Selection of onshore sites based on monitoring possibility evaluation of exhausts from individual ships for Yantian Port, China

Based on the feasibility evaluation of measuring individual ship emissions, layout of onshore monitoring sites in Yantian Port, China was studied. Four categories of representative ships were selected and WRF/CALPUFF was used to simulate the transmission and diffusion of exhaust pollutants from each individual ship. Statistical analysis was conducted on the measurable SO2 range for all categories of representative ships under 24 types of typical meteorological conditions. The measurable extent was the largest when the wind direction was perpendicular to the route. Additionally, the measurable distance increased with increasing wind speed under stable stratification, while the opposite held true under unstable stratification. Moreover, the ship?s main engine power had significant impact on the measurable extent. Overall, the most favourable monitoring direction is southwest and establishing monitoring sites on the southern island of Yantian Port was deemed optimal. The measurable distances of category A, B, C and D ships southwest of the monitoring sites were large, at 2.55 km, 2.64 km, 3.04 km, and 3.28 km, respectively. The measurable distance was 2.64 km on the annual average scale in this direction. The monitoring efficiencies of the six pre-set monitoring sites ranged from 15.32% to 64.34%; Sites 5 and 6, located on the southern island, had the highest monitoring efficiencies, followed by Site 3 north of the ship routes. The monitoring efficiency would reach 98.16% if onshore monitoring sites were set up simultaneously at Site 5 and Site 3.

Automated summary

This study determined the optimal direction and location of onshore monitoring sites for measuring individual ship emissions in Yantian Port, China, as well as the favorable meteorological conditions. By simulating the transmission and diffusion of exhaust pollutants from different categories of ships, it was found that wind direction, wind speed, and ship's main engine power significantly affect the measurable extent.