Assessing the reachability of hazard map pages on the official websites of all municipalities in Japan via route analysis

Abstract

This study analyzes the access paths to hazard map pages on the official websites of all municipalities in Japan. Using both manual exploration and web crawling, the study examines the paths from three perspectives: number of clicks, vocabulary, and structural characteristics. The results show that over 90% of municipalities allow access to the hazard map page within three clicks from their top page. However, municipalities with smaller populations tend to require more clicks. Vocabulary such as “disaster prevention” and “daily life” frequently appears, with patterns varying depending on the number of clicks. Structurally, the access paths were categorized into types such as linear, tree-like, and convergent. Furthermore, a contraction of the shortest path structure revealed that about 20% of municipalities have web structures that make hazard maps more difficult to find. These findings provide insights into systematically understanding the characteristics of disaster information delivery and designing more accessible web structures.