Modelling of NO 2 concentration in the exceedance area in Helsinki - Present state and projections

Transcription

1 Appendix 3 Modelling of NO 2 concentration in the exceedance area in Helsinki - Present state and projections Anu Kousa, Liisa Matilainen, Tarja Koskentalo, Helsinki Region Environmental Services Authority HSY Outi Väkevä, City of Helsinki Environment Centre

2 2 Modelling of NO 2 concentration Dispersion modelling was used to evaluate the development of NO x emissions and NO 2 concentrations in Helsinki in those areas where there is the highest risk of the limit value to be exceeded. Model For modelling NO 2 concentrations a street canyon model OSPM (Operational Street Pollution Model) was used. The model has been developed by the National Environmental Research Institute, Department of Atmospheric Environment, Denmark (Berkowicz, 2000). Emission factors Emission factors from the HBEFA (version 3.1) database for congested traffic have been used for most of the vehicles. Because of lack of sufficient EEV data in the HBEFA database the emission factors for EEV buses are based on the three-year RASTU project (RASTU project, 2009). According to this study the emission factors for EEV buses are 30 % better than for EURO IV buses. Besides research on fuel savings for heavy-duty vehicles the research integrate also included tasks relating to conventional exhaust gas emissions, IT applications and safety issues. During the research period, a total of approximately 140 heavy-duty vehicles were tested using a chassis dynamometer. Background and meteorological data Background concentration data measured at the urban background station (Kallio) is used from year 2010 in all projections assuming that the concentration decreases 1 % per year as a result of emission reductions. Also meteorological data is used from year 2010 in all projections. NO 2 concentration levels were higher in 2010 than earlier years in Helsinki region most probably because of unfavourable weather conditions (Malkki et al 2011). Thus the background and meteorological data that were used in this modelling represent the realistic worst case scenarios. Traffic volumes and vehicle distributions in different vehicle categories The total number of vehicles and their share in different vehicle categories has been provided by the Helsinki City Planning Department. Töölöntulli vehicles/year sum Passanger Car - Gasoline Passagen Car - Diesel Van Truck t Truck > 32 t Buses Without measures BAU Traffic volume change BAU Traffic volume change BAU Traffic volume change Environmental zone Smoother traffic BAU Traffic volume change Environmental zone Smoother traffic BAU Traffic volume change Environmental zone Smoother traffic The share of primary NO 2 Primary NO 2 is estimated to be 17.5 % (year 2010), 17.5 % (year 2011), 18 % (year 2012), 18.5 % (year 2013), 19.5 % (year 2014) and 20 % (year 2015) of total NO x emissions. This estimation is based on a study by Anttila et al., 2011 and on an expert evaluation by HSY.

3 Share of diesel passenger cars The share of diesel passenger cars is much lower in Finland than in the Central Europe. However, in the Helsinki Region the share of diesel passenger cars is higher than the average share in the whole country. For example in the Helsinki region the share of diesel passenger cars varied between 19 % and 36 % in the main roads in 2008 when the whole country average was 17 % (Figure 1 and 2). 3 Figure 1. Share of diesel passenger cars in the main roads in Helsinki in 2008 (Kärkinen, 2009). The number of new registrations of diesel cars increased considerably in year 2008 as a consequence of changes in Finnish tax legislation. Vehicle taxes were differentiated according to CO 2 emissions and diesel cars became more attractive than earlier. In % of new registrations were diesel cars but it seems their share has started to decline after the peak in In 2010 the share of diesel cars in new registrations was 42 % (Figure 2).

