Options for research to enhance
national air quality information for
environmental reporting
Prepared for Ministry for the Environment
June 2015
Prepared by:
Guy Coulson, Elizabeth Somervell, Ian Longley, Sally Gray and Gustavo Olivares
For any information regarding this report please contact:
Guy Coulson
Group manager
Air Quality and Health
+64-9-375 4503
Email: guy.coulson@niwa.co.nz
National Institute of Water & Atmospheric Research Ltd
Private Bag 99940
Viaduct Harbour
Auckland 1010
Phone +64 9 375 2050
NIWA CLIENT REPORT No:
Report date:
NIWA Project:
AK2015-15
June 2015
MFE15102
Quality Assurance Statement
Reviewed by:
Annette Semadeni-Davies
Approved for release by:
Ken Becker
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contained herein, or that it will be suitable for any purpose(s) other than those specifically contemplated
during the Project or agreed by NIWA and the Client.
Contents
Executive summary ............................................................................................................. 5
1
Introduction .............................................................................................................. 6
1.1
2
3
4
5
Development Process ............................................................................................... 6
Potential improvement projects ................................................................................. 7
2.1
Potential Projects: General indicators and data framework questions.................... 8
2.2
Potential projects: indicators of pressure................................................................. 9
2.3
Potential projects: indicators of state .................................................................... 10
2.4
Potential projects: indicators of impact ................................................................. 11
Prioritisation process ............................................................................................... 13
3.1
Prioritisation criteria ............................................................................................... 13
3.2
Introducing dependencies into the prioritisation................................................... 16
Suggested work packages for the improvement projects ........................................... 17
4.1
Project workflow framework .................................................................................. 17
4.2
Process to review and update indicators ............................................................... 18
4.3
Creating indicators of PM2.5 state and impact ........................................................ 18
4.4
Robust estimates of the contribution of natural sources to PM10 ......................... 22
4.5
Establishment of a national monitoring network ................................................... 26
4.6
Creation of an easily updated and improved national emissions inventory suitable
for tracking trends in pressures .............................................................................. 29
4.7
Improving the indicators of PM10 state and impact ............................................... 34
Detailed Work Packages ........................................................................................... 38
5.1
Creating indicators of NO2 state and impact .......................................................... 38
5.2
What are the meteorological impacts on trends in ambient pollution? ................ 44
6
Completion schedule ............................................................................................... 50
7
References............................................................................................................... 51
Options for research to enhance national air quality information for environmental reporting
Tables
Table 3-1:
Table 3-2:
Table 4-1:
Table 4-2:
Table 4-3:
Table 4-4:
Table 5-1:
Table 5-2:
Table 6-1:
The project-criteria matrix.
Projects grouped by dependencies.
Estimated timings for the PM2.5 work package.
Estimated timings for the PMn work package.
Estimated timings for the inventory work package.
Estimated timings for the PM10 work package.
Estimated timings for the NO2 work package.
Estimated timings for the meteorological work package.
Recommended Sequencing of work.
15
16
20
24
31
36
40
46
50
Figures
Figure 4-1:
Anticipated workflow framework.
17
Options for research to enhance national air quality information for environmental reporting
Executive summary
The Ministry for the Environment (MfE) and Statistics New Zealand (Stats NZ) are jointly responsible
for the publication of environmental domain reports and the continual improvement of the reporting
of environmental measures. The first air domain report was published in 2014. The Parliamentary
Commissioner for the Environment (PCE) and the Technical Advisory Group (TAG) set up by MfE as
part of the reporting process have both provided suggestions for potential improvements. NIWA was
subsequently commissioned by MfE to undertake the development of a prioritised list of projects to
enhance and expand the air domain report.
This report presents this list of proposed projects, and documents the process of its development.
The process was iterative and involved rounds of consultation with MfE and StatsNZ. An initial list of
project ideas based on feedback and expert opinion, was developed by NIWA, who also devised
criteria for each potential project to be scored against. The resulting high priority projects were
grouped by their interdependencies and re-configured into proposed work packages which align with
a common workflow sequence.
The proposed workflow breaks the recommended work package into staged projects, each of which
allows for the generation of improved interim outputs (such as case studies, draft indicators) when
required. Projects feature a mixture of literature reviews, method development and modelling, and a
mixture of campaign and continuous monitoring. Some projects are reliant on original research, or
allow for alignment with ongoing research by NIWA or others. Outline costs are provided in those
areas where it is possible to do so. In other areas costs will depend on scope which is often defined
at various milestones within each work package. We do not propose a detailed implementation plan
but indicate that in the case of monitoring especially implementation may be dependent upon other
agencies, especially Regional Councils and NZTA.
The list of potential projects can be found in Section 2, the criteria used to score them in Section 3.
Section 4 begins with the workflow framework and then describes the work packages developed to
complete the high priority projects. These are:
 Creating indicators of PM2.5 state and impact

Robust estimates of the contribution of natural sources to PM10

Establishment of a national monitoring network

Creation of an easily updated and improved national emissions inventory suitable for tracking
trends in pressures

Improving the indicators of PM10 state and impact
At the request of MfE and StatsNZ, two work packages have been developed in more depth in
Section 5. These are:
 Creating indicators of NO2 state and impact

What are the meteorological impacts on trends in ambient pollution
This report also recommends establishing a National Monitoring Strategy: a working document that
outlines the critical monitoring dependencies for the Air Domain Report, to share with stakeholders.
Options for research to enhance national air quality information for environmental reporting
5
1
Introduction
In early 2014 the Ministry for the Environment (MfE) and Statistics New Zealand (Stats NZ) published
the 2014 air domain report (MfE and StatsNZ 2014), the first of a series of intended environmental
domain reports. This was followed in early 2015 by a report from the Parliamentary Commissioner
for the Environment (PCE 2015) commenting on the air domain report, which was part of the
process for environmental reporting. The PCE report made several recommendations for
improvements to the domain report including clearer objectives and conclusions The domain
report’s Technical Advisory Group (TAG) have also commented potential improvements. Continued
development to enhance the quality of reporting is an integral part of the environmental reporting
framework and accordingly, MfE and Stats NZ have requested that NIWA: consolidate suggestions
for improvements; identify any research required; assess the importance of the research; and assess
the effort required to carry it out. The objective of this report is to document the development of a
prioritised list of potential research projects and implementation plans (work packages) to assist MfE
and Stats NZ with their planning for future air domain reports.
1.1
Development Process
The rest of this report is arranged in four sections as follows. Section 2 lists potential projects that
could improve the reporting of air quality in New Zealand. The list was drawn up after the release of
the PCE recommendations and TAG feedback in consultation with MfE and StatsNZ. Section 3
presents a set of prioritisation criteria that can be used to score the projects. The potential projects
were scored as though they were fully completed to take into account the full range of impact each
could eventually have. The highest ranking projects were reconfigured into work packages (Sections
4 and 5). These included the essential dependencies required to complete the work. The final work
packages described in Section 4 evolved out of a series of meetings and brainstorming sessions. At
this point the similarities between the work packages became apparent and a workflow framework
(Figure 4-1) was created to illustrate the iterative and flexible nature of most of the proposed work.
Further feedback from MfE resulted in extended descriptions of two of these work packages: the
NO2 and meteorology work packages. These are described in Section 5. Finally, Section 6 provides a
completion schedule for the list of prioritised projects.
6
Options for research to enhance national air quality information for environmental reporting
2
Potential improvement projects
Consultation with MfE and Stats NZ regarding suggested improvements (informed by improvements
identified by the TAG and the PCE) to environmental domain reporting led to the creation of a list of
potential projects to improve the air domain report which are detailed in this section.
Many of the suggested improvements are about finer scale reporting, e.g. regional rather than
national reporting of emissions or health impacts on Maori, but the data are scarce. Other suggested
improvements call for reporting of pollutants other than PM10. Most of the suggestions se do not
currently meet MfE and Stats NZ data framework requirements. All such work would need to
examine how available data on geographic and demographic factors or multiple pollutants compare
to the national data framework. For completeness, all potential improvements are examined in this
section, regardless of any on-going work or plans to address these needs.
The exception to this are developments in the harmonisation of reporting. Currently, Regional
Councils and other statutory bodies are working on the standardisation of the pollutant
measurements they report upon. This will make a valuable contribution to the robustness of
national reporting. It is recommended that any work on improvements to environmental reporting
keep a watching brief on these developments.
The potential projects have been grouped into four categories. These are listed below and are
described in Sections 2.1-2.4:


General indicators and data framework questions
−
Is an Air Quality Index (AQI) a suitable metric for use as an indicator?
−
What are the benefits and shortcomings of single-number indicators to characterise all of
New Zealand's air quality?
−
Creating and maintaining a national database of air quality measurements and associated
information and enabling automated generation of environmental reports. (Currently
partly addressed by the development of LAWA)
Indicators of pressure
−
What are the meteorological impacts on the state and trends in ambient pollution?
−
How accurate is a home heating emissions indicator?
−
Creation of an easily updated and improved national emissions inventory suitable for
tracking trends in emissions
−
Primary NO2 emissions
−
Improvements to the road vehicle emissions estimates
−
How much PM10 is natural?
−
Impacts of climate (i.e., indicators in atmosphere and climate domain report) on indicators
in air domain report?
Options for research to enhance national air quality information for environmental reporting
7


2.1

Indicators of state
−
Creating models of unmonitored areas
−
Improving understanding of the state of PM2.5
−
How does spatial variation of PM10 in Christchurch affect the reported population
weighting?
−
Improving NO2 coverage
−
Creation of a National Monitoring Network
Indicators of impact
−
New national exposure (and impacts) model scoping study
−
Further evaluate the accuracy of HAPiNZ (Health and Air Pollution in New Zealand) and
recommend any necessary improvements
−
What are the health impacts of NO2, PM2.5, PMcoarse and PMnatural?
−
Impacts of air indicators on climate (i.e., indicators in atmosphere and climate domain
report)?
Potential Projects: General indicators and data framework questions
Is an Air Quality Index (AQI) a suitable metric for use as an indicator?
An Air Quality Index (AQI) is a composite indicator created from a variety of pollutant
metrics. This work will investigate options and suitability of AQIs for reporting air quality
in New Zealand. Investigation could include, for example, whether any bias is
introduced by particular pollutants due to monitoring bias (peak sites – that is sites
where concentrations are known or expected to breach the standards), availability of
data etc.

