Preparation of the guidelines Preparation of the guidelines for vehicle non-exhaust for vehicle non-exhaust

emission modelling of PM10 emission modelling of PM10 and PM2.5 in Latviaand PM2.5 in Latvia

Aiga Kāla, Valts VilnītisAiga Kāla, Valts Vilnītis

SIA Estonian, Latvian & LithuanianSIA Estonian, Latvian & Lithuanian

EnvironmentEnvironment

February 10, 2009 

• Main tasks of the project

• Work programme:– field work,– evaluation and modelling

• Results of the project

Outline

The project• Started in 2007• In line with new requirements of

CAFE directive on exceedances attributable to winter-sanding or -salting of roads

• Co-financed by Latvian Environmental Protection Fund, Latvian Environment, Geology, and Meteorology Agency and ELLE

Main tasks of the project

• To indentify and compare the existing emission factors attributable to vehicle non-exhaust emissions

• To perform the field measurements• To compare dispersion modelling

results to the monitored values• To prepare guidelines

PM contributions to an urban agglomeration*

* Source: Marcus Pesch, 2008. Source apportionment of PM

Method for estimating resuspension

Assumptions:– PM2.5 is solely attributable to vehicular exhaust

sources

– Coarse fraction PM2.5–10 – to non-exhaust sources

ETOTAL = ETYRE + EBRAKE + ERESUSP

ETOTAL - the total non-exhaust PM emission,

EBRAKE - the PM emission due to brake ware,

ETYRE - the PM emission due to tyre ware,

ERESUSP - the PM emission corresponding to resuspension

Field work

• PM10 and PM2.5 measurements in the two measurement sites (GRIMM-EDM107):– traffic station;– urban background.

• Continuous traffic counts (RTMS model K3)

Measurement sites

Monthly average concentrations PM2.5 and PM10 , µg/m3

Daily traffic average

Hourly traffic average

STL – Heavy duty vehicles, VTL – Light duty vehicles

Estimation of emission factor

• Based on measured roadside increments of PM10 and PM2.5 and traffic counts

• Contribution of abrasion sources (tyre, brake) – according to EMEP/CORINAIR Emission Inventory Guidebook (2007)

• Resuspension emission factor estimated using dispersion modelling (ADMS)

Non-exhaust PM emission factors/models

• EMEP/CORINAIR Emission Inventory Guidebook – 2007

• RAINS (Regional Air Pollution INformation and Simulation)

• CEPMEIP (Co-ordinated European Programme on Particulate Matter Emission Inventories, Projections and Guidance)

• MOBILE 6.2

Advantages of EMEP/CORINAIR methodology

• Emission factor depends on:– Vehicle speed, – Load correction factor (heavy-duty

tracks),– Truck size.

• In all cases provide emission factor for PM10 and PM2.5

Emission factor for resuspension

Vehicle category Emission factor, g/km

Litgh-duty vehicle0.9

Heavy-duty vehicle2.7

Emission factors reported for other countries

Traffic monitoring sites

Dispersion modelling for traffic monitoring sites

Average concentrations of PM10 (μg/m3)

(without/with resuspension)

Monitoring siteMonitored

value

Modelled value,

(ratio*)

Modelled value,

(ratio*)K.Valdemāra iela 45.02 26.21

(0.58)34.96 (0.78)

Brīvības iela 52.55 26.56 (0.51)

41.14 (0.78)

S. Eizenšteina iela 32.49 21.73 (0.53)

26.94 (0.83)

* Ratio of modelled to observed concentration

Source apportionment of PM10 results

Brīvības street Valdemāra street

Further work

• Relationship of emission factor with meteorological factors (precipitation level, wind speed and direction)

• Source apportionment of urban background (62 – 77%):– Transboundary part,– Natural sources....