An experience on modelling-based assessment of the air quality within the Air Quality Directive...

An experience on modelling-based

assessment of the air quality within the Air

Quality Directive framework

Ana Isabel Miranda, Isabel Ribeiro, Patrícia Fernandes, Alexandra Monteiro,

Cristina Monteiro, Carlos Borrego

Con

cent

ratio

n

Fixed measurements shall be used

Combination of fixed measurements and modelling techniques and or indicative measurements may be used

Upper assessment threshold

Lower assessment threshold

Modelling techniques or objective-estimation shall be sufficient

SO2, NO2, NOx, PM10, PM2,5, Pb, C6H6, CO

Those fixed measurements may be supplemented by modelling techniques and/or indicative measurements to provide adequate information on the spatial distribution of the ambient air quality.

2008 Air Quality Directive| air quality assessment

Assessment strategy depends on upper and lower assessment thresholds

Exceedances of upper and lower assessment thresholds shall be determined on the basis of

concentration during the previous 5 years where sufficient data are available.

An assessment threshold shall be deemed to have been exceeded if it has beed exceed

during at least 3 separate years out of those previous five years.

Assessment for 2010 and 2011

Upper and lower thresholds exceedances for 2006-2010 (5 years

period).

1. Model application to Portugal (5 km x 5 km), 2010 and 2011

2. Bias correction based on the multiplicative ratio adjustment technique

3. Evaluation (using the DELTA tool when possible)

The approachThe approach

Monitoring

1. Monitoring stations selection and data treatment, for the period 2006-2010

2. Comparison with the upper and lower thresholds, for every pollutant

3. 2010 data treatment for the model evaluation

AQ assessment based on a combination of Modelling and

Measuring values

NO2, O3, PM10, PM2.5, SO2, CO,

C6H6.

MM5-EURAD

Meteorological conditions

Emissions

125x125 km2

25x25 km2

5x5 km2

Simulation domains

Emissions EMEP 2008 for the larger domains

Portuguese inventory 2008 for the portuguese domain

Transports

Industrial processes

Monitoring stations

),)(1

, modmod day(hCCCndays

day)(hC el

ndays

obsh

elh

corrected

),(),(

),(),( mod

mod dayhCdayhC

dayhCdayhC el

ndays

elndays

obs

corrected

SUBSTan additive correction of the mean bias

RATa multiplicative ratio correction

We started to compare…

Bias-correction techniques

• after BIAS correction, model results have a decrease > 70% on the average systematic

error• the multiplicative ratio: better correction technique

Bias-correction techniquesRAT & SUBST

• synoptic conditions are characterized by a 3-4 day period.

(Borrego et al., 2011, Atmospheric Environment)

O3PM10

ValidationValidationSO2 Hourly values – Calendário 2010

RDE = 15%; R = 0.63; bias = -1.01 µg.m-3; MSE = 4.31 µg.m-3

measured

modelled

SO2 4th maximum of the daily averages (protection of human health)

Threshold values were not exceeded

UpperLowerLV

Zones and agglomeration

s

a) b) c)

SO2

2010 2011It was not possible to have the needed data everywhere

4th maximum of the daily averages (protection of human health)

< LAT

LAT-UAT

> UAT

a) b) c)

SO2 Annual average winter period (ecosystem protection)

2010 2011

< LAT

LAT-UAT

>UAT

SO2

Zone Zone code

2010 – Above LV for vegetation (SO2 winter mean)

Area Vegetation area exposed

km2 Method km2 Method Braga PT1001

Vale do Ave PT1002 Vale do Sousa PT1003 Porto Litoral PT1004 Norte Litoral PT1005 Norte Interior PT1006 Aveiro/Ílhavo PT2001

Coimbra PT2002 Zona de Influência de Estarreja PT2003

Centro Litoral PT2004 Centro Interior PT2005

Área Metropolitana de Lisboa Norte PT3001 Área Metropolitana de Lisboa Sul PT3002 46.08 A 12.54 A

Setúbal PT3003 Vale do Tejo e Oeste PT3004

Penísula de Setúbal/Alcácer do Sal PT8001 103.92 A 59.54 A Zona Sul (região Alentejo+Região Algarve) PT8002

Alentejo Litoral PT4001 Alentejo Interior PT4002 Portimão/Lagoa PT5001 Albufeira/Loulé PT5002

