Post on 01-Apr-2015
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
ValidationValidationNO2 Hourly data
NO2 Annual mean
Zones and agglomeration
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
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 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
Alentejo Litoral PT4001 Alentejo Interior PT4002 Portimão/Lagoa PT5001 Albufeira/Loulé PT5002
Faro/Olhão PT5003 Algarve PT5004
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)
Zones and agglomeration
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
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 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
Alentejo Litoral PT4001 Alentejo Interior PT4002 Portimão/Lagoa PT5001 Albufeira/Loulé PT5002
Faro/Olhão PT5003 Algarve PT5004
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
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!!!!