How Many Floods Have Occurred in China in the Past
Decade? A Perspective From Social Media
D. Shen1,2 , H. Gu1,2, W. Chen3, C. Zhang4 , S. Xiao1,2, and S. Zhang1,2
1Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province, Central China Normal University,
Wuhan, China, 2College of Urban and Environmental Sciences, Central China Normal University, Wuhan, China, 3Jiangsu
Provincial Planning and Design Group, Nanjing, China, 4School of Information Engineering, China University of
Geosciences in Beijing, Beijing, China
Abstract
Global climate change has led to frequent and widespread flood disasters in China. Traditional
flood disaster investigations mainly focus on major flood events, and small‐scale flood events are often
overlooked. This study utilized the Sina Weibo social media platform to detect flood events in 370 cities in
China from 2012 to 2023. We downloaded 73.52 million Weibo posts and developed a two‐step flood detection
algorithm. In the first step, the algorithm initially identifies 956 flood events based on changes in posting
frequency. In the second step, an LDA topic model is used to detect topics for these flood events and
automatically filter out false events, resulting in 729 flood events. Verification of these events confirmed that
629 of the 729 were real flood events, achieving a detection accuracy of 86.28%. In the end, after excluding all
false flood events and reinstating the mistakenly removed real ones, we obtained a total of 674 verified flood
events. Among these 370 cities, 194 cities experienced flood disasters, accounting for 52.43% of the total.
Additionally, we compared our findings with online news reports, as well as the flood data sets from the
GDACS and EM‐DAT. We found that our study had a high detection rate for urban waterlogging events.
However, there were cases of missed detection for flash floods and small watershed flood disasters.
Nevertheless, this study represents the most comprehensive publicly available detection of flood events in China
to date, which is of great significance for the government’s flood management and decision‐making.
to read the full article please click on
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How Many Floods Have Occurred in China in the Past
Decade? A Perspective From Social Media
D. Shen1,2 , H. Gu1,2, W. Chen3, C. Zhang4 , S. Xiao1,2, and S. Zhang1,2
1Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province, Central China Normal University,
Wuhan, China, 2College of Urban and Environmental Sciences, Central China Normal University, Wuhan, China, 3Jiangsu
Provincial Planning and Design Group, Nanjing, China, 4School of Information Engineering, China University of
Geosciences in Beijing, Beijing, China
Abstract
Global climate change has led to frequent and widespread flood disasters in China. Traditional
flood disaster investigations mainly focus on major flood events, and small‐scale flood events are often
overlooked. This study utilized the Sina Weibo social media platform to detect flood events in 370 cities in
China from 2012 to 2023. We downloaded 73.52 million Weibo posts and developed a two‐step flood detection
algorithm. In the first step, the algorithm initially identifies 956 flood events based on changes in posting
frequency. In the second step, an LDA topic model is used to detect topics for these flood events and
automatically filter out false events, resulting in 729 flood events. Verification of these events confirmed that
629 of the 729 were real flood events, achieving a detection accuracy of 86.28%. In the end, after excluding all
false flood events and reinstating the mistakenly removed real ones, we obtained a total of 674 verified flood
events. Among these 370 cities, 194 cities experienced flood disasters, accounting for 52.43% of the total.
Additionally, we compared our findings with online news reports, as well as the flood data sets from the
GDACS and EM‐DAT. We found that our study had a high detection rate for urban waterlogging events.
However, there were cases of missed detection for flash floods and small watershed flood disasters.
Nevertheless, this study represents the most comprehensive publicly available detection of flood events in China
to date, which is of great significance for the government’s flood management and decision‐making.
to read the full article please click on
^
