基于AIS信息的我国东部近海船舶废气排放季节变化与空间分布研究

Ship emission has become one of the most important anthropogenic emission sources, and caused severe impact on air quality and human health in coastal region. Over the past decade, owing to rapidly growing sea-borne commerce, marine traffic activities have risen dramatically in adjacent eastern China sea. However, the knowledge of ship emission and its temporal and spatial distribution in this region is still lack. Most global emission inventory of shipping was developed based on ship activity database of 2000～2006. Despite this inventory had included emission from marine traffic in adjacent eastern China sea, it was low spatial resolution and only taken ocean-going vessel emission into consideration, rather than coastal and domestic vessels emission. Based on information provided by automatic identification system (AIS) during 2011 to 2012, together with ship attributes and emission factors, this study will develop a regional ship emission inventory in high spatial resolution (0.05 ×0.05 ) by method of bottom-up for adjacent eastern China sea. Here, NO2, SO2, and PM are chose as the characteristic pollutants of ship emission. Seasonal variation and spatial distribution of ship emission in this region will be addressed. This study focuses on ship emission especially in the main harbors. The contribution rate of ocean-going, coastal and inland vessels to emission will be estimated. Classifies of ship emission by ship type, engine/boiler, or operation modes will also be presented. Finally, uncertainty of emission inventory will be evaluated by method of Monte Carlo Simulation, as well as the key source of this uncertainty.

船舶废气排放已成为人为大气污染的重要来源之一，其在沿海地区造成的空气质量污染和人群健康问题尤为严重。近十多年来，由于海上贸易的快速发展，我国东部近海船舶活动日益频繁，但对该区域船舶排放污染物量及其时空分布的认识却不足。全球船舶排放清单多基于2000～2006年远洋船舶活动信息建立的，尽管包括该区域船舶排放，但其空间分辨率较低，也没有考虑沿海和内河船舶排放。本研究基于2011-2012年船舶AIS信息，关注主要污染物NO2、SO2和PM，采用自下而上法结合船舶档案和特征污染物排放因子，建立高分辨率（0.05 ×0.05 ）的我国东部近海船舶废气排放清单。给出船舶排放特征污染物量，阐明其季节变化与空间分布，重点关注主要港口的船舶排放，同时分析远洋、沿海和内河船舶排放贡献率，以及不同类型船舶、不同引擎、不同航行状态下的污染物排放分担率，并采用蒙特卡罗模拟法分析清单的不确定性，识别其关键来源。

近年来， 随着全球贸易和我国经济的迅速发展，我国东部沿海港口发展迅速，如上海港、宁波舟山港、青岛港等已成为世界贸易的重要港口。本项目利用船舶档案信息与特征污染物排放因子，以及解析AIS数据获得的我国东部近海船舶活动信息，建立了高分辨率（0.05°×0.05°）的我国东部近海船舶废气排放清单，分析了清单的不确定性及其关键来源。. ⑴基于对船舶活动 AIS 信息的解析结果，结合船舶档案信息与特征污染物排放因子，采用自下而上法估算了船舶废气排放PM、SO2、NOx的量，2011-2012年我国东部近海船舶排放PM、SO2和NOx量分别为0.29Mt/a、2.96Mt/a和3.76Mt/a。与全球排放清单相比较，我国东部近海船舶废气排放PM量占全球排放量的18.6%~22.3%，SO2排放量占29.9%~32.6%，NOx排放量占23.8%~24.3%。.⑵空间分布来看：船舶排放污染物量主要分布于主要港口和重要航线上，港口的排放量以上海港、宁波－舟山港的为首，航线的排放量以成山角至长江口、渤海湾内港口间、以及东南沿海近岸的为主，船舶排放特征污染物量分布与船舶活动信息较为一致。.⑶季节变化来看: 船舶PM排放量冬季>春季>夏季>秋季；SO2排放量冬季>夏季>春季>秋季；NOx排放量冬季>春季>夏季>秋季。.⑷远洋与沿海和内河船舶相比，远洋船舶排放贡献率50%～60%，大于沿海和内河船舶排放量贡献率40%～50%。.⑸集装箱船排放分担率最高36%，货船次之26%，散货船和油轮占比21%，这四种类型船舶废气排放分担率超过80%，表明控制大型船舶排放将有助于减少船舶废气排放量，其他类型船舶的分担率19%。.⑹船舶主机排放PM、SO2和NOx的分担率分别为86%、84%和85%，远大于副机动排放分担率；航行状态下污染物排放分担率最大，PM、SO2和NOx的贡献率分别为89%、90%和89%，其次为停泊工况下的分担率，机动状态下分担率最低仅占1%～3%。.⑺船舶废气排放清单不确定性主要来自船舶档案信息和特征污染物排放因子。船舶档案信息不确定度为±30%。特征污染物排放因子不确定度为±80%，假设输入数据符合对数正态分布，利用蒙特卡洛数值分析方法传递不确定性。经模型10000次重复计算，我国东部近海船舶废气排放清单PM、SO2、NOx的不确定性分别是±79%、±86%和±88%。