Environmental Risk Assessment of the Zhengrunzhou Water Source under the Influence of Oil Spill Accidents at the Wharf Group

Abstract

To compensate for the research defects of strong subjectivity in determining oil spill amount, insufficient consideration of wharf distribution, and incomplete indexes for reflecting the influence degree of oil spill accidents on water sources, and to enhance the supervision efficiency of the supervision department, this paper constructs a risk assessment system of water sources under the influence of the wharf group. The system includes a wharf group division method considering the wharf distribution situation; the calculation method of oil spill amount at wharves considering the oil tank capacity of main ship types and the production supervision risk at the wharves; the calculation method of the oil spill amount at the wharf group considering the wharf number, distribution density, production supervision risk and wharf oil spillage; the determination method for the influence degree of oil spill at the wharf group on the water sources and judgment method of supervision level at the wharf group, which takes the arrival time of oil slicks, the duration of over-standard petroleum concentration and the maximum over-standard multiple of petroleum concentration at the water intake as indexes; the method of determining the risk of oil spill accidents at the water source considering the cumulative effect of oil spill at the wharf group on the risk of the water sources; and the environmental risk assessment method of water sources considering oil spill accident risk and the anti-risk ability. Applying this system to the environmental risk assessment of the Zhengrunzhou water source in Zhenjiang City, we discovered that the flow field, wind field, oil spill location and oil spill amount were correlated with the influence degree of oil spill accidents on water sources, for which the flow field demonstrated the strongest correlation, while the wind field presented the weakest. The supervision level of the wharf group is mainly sub-key or non-key levels, but the level of the wharf group SD07 is approximate to the key supervision level during rising tide. Due to the strong anti-risk ability of the Zhengrunzhou water source, the environmental risks of the Zhengrunzhou water source under different working conditions are scarcely different and belong to the medium-risk level.