Study Of Characteristics Of Marine Vessel Emission And Its Impact On Regional Air Quality Of The Pearl River Delta Region

The Pearl River Delta (PRD) Region with densely distributed waterway network andports has been one of the most prosperous marine trading areas in Guangdong Province.Meanwhile, exhaust emissions from marine vessels has posed great challenges on regional airquality management. During the past decade, a series of control measures have beenimplemented to reduce emissions of major sources such as power plants and mobile vehicles,while marine emissions have not received enough attention yet. With the promulgation of newNational Ambient Air Quality Standards as well as continuously improving of regional airquality, great pressure has been posed on emission reductions. Thus, there is an urgent need toconduct researches on marine emissions and control measures in the PRD region.First, emission inventories of passenger ships, cargo vessels and fishing boats inGuangdong Province were developed and overall characteristics of marine emissions alongwith problems existing in inventory compilation, temporal allocation and spatial distributionwere identified. According to that, the PRD region has been chosen as a new domain tofurther improve studies of marine vessels.Second, vessel track data from the Automatic Identification System (AIS) and vesselfiles from the Lloyd’s Register of Ships (LRS) were utilized to obtain detailed and reliablemarine vessel activity data, and activity-based approach was used to develop the2010PRDmarine vessel emission inventory. Results showed that, marine emissions of SO2, NOX, CO,PM10, PM2.5and VOCs were6.3×104,14.4×104,1.7×104,8.1×103,7.5×103and6.4×103tonnes, respectively. Container vessels, general cargo vessels, fishing boats and bulk carrierswere the top four contributors. Contributions of main engines were generally larger thanauxiliary engines. For SO2, NOX, PM10and PM2.5, emissions under cruise mode were the mostsignificant. But for CO and VOCs, emissions mainly derived from the maneuvering mode.Besides, qualitative and quantitive analysis indicated that uncertainties of marine emissioninventories may be contributed by various sources and emission estimation of differentvessels carried rather high uncertainty, which needed to be further evaluated and improved.Meanwhile, temporal and spatial profiles of different marine vessels in the PRD regionwere developed based on the AIS vessel track data. It was found that hourly marine emissions during daytime were generally high while emissions during night time were much lower. Suchphenomena were closely associated with vessel activities. With respect to spatialdistributions, marine emissions mainly concentrated in coastal cities such as Huizhou,Shenzhen, Zhuhai and Jiangmen, with the spatial pattern characterized by a significantbanding distribution along the coastline. While marine emissions in other cities mainlydistributed within the PRD high level waterways.Finally,various cases were established and simulated via the WRF/SMOKE-PRD/CMAQmodeling system to investigate marine emission impacts on regional air quality. Resultsshowed that marine emissions have led to increasing concentrations of simulated NO2, SO2and PM10in most areas of the PRD region, while concentrations of simulated O3decreased,which was closely associated with the fact that O3formation in the PRD region was mainlyVOC-limited. The above results demonstrated that marine emission impacts on regional airquality could not be neglected and were largely depend on both wind directions and marineemission amounts in upper wind locations. Therefore, studies on marine emission controlshould be conducted immediately.