Faro/Olhão PT5003 Algarve PT5004

Portugal (total) PT9000 150.00 A 72.08 A

Modelling results

CORINE Land Cover 2006

GIS

Annual average winter period (ecosystems protection)

a) b)

SO2 25th maximum hourly value

2010 2011

LV

ValidationValidationNO2 Hourly data

NO2 Annual mean


s

UpperLowerLV

NO2 Annual mean

2010 2011

LV

< LAT

LAT-UAT

> UAT

Zone Zone code

2010 – Above LV for human health (NO2 annual mean)

2011 – Above LV for human health (NO2 annual mean)

Area Road length Population exposed Area Road length Population exposed km2 Method km Method Number Method km2 Method km Method Number Method

Braga PT1001 Vale do Ave PT1002

Vale do Sousa PT1003 Porto Litoral PT1004 Norte Litoral PT1005 Norte Interior PT1006 Aveiro/Ílhavo PT2001



Área Metropolitana de Lisboa Norte PT3001 Área Metropolitana de Lisboa Sul PT3002 50.94 A 121.46 A 386080 A 71.48 A 170.44 A 541693 A

Setúbal PT3003 Vale do Tejo e Oeste PT3004

Penísula de Setúbal/Alcácer do Sal PT8001 0.39 A 0.12 A 379 A 30.99 A 9.63 A 202130 A Zona Sul (região Alentejo+Região Algarve) PT8002



Portugal (total) PT9000 51.33 A 121.58 A 386459 A 102.47 A 180.07 A 743823 A

NO2 Annual mean

Modelling results

Population data at sub-municipality

level

GIS

National roads

network

NO2 19th maximum of the hourly averages (protection of human health)


s

UpperLowerLV

a) b) c)

NO2

2010 2011

19th maximum of the hourly averages

< LAT

LAT-UAT

> UAT

LV

Zone Zone code

2010 – Above LV for human health (NO2 hourly mean)

2011 – Above LV for human health (NO2 hourly mean)

Area Road length Population exposed Area Road length Population exposed km2 Method km Method Number Method km2 Method km Method Number Method

Braga PT1001 Vale do Ave PT1002

Vale do Sousa PT1003 Porto Litoral PT1004 91.14 A 261.55 A 587933 A 87,26 A 228.22 A 569128 A Norte Litoral PT1005 Norte Interior PT1006 Aveiro/Ílhavo PT2001



Área Metropolitana de Lisboa Norte PT3001 Área Metropolitana de Lisboa Sul PT3002 1.34 A 3.20 A 10155 A 1.08 A 2.58 A 8171 A

Setúbal PT3003 Vale do Tejo e Oeste PT3004 51.79 A 3.24 A 33938 A 33.43 A 1.9 A 21905 A

Penísula de Setúbal/Alcácer do Sal PT8001 0.96 A 0.53 A 928 A 4.76 A 1.48 A 4622 A Zona Sul (região Alentejo+Região Algarve) PT8002



Portugal (total) PT9000 145.23 A 268.52 A 632954 A 126,53 A 234.18 A 603826 A

NO2 19th maximum of the hourly averages

NO2 Number of hours exceeding the LV

2010 2011

ValidationValidationPM10 Daily average

PM10 Annual average

20112010

< LAT

LAT-UAT

> UAT

LV

20112010

PM10 Daily average

< LAT

LAT-UAT

> UAT

LV

Notwithstanding this modelling work no modelling-based report to the Comission was delivered.

This work was requested by the Portuguese Agency for the Environment.

It was presented to the national agency and to the different regional entities in charge of the air quality assessment in Portugal. Several comments and feedbacks were received.

They were very interested and willing to do a cost-benefit analysis of using modelling tools and reducing monitoring stations instead of keeping the maintenance costs they’re facing nowadays.

We’re doing 2012 and we’re going to increase spatial resolution.

Final comments

But …There is a strong difficulty to trust models and people is afraid of using them, because:

• they were always working with AQ monitoring networks and that’s what they know

• they think models are a kind of “monster” and they do not provide a really added value

February 2009

Attitude towards models changed and people are much more receptive to their use for air quality

assessment.

Thanks to FAIRMODE!!!!

www.ua.pt/gemac

[email protected]

Thank you very much!!!Thank you very much!!!

http://www.ua.pt/gemac

An experience on modelling-based assessment of the air quality within the Air Quality Directive...

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