4 4 Figure 2. The share of diesel cars in new registrations and in the car fleet in Finland (Autoalan tiedotuskeskus, 2011). The share of diesel passenger cars in the city centre is estimated to be 27 % (year 2010), 27 % (year 2011), 28 % (year 2012), 29 % (year 2013), 30 % (year 2014) and 30 % (year 2015) in the modelled projections. Average speed Average speed in the street canyons is based on the study conducted by the Helsinki City Planning Department (Hellman, 2009). Emission standard categories The vehicle fleet composition in different emission standard categories for vehicles is based on the LIPASTO database developed by VTT Technical Research Centre of Finland (LIPASTO, 2011). The more detailed estimation for passenger cars is based on an expert evaluation by VTT. The estimated percentage of urban buses falling into different emission standard categories is based on information from the Helsinki Regional Transport Authority HSL. Exceedance area The estimated exceedance area is 8 km of street canyons in the centre of Helsinki city. According to our measurements and modelling results the street canyon Töölöntulli is the most polluted site in Helsinki and is the most challenging site in terms of achieving the limit value by 2015.The length of the street canyon Töölöntulli is 1.8 km.

5 5 Projections 1) 2010 The 2010 projection was calculated by using 2010 concentration data from an urban background station (Kallio). Also the meteorological data is from NO 2 concentration levels were higher in 2010 than earlier years in the Helsinki region because of unfavourable weather conditions (Malkki et al 2011). The total number of vehicles and their amount in different vehicle categories was estimated by the Helsinki City Planning Department. Primary NO 2 is estimated to be 17.5 % year At the moment the share of diesel passenger cars in Helsinki region is estimated to be 27 %. The vehicle fleet composition in different emission standard categories is based on the LIPASTO database developed by VTT Technical Research Centre of Finland (LIPASTO, 2011). The more detailed estimation for passenger cars is based on an expert evaluation by VTT. The estimated percentage of urban buses falling into different emission standard categories is based on information from the Helsinki Regional Transport Authority HSL. 2) Business as usual projection (BAU ) In the BAU projections the known improvements in the vehicle technology regulated by the Union law (Euro standards) is taken into account. The vehicle fleet is assumed to be renewed according to the normal rate. The annual NO 2 urban background concentration is expected to decrease 1 % per year. The estimation is based on the study by Anttila and Tuovinen (2010). The total number of vehicles and their share in different vehicle categories are based on the estimation done by the Helsinki City Planning Department. Primary NO 2 is evaluated to be 17.5 % (year 2010), 17.5 % (year 2011), 18 % (year 2012), 18.5 % (year 2013), 19.5 % (year 2014) and 20 % (year 2015) of total NOx emissions. This estimation is based on an article by Anttila et al., 2011 and expert evaluation by HSY. The vehicle fleet composition in different emission standard categories for vehicles is based on LIPASTO database developed by VTT Technical Research Centre of Finland (LIPASTO, 2011).The more detailed estimation for passenger cars is based on an expert evaluation by VTT. In Finland the average age of vehicles is higher than in the Central Europe. E.g. the average age of passenger cars was 11.9 years in 2010 (Source: Statistics Finland/TraFi). The estimated share of urban buses falling into different emission standard categories is based on information from the Helsinki Regional Transport Authority HSL Euro I 1 % 0 % 0 % 0 % 0 % 0 % Euro II 31 % 17 % 15 % 10 % 5 % 0 % Euro III 29 % 29 % 27 % 25 % 22 % 15 % Euro IV 7 % 7 % 7 % 7 % 7 % 7 % Euro V 4 % 4 % 4 % 4 % 4 % 4 % EEV 28 % 43 % 47 % 49 % 48 % 53 % Euro VI 5 % 14 % 22 %