What are the benefits and shortcomings of single-number indicators to characterise all of
New Zealand's air quality?
Indicators used for the domain report were formulated under unfavourable time
constraints without a rigorous and documented decision-making process. The PCE
suggests that reporting and hence indicators are considered a “…work in progress…”
which will require a review process (e.g. continual or occasional). This work will examine
and document the process of choosing and maintaining indicators including the tradeoffs between coverage and accuracy. It will use air quality as an example but may be
applicable across other domains.
Other suggested improvements call for reporting a range of pollutants other than PM10.
Most of these would not currently meet data framework requirements, which was the
primary reason that only PM10 was included in the domain report. This work will
(briefly) re-assess whether adding more pollutants to the reporting schedule will
enhance the information content of the reporting. It will look at which pollutants might
be included and which will either not add substantially to the information content or
will not meet data framework requirements without major changes.
8
Options for research to enhance national air quality information for environmental reporting

Enabling automated generation of environmental reports
Currently models such as HAPiNZ (Kuschel et al., 2012) are static, any updates to
available data have to be individually commissioned and carried out laboriously by
hand. This work will investigate the processes required for updates to be carried out on
a regular basis and for automating as much of the process as possible.
2.2

Potential projects: indicators of pressure
Creation of an easily updated and improved national emissions inventory suitable for tracking
trends in emissions
Indicators of pressure all depend to some extent on emissions inventories, but the
existing inventories in New Zealand have some limitations in their ability to track trends.
Improved national inventories will also enable better understanding of the links
between pressure and state at a national scale. This work will create a single national
emissions inventory for major pollutant sources, including wood-burning and shipping.
It will also assess the requirements for upkeep and maintenance responsibilities.
The need and possibility of regional or other breakdown will also be assessed

Improvements to the road vehicle emissions estimates
The Vehicle Emissions Prediction Model (VEPM) is currently un-validated but is the only
vehicle emissions model available for the New Zealand vehicle fleet. Some work has
been done to evaluate it against on-road emissions measurements using remote
sensing (RSD) measurements (Kuschel et al., 2012), and it is possible to extend that
validation work. Data-mining and targeted RSD (and other) measurement campaigns
may be able to improve (e.g.) diesel versus petrol emissions (Smit and Somervell, 2015).
This project would continue and extend initial validation work and rolls into the
emissions inventory review described above.

Primary NO2 emissions
While emissions of oxides of nitrogen (NOx) are decreasing, measured NO2
concentrations are not. One possible reason for this anomaly is that the proportion of
NOx emitted directly from the tailpipe as primary NO2 is increasing. This work will
investigate methods to quantify and track trends in direct NO2 emissions from traffic.
Results may be used to update traffic emissions models

How much PM10 is natural?
Some of the suggested improvements to the air domain report regard the balance of
the indicators and part of the balance is the split between natural and anthropogenic
emissions. This work will look at several questions regarding natural sources:
−
What is the definition of natural PM10? (For example, how much crustal and biological
material (e.g. pollen) is caused by anthropogenic activity?)
−
What is the spatial variation in natural PM10?
−
What is the long-term temporal variation?
Options for research to enhance national air quality information for environmental reporting
9

−
Is gathering new data required or can questions be answered with data that are currently
available? If new data are required, what, where and how should they be collected?
(Scoping study)
−
What are the seasonal variations in anthropogenic emissions and natural contributions?
−
How can we quantify human-mediated natural emissions? (e.g., agricultural generated
dust)
How accurate is a home heating emissions indicator when being used to track emissions
trends and inform trends in PM10 and PM2.5 concentrations?
If a home heating indicator of pressure is developed, a review of its accuracy should be
carried out to determine, for example, the risk of an indicator indicating that emissions
are going up when they are actually going down? This work will assess the individual
components of an indicator (wood use, burner use, fleet composition, emissions factors
etc.) to understand how critical each is to the overall result. It will also test the accuracy
of emission predictions to ascertain how the indicator is actually tracking total
woodburner emissions and is therefore sufficiently informative regarding trends in PM
concentrations. If necessary, it will recommend further work to improve weaknesses.

What would be a suitable indicator of the impact of meteorological variation on ambient air
pollution? Is a weather-focussed indicator of pressure either desirable or feasible?
If the purpose of the indicators is to report on the condition (and any changes in
condition) of the environment, it is necessary to identify (and quantify) the impact of
weather (and climate in a longer time scale) on them. Preliminary work for the domain
report (Somervell et al., 2014) explored the viability of a weather-focussed indicator of
pressure and concluded that although possible, it would take considerable work to
meet the indicator criteria. This work will quantify the impact of weather events on
long-term local air quality, in particular trends in state and impact.

Impacts of climate (i.e., indicators in atmosphere and climate domain report) on indicators in
air domain report?
Climate and changes in climate have direct (but unquantified) effects on air quality. This
work will investigate how indicators (current and potential) used in the atmosphere
domain report are impacted by changes in the air quality domain.
2.3

Potential projects: indicators of state
Creation of a national monitoring network
Some suggested improvements rely on improvements in monitoring, particularly
coverage of non-peak sites. This work will develop a national monitoring strategy, based
on the on-going needs of the air domain report. It will investigate requirements for
national coverage and design of a national monitoring network, the geographical and
demographic coverage/representation required and which pollutants should be
included. A stratified approach may be taken to allow for resourcing constraints. It will
also review the representativeness of existing sites and recommend nomination of key
sites required to generate national indicators of state and impact. It will make
recommendations for a process to deal with the shutdown or relocation of key sites.
10
Options for research to enhance national air quality information for environmental reporting

Creating models of unmonitored areas
In order to improve spatial coverage and accuracy, monitoring gaps can be filled in by
modelling. This work will investigate a typology of AQ locations to characterise different
geographical areas by type and to generalise AQ results from measurements in similar
types of location. This will include understanding the micro-scale effects of topography,
land cover and meteorology on pollution processing.

Improving understanding of the state of PM2.5
There have been many calls for reporting of PM2.5 as a full indicator. Whereas there is
currently sufficient PM2.5 data from a few locations to enable international comparison,
improved coverage and representativeness of the data is required before a full indicator
can be developed. This work will first summarise the current state of PM2.5 knowledge
before outlining and carrying out further research.

Improving NO2 coverage
Improvement suggestions include reporting on NO2, especially health effects. Although
NO2 is monitored predominantly at peak sites around NZ, there is very little information
about the spatial variation in background concentrations, particularly in urban areas.
This work will explore spatial modelling techniques and could instigate related urban
background monitoring.

How does spatial variation of PM10 in Christchurch affect the reported population weighting?
During the creation of the indicators for the air domain report, it became apparent that
the PM10 indicator was sensitive to the pollutant concentration chosen for Christchurch,
due to a large population being represented by only two monitoring sites. Thus poor
representation of spatial variation in Christchurch may constitute one of the larger
errors in the current indicators of state and impact. This work will investigate the spatial
variation of PM10 across Christchurch in order to evaluate the effect of population
weighting on the indicator. Although focussing on Christchurch, this work could also
feed into the work on coverage and accuracy outlined above.
2.4

Potential projects: indicators of impact
New national exposure (and impacts) model scoping study – (implementing improvements to
HAPiNZ)
The original concept and implementation of HAPiNZ followed international best practice
at the time. However, new information and understanding is now available. This work
will consider whether the model needs to be amended and recommend a development
and implementation plan.

Evaluate the accuracy of HAPiNZ and recommend any necessary improvements
As was noted above, it is recognised that further evaluation of the accuracy of the
HAPiNZ model would be valuable. This work will attempt to evaluate the accuracy of
HAPiNZ by, for example, by ground truthing, in order to identify its most sensitive inputs
and make recommendations for any necessary improvements. This project may also
include assessing estimates of the economic costs of poor air quality.
Options for research to enhance national air quality information for environmental reporting
11

What are the health impacts of NO2, PM2.5, PMcoarse and PMnatural?
Improvement suggestions have included estimates of the health impacts of pollutants
other than PM10. This work will investigate the feasibility of such estimates considering
the available data and what improvements to data would be needed to undertake such
estimates.

Impacts of climate indicators on indicators in air domain report
Air quality and changes in air quality have direct (but unquantified) effects on climate.
This work will investigate how indicators which may be used in any future atmosphere
domain report are impacted by changes in the air domain.
12
Options for research to enhance national air quality information for environmental reporting
3
Prioritisation process
3.1
Prioritisation criteria
In order to rank the potential projects listed in Section 2, each item was compared to the list of
criteria below and given a score of 1 to 5 (1 = low, 5 = high). Scores were weighted based on
feedback from MfE/StatsNZ on the relative importance of each criterion. The projects were scored
as if they had been completed.

Importance, Necessity
This criterion assesses projects on their ability to fill the perceived gaps in the domain report by
asking, for example, how large the gaps are and whether they can be filled in other ways?
− Perceived gaps in reporting include but are not limited to:

−
Pollutants represented as Indicators:
Although a range of pollutants are covered in the Indicator of Pressure, only
PM10 is currently used in the Indicators of State and Impact (other pollutants
represented as case studies only). This is because PM10 has the widest coverage
of any currently measured pollutant. However, many other pollutants are of
interest.
 Whole of domain reporting - rebalancing the domain report:
Each of the indicators in the domain report considered only a small part of the
domain and is not necessarily linked to the other indicators. Prioritising
indicators that fill in an area not previously addressed is beneficial.
 Does data availability fit the lifecycle of reporting? Are data updates available on
a periodic basis, are they easily accessible and assimilated into the reporting
process?
Dependencies


Are there other high priority pieces of work that cannot be carried out without
this work occurring first?
Allows international comparison
An important function of environmental reporting is to allow international comparisons of air
quality at various levels..
− Will the work better align reporting with international good practice?

