Over the past few decades, an increase in natural hazards has imposed
greater challenges on natural disaster management. To reduce the impact
of natural disasters on humanity, disaster management requires more
human-centric information in addition to objective disaster information.
Since disaster management demands a large amount of information in the
face of low availability, social media (e.g., Twitter, Facebook, or Sina-Weibo)
is an additional information source that is gaining increasing attention
from geographic information scientists and disaster researchers. Social
media is not only a platform for sharing people’s personal lives but can
also be used to examine public opinion and perceptions, which may be comparable
to the public comments collected by traditional approaches(e.g., questionnaires).
Combined with spatial-temporal information collected from social media, the
public opinions and feelings on a disaster mined from social media can assist
government decision-making and help people better understand the state of
disaster events. However, social media texts are unstructured and people’s
conversational content on social media varies in toic and tone. Thus, a
significant challenge remains in accurately identifying public sentiments
about a disaster from social media texts.
Shouguang is a county-level city belonging to Weifang city, Shandong Province,
China. Figure 1 shows the geographical position of Shouguang City, located
in the coastal plain area of north-central Shandong Province. There are five
sub-districts and nine towns in Shouguang City, with a total population of
1,084,870. The Mihe River flows through the city. The area belongs to the
warm temperate monsoon zone of continental climate, which is suitable for
vegetable cultivation. Shouguang is one of China’s important producers of
vegetables, mainly for the Beijing market.
On August 18–19, 2018, there was torrential rain in Shouguang caused by typhoon
“Rumbia.” Affected by the heavy rain, three reservoirs upstream simultaneously
released floodwater to protect dams from collapsing, which was considered one
of the reasons for the flood. By August 20, widespread flooding submerged many
villages, houses, and farmland, leaving 13 people dead and at least three people
missing. Beyond the direct loss of lives, this flooding disaster also affected
vegetable prices in the surrounding cities. Hence, this flood aroused widespread
Figure 1. The administrative region of the Shouguang study area.