6 6 3) Traffic volume change In the Traffic volume change projection the number of vehicles is expected to decrease at some points (including Töölöntulli) as a consequence of increased attractiveness of public transport and improved public transport connections. The total number of vehicles and their number in different vehicle categories are based on an estimate by the Helsinki City Planning Department. The projection includes also the known improvements in vehicle technology. 4) Environmental zone The City Board of Helsinki decided on to implement an environmental zone in the city centre. The zone extends to the south of Hakamäentie Road and covers the areas that are most problematic from the point of view of air quality, including the busiest street canyons (see Figure 3). This zone overlaps with the restriction area where heavy goods vehicles (HGVs) with a length over 12 meters are not allowed. This restriction does not apply to buses nor to HGV`s which have been granted a special permission. HGVs traffic to the city harbours is directed along designated routes that do not pass through the city centre. The environmental zone applies only to the internal and regional bus traffic and waste transport vans. The bus traffic is submitted to competitive tendering by HSL (Helsinki Regional Transport Authority) and waste transport is submitted to competitive tendering by HSY (Helsinki Region Environmental Services Authority). HSL and HSY apply stricter emission criteria for buses and waste trucks in the environmental zone. When new contracts are submitted to tendering, buses in the environmental zone must comply with Euro 3 standards and waste transport vans with Euro 5 standards. The impact of waste transport vans on air quality is marginal, but the impact of city buses is significant.

7 7 Figure 3: The environmental zone of the city of Helsinki (delineated in green) and the restriction area of the heavy goods vehicles (delineated in orange). In the Environmental zone projection the renewal of buses is faster than in the BAU projection. The estimated share of urban buses falling into different emission standard categories is based on information from the Helsinki Regional Transport Authority HSL Euro I 1 % 0 % 0 % 0 % 0 % 0 % Euro II 31 % 17 % 15 % 10 % 5 % 0 % Euro III 29 % 29 % 27 % 20 % 14 % 0 % Euro IV 7 % 7 % 7 % 7 % 7 % 7 % Euro V 4 % 4 % 4 % 4 % 4 % 4 % EEV 28 % 43 % 47 % 54 % 56 % 67 % Euro VI 5 % 14 % 22 % The projection includes also improvements in vehicle technology and the estimated decrease in the number of vehicles. 5) Smoother traffic In the final projection it is assumed that traffic is smoother because there is less traffic. The average speed is 3 km/h higher than in the BAU projection. The projection includes also improvements in the vehicle technology, the estimated decrease in the number of vehicles and stricter emission criteria applied to urban buses within the environmental zone. 6) Reference cases 2005 and 2010 The emissions of NO x and annual NO 2 concentrations were modelled also for two other situations: a) No measures 2010: It is assumed that there have been no measures to achieve compliance. Traffic volumes are from 2006, which result in a lower average speed (-3 km/h) than in the b) 2005: In this backward projection concentration data measured at the urban background station (Kallio) is used from year Also meteorological data is from year Emission factors from the HBEFA database for year 2005 are used. Primary NO 2 is evaluated to be 15 % year The share of diesel passenger cars in Helsinki region was 12.5 %.

8 8 Modelling results Töölöntulli According to the modelling results it is possible to achieve the limit value the street canyon Töölöntulli where the concentrations are the highest in the region (table 1). It is possible to reach the limit value in Helsinki by 2015 but not earlier (see table 1 and figure 4). NO x emissions in Töölöntulli in the different projections between 2005 and 2015 are presented in figure 5. Similar model run results for Mannerheimintie, Kaisaniemenkatu, Mäkelänkatu, Hämeentie, Sturekatu, Unioninkatu, Runeberginkatu and Lönnrotinkatu are presented in Figures Table 1 Modelled NO 2 concentrations in the present state in 2010 and in projections for 2015 in the street canyon Töölöntulli. Töölöntulli Vehicles / day Concentration µgno 2 /m BAU 2015 Improvements in vehicle technology (Euro I VI) Traffic volume change 2015 The number of vehicles decreased Environmental zone 2015 Urban busses: faster improvements in different emission standard categories (Euro I VI) Smoother traffic 2015 Average speed +3 km/h *) *) *) *) The result of the projection includes measures already introduced in the BAU and other previous projections.

9 9 Figure 4. Modelled NO 2 concentration in the different projections in Töölöntulli. Figure 5. NO x emissions in the different projections in Töölöntulli.

