Study on oil spill risk zoning in the Yangtze River Estuary based on the visited probability method of sensitive targets

Taking the main environmental sensitive targets in the Yangtze River Estuary in Shanghai as the research object, the Oilmap visited probability model was used to calculate the oil spill risk probability of the main eco-environmental sensitive targets in the Yangtze River Estuary, such as Qingcaosha centralized drinking water source, Dongtan Wetland National Nature Reserve, urban coastline tourism area and fishery fishing area. The oil spill risk index system was established based on the probability of oil spill occurrence, impact factors, meteorological and hydrological conditions and the sensitivity coefficients of sensitive target, to form a secondary zoning of oil spill risk in the Yangtze Estuary. According to the calculation results of oil spill risk index, the oil spill risk zoning of the Yangtze River Estuary in Shanghai was divided into four levels: >5 (highest risk area), 3-5 (higher risk area), 1-3 (medium risk area) and <1 (low risk area). The area of each risk level was 335, 2375, 5695 and 3068 km², respectively. For four key prevention and control areas, such as the oil spill risk prevention and control area in the water source area of the Yangtze River Estuary, some suggestions on zoning and classification requirements for prevention and control were put forward, the primary protection objectives of different zones were defined, and early warning, prevention and control levels in different regions were put forward according to the hierarchical control requirements, so as to provide basic decision-making basis for oil spill risk prevention and control management in the Yangtze River Estuary.