Oil pollution risks on coastlines in the Eastern China Seas.

As maritime transportation experiences continuous development, the escalating potential risk of oil spills necessitates thorough and detailed risk assessments. Realizing the inherent contingency and unpredictability of oil spill incidents, this study employs a 3D oil spill model combining with long-term hydro-meteorological data to evaluate the oil pollution risk (OPR) along the coastlines of the Eastern China Seas. Through simulations spanning four seasons over 21 years (2001-2021), diverse scenarios are captured. Specifically, surface oil spills in the Bohai Sea mainly spread along coastal currents but have a relatively limited diffusion range due to ocean dynamic conditions. Surface oil spills occurring in the Yellow Sea mainly threaten the ecological environments of the Korean Peninsula, Shandong Peninsula, and Subei Shoal, while those occurring in the East China Sea significantly impact the coastal areas of Zhejiang, Fujian, and Kyushu. Furthermore, the distribution of OPR exhibits clear and stable seasonal characteristics, with interannual variabilities less than 2%. Coastlines affected by the Kuroshio and its branches are at a higher risk year-round but with smaller interannual variabilities. Conversely, coastlines exhibiting large interannual variabilities are mainly distributed in regions that undergo significant seasonal changes in current and wind fields.