a conse-
              quence of the assumption in H2—may provide more local details (e.g., “2014
              Pacific typhoon season” in English or “2014年太平洋季” in Chinese). We then
              calculate the center point of all obtained latitude/longitude pairs.
                  In a final step, once a given confidence threshold has been reached and upon
              human inspection, we plan to send out a notification according to the Common
              Alerting Protocol following the format that (for GDACS) can be seen in Listing 1.


              3.4    Implementation Details

              We have created a publicly available prototypal demo application deployed23
              at http://disaster-monitor.herokuapp.com/ that internally connects
              to the SSE API from [8]. It is implemented in Node.js on the server, and as
              a JavaScript Web application on the client. This application uses an hourly
              refreshed version of the “monitoring list” from Subsection 3.2 and whenever
              an edit event sent through the SSE API matches any of the articles in the
              list, it checks if, given this article’s and its language links’ edit history of the
              past 24 hours, the current edit event shows spiking behavior, as outlined in
              Subsection 3.3. The core source code snippet of the main monitoring loop can
              be seen in Listing 2, a screenshot of the application is shown in Figure 2.


              4     Proposed Steps Toward an Evaluation

              We recall our core research questions that were Q1 How timely and accurate
              for the purpose of natural disaster detection is content from Wikipedia compared
              to authoritative sources mentioned above? and Q2 Does the disambiguated na-
              ture of Wikipedia surpass keyword-based natural disaster detection approaches,
              21
                 Wikipedia last revisions: http://en.wikipedia.org/w/api.php?action=
                 query&prop=revisions&rvlimit=6&rvprop=timestamp|user&titles=
                 Typhoon_Rammasun_(2014)
              22
                 Article geo coordinates: http://en.wikipedia.org/w/api.php?action=
                 query&prop=coordinates&format=json&colimit=max&coprop=dim|
                 country|region|globe&coprimary=all&titles=September_11_attacks
              23
                 Source    code:   https://github.com/tomayac/postdoc/tree/master/
                 demos/disaster-monitor




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              8          Comprehensive Wikipedia Monitoring for Natural Disaster Detection

              e.g., via online social networks or search logs? Regarding Q1, only a manual
              comparison covering several months worth of natural disaster data of the rel-
              evant authoritative data sources mentioned in Subsection 1.1 with the output
              of our system can help respond to the question. Regarding Q2, we propose an
              evaluation strategy for the OSN site Twitter, loosely inspired by the approach
              of Sakaki et al. in [7]. We choose Twitter as a data source due to the publicly




              var init = function() {

                  // fired whenever an edit event happens on any Wikipedia
                  var parseWikipediaEdit = function(data) {
                    var article = data.language + ’:’ + data.article;
                    var disasterObj = monitoringList[article];
                    // the article is on the monitoring list
                    if (disasterObj) {
                      showCandidateArticle(data.article, data.language, disasterObj);
                    }
                  };

                  // fired whenever an article is on the monitoring list
                  var showCandidateArticle = function(article, language, roles) {
                    getGeoData(article, language, function(err, geoData) {
                      getRevisionsData(article, language, function(err, revisionsData) {
                        if (revisionsData.spiking) {
                          // spiking article
                        }
                        if (geoData.averageCoordinates.lat) {
                          // geo-referenced article, create map
                        }
                        // trigger alert if article is spiking
                      });
                    });
                  };

                  getMonitoringList(seedArticle, function(err, data) {
                    // get the initial monitoring list
                    if (err) {
                      return console.log(’Error initializing the app.’);
                    }
                    monitoringList = data;
                    console.log(’Monitoring ’ + Object.keys(monitoringList).length +
                        ’ candidate Wikipedia articles.’);

                   // start monitoring process once we have a monitoring list
                   var wikiSource = new EventSource(wikipediaEdits);
                   wikiSource.addEventListener(’message’, function(e) {
                     return parseWikipediaEdit(JSON.parse(e.data));
                   });

                  // auto-refresh monitoring list every hour
                  setInterval(function() {
                    getMonitoringList(seedArticle, function(err, data) {
                      if (err) {
                        return console.log(’Error refreshing monitoring list.’);
                      }
                      monitoringList = data;
                      console.log(’Monitoring ’ + Object.keys(monitoringList).length +
                          ’ candidate Wikipedia articles.’);
                    });
                  }, 1000 * 60 * 60);
                });
              };
              init();

                           Listing 2. Main monitoring loop of the natural disaster monitor




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                      Comprehensive Wikipedia Monitoring for Natural Disaster Detection            9




              Fig. 2. Screenshot of the mobile-friendly “Natural Disaster Monitor” application proto-
              type available at http://disaster-monitor.herokuapp.com/ showing detected
              natural disaster types connected with the (currently non-spiking) article “Japan”


              available user data through its streaming APIs,24 which would be considerably
              harder, if not impossible, with other OSNs or search logs due to privacy con-
              cerns and API limitations. Based on the articles in the “monitoring list”, we put
              forward using article titles as search terms, but without disambiguation hints
              in parentheses, e.g., instead of the complete article title “Typhoon Rammasun
              (2014)”, we suggest using “Typhoon Rammasun” alone. We advise monitoring
              the sample stream25 for the appearance of any of the search terms, as the filtered
              stream26 is too limited regarding the number of supported search terms. In order
              to avoid ambiguity issues with the international multi-language tweet stream, we
              recommend matching search terms only if the Twitter-detected tweet language
              equals the search term’s language, e.g., English, as in “Typhoon Rammasun”.

              5    Conclusions and Future Work
              In this paper, we have presented first steps of our ongoing research on the cre-
              ation of a Wikipedia-based natural disaster monitoring system, in particular,
              we have finished its underlying code scaffolding. While the system itself already
              works, a good chunk of work still lies ahead with the fine-tuning of its parame-
              ters. A first examples are the exponential smoothing parameters of the revision
              intervals, responsible for determining whether an article is spiking, and thus
              a potential new natural disaster, or not. A second example is the role that natu-
              ral disasters play with articles: they can be inbound, outbound, or mutual links,
              24
                 Twitter streaming APIs: https://dev.twitter.com/docs/streaming-
                 apis/streams/public
              25
                 Twitter sample stream: https://dev.twitter.com/docs/api/1.1/get/
                 statuses/sample
              26
                 Twitter filtered stream: https://dev.twitter.com/docs/api/1.1/post/
                 statuses/filter




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              10       Comprehensive Wikipedia Monitoring for Natural Disaster Detection

              and their importance for actual occurrences of disasters will vary. Future work
              will mainly focus on finding answers to our research questions Q1 and Q2 and the
              verification of the hypotheses H1–H3. We will focus on the evaluation of the sys-
              tem’s usefulness, accuracy, and timeliness in comparison to other keyword-based
              approaches. An interesting aspect of our work is that the monitoring system
              is not limited to natural disasters. Using an analog approach, we can monitor
              for human-made disasters (called “Anthropogenic hazard” on Wikipedia) like
              terrorism, war, power outages, air disasters, etc. We have created an exemplary
              “monitoring list” and made it available.27 Concluding, we are excited about this
              research and look forward to putting the final system into operational practice.

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               2. R. Falor. Search data reveals people turn to the internet in crises, Aug. 2011.
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              27
                   Anthropogenic hazard “monitoring list”: https://github.com/tomayac/
                   postdoc/blob/master/papers/comprehensive-wikipedia-monitoring-
                   for-global-and-realtime-natural-disaster-detection/data/
                   monitoring-list-anthropogenic-hazard.json




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