−
Will the work improve confidence in alternative metrics (species, units), enabling
international comparison across a range of pollutants?
−
Will improved methods allow harmonisation with international reporting?
−
Tier one statistic: will the work strengthen the current tier one statistic or allow alternative
formats?
Supports trend analysis
Another important function of environmental reporting is to track changes over time, not only in
pollutant concentrations but also in pressures and impacts of pollutants. Will the potential
project allow improved tracking of trends?
Options for research to enhance national air quality information for environmental reporting
13

Practicality, Feasibility
Regardless of importance or desirability of any given piece of work listed in this document, it
needs to be achievable within the timeframes and resources available. Timeframes and budgets
are not known. Therefore, this criterion is based on the practicality or feasibility of a project
assuming sufficient resources can be made available.
− Feasibility – can the objective be achieved using current knowledge and data or will
extensive research or data gathering be required?

−
Timing
−
 Duration – short or long term?
 One-off, periodic, updateable etc.
Capability (NZ) – does the capability exist in NZ or will it have to be resourced from abroad?
Impact
What will be the impact on environmental reporting if the objectives of a piece of work are
achieved? Will it significantly change what is reported (e.g., including measures to fill gaps or
changes in methods?), how it is reported or increase confidence in the reporting?
− Better reporting: will it create greater confidence in the reporting or enable faster/cheaper
data gathering and assessment?
−
Cost/benefit: how great an impact on reporting will it have compared to the effort
required?
−
Will it significantly change the formulation of an indicator?
−
Will it significantly change the value of an indicator?
Comparing each potential project against these criteria and the relative weight the criteria have
been given by MfE and Stats NZ, yields the results in Table 3-1.
14
Options for research to enhance national air quality information for environmental reporting
Table 3-1:
The project-criteria matrix.
Rank
Project
Importance,
Necessity
International
comparison
Trend
analysis
Practicality,
Feasibility
Impact
TOTAL
5
4
4
5
5
23
4.5
3
5
5
5
22.5
1
What are the health impacts of NO2, PM2.5, PMcoarse and PMnatural?
2
Improving NO2 coverage
2
Creation of a National Monitoring Network
5
4
4
5
4.5
22.5
4
Creation of an easily updated and improved national emissions inventory suitable for
tracking trends in emissions
4
5
4
4
3
20
4
Improving understanding of the state of PM2.5
4.5
2
4
5
4.5
20
6
How does spatial variation of PM10 in Christchurch affect the reported population
weighting?
4
4
3
4
4
19
6
Creating and maintaining a national database of air quality measurements and associated
information to enable automated generation of environmental reports
4
2
3
5
5
19
6
How accurate is a home heating emissions indicator when being used to track emissions
trends?
4
3
4
5
3
19
9
How much PM10 is natural?
4
1
5
5
3.5
18.5
10
What are the meteorological impacts on trends in ambient pollution?
4
2
5
4
3
18
10
Impacts of climate (indicators in atmosphere domain report) on indicators in air domain
report and vice-versa?
3
2
4
5
3
17
12
New national exposure (and impacts) model scoping study
3
3
3
4
3
16
13
Further evaluate the accuracy of HAPiNZ and recommend any necessary improvements
5
2.5
2
3
3
15.5
14
Is an Air Quality Index a suitable metric for use as an indicator?
2
4
1
5
3
15
14
Creating models of unmonitored areas
3
1
3
5
3
15
16
What are the benefits and shortcomings of single-number indicators to characterise all of
New Zealand's air quality?
3.5
1
1
4.5
2.5
12.5
Options for research to enhance national air quality information for environmental reporting
15
3.2
Introducing dependencies into the prioritisation
Table 3-1 lists potential projects in order of ranking regardless of their relationship to other projects.
However, some important projects are dependent on the completion of lower ranked projects. For
example, the highest ranked project, health impacts of NO2, PM2.5 and PMnatural, is dependent on the
improvement of data available on concentrations of NO2, PM2.5, and PMnatural. Therefore, some lower
ranked projects were awarded a higher ranking in order to enable high priority projects to take
place. The projects have therefore been regrouped into related, interdependent projects as shown
in Table 3-2.
Table 3-2:
Projects grouped by dependencies.
Higher priority projects
What are the health impacts of NO2, PM2.5, PMcoarse and
PMnatural?
Interdependencies
Improving understanding of the state of PM2.5
Improving NO2 coverage
How much PM10 is natural?
Creation of a National Monitoring Network
Creation of an easily updated and improved national
emissions inventory suitable for tracking trends in emissions
How accurate is a home heating emissions indicator when
being used to track emissions trends?
What are the meteorological impacts on trends in ambient
pollution?
Lower Priority projects
How does spatial variation of PM10 in Christchurch affect the
reported population weighting?
Interdependencies
Further evaluate the accuracy of HAPiNZ for
PM10 and recommend any necessary
improvements
Creating models of unmonitored areas
New national exposure (and impacts) model scoping study
Creating and maintaining a national database of air quality
measurements and associated information to enable
automated generation of environmental reports
Impacts of climate (indicators in atmosphere domain report)
on indicators in air domain report and vice-versa?
Is an Air Quality Index a suitable metric for use as an
indicator?
What are the benefits and shortcomings of single-number
indicators to characterise all of New Zealand's air quality?
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Options for research to enhance national air quality information for environmental reporting
4
Suggested work packages for the improvement projects
Each of the high priority potential improvement projects and the relevant dependencies are
discussed below and developed into work packages. The goal of each work package is to create one
or more new Domain Report indicators. Where this is not achievable with available resources, or if
the work package is not competed, each work package will deliver improved case studies suitable for
incorporation in the Domain Report. Following completion of each work package a separate process
is recommended for the continuing review and update of indicators as required.
Two work packages are described in greater detail in Section 5. They are ‘Creating indicators of NO2
state and impact’ and ‘What are the meteorological impacts on trends in ambient pollution?’.
4.1
Project workflow framework
Most of the work packages follow the same general workflow and a framework has been developed
to take advantage of this, illustrated by Figure 4-1.
Figure 4-1:
Anticipated workflow framework.
The first stage with any project is to define the needs of the desired output. Typically this will be a
new or improved indicator and so the MfE and Stats NZ reporting criteria feed into this step.
However, other project-specific criteria, such as the desired confidence intervals around dependent
indicators, will be defined at this stage of the workflow. Although the default final output described
throughout this report is a new or improved indicator, it may be concluded at this stage that a case
study is sufficient or more appropriate, considering the cost-benefit of ‘upgrading’ to a full indicator.
Alternatively, this conclusion may be reached later in the process.
The next stage in the workflow framework will be to review current relevant data and science to
develop what is currently available into a working model or method to create a first-attempt working
output. This will then be evaluated against the needs outlined in the first step. If found to be
Options for research to enhance national air quality information for environmental reporting
17
sufficient then the output is ready to be incorporated into the next domain report as an indicator.
More likely at this first iteration, shortcomings in performance will be identified that require the
gathering of new monitoring data or new research. This will feed back into the model or method
development stage to ‘flesh out’ the first attempt. This second version will then be evaluated in
against the same criteria from stage one. If more than one gap/data need is identified as essential
they may be worked on in parallel and implemented into the next version together or they may be
worked on sequentially with the project output developing over multiple iterations to an ideal point,
where it meets all the criteria from stage one (including the MfE and Stats NZ criteria) to an adequate
level.
If a domain report is pending during the workflow of a project, the most current version may be
reported on as a case study or work in progress or as an Indicator for a subset of variables.
At the decision point in the workflow, an outcome of the performance evaluation may be that the
indicator/potential indicator is dependent not upon a particular data gathering exercise for its
development or continuing performance, but upon ongoing monitoring at particular sites. This
dependency then feeds into the national monitoring network plan (NMP).
4.2
Process to review and update indicators
Once a work package has been completed and a new indicator has been developed, there needs to
be a process for maintain the indicator. This will largely be a three-stage process, as listed below .The
order of the stages may be different for different indicators.

Collect or collate new data and re-calculate indicator(s).

Review whether indicator still satisfied the criteria for the indicator

Review that the indicator is still fit for purpose and is a suitable representation of good practice
and latest scientific understanding. Consider whether re-formulation is appropriate.
The process should be aided by the establishment of a centralised database (e.g. LAWA). Once this
exists the update process may be further aided through automation by developing appropriate
software. This was one of the project ideas proposed in this work (see section 2.1), which narrowly
missed being listed as a ‘high priority’.
4.3
Creating indicators of PM2.5 state and impact
4.3.1 Rationale
PM2.5 is recognised as having significantly different sources and different health effects compared to
the coarse fraction of PM10. Having a good understanding of PM2.5 in New Zealand is therefore is
vital to manage air quality and its impacts. In particular reporting on the levels and impacts of PM2.5
has been identified as a key concern by the PCE.
PM2.5 was incorporated as a case-study in the first domain report; the lack of geographical coverage
did not allow for a robust indicator of State to be established. However, estimates of PM2.5 did
contribute to the indicators of impact, despite the estimates being unvalidated and based on a weak
method. The availability of PM2.5 data in New Zealand is growing significantly meaning that more
robust methods can now be developed.
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Options for research to enhance national air quality information for environmental reporting
This work will first summarise the current state of PM2.5 knowledge before outlining and carrying out
further research.
4.3.2 Objectives and Outcomes
To summarise the current state of New Zealand PM2.5 data and make recommendations to ‘complete
the picture’, through model development which may be supported by additional monitoring.
This work should generate a new Indicator of State for PM2.5, and well as supporting indicators of
Impact with improved accuracy and coverage.
Options for research to enhance national air quality information for environmental reporting
19
4.3.3 Timing
Table 4-1:
Estimated timings for the PM2.5 work package.
Stage/task
20
Indicative
duration
Other links
outputs
1.
Define needs
1 month



Preferred form of new indicators of state and impact
Criteria for acceptance of indicators that are specific to this work package
The scope for stage two
2.
Model
development
3 months+




Interim national PM2.5 model
Draft new indicators of state and impact (or case-studies if further improvement is required)
Improvement plan (scope for stage three)
Recommendations for National Monitoring Network Plan
3.
Improvement,
(and
subsequent
stages)
1-2 years



National PM2.5 model
Draft new indicators of state and impact
Review and Update plan
Regional
Councils
Options for research to enhance national air quality information for environmental reporting
4.3.4 Steps required to complete the work package
 Stage one: Define needs
Formulating the indicator of state for PM2.5 (Single index? Spatial scale? Annual mean or other
metric? Population-weighted? Coverage? Error tolerance?)
Formulating the indicator of impact for PM2.5 (Chronic and/or acute effects? Which dose-response?
Which impacts?)