10 10 Other Figure 6. Modelled NO 2 concentration in the different projections in Mannerheimintie. Figure 7. NO x emissions in the different projections in Mannerheimintie.

11 11 Figure 8. Modelled NO 2 concentration in the different projections in Kaisaniemenkatu. Figure 9. NO x emissions in the different projections in Kaisaniemenkatu.

12 12 Figure 10. Modelled NO 2 concentration in the different projections in Mäkelänkatu. Figure 11. NO x emissions in the different projections in Mäkelänkatu.

13 13 Figure 12. Modelled NO 2 concentration in the different projections in Hämeentie. Figure 13. NO x emissions in the different projections in Hämeentie.

14 14 Figure 14. Modelled NO 2 concentration in the different projections in Sturenkatu. Figure 15. NO x emissions in the different projections in Sturenkatu.

15 15 Figure 16. Modelled NO 2 concentration in the different projections in Unioninkatu. Figure 17. NO x emissions in the different projections in Unioninkatu.

16 16 Figure 18. Modelled NO 2 concentration in the different projections in Runeberginkatu. Figure 19. NO x emissions in the different projections in Runeberginkatu.

17 17 Figure 20. Modelled NO 2 concentration in the different projections in Lönnrotinkatu. Figure 21. NO x emissions in the different projections in Lönnrotinkatu.

18 µg/m3 18 Comparison of modelled results to measured concentrations Töölöntulli was estimated to be the worst case scenario, where the concentrations are the highest so far measured in the area. Because of the precautionary principle we have used HBEFA emission factors. These emission factors seem to slightly overestimate the concentrations in Töölöntulli, whereas VTT emission factors would seem to underestimate them. Figure 22 shows that modelling with HBEFA factors gives an annual concentration of NO 2 which is slightly higher than the concentration measured at the Töölöntulli monitoring site in Thus the real concentrations are estimated to be slightly lower than those modelled at the Töölöntulli monitoring site. Töölöntulli measured modelling (HBEFA) modelling (VTT) Figure 22. Modelled and measured concentrations at the Töölöntulli monitoring site. Modelling was carried out using HBEFA and VTT emission factors.

19 19 References Anttila, P., Juha-Pekka Tuovinen, Jarkko V. Niemi (2011). Primary NO 2 emissions and their role in the development of NO 2 concentrations in a traffic environment. Atmospheric Environment 45(2011) Anttila P. and Tuovinen J.-P, Trends of primary and secondary pollutant concentrations in Finland in Atmospheric Environment 44, Autoalantiedotuskeskus, F1dG9qZW5fb3N1dXNfZW5zaXJla2lzdGVyb2lubmVpc3RhX2phX2thbm5hc3RhXy5odG0&tyyppi=SK&jul _id=19832&ain_id=&suoj=&jul_nimi=dieselautojen+osuus+henkil%f6autojen+ensirekister%f6inneist%e 4+ja+kannasta+%7C+Share+of+diesel+cars Berkowicz, R. (2000) OSPM - A parameterised street pollution model, Environmental Monitoring and Assessment, Volume 65, Issue 1/2, pp Hellman, Liikenteen sujuvuus Helsingissä vuonna Helsingin kaupunkisuunnitteluviraston julkaisuja 2009:7 a+_raportti_2009.pdf?mod=ajperes&cacheid=a7f23e004a1723cfad7fed3d8d1d4668 Kärkinen, T., Virpi Pastinen, Pipsa Eklund, Sakari Nurmela, Pääkaupunkiseudun työssäkäyntialueen ajoneuvoliikenteen määräpaikkatutkimus YTV:n julkaisuja 24/ LIPASTO, Report (in finnish): Malkki, et al., Ilmanlaatu pääkaupunkiseudulla vuonna HSY:n julkaisuja 3/2011 RASTU-project, Heavy-duty vehicles: Safety, environmental impacts and new technology, RASTU. Summary report. Edited by Matti Kytö, Kimmo Erkkilä and Nils-Olof Nylund. VTT-R