Among Japan’s maritime transport infrastructure, there are critical navigational points known as 'hotspots' where vessel disruptions would have serious impacts on the national economy. The Central Fairway in Tokyo Bay is considered as one of such hotspots, which is vital for maintaining the Tokyo metropolitan economy. Past incidents, such as the 10th Yuyo Maru explosion (1974) and the Diamond Grace oil spill (1997), disrupted port operations and key coastal industries like power, steel, and chemicals. However, since such incidents have occurred very rarely, quantitative risk assessment methods remain underdeveloped. This paper proposes employing a Markov chain-based method to quantify maritime transport disruption risks at these hotspots.

The purpose of this study is to analyze the relationship between natural environment and mental health of local residents in coastal area through questionnaire surveys. The target area of this study was the Karouto district, Kurahashi-cho, Kure City, Hiroshima Prefecture, Japan. 48 subjects (21 males and 27 females) were surveyed, with a mean age of 69.96 ± 11.89 years. An interview-based questionnaire survey was conducted, asking about the subjects' gender, age, length of residence, distance to the coast, outdoor physical activity index, frequency of consumption of local marine products, and degree of marine visibility and contact. Correlation and multiple regression analyses were conducted using the GHQ12 mental health scale as an indicator. The results showed that the GHQ12 had significantnegative correlation coefficients and standard partial regression coefficients with the outdoor physical activity index and degree of marine visibility and contact. These results suggest that outdoor activity and perception of the sea mayenhance mental health of local residents.