Stage two: Model development
−
Review and collate new data –NIWA modelling, Regional Council monitoring, GNS
monitoring
−
Synthesis and model/method development – national PM2.5 model meeting needs defined
in Stage one
−
Performance evaluation – model validation
−
Interim implementation – create indicators/case-studies
Stage three: Improvement
−
Review and collate new data - as above including additional data gathering
−
Synthesis and model/method development – validating, calibrating, adjusting model
−
Performance evaluation – as above
−
Interim implementation
−
Additional data gathering – depending on evaluation
−
Implementation – create indicators/case-studies
4.3.5 Consultation

Regional councils, for data and for scoping potential new data

GNS
4.3.6 Outline of required steps

Collate PM2.5 data:
Collating the data may be simple depending on the establishment of the LAWA portal, or may
require consulting with each Regional Council individually. Other agencies, such as NIWA and
GNS should also be contacted to provide data.

List and prioritise gaps in the PM2.5 data and ongoing needs:
This may be used to assess how easy it is to incorporate PM2.5 health effects into the HAPiNZ
model and also to analyse the sensitivity of any PM2.5 indicator to changes in coverage.

Scope, develop and evaluate modelling approaches to estimating PM2.5 across the country:
The aim is to generate estimates of PM2.5 at least across all of the urbanised parts of the country
which can be used to replace current estimates in the HAPiNZ exposure model. Areas of high
Options for research to enhance national air quality information for environmental reporting
21
uncertainty or sensitivity in the model should be identified and prioritised for additional
monitoring.
4.4
Robust estimates of the contribution of natural sources to PM10
4.4.1 Rationale
As an island nation with a minority of land under human development, the contribution of natural
sources to the overall PM concentration plays an important role in New Zealand. A method to
estimate natural contribution to PM from filter sampling has been demonstrated by GNS and is the
basis of the current pressure case-study and Impact indicators. However the method is expensive
and currently dependent upon Regional Councils contracting GNS to do the work. Consequently data
has been gathered in an incoherent and ad hoc manner.
This project seeks to assess whether this erratically expanding database is sufficient to replace
assumptions that determine how data is spatially extrapolated, or whether additional data needs to
be purposely gathered. This project also seeks to determine whether there are long-term trends or
significant fluctuations in natural PM (PMn), and if so, how they can be tracked. This is important
because any trends in the anthropogenic PM10 may be confounded by a currently unknown natural
contribution. In both cases additional data may be captured by commissioning further work by GNS
similar to that conducted previously. However, there are also other methods to estimate natural PM,
including modelling approaches. Given the likely resource constraints this project explicitly seeks to
deliver value for money and make sure any additional monitoring is carefully justified.
Estimates of PMn contribute to:
 an indicator of pressure (currently of case-study status only due to limited spatial and temporal
coverage)

an indicator of state –describing the composition of the PM10 that makes up the total for the
current indicator of state.

an indicator of impact in which natural contributions are subtracted from total PM to estimate
impacts from anthropogenic PM.
The current method of estimating natural PM at unmonitored locations is internally inconsistent and
likely to include errors. Furthermore the introduction of new data in the 2014 domain report caused
some confusion over whether the new estimates of natural PM were influencing the estimate of
anthropogenic impacts. This is because it is currently unknown whether there are any long-term
trends in natural PM, or the scale of inter-annual variability, or whether an assumption that it is
constant is valid. The current indicator of impact (health effects of anthropogenic PM10) is critically
sensitive to an accurate estimate of the natural contribution to the total measured PM10 around the
country.
In brief this project seeks to improve the accuracy, coverage and timeliness of the data available,
and bring robustness, consistency and transparency to the method by which data from limited
locations is extrapolated across the country.
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Options for research to enhance national air quality information for environmental reporting
New data could be used to:

elevate the indicator of pressure from case-study to full indicator status

enable new indicators of state for natural and/or anthropogenic contributions to PM10

improve the robustness of the indicators of impact, including directly indicating the impact that
changes in PMn might be contributing (i.e. assisting in trend analysis)

enable a new indicator on the impact of climate change on air quality (i.e. natural PM)

eliminate the current confusion and doubt surrounding the method (as evidenced in the PCE
Report, for example).
4.4.2 Objectives and Outcomes
To produce an accurate representation of natural PM10 concentrations across the country that meets
the requirements of the data framework. This will include accurate estimates of spatial and temporal
(both seasonal and long term) patterns.
A consistent definition of natural PM and its sources will enable better long-term tracking of the
natural fraction of measured PM.
There will be greater confidence in the reported impacts of anthropogenic PM due to better
understanding of the natural contribution to measured PM10. Additional indicators of pressure and
state can be developed including the health and economic impacts of the natural fraction of PM.
Options for research to enhance national air quality information for environmental reporting
23
4.4.3 Timing
Table 4-2:
Estimated timings for the PMn work package.
Stage/task
1.
Indicative
duration
Define needs
Other links
outputs

1 month


2.
3.
24
Model
development
Improvement,
(and
subsequent
stages)


3 months+
1-2 years
Regional
Councils,
GNS
Preferred form of new indicators of pressure and state, and requirements for PMn data in
indicators of impact
Criteria for acceptance of indicators that are specific to this work package
The scope for stage two


Interim national PMnatural model
Draft new indicators of pressure and state, and changes to indicators of impact (or casestudies if further improvement is required)
Improvement plan (scope for stage three)
Recommendations for National Monitoring Network Plan



National PMnatural model
Draft new indicators of pressure and state and revised indicator of impact
Review and Update plan
Options for research to enhance national air quality information for environmental reporting
4.4.4 Steps required to complete the work package
 Stage one: Define needs
Formulating the indicator of state (Single index? Regional? Annual mean, median or other metric?
Population-weighted? Roadside? Coverage? Error tolerance?)
Formulating the indicator of impact (Chronic and/or acute effects? Which dose-response? Which
impacts?)


Stage two:
−
Review & collate new data – NIWA modelling, RC monitoring, GNS monitoring
−
Synthesis & model/method development – national PMn model meeting needs defined in
Stage one
−
Performance evaluation – model validation
−
Interim implementation – create indicators/case-studies
−
Additional data gathering – to be defined, likely to be urban background campaign
monitoring
Stage three:
−
Review & collate new data - as above including additional data gathering
−
Synthesis & model/method development – validating, calibrating, adjusting model
−
Performance evaluation – as above
−
Implementation – create indicators/case-studies
−
Additional data gathering – depending on evaluation
The first three steps, although preliminary to the collection of any new data or model development,
are essential to produce a robust estimate of natural PM in New Zealand. Any new monitoring and
model development will then be informed and effectively targeted to generate the most useful
information.
4.4.5 Consultation
At this stage we recommend consulting the following people or organisations;
 GNS - current state of knowledge of NZ natural PM10 and perceived gaps in knowledge

Landcare and agResearch - quantification of soil-driven PM and anthropogenic-mediated natural
sources

