Post on 06-Dec-2021
Modeling Respirable
Particulate Matter
Concentration in
Metro ManilaOverview and key findings of the study
Atty Glynda Bathan
Deputy Executive Director
Clean Air Asia
4 August 2016
Previous studies on MM air quality and
emission sources
Previous modelling studies:
Manins (1990), UrbAir (1997), Manila Observatory (2003 and later)
MO 2003 study features• Georeferenced roads and stationary sources
• Two versions of mobile emissions: one at road level (barangay to national),
another at transport zone level (based on a traffic demand model)
Modelling approach constrained by limitations• No hourly data, so long-term concentrations only
• Single meteorological condition applied to whole domain
Common limitations:
Emissions inventory and meteorological data
How to understand air pollution?Identify emission sources and recognize its impact
Various potential uses of dispersion modeling in decision
making:
Identify air pollution hotspots
Guide for siting of future air quality monitors
Can be interfaced with population/poverty maps for urban planning
Aid in Environmental Impact Assessment
Dispersion model
Replicates atmospheric conditions (i.e., wind speed and direction, air
temperature and mixing height), and provide an estimate of the
concentration of pollutants as they travel away from (an) emission sources. Source: USEPA
Project Objective
Main Objective:
Further strengthen air quality management (AQM) in Metro Manila by improving the understanding of PM pathway through an updated dispersion map and emissions inventory
Key questions answered by the project:
1. Considering major emission sources, are we within or exceeding national air quality guideline values? Which cities/areas have highest number/share of population exposed to higher PM levels?
2. What are the major sources of PM pollution in Metro Manila which may be targeted by the Metro Manila Airshed?
3. What are the possible scenarios which would contribute to an air pollution episode?
Next steps?
What is the potential for use of a dispersion model in AQM planning for airsheds?
Project Approach and Partners
1. Emissions Inventory
2. Dispersion Modeling
3. Validation
4. Dissemination, Capacity Building
Partners
Project Approach and Partners
Environmental Management Bureau of the Department of Environment and
Natural Resources – Central Office and NCR
Department of Public Works and Highways – NCR District Engineering
Offices
Philippine Statistics Authority
Land Transportation Office
Metro Manila Development Authority
National Solid Waste Management Commission
City Governments: Caloocan, Las Piñas, Makati, Malabon, Mandaluyong, Manila,
Marikina, Muntinlupa, Navotas, Parañaque, Pasay, Pasig, Quezon City, San Juan,
Taguig, Valenzuela
Municipal Government: Pateros
Students and researchers of Ateneo de Manila University, Rizal Technical
University, University Malaysia Terengganu, University of Santo Tomas
Developing the Dispersion Model for
Metro Manila
JANUARY
JULY
Meteorology and land use:
Wind flow over Metro Manila:
• Northeast during Nov-Apr (Amihan)
• Southwest during Jun-Oct (Habagat)
Terrain and land use – influencing
turbulence
FACTORS THAT AFFECT AIR QUALITY
Emissions from sources, determined by:
Location of source
Fuel type for combustion
Hours of operation of fuel burning
equipment
WHAT WE DID
Improved modelling methodology
Use of the CALPUFF Modelling System
Complex terrain and land use in Metro
Manila are accounted for
Hourly winds and concentrations are
predicted
Huge increase in number of sources
modelled
Emissions from cooking, small
generators included
Household emissions defined at
barangay level
Hourly emissions from city roads and
bigger road network
Dispersion Model
● Main components: meteorological model (CALMET) and dispersion model (CALPUFF)
● Incorporates variations of met conditions in space (3D model) –needed if the entire MM airshed is to be modelled
● Widely used outside US and recommended in EMB modelling guideline (MC 2008-003
● 500 m x 500 m grid
● Base year - 2012
Emission Inventory: Stationary Source
Data source: Self Monitoring Reports from EMB NCR
• Type of source, facility name, fuel consumption and hours of operation
Added by study team:
• UTM coordinates
• Annual emission rates of PM10 and PM2.5
estimated using published emission factors
• No stack information; stack parameters assigned based on class:
o Classes: continuous or temporary, large or small
o Large sources assigned stack parameters typical for type
o Small sources are assumed to be downwashed, so emission are assigned to cells (volume sources)
Location of establishments
Source: Clean Air Asia
Emission Inventory: Area Source
Data source: NSO Census of Population and Housing
• Total fuel use (city level); fuel consumption per household (national average)
• Barangay-level household data (e.g., average house floor area, type of roof)
Required: Fuel consumption by type per barangay
• Assumption: Higher income HH uses mainly LPG; lower-income HH will use more kerosene, charcoal, and wood
• Five income classes identified based on house floor area distribution
• Method estimates the consumption rate of each fuel type for each class
• Resulting distribution must still be consistent with total fuel use per municipality Population Density Map
Emission Inventory: Mobile Source
Date source: DPWH
• 24 hour traffic survey
Based on a transport model for Metro Manila (2010 JICA/DPWH High Standard Highway Study)
• Cube Transport Model Software
• Provides hourly emission rates of PM from six vehicle types
• Includes more than 5,200 road segments
• Emission factors based on HBEFA and MM Drive Cycle testing. Considers road function, speed, fuel type, and engine technology.
