European Topic Centre on Air Emissions (ETC/AE) and is common for emission
inventories used as model inputs. In this nomenclature, sources are classified in
three levels of details:
• Macro-sectors (SNAP level 1, e.g. “energy transformation sector”); it exists 11
different macro-sectors,
• Sectors activity (SNAP level 2, e.g.” public power”) which are a disaggregation
of macro-sectors level,
• Activity levels (SNAP level 3, e.g. “combustion plants ! 300 MW (boilers)”)
which are a further disaggregation of sectors levels.
For each disaggregation level, more details can be added with definition of fuel
specification.
Emission inventories with disaggregation to the sector activity and activity levels
are most commonly used (Fig. 3.2). Together they cover one half of the questionnaires. Only 10 % of the studies use a macro-sector disaggregation level.
A combination of different levels of disaggregation is often used. Fuels specification is used in more than 50 % of the cases. According to the database, there is no
relation between the category disaggregation level and the spatial scale of the study.
Concerning the approach used to set up the inventory, a combined approach
using both a bottom-up and top down methodology is most common (58 %). This
is not surprising as official national and regional inventories are usually constructed
using this complementary approach. A top-down approach alone is used in few
cases (8 %), while bottom-up approaches alone represent about 22 % of the cases.
For the studies using a bottom-up approach, a majority of them have created a
project specific emission inventory over a small area. Urban, local and street level
studies represent more than 80 % of the studies using a bottom-up approach.
0%
5%
10%
15%
20%
25%
30%
35%
macro-sector
sector
activity
other
without fuel disaggregation with fuel disaggregation
Fig. 3.2 Disaggregation
level used in AQP and RP as
reported in the APPRAISAL
database
3 Current European AQ Planning at Regional …
41
inventories used as model inputs. In this nomenclature, sources are classified in
three levels of details:
• Macro-sectors (SNAP level 1, e.g. “energy transformation sector”); it exists 11
different macro-sectors,
• Sectors activity (SNAP level 2, e.g.” public power”) which are a disaggregation
of macro-sectors level,
• Activity levels (SNAP level 3, e.g. “combustion plants ! 300 MW (boilers)”)
which are a further disaggregation of sectors levels.
For each disaggregation level, more details can be added with definition of fuel
specification.
Emission inventories with disaggregation to the sector activity and activity levels
are most commonly used (Fig. 3.2). Together they cover one half of the questionnaires. Only 10 % of the studies use a macro-sector disaggregation level.
A combination of different levels of disaggregation is often used. Fuels specification is used in more than 50 % of the cases. According to the database, there is no
relation between the category disaggregation level and the spatial scale of the study.
Concerning the approach used to set up the inventory, a combined approach
using both a bottom-up and top down methodology is most common (58 %). This
is not surprising as official national and regional inventories are usually constructed
using this complementary approach. A top-down approach alone is used in few
cases (8 %), while bottom-up approaches alone represent about 22 % of the cases.
For the studies using a bottom-up approach, a majority of them have created a
project specific emission inventory over a small area. Urban, local and street level
studies represent more than 80 % of the studies using a bottom-up approach.
0%
5%
10%
15%
20%
25%
30%
35%
macro-sector
sector
activity
other
without fuel disaggregation with fuel disaggregation
Fig. 3.2 Disaggregation
level used in AQP and RP as
reported in the APPRAISAL
database
3 Current European AQ Planning at Regional …
41