University of Canterbury - methods of modelling natural sources

Regional Councils- feasibility of running remote monitoring sites for gathering required data
Options for research to enhance national air quality information for environmental reporting
25
4.4.6 Outline of required steps
Literature Review
It is important to assess what the latest research tells us about natural PM and how to characterise
and quantify the effects of anthropogenic mediated PM. A review of the international literature will
enable the latest methods and knowledge on the effects of natural PM, methods of apportionment
and modelling to be collated and critically reviewed in the New Zealand context. This work will be
disseminated to all interested and relevant parties to facilitate informed debate and full participation
in the next step.
Development of a proposed method
Following on from the literature review a robust method for assessing spatial and temporal variation
suitable for execution in New Zealand and tailored to the New Zealand environment will be
formulated. Any model development for estimating the spatial and temporal pattern of natural PM
will be outlined. This step will involve consultation with relevant parties.
Gap Analysis of New Zealand data and formation of a data gathering plan.
Existing data will be analysed to quantify the degree of long-term temporal variation and existence of
possible trends. The sensitivity of indicators to temporal variation will be quantified. A modelling
approach will be developed and applied across the country (validated using GNS or other
independent data where available) and compared to current estimates embedded in the domain
report method. From this, the representativeness of existing and future data n will be assessed. This
step will identify if any additional monitoring is still required to adequately support any model
development or provide ongoing monitoring of long-term trends. This step will involve consultation
with relevant parties and full costing and recommended scale and duration for any monitoring to be
conducted. This step should be conducted in conjunction with the National Monitoring Network
project in order to maximise efficiencies.
Monitoring Programme and analysis of new data
If the plan deems it to be necessary and justified, instrumentation will be deployed in accordance
with the monitoring requirements/plan. New data will then be synthesised with pre-existing data to
inform or ground-truth the model/national representation of natural PM.
Integration into the domain report
(required step regardless of whether any additional monitoring has been conducted)
The findings will be used to define a revised method for creating domain report indicators.
Review and update
A periodic review of natural PM in New Zealand is advised, perhaps for every new domain report
(i.e., every three years). This review would consist of an update of the literature and assessing any
new data in light of the now established understanding of spatial and temporal patterns of natural
PM in New Zealand.
4.5
Establishment of a national monitoring network
4.5.1 Rationale
The data requirements of national statistics are different from NES compliance - they require
national coverage that is representative of the population of the country rather than local coverage
at peak locations. By being dependent on Regional Council NES compliance monitoring, and
particularly Council resource constraints, the domain report is vulnerable to loss of data as Councils
reallocate or reduce their monitoring resources. For example, the PM10 indicator of state has been
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Options for research to enhance national air quality information for environmental reporting
constructed from data from a set of monitoring stations which have changed every year. Feedback
from various sources including the PCE and TAG indicates an interest in reporting of pollutants other
than PM10, particularly NO2 and PM2.5. In addition, the health and economic impacts of pollutants are
based on peak measurements applied to whole populations or untested models of population
exposure.
Therefore, there is a need to ensure that data will continue to be available to maintain the timeliness
and coverage of future domain reports, which may require additional pollution monitoring that is
designed for the purpose of environmental reporting and population exposure above and beyond
what is required for NES compliance.
4.5.2 Objectives and Outcomes
This work will develop a national monitoring strategy and implementation plan, based on the needs
of the air domain. It will define the requirements for national coverage, the geographical and
demographic coverage/representation required and which pollutants should be included. It will
make recommendations for a process to deal with the shutdown or relocation of key sites. The Plan
will act as on ongoing summary of the data needs of the air domain report and enable discussions
amongst agencies and providers regarding responsibility for establishment, operation, maintenance
and reporting.
A national strategy for air quality monitoring will enable plans to be drawn up to ensure ongoing
provision of monitoring which provides sufficient coverage to adequately represent the New Zealand
population’s exposure to pollutants for the purpose of environmental reporting.
The strategy, and the establishment of the monitoring network, will ensure the improved stability
and timeliness of the PM10 indicator of state, will support the establishment and continuing
timeliness of indicators of state for other species, especially PM2.5 and NO2, and provide data to
support improvements to indictors of impact.
4.5.3 Total Cost and Timing
Establishment: $5k
Update (annually or other regular timeframe): $5k
Costs do not include monitoring itself which is considered independently of the establishment of a
network plan.
4.5.4 Steps required to complete the work package

Establishment of the form of the strategy and implementation plan documents.

Update of the plan in response to the completion of each stage of the other environmental
reporting improvement projects proposed in this work.
4.5.5 Consultation
Organisations to be consulted:
 MfE (purpose and objectives of network)

NIWA

RCs (to gauge interest in cooperation)

NZTA
Options for research to enhance national air quality information for environmental reporting
27
4.5.6 Dependencies and sequencing
The national monitoring strategy and implementation plan will arise as part of the process to
progress the other work packages. The accumulation of stage one outputs from the various work
packages will constitute the strategy. At the completion of subsequent stages recommendations for
monitoring will be made which will be incorporated into the implementation plan from which a
national monitoring network can be formed.
4.5.7 Outline of required steps
The envisaged network plan arises by compiling the recommendations of other work packages into a
single document. The plan will summarise the ‘needs’ of the network, identification of those existing
data sources upon which air domain report indicators are dependent, and monitoring gaps.
Development phase
The development phase of the project will constitute the definition, planning and formulation of a
national monitoring strategy for environmental reporting. Its output will be the publication of a
strategy.
Definition of objectives of a monitoring network
In consultation with MfE and other stakeholders (for example the members of the domain report
TAG) the objectives of a national monitoring network will be defined. This will include consideration
of factors such as: What are the (monitoring) data requirements of the domain report now and into
the future? How the outputs of the monitoring are to be used; which national reporting
requirements will need to be met; which pollutants will need to be monitored; what coverage will be
needed to result in a representative picture of air pollution and population exposure in NZ.
Availability and suitability of current monitoring methods
Given the objectives of the monitoring network, the next step will be to determine which monitoring
methods are best suited to the task. A review will need to be undertaken to assess current
technology against the requirements of the monitoring network and to recommend suitable
methods.
Examination of current network for suitability
The current regional council networks may contain sites that align with the objectives of a national
monitoring network and could therefore be included at minimal or zero cost. A review of existing
monitoring sites will provide a gap analysis of which types of locations and which pollutants will need
to be established to complete the requirements of the network. A quantitative review of the
representativeness of current monitoring sites for each of the key pollutants will be conducted. The
sensitivity of the indicators of state and impact to the inclusion or exclusion of sites will be
quantitatively tested.
Formulation of national monitoring strategy
The final output of the development stage will be a national monitoring strategy for environmental
reporting. It will detail the scope and objectives of the strategy and the pollutants and spatial
coverage required to maintain adequate data and information for the purpose of environmental
reporting. The strategy will detail how representativeness and coverage will be achieved and
maintained, including identifying the need for new locations, maintaining existing locations and
replacing old locations. It will also detail the expected information generated by the network.
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Options for research to enhance national air quality information for environmental reporting
Implementation phase
The implementation phase will take the strategy as a starting point and see it through to the
installation and operation of a suitable monitoring capability for environmental reporting. The first
task will be the development of the implementation plan, which will;
 Identify requirements and locations for new monitoring sites

Agree contributions to maintaining or augmenting existing sites

Develop contingency plans for replacing or otherwise allowing for discontinued sites
Putting the implementation plan into operation is likely to entail the establishment of new
monitoring locations, followed by the ongoing operation and maintenance of the network.
The nature of the Network depends upon the outcome of the Development phase. However, it may
include one or more of the following:
1.
Nomination of certain Council sites as “indicator” sites
2.
Nomination of certain Council sites as “super-sites” with an enhanced range of pollutants
monitored, instrumentation, or to be used for co-location studies.
3.
Establishment of one or more new permanent sites
4.
Establishment of one or more temporary/campaign sites
5.
Screening monitoring campaigns
4.6
Creation of an easily updated and improved national emissions inventory
suitable for tracking trends in pressures
4.6.1 Rationale
A national emissions inventory should be the basis of several indicators of Pressure. The first domain
report however, was able to report on emissions from road transport only. Data on emissions from
other sources were considered not to have meet the reporting criteria, particularly due to lack of
internal consistency, lack of geographical coverage and much of the available data being out-of-date.
Whereas emission inventories are a preferred basis for an indicator of pressure, most inventories are
not designed with the purpose of an updatable indicator in mind. Inventories typically consist of
three components: number of units, activities per unit and emissions per activity. For example, for
home heating emissions the ‘activity’ is typically represented by the mass of fuel consumed, such
that emissions are a product of the number of appliances in use, the rate of use (e.g. fuel
consumption) and the emissions per kilogram of fuel. Current home heating inventories rely on a
telephone survey technique to estimate the number of appliances and fuel consumption, but with
substantial uncertainties. The method is unable to track changes in emissions through improvements
in fuel quality, operator technique and it assesses improvements in burner technology only very
crudely. As these factors represent key emission management options it is unclear if the method is
sufficiently fit-for-purpose to inform an indicator of pressure. The method also requires additional
surveys every time the indicator is to be updated. Consistency of follow-up surveys is not assured
and it is questionable whether such a method is truly able to track trends in all three components:
units, activity and emission factors.
Options for research to enhance national air quality information for environmental reporting
29
Although the road transport emission indicator is the most developed of all pressure indicators and
has full indicator status, primary NO2 emissions are currently absent. This is important because of the
reported rise in ambient NO2 concentrations across the country, despite (predicted/reported)
reductions in NOx emissions. This inconsistency in trends requires explanation, especially as current
trends indicate a growing risk of exceedances of the NES or World Health Organisation (WHO)
guidelines, and increasing health impacts.
Existing information regarding shipping emissions is highly variable and inconsistent. However,
estimates indicate that it is potentially the third largest source of particulate matter emissions in
New Zealand. It is also a source which is growing.
4.6.2 Objectives and Outcomes
To produce a national emissions inventory covering the most important sources in a manner
which accurately tracks changes in pressures into the future in a timely manner.
To ensure that the Residential Heating indicator of pressure will continue to meet the
StatsNZ criteria into the future, whilst also being updatable at a reasonable cost.
To create an indicator of primary NO2 emissions that meets the StatsNZ criteria now and into
the future.
To create an indicator of shipping emissions that meets the StatsNZ criteria now and into the
future.
This work intends to ensure a national emission inventory exists which is explicitly designed to
support indicators of pressure on an ongoing basis into the future, thus future-proofing this aspect of
the air domain report. As such, its primary purpose is to report on changes and trends and should
meet the criteria set by MfE and StatsNZ. In brief, this work package seeks to improve the accuracy,
coverage and timeliness of the data available, and maintain these into the future. The work package
will enable the link between emissions and concentrations be better accounted for.
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Options for research to enhance national air quality information for environmental reporting
4.6.3 Timing
Table 4-3:
Estimated timings for the inventory work package.
Stage/task
Indicative
duration
Other links
outputs
1.
Define needs
1 month



Preferred form of new indicators of pressure
Criteria for acceptance of indicators that are specific to this work package
The scope for stage two
2.
Inventory
development
2 months




Evaluated interim national inventory
Draft new indicators of pressure
Improvement plan (scope for stage three)
Recommendations for National Monitoring Network Plan
3.
Improvement
Dependent on
stage two; 3 –
24 months



National inventory
Draft new indicator of pressure
Review and Update plan
MoT, NZTA,
Regional
Councils
Options for research to enhance national air quality information for environmental reporting
31
4.6.4 Steps required to complete the work package
This project is broken up into four stages:

Stage one: Define needs
The domain report criteria need to be interpreted for each pressure (emission) indicator
to determine the degree of accuracy, coverage and timeliness required. It is possible that for
primary NO2 and shipping emissions, the issue will be considered of insufficient importance, or
too difficult or expensive, to progress.