NCR Road Network
Model Validation –
Comparison with AQ monitoring data
Dispersion modelling results generally compare well
with observed concentrations
Underestimation at Taft station: potential model limitation because traffic model was not able to fully capture intra-zonal trips
Dispersion Model Key Results
Considering major emission sources, are we
within or exceeding national air quality guideline
values?
Annual average PM10 and PM2.5 levelsAll Sources (not including background contribution)
PM2.5
• AQ guideline values are exceeded considering all major sources
• 3% of MM exceeding NAAQGV for PM10 (60µg/m3), 21% for PM2.5 (25g/m3)
• 30% of MM exceeding WHO IT-3 for PM10 (30µg/m3), 42% for PM2.5
(15µg/m3)
PM2.5PM10
Annual average PM10 and PM2.5 levels
All Sources (not including background contribution)
• Increased development in Region 4-A may contribute to air pollution in
cities in the south of Metro Manila [not yet covered in the study]
• Around 23% of construction permits issued in 2014 were from Region 4-A
PM10PM2.5
Annual average PM10 and PM2.5 levels
All Sources (including background contribution)
• 12% of MM exceeding NAAQGV PM10 (60µg/m3), 42% for PM2.5 (25g/m3)
• 58% of MM exceeding WHO IT-3 PM10 (30µg/m3), 85% for PM2.5 (15µg/m3)
PM2.5PM10
• Background concentration of PM10 (15 µg/m3) was added (based on Manila Observatory Nueva
Ecija Station)
Maximum (98th percentile) 24-hour PM10 and PM2.5 levels
All Sources (not including background contribution)
PM2.5
• AQ guideline values are exceeded considering all major sources
• 18% of MM exceeding NAAQGV for PM10 (150µg/m3), 53% for PM2.5 (50
150µg/m3)
PM10
Dispersion Model Key Results
Which cities/areas have highest number/share of
population exposed to higher PM levels?
3 cities have at least 30% population exposed to annual PM10 levels above NAAQGVs
15 cities have at least 30% population exposed to levels above WHO IT3
Percent of population exposed to annual Average PM10 levels
25% of the population in MM exposed to NAAQGVs exceedance
Health: 79% of population exposed to levels above WHO IT3
Percent of population exposed to 98th percentile 24-hr PM10 levels
24-hour PM10: 35% of the population in MM exposed to
NAAQGVs exceedance
8 cities have at least 30% population exposed to 24-hour PM10 levels above NAAQGVs
Dispersion Model Key Results
What are the major sources of PM pollution in
Metro Manila which may be targeted by the
Metro Manila Airshed?
Annual average PM10 and PM2.5 levels
All Sources (not including background contribution)
PM2.5
Percent contribution of sources• Area sources: 20%
• Mobile sources: 76%
• Point: sources 4 %
PM10
Emissions from Mobile Sources
Total PM10 Emissions from Vehicles (tpy)
Cars Jeepneys
BusesTrucks
Primary sources of mobile source PM10:
Jeepneys, trucks and buses running on diesel
Motorcycles
Tricycles
Further study needed on intrazonal trips – especially significant to fully capture
tricycle emissions.
Emission from Area Sources
PM10 Emissions from households (tpy)
Wood Charcoal
LPG Kerosene
Potentially significant source:
Emissions from household/commercial cooking using solid fuels
Dispersion Model Key Results
What are the possible scenarios which would
contribute to an air pollution episode?
Potentially significant contribution from generator sets
During POWER OUTAGE…
Emissions from diesel generator sets can
exceed the guidelines on source specific
emissions from industrial sources and
operations
(200 µg/Ncm, DAO 2000-81)
Expected increase in demand due to
growth in industrial, residential and
commercial sectors and during summer
months
Maximum 1-hr PM10 concentrations
(from generator sets)
Other potential scenarios to
be explored
• Impact of Euro4 on air quality
• Impact of fireworks
• Impact of Interruptible Load
Program (ILP)
Next steps: potential for use in AQM planning
for airsheds
Supplement AQ monitoring and associated activities of the DENR-EMB thereby arriving at a more holistic Air Quality Management Plan
Assist NCR Airshed Governing Board in exercising its mandate [target key sources] Results presented at the NCR Airshed Governing Board Meeting in Clark last June
Discussions with EMB-NCR to share the data and model and collaborate to build
capacity to use the dispersion model for planning
Increase awareness on scale of impact of air pollution in Metro Manila [population exposure]
Assist in evaluating potential air quality impact of new/planned policies:
DENR, DOTC, DOE – on fuel quality and vehicle emission standards
MMDA – on traffic management
LGUs – on permits and regulation of establishments and of area source activities, controlling open burning, regulations for commercial grilling
Movement of development to neighboring regions of Metro Manila
Share results with industry/establishments for guidance in the exercise of their CSRs (oil companies, vehicle manufacturers, transport operators, operators of Air Pollution Source Equipment (APSE))