基于共词网络的雾霾事件下微博关注话题差异性——以中国北方雾霾严重地区典型城市为例

雾霾对人体健康、生态环境及交通运输等方面影响重大,雾霾来临时,人们会在微博等媒体上表达对雾霾的关注。微博中蕴含了网民对雾霾的关注话题及心理反映,通过微博掌握微博网民对于雾霾的相关反应,有助于城市管理者有针对性的调节雾霾情形下的舆论宣传和资源调配。考虑到微博文本中相同词语共现频率越高就越倾向于表达同一主题,采用基于社区的共词网络法挖掘微博话题,首先,采集2017年冬季以"雾霾""空气"等为关键词的微博数据,利用TF-IDF(term frequenly-inverse document frequency)算法对预处理之后的微博数据提取关键词,并获取关键词间的共现关系,然后基于共现关系构建共词网络,根据Louvain算法探测话题社区,最后,以中国雾霾污染最严重的华北地区、华东地区、东北地区7个典型城市为研究区,结合关键词节点的Pagerank值,分析各城市共词网络话题社区的差异程度。实验结果表明,不同城市对于雾霾事件的关注既有相同点也有差异性。研究结果对雾霾情形下城市差异化管理具有一定的理论指导作用。

Research on Differences of Microblog Concerning Topics under Haze Events Based on CO- word network:A Case Study of Typical Cities in China with Severe Haze

Haze has a significant impact on human health, ecological environment, transportation and other aspects. When haze comes, public concerns are widely expressed on micro-blogs and other media, which contain netizens'' psychological reflections on haze. It is helpful for city managers to adjust public opinion propaganda and resource allocation in haze situation by grasping the relevant reactions of micro-blog netizens to haze. Considering that the higher the co-occurrence frequency of the same words in micro-blog text is, the more likely the same topic is addressed, a community-based co-word network method was used in this paper to mine micro-blog topics. Firstly, keywords like "haze", "air" were used to collect micro-blog data in winter 2017. Secondly, TF-IDF algorithm was applied to extract keywords from pre-processed micro-blog data, from which the co-occurrence relationship between keywords was obtained. Then the co-word network was constructed based on the co-occurrence relationship, and the topic community was detected according to the Louvain algorithm. Finally, taking seven typical cities in North China, East China and Northeast China with the most serious haze pollution as the research areas, the difference degree of topic communities in co-word network of each city was analyzed combined with the Pagerank value of keyword nodes. From the experimental results, it can be shown that there are similarities and differences in different cities'' attention to haze events. The results of the study have a certain theoretical guidance for the urban differentiated management in the haze situation.