Stage two: Evaluation of current inventories
Uncertainties in the emission inventories will be estimated by considering each of the inputs
individually. A sensitivity analysis will be conducted of the contributions of each uncertainty to
the uncertainty in the ultimate indicators. This will include a projection of likely future scenarios
and the ability of the indicators to correctly track trends in their current form. Confidence
intervals for the indicators will be generated for comparison with the needs identified in Stage
one. The root causes of any risk in poor performance of the indicators going forward will be
identified and mitigation measures recommended. We anticipate the following outcomes being
considered:
−
Existing data/method is sufficient – only repeat surveys are required
−
A new purposeful survey (independent of previous surveys) is initiated and updated as
required
−
A modelling approach (as, for example, is used to underpin the road transport emissions
indicator) is developed, initiated and a method for update documented.
−
An ongoing observational technique to monitor long-term trends in activity and emission
factors.
−
Some combination of the approaches described above.
−
Interim implementation – create indicators/case-studies
The focus of Stage three and beyond will be determined on the basis of the outcome of Stage two.
We anticipate that Stage three will focus on one or more of the following, each of which is further
detailed below:

−
Home heating emissions
−
Primary NO2 from road transport
−
Shipping emissions
Stage three (Home-heating):
−

Stage three (Primary NO2):
−
32
Additional data gathering – to be defined by the previous step
Review & collate all data – NZTA network, NIWA modelling, RC monitoring
Options for research to enhance national air quality information for environmental reporting
−

Synthesis & model/method development may include:
−
A data-mining method of ambient NOx data (see published literature for possible
methods)
−
A modelling approach (e.g. incorporating primary NO2 emissions into VEPM using
international data)
−
An ongoing or campaign-based observational technique to directly measure and
monitor long-term trends based on established methods (e.g. tunnel studies).
−
Performance evaluation – model validation
−
Implementation – create indicators/case-studies
−
Additional data gathering – to be defined
Stage three (Shipping):
−
Review & collate all data – Regional Councils, MoT, Port Authorities, International literature
−
Synthesis & model/method development may include:
−
−
Compilation of a nationally consistent database of ships frequenting NZ ports
−
Compilation of a nationally consistent database of ships movements to/from NZ
ports
−
Compilation of a nationally consistent database of ships fuel use in and around NZ
ports
−
Development of a nationally consistent database of ship emission factors as a
function of fuel used
Performance evaluation – model validation should include:
−
Ensuring means of simple and timely update of each database
−
Estimate emission rates per port, plus sensitivity/uncertainty analysis.
−
Interim implementation – create indicators/case-studies
−
Additional data gathering – to be defined
4.6.5 Consultation
The following organisations should be consulted:
 The supplier of existing home heating emission inventory to MfE (i.e., Environet and Golder
Associates).

Regional Councils

NZTA and MoT

European experts could be consulted
Options for research to enhance national air quality information for environmental reporting
33
4.7
Improving the indicators of PM10 state and impact
4.7.1 Rationale
Environmental reporting, particularly for indicators of state, relies on measured pollution
concentrations. Currently available measurements have largely been made by Regional Councils for
the purposes of complying with the NES. The result of this is that measurements are biased towards
PM10 and from peak sites. Therefore, the availability of measurements suitable for constructing
nationally representative statistics is limited. There is a lack of urban background, rural and regional
background measurements and a consequent lack of information regarding the spatial variation in
concentrations between peak monitoring sites.
HAPiNZ is currently New Zealand’s only health effects model for air quality, and is the basis for the
current indicators of impact. HAPiNZ consists of two coupled models:

An exposure model. This extrapolates monitored PM10 data to every census area unit in the
country, providing full coverage but at the risk of a reduction in accuracy.

A health risk assessment model, which attributes health outcomes to the exposed population
based on population records, baseline health data and dose-response relationships.
The health risk assessment model is well-established and based on methods used widely
internationally. However, like all models the health risk assessment model and the exposure model
incorporate uncertainties, are subject to assumptions and rely on a very active area of international
research. The outputs would benefit from being ground-truthed or validated which would assist in
further evaluating the model’s accuracy.
HAPiNZ was originally designed to assess health impacts at a single moment in time, not to track
trends across time. Methods or rationales for continuous updating of the underlying data do not
exist especially for places where monitoring has been discontinued and in unmonitored areas.
Given the importance of the indicators of impact it is highly recommended that the underlying
modelling method is reviewed and evaluated to allow for the incorporation of new science and
improved methods so that uncertainties can be reduced and accuracy improved. There are a number
of areas that ought to be evaluated:

The dose-response relationships, which may be reviewed in light of the latest research.

Independent evaluation of health outcomes estimates (e.g. potential for generating NZ-specific
dose-response relationships).

The estimates of exposure, in terms of the estimates of PM10 of unmonitored areas and
estimates of the natural component.

The costs associated with certain health outcomes.

Whether the structure of the model is flexible enough to incorporate other pollutants.
34
Options for research to enhance national air quality information for environmental reporting
4.7.2 Objectives and Outcomes
Quantify the bias in the PM10 monitoring network, and compensate for it in the indicator of state, so
that its representativeness is assured.
Further evaluate the accuracy and sources of uncertainties within HAPiNZ-based indicators of impact,
and make improvements where needed to ensure the indicators continue to meet criteria and
represent the latest scientific understanding.
This work package will quantify the strengths and weaknesses of HAPiNZ and make
recommendations for improvements. It will improve the robustness of the indicators of impact and
indicate how accuracy and timeliness can be maintained and improved into the future.
Options for research to enhance national air quality information for environmental reporting
35
4.7.3 Timing
Table 4-4:
Estimated timings for the PM10 work package.
Stage/task
36
Indicative
duration
Other links
outputs
1.
Define needs
1 month



Updated definition of indicators of state and impact
Criteria for acceptance of indicators that are specific to this work package
The scope for stage two
2.
Model
development
3 months





Improved interim national PM10 exposure model
Draft improved indicators of state and impact
Improvement plan (scope for stage three)
Recommendations for National Monitoring Network Plan
Recommendations for independent evaluation of health effects
3.
Improvement,
(and
subsequent
stages)
1-2 years



Improved national PM10 exposure model
Draft improved indicators of state and impact
Review and Update plan
Regional
Councils
Options for research to enhance national air quality information for environmental reporting
4.7.4 Steps required to complete the work package

Stage one: Define needs
− Review formulation of the indicator of state (Single index? Regional? Annual mean or other
metric? Population weighted? Coverage? Error tolerance?)
−

Stage two: Evaluation of HAPiNZ PM10 exposure and health effects models
−
Review and collate new data –NIWA modelling, Regional Council monitoring, health
outcomes data, international literature
−
Uncertainty and sensitivity analyses of PM10 exposure model
−
Independent validation of PM10 exposure model
−
Scope potential for conducting independent validation of health outcomes estimates
−
Recommend additional data gathering – to be defined, but likely to include one or more of
the following:
−

Review formulation of the indicators of impact (Dose-response functions to be used,
Maori/ethnic breakdown? Acute and/or chronic effects? Regional? Coverage? Error
tolerance?)
−
Additional rural coverage
−
Previously unmonitored airsheds
−
Additional coverage in Christchurch
−
Additional morbidity outcomes or health behaviours data (e.g. inhaler use)
Interim implementation – create indicators/case-studies
Stage three: Improvement
−
Feed outstanding data needs to National Monitoring Plan
−
Review & collate new data - as above including additional data gathering
−
Synthesis & model/method development – validating, calibrating, adjusting PM10 exposure
model
−
Performance evaluation – as above
−
Implementation – create indicators/case-studies
4.7.5 Consultation
Organisations to be consulted:
 Health Economists

Epidemiologists

Original HAPiNZ team
Options for research to enhance national air quality information for environmental reporting
37
5
Detailed Work Packages
After feedback from MfE, two work packages have been developed in greater detail. These can be
found below.
5.1
Creating indicators of NO2 state and impact
5.1.1 Rationale
Nitrogen dioxide is an important pollutant in two ways. Firstly, it is subject to a National
Environmental Standard, which has been breached in New Zealand in the past. Secondly, it functions
effectively as a marker for road traffic exhaust emissions. In recent years concentrations of NO2 have
been shown to be rising despite sharp falls in NOx emissions and contrary to most trends in PM10.
Inclusion of a robust indicator of the state and impacts of NO2 are therefore deemed to be crucial to
making sure domain reporting describes a complete picture of the most important trends in New
Zealand’s air quality.
Although there is a substantial amount of existing monitoring of NO2, this is conducted
predominantly at peak sites around NZ, and mainly in Auckland making the dataset spatially biased.
Compliance monitoring for the National Environmental Standards (NES) is explicitly carried out in
locations where concentrations are expected or known to breach the standards (that is, at peak
locations). Some passive screening monitoring is also routinely carried out, mostly at roadside
locations around the country. There is very little information about the spatial variation, particularly
urban background concentrations. What data that has been collected, plus the results of research by
NIWA and others, has indicated that there is a large difference between roadside concentrations and
concentrations at background residential locations, with roadside sites being 2 – 4 times higher. Thus
the errors associated with assuming peaks sites are representative of the full airshed, and of longterm population exposure, are considerable.
Consequently, the currently available NO2 monitoring data is considered to have insufficient
coverage to inform a full indicator of state, although a case-study of NO2 concentrations was
provided in the first domain report.
Health impacts of NO2 have been identified as a high priority in this report (Section 3.2) but those
impacts cannot be estimated without an ability to estimate population exposure to NO2. There is
currently insufficient data on spatial variation, particularly urban background concentrations to
enable a robust NO2 exposure model to be constructed in NZ. However, with the addition of a small
amount of urban background data, collected through a short-term passive monitoring campaign,
there will be enough to create an initial model of national NO2 concentrations that will be of a similar
accuracy to the HAPiNZ model used for PM10 exposure estimates.
A project to improve the state of knowledge of NO2 distribution is required before estimates of the
health (and other) impacts can be estimated with sufficient confidence for environmental reporting.
Understanding NO2 variation and behaviour will enable coverage to be improved by helping to create
better models.
This work package, as others, is built on the notion that national population coverage is important for
reporting on state, and vital for reporting on impacts. New Zealand’s air quality is characterised by
very strong spatial variation making reliance on monitoring alone very challenging and costly.
Whereas monitoring delivers accuracy it cannot, on its own, deliver coverage and
representativeness. Thus spatial models of air quality are deemed to be a much more cost-efficient
38
Options for research to enhance national air quality information for environmental reporting
way of delivering a balance between accuracy and coverage than could be achieved by monitoring
alone.
NIWA has been conducting research to develop a validated national NO2 model for some years,
based on central government funding for the national benefit. It is recommended that this model be
the basis of this task, or that any alternative method is justified.
5.1.2 Ultimate Objectives of the Work Package
To produce a national model of NO2 concentrations, exposure and impacts across NZ (at census
meshblock scale).
Identify and instigate any extra monitoring required to inform or validation the model (through the
National Monitoring Network Plan).
This will enable:
− Improved understanding/estimates of NO2 variation and urban backgrounds
−
Extended coverage through combination of measurement and modelling
−
Estimates of population exposure leading to estimates of health (and other) impacts of NO2
in NZ
5.1.3 Ultimate Outcomes of the Work Package

Upgrade of NO2 concentrations case-study to a full indicator of state

Enabling NO2 to be integrated into impact indicators

Provide more complete commentary on air quality trends, specifically relating to road transport
emissions.

