Characterization of pollutant discharges from ships within 100 nautical miles of China's coastline and certain inland river ports, 2022

Abstract

With the rapid development of global maritime trade, the impact of ship emissions on the environment and public health has become increasingly severe, making the construction of an accurate ship emission inventory an important research focus in the field of marine environmental protection. Currently, most of the relevant studies in China are limited to a single port scale and lack a systematic analysis of a large-scale region. Therefore, this study breaks through regional limitations and focuses on the important economic and maritime hub of the eastern coastal region of China. Using AIS data and employing a “bottom-up” approach, it constructs a ship pollutant emission estimation model in 2022 within 100 nautical miles of China's coastline and certain inland river ports, and further analyzes the characteristics of the pollutants. The results show that the total ship emissions in the study area for NO_X, SO₂, CO, PM_2.5, HC, and VOCs were 4.87 × 10⁵ t, 1.33 × 10⁵ t, 4.55 × 10⁴ t, 1.52 × 10⁴ t, 2.34 × 10⁴ t, and 2.35 × 10⁴ t, respectively, with NO_X and SO₂ emissions dominating. The Yangtze River Delta, Pearl River Delta, and Bohai Bay are major emission hotspots, and the emission intensity of some inland river ports is higher than that of coastal ports. Ship emissions show obvious seasonality and daily regularity, and the contribution of pollutant emissions from cargo ships is >50 %, with main engine emissions dominating. Based on these analyses, this study puts forward targeted emission reduction proposals, which provide an important reference basis for the formulation of environmental protection policies.