634
(2009) developed the total emissions using
comprehensive maritime transport database of
activity data, specific energy consumption, emission
factors. These studies demonstrated useful methods
to quantify ship emissions and their composition.
However,thedataformodellingtheshipemissionin
certain area is very much limited. Therefore,
calculatingtheshipemission
inventoryischallenging.
Since2002newshipsandlateralllargersea‐going
vessels (>300 GT) and all passenger vessels are
requiredtocarryanAutomaticIdentificationSystem
(AIS)onboard.ThroughdedicatedVHFfrequencies,
AISinformationistransmittedbetweenvessels,from
vesselstoshore,orviceversa.Insimple
terms,AISis
a technology to make ships “visible” to each other.
AISdataistherealisticdataoftrafficdataincluding
dynamic information (position, speed, course, etc.)
andstaticinformation(shiptype,dimensions,name,
etc.). Such development provides profound data
foundation of individual ship activity information
and regional traffic situation
to study on ship
emissions.Therefore,severalresearchersappliedsuch
perspectiveontheirstudyasnewapproachtoobtain
shipemissioninventoriesaccurately.
The Ship Traffic Emission Assessment
Model(STEAM) was established by Jalkanen et al.
(2007)toestimatetheemissionsofSO
X,NOX,CO2in
the Baltic sea. Laurie and Brett (2014) established a
model to calculate ship engine exhaust emissions in
ports and extensive coastal waters using terrestrial
Automatic Identification System data for ship
movements and operating modes. Winther et al.
(2014) calculated a detailed Black Carbon(BC), NO
X
and SO
2 emissions inventories in the Arctic in 2012
and under two shipping scenarios (with or without
arctic diversion routes). Meanwhile, they forecasted
theemissionfortheyears2020,2030and2050.Since
ships emission inventory is closely linked with the
activity of every ship, and AIS data can explicitly
reflectindividual
shipactivityandmacroscopictraffic
situationofcertainregion,methodsbasedonAISdata
can estimate emissions more accurately and become
promising.
However, the relevant research and management
of ship emission are backward in China to some
extent.ThedrasticdevelopmentofChineseeconomy
has boosted the increment of ship number
and the
intensityofshiptrafficincongestedwaterareassuch
as estuaries, which causes serious environment
pollution due to ship emissions. The estuary of
Yangtze River plays a vital role in connecting the
inland and oversea shipping, and witnesses heavy
vesseltraffic.Suchproblemsareobviousinthisarea.
With improvement and implementation of ship
pollution prevention and control requirements,
government of China has been speeding up the
establishment of the ship Emission Control Areas
(ECA) all over the country. Three ECAs are
establishedinthePearlRiverDelta,theYangtzeRiver
Delta and the Bohai Rim (Beijing City, Tianjin
City
andHebeiProvince)respectively.TheYangtzeRiver
Delta has already started the implementation of
emission reduction measures from April 1, 2016.
Those port authorities encourage ships to use low
sulfur fuel (less than 0.5%m/m) when they are
mooring in the hub port areas along the Yangtze
River delta ECA.
To control the emission in ECAs,
shipemissioninventoryshouldbedeveloped.JINet
al.(2009)presented the emissionsinventory ofNO
X,
HC,COandPM10fortheTianjinportin2006based
fuel consumption data. FU et al. (2012) applied a
bottom‐up dynamic approach to calculate the ship
emissions for Shanghai port. YE et al. (2014)
presented the ship emissions inventories for
Guangdong province in 2010 using two different
methods
for emission factors, and analyzed the
temporalandspatialcharacteristicsofemissionsfrom
different ship type. However, it is very difficult to
build the bottom‐up approaches with satisfactory
accuracy for ship emission on the basis of fuel
consumptionorturnovervolumeofgoods.
In this context, this paper presents
a bottom‐up
AIS‐based method to calculate the ship emission
inventories in the estuary of Yangtze River. We
establish emission calculation models for different
ship types to present a detail CH
4, CO2, CO, DPM,
HC, N
2O, NOX, PM10, PM2.5 and SOX emission
inventories for ships in the estuary of the Yangtze
Riverin2010.Theemissioncontributionwhichcomes
from each ship type to the whole‐year emissions
inventories are reckoned. From emission spatial
allocation, the highest emission period of each ship
typeis identified,and theshipping routecomprised
the region
with the highest emissions can be
distinguished.
Hopefully, the proposed method can serve as a
reference for other researchers and policy makers
workinginthisfield.
2 METHODOLOGY
Emissions from the shipping industry will be
calculatedusinga bottom‐upAIS‐basedmethodand
AIS data to derive vessel activity.
The ship length
interval, sailing speed, sailing time and position are
abstracted from AIS data to calculate the ship
emissions. The ships within the study area will be
divided into several different types. Before
developing the ship emissions inventory, the length
between perpendiculars (Lpp) should be calculated
usinga formula.Lpp
canbeusedasinputparameter
for calculation of the propulsion power. Then, a
method will be developed based on the emissions
calculation formula to enable the calculation of
emissionsusingenginepower,engineoperatingtime,
emissionsfactorsandloadfactor.Fig.1illustratesthe
frameworktocalculatetheshipsemissions.
2.1 Emissionsunderdifferentloadconditions
Theship emissions isclosely relatedtospeed ofthe
ship because the load factor of main engine is
different at different speed. Therefore, ship sailing
state is divided into three statuses: in port or at
anchor,maneuveringandcruising.
When ship speed is less
than 1knot, we believe
thattheshipisinportoratanchor,atthistime,the
auxiliaryengineisconsideredtobethesoleworking
engine (WEN et al., 2016). The installed auxiliary
enginepowercanbeusedtocalculatetheemissions