Reduced cost of maintaining the validity, accuracy and timeliness of the indicators into the
future.
Options for research to enhance national air quality information for environmental reporting
39
5.1.4 Timing
Table 5-1:
Estimated timings for the NO2 work package.
Stage/task
40
Indicative
duration
Other links
outputs
1.
Define needs
1 month



Preferred form of new indicators of state and impact
Criteria for acceptance of indicators that are specific to this work package
The scope for stage two
2.
Model
development
3 months




Interim national NO2 model
Draft new indicators of state and impact (or case-studies if further improvement is required)
Improvement plan (scope for stage three)
Recommendations for National Monitoring Network Plan
3.
Improvement,
(and
subsequent
stages)
1-2 years



National NO2 model
Draft new indicators of state and impact
Review and Update plan
Regional
Councils
Options for research to enhance national air quality information for environmental reporting
5.1.5 Steps required to complete the work package
1.
2.
3.
4.
Define needs
i.
Define purpose of indicators
ii.
Interpret criteria for success
iii.
Propose form of indicators and data needs
Model development
i.
Build interim draft NO2 model
ii.
evaluate
iii.
scope improvement plan
iv.
Build indicator or case-study for air domain reporting
v.
Update National Monitoring Plan
Improvement
i.
Additional data collection
ii.
Update model
iii.
Evaluate updated model
Further Improvement (if required)
5.1.6 Implementation of stages
The proposed work package has been broken into stages. Each stage delivers an improved outcome.
It also gives an opportunity for peer review, or consultation with the TAG. At the end of each stage
(other than Stage one) the new data generated is evaluated against the criteria which have been
specified in stage one. Each stage proposes a recommended scope for the next stage. Thus each
stage introduces a decision point as to whether the next stage of improvements should be
implemented, or whether the improvements, and therefore this work package, are complete.
Each stage could be commissioned as a single piece of work or broken into smaller projects. Some
tasks within each stage constitute research that is most likely to be progressed within NIWA’s air
quality research programme, or by other external parties as summarised in Table 5-1.
The first two stages are described in greater detail below.
5.1.7 STAGES IN MORE DETAIL: Stage One – Define needs
Rationale
The 2014 air domain report includes a case-study on concentrations NO2 (state). This data is
considered to not meet the criteria for an indicator because “The population coverage of the
monitoring network is unknown, meaning a nationally representative average cannot be compiled.”
(p.62). It follows that the report contains no indicator of impact of NO2. Furthermore the case-study
provided is very difficult to interpret displaying a wide degree of scatter and unsuitable for
Options for research to enhance national air quality information for environmental reporting
41
supporting a discussion of trends, geographical variation, or relationship to pressures. These
limitations do not arise due to lack of data – the amount of data on NO2 concentrations is
considerable – but to a lack of structure with which to extract the meaning from the data.
Objectives
The aim of this Stage One project is to develop and define indicators of state and impact of NO2 that
meet the aims of environmental reporting and that can feasibly be delivered. It is also to interpret
the MfE/StatsNZ criteria for indicators for the specific case of NO2 indicators, so that any new data
generated can be transparently evaluated and further improvement justified where required. A
preferred recommendation for one or more indicators of state and impact should be presented,
alongside one or more alternatives.
Tasks within Stage One
Tasks within stage one are listed below. It may not be necessary to follow this list strictly
sequentially, but it is recommended that each task or issue is covered.
1.
Define purpose of indicators
The following issues should be considered:

Should the indicators relate to guidelines and standards?

Should the indicators allow trends to be evaluated?

Should the indicators provide geographical breakdown? To what scale? Which populations
should be covered?

How important is it that NO2 impacts are comparable to PM10 impacts, or to avoid doublecounting?
2.
Interpret criteria for success

How accurate do the data need to be? How is accuracy related to purpose (how accurate to
discern a trend, or to compare with PM10?)

How much coverage do we need? Are the most populous six cities sufficient? 50 % of
population? All urban populations?

How should the indicators deal with unstable or biased data points (e.g. sites subject to atypical
traffic trends)? Is it acceptable to discard them? When?
3.
Propose form of indicators and data needs

A review of available dose-response relationships for NO2 outcomes is a critical step. Questions
include whether indicators should focus on chronic or acute outcomes, on exposure at residence
of elsewhere, can be disaggregated by vulnerability (e.g. age), etc.?

A review of how NO2 is reported internationally is also strongly recommended.

A crucial decision is to be made over how background and peak site data are treated. Are
independent indicators for background (suburban) and peak road-influenced locations
preferred?
42
Options for research to enhance national air quality information for environmental reporting

Should indicators of state include population weighting? Should they be annual statistics, subannual or multi-year running means?

What spatial scale is required? A desire to explicitly evaluate roadside locations may require
concentrations to be specified at census meshblock level.

A review of how any impact indicator could be validated or ground-truthed is recommended as
valuable for future improvements.

A preferred set of indicators should be proposed, with some alternatives. This should include
the method of how the indicator is constructed and a method for dealing with data gaps (either
temporary or permanent if sites are closed). Documentation should justify the preferred
recommendation in terms of the criteria and needs developed.
Outputs and outcomes from stage one
Stage one delivers:
 Preferred form of new indicators of state and impact

Criteria for acceptance of indicators that are specific to this work package

Opportunity for stakeholders to review the new indicators and MfE to indicate acceptance or
otherwise.

The scope for stage two
5.1.8 STAGES IN MORE DETAIL: Stage Two – Model Development
Rationale
Stage one will have defined the form of two or more new indicators of state and impact. Stage two
builds those indicators using currently existing data and understanding.
Objectives
Use existing data to construct an interim national model of NO2 concentrations. Use the model to
construct the proposed new indicators. Evaluate the proposed indicators against the criteria
developed in Stage one.
Tasks within Stage Two
Stage two links to NIWA’s ongoing research programme which includes the building of a national
model of long-term NO2 concentrations. Learning from this research should be used to inform the
qualitative evaluation of the representativeness of available observational data.
1.
Build the basic model
Issues to be covered:

Review of potential biases affecting existing sites (representativeness)

Develop method to deal with data gaps

Sensitivity analysis to identify key inputs and assumptions, including gaps in monitoring
coverage, potentially biased and unrepresentative sites, rules for extrapolation, spatial scale of
evaluation.
Options for research to enhance national air quality information for environmental reporting
43
2.
Build draft indicators
It is assumed that indicators should be built within a spreadsheet but alternatives should be
considered.
3.
Evaluate indicators against criteria
4.
Develop proposed improvement plan (i.e. scope stage three)
To include:

requirements of an improved model (scope, accuracy, coverage, scale)

specific purposes for an improved model (e.g. evaluation of which sites meet criteria, most
valuable places for new sites, quantifying representativeness, etc.)

specific data gaps to be filled by long-term or continuous monitoring

specific data gaps to be filled by one-off or occasional monitoring
Outputs and outcomes from Stage Two
 Interim national NO2 model

Draft new indicators of state and impact (or case-studies if further improvement is required)

Improvement plan (scope for stage three)

Recommendations for National Monitoring Network Plan (basis of discussions with potential
commissioning agencies)
5.2
What are the meteorological impacts on trends in ambient pollution?
5.2.1 Rationale
The weather impacts air quality directly, through controlling the dispersion of air pollutants
(windspeed, inversion layers, precipitation) and indirectly through impacting emission behaviour
(temperature).
The physical mechanisms of how meteorological factors affect air quality are well known. For
instance, stronger winds disperse a pollutant further from the source, diluting it through a greater
volume of air and attenuating its impact. An inversion layer effectively 'caps' the volume of air
available for dilution and limits vertical mixing. Precipitation 'washes' pollutants out of the
atmosphere. The impacts of temperature on domestic wood-burning are less straight forward.
Wilton and Bluett (2012) found no strong relationships between immediate temperature and woodburning behaviour, but at the population level, there is clearly a temperature induced, seasonal
pattern.
Year by year variability in the persistence of certain meteorological conditions affects air quality
‘performance’ by introducing noise that obscures the relationships between trends in emissions and
pollutant concentrations. A measure that accounts for this variability would allow a more in-depth
interpretation of air quality data.
44
Options for research to enhance national air quality information for environmental reporting
An outstanding issue is whether these mechanisms can be scaled up to a national spatial scale and an
annual temporal scale so that they can be easily related to the indicators of state.
Preliminary research has identified promising methodologies for creating a meteorological indicator
of pressure. For instance, NIWA’s Seven Station temperature series (NIWA, 2013) is derived from an
established group of meteorological stations situated throughout the country that have been chosen
because they provide broad geographical coverage and long records. Although considered
representative of the country for temperature, their representativeness has not been verified for any
other meteorological parameter that affects air quality. Such a series of stations could be identified
for air quality purposes and the aggregate or individual stations might be reported. Another potential
method is based upon the climatological record and quantifying monthly, seasonal or annual
anomalies from the climatological average. Other methods were not explored in the preliminary
project due to time constraints. Advanced statistical analyses (for example, principal component
analysis or cluster analysis) may also be suitable.
A project is required that investigates and assesses methods of relating meteorological factors to air
quality. The questions that need answering are:

What exactly is the purpose of the meteorological indicator of pressure. How should it be
formulated?

Is it possible to relate national or annual scale meteorological metrics directly to indicators of
state?

What meteorological variables should be covered? Is it necessary to quantify the effect of every
variable that affects air quality?
5.2.2 Ultimate Objectives of the Work Package
To identify a suitable metric to quantify the effect of meteorology on air quality
5.2.3 Ultimate Outcomes of the Work Package
A measure that shows a clear relationship to the indicators of state.
Options for research to enhance national air quality information for environmental reporting
45
5.2.4 Timing
Table 5-2:
Estimated timings for the meteorological work package.
Stage/task
46
Indicative
duration
Other links
outputs
1.
Define needs
1 month



Preferred form of new indicator of pressure
Criteria for acceptance of indicators that are specific to this work package
The scope for stage two
2.
Model
development
2 months+




Interim method for evaluating draft indicator
Draft new indicators of pressure (or case-study if further improvement is required)
Improvement plan (scope for stage three)
Recommendations for National Monitoring Network Plan
3.
Improvement,
(and
subsequent
stages)
2 months+



Verified method for evaluating indicator
Draft new indicator of pressure
Review and Update plan
Options for research to enhance national air quality information for environmental reporting
5.2.5 Steps required to complete the work package
1.
2.
3.
4.
Define needs
i.
Define purpose of indicators
ii.
Interpret criteria for success
iii.
Propose form of indicators and data needs
Method development
i.
Build interim metric for meteorological impact
ii.
evaluate
iii.
scope improvement or alternate plan
Alternative formulation
i.
Build alternate metric for meteorological impact
ii.
Additional method development
iii.
Update metric
iv.
Evaluate updated metric
Update national monitoring plan
5.2.6 Implementation of stages
Each stage listed above delivers an improved outcome. It also gives an opportunity for peer review,
or consultation with the TAG. At the end of Stages two and three, the new data generated is
evaluated against the criteria specified in stage one. Each stage proposes a recommended scope for
the next stage. Thus each stage introduces a decision point as to whether the next stage of
improvements should be implemented, or whether the improvements, and therefore this project,
are complete.
Each stage could be commissioned as a single piece of work or broken into smaller projects. Some
tasks within each stage constitute research that is most likely to be progressed within NIWA’s air
quality research programme, or by other external parties. This is summarised in Table 5-2.
5.2.7 STAGES IN MORE DETAIL: Stage One – Define needs
Rationale
How to capture the effect meteorology has on a national annual measure of air quality is not clear.
Objectives
The aim of Stage one is to develop and define the meteorological indicator of pressure that meets
the aims of environmental reporting and that can feasibly be delivered. It is also to interpret the
MfE/StatsNZ criteria for indicators for the specific case of meteorology, so that any new method
generated can be transparently evaluated and further improvement justified where required. A
Options for research to enhance national air quality information for environmental reporting
47
preferred recommendation for one or more indicators of pressure should be presented, alongside
one or more alternatives.
Tasks within Stage One
Tasks within Stage one are listed below. We recognise that it may not be necessary to follow this list
strictly sequentially, but do recommend that each task or issue is covered.
1. Define purpose of indicators
The following issues should be considered:

Should the indicator allow trends to be evaluated?

Should the indicator provide geographical breakdown? To what level?
2. Interpret criteria for success

How accurate need the data be? How is accuracy related to purpose (e.g., what level of accuracy
is required to discern a trend in a pollutant?)

How much coverage is needed? Do all air quality sites used in the indicators of state need to
relate to the indicator of pressure? What proportion relating is acceptable?

How representative does a meteorological site need to be (of a region, population etc.)?
3. Propose form of indicators and data needs
A preferred formulation should be proposed, with some alternatives. This should include the method
of how the indicator is constructed and a method for dealing with relating future air quality sites to
the meteorological indicator of pressure. Documentation should justify the preferred
recommendation in terms of the criteria and needs developed. This stage links to NIWA’s ongoing
research programme which includes understanding the role of meteorology on air quality.
Outputs and outcomes from Stage one
Stage one delivers:
 Preferred formulation of a new meteorological indicator of pressure

Criteria for acceptance of a newly formulated meteorological indicator of pressure

Opportunity for stakeholders to review the new indicator and MfE to indicate acceptance or
otherwise.

The scope for stage two
5.2.8 STAGES IN MORE DETAIL: Stage Two – Model Development
Rationale
Stage one will have defined the form a meteorological indicator of pressure should take. Stage two
builds the indicator using existing data and the preferred method as defined in stage one. Unlike
other indicators where coverage is of concern and extra monitoring would enhance the indicator,
there is a wealth of meteorological data recorded around the country. The challenge is choosing
which data to use.
48
Options for research to enhance national air quality information for environmental reporting
Objectives
To choose which data is best suited to building the meteorological indicator of pressure using the
formulation chosen in Stage one and evaluate its performance against the criteria developed in Stage
one.
Tasks within Stage Two
1. Choose best meteorological data to use.
Issues to be covered include:

Review of potential biases affecting existing sites (representativeness)

How to link meteorological sites with air quality sites
2. Build a preliminary meteorological indicator of pressure
3. Evaluate the meteorological indicator of pressure against criteria
4. Develop proposed improvement plan (i.e. scope Stage three) if required, including
requirements of the next method (most likely defined in stage one as a second
preferred method).
Outputs and outcomes from Stage two
 Meteorological indicator of pressure or case study

Improvement plan (scope for stage three)

Recommendations for National Monitoring Network Plan (to ensure continuity of required data)
Options for research to enhance national air quality information for environmental reporting
49
6
Completion schedule
Due to the interdependencies of the individual projects, some projects need to be completed before others can begin, while some are completely
independent projects. Table 6-1 below gives an outline of some recommended sequences.
It is recommended that projects are progressed in the sequences indicated. If simultaneous projects cannot be resourced then we recommend they are
executed in priority order, i.e. left to right across the page.
Table 6-1:
Recommended Sequencing of work.
Stage
WP1: NO2
WP2: PM2.5
WP3: PMnatural (PMn)
WP4: National Emissions Inventory
(NEI)
WP5: Meteorology
WP6: PM10
1
NO2: define indicators
PM2.5: define indicators
PMn: define indicators
Define indicator needs
Define indicator needs
2
NO2 model
PM2.5 model
PMn model
evaluate NEI
Method development
PM10: refine
indicators
HAPINZ PM10
evaluation
Outputs:
NO2 indicator of state (or
improved case-study)
NO2 indicator of impact (or casestudy)
Update of National Monitoring
Plan
PM2.5 indicator of state (or
improved case-study)
PM2.5 indicator of impact (or casestudy)
Update of National Monitoring
Plan
Improvements to indicator of
pressure
Improvements to indicator of PM
impacts
Update of National Monitoring
Plan
Decision point 1
3.1
NO2 monitoring
PM2.5 monitoring
PMn monitoring
3.2
NO2 model update
PM2.5 model update
Outputs:
NO2 indicator of state
Update of National Monitoring
Plan
PM2.5 indicator of state
PM2.5 indicator of impact
Update of National Monitoring
Plan
50
Home
primary
shipping
Heating
NO2
Inventory
Improved indicators of pressure (or
improved case-studies)
Update of National Monitoring Plan
Meteorology indicator
of pressure (or
improved case-study)
Update of National
Monitoring Plan
Improved PM10
indicator of state
Improved PM10
indicator of impact
Update of National
Monitoring Plan
Ongoing observation
Additional research
PM10 monitoring
PMn model update
method development
method development
Improved indicator of pressure
Improved to indicator of PM
impacts
Update of National Monitoring
Plan
Improved indicators of pressure
Update of National Monitoring Plan
Meteorology indicator
of pressure
Update of National
Monitoring Plan
Improving PM10
model
Improved PM10
indicator of state
Improved PM10
indicator of impact
Update of National
Monitoring Plan
Options for research to enhance national air quality information for environmental reporting
7
References
Kuschel, G., Bluett, J., and Unwin, M., 2012, Trends in Light Duty Vehicle Emissions 2003 to
2011. Prepared by NIWA and Emission Impossible Ltd for Auckland Council. Auckland
Council Technical Report TR2012/032.
Kuschel, G, Metcalfe, J, et al., 2012. Updated health and air pollution in New Zealand study;
Volume 2: Technical Reports. Prepared for the Health Research Council of New Zealand,
Ministry of Transport, Ministry for the Environment and New Zealand Transport Agency.
March 2012.
Ministry for the Environment and Statistics New Zealand, 2014. New Zealand’s
Environmental Reporting Series: 2014 Air domain report.
NIWA, 2013 http://www.niwa.co.nz/our-science/climate/information-and-resources/nztemp-record/seven-station-series-temperature-data, accessed 19/12/2013
PCE, 2015. The state of air quality in New Zealand. Commentary by the Parliamentary
Commissioner for the Environment on the 2014 Air Domain Report. March 2015
Smit, R. & Somervell, ER, 2015. The use of remote sensing to enhance motor vehicle
emission modelling in New Zealand. NIWA report AKL2015-012.
Somervell, ER, Gray, S, Longley, ID, 2014, Exploration of Meteorological Indicators for
Environmental Domain Reporting, NIWA Client Report
Wilton, E. & Bluett, J., 2012. Wood Burner Testing Christchurch 2009: Diurnal variation in
emissions, wood use, indoor temperature and factors influencing start-up. NIWA report
AKL 2012-020.
Options for research to enhance national air quality information for environmental reporting
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