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Annex 6: Quality assurance and quality control

During preparation of the New Zealand 2004 national greenhouse gas inventory, work continued on the implementation of the "New Zealand National Greenhouse Gas Inventory Quality Control and Quality Assurance Plan". Specific checks have been completed as time and resources have allowed.

A6.1 QC procedures implemented in preparation of the 2004 inventory

Tier 1 quality control (QC) checks for key sources (as identified in the level and trend analysis of the 2003 national inventory) and a selection of non key sources were completed on the 2004 data. Two of these checklists with the results are included as examples in this Annex. The checks incorporated in the CRF reporter (time-series consistency, recalculation and completeness checks) were undertaken to identify any outliers and inconsistencies in the trends from 1990-2004.

Some specific findings of the 2004 quality control process included:

  • CO2 emissions were found to be included for liquid fuels for iron and steel for this submission whereas the 2005 submission did not include emissions at this level. This error was corrected after consultation with the data providers Ministry of Economic Development.
  • LULUCF net removals data was found to be too high and on re-checking discovered the inclusion of soil carbon information in forest land was effectively causing double counting. This was corrected.
  • An error in activity data for road paving with asphalt was found for the years 2000-2003. Only activity data for cut-back was included in the CRF in the 2003 inventory. This has been corrected to include activity data for all bitumen use for roading in the 2004 inventory.

A6.2 QA procedures implemented

A checklist of recent reviews of specific sectors (including emission factors) undertaken as part of the quality assurance of the New Zealand national inventory is included in this Annex.

During 2005 a number of recommendations from the quality management report produced in late 2004 were addressed.

  • The improvement plan was updated with the objective of the greenhouse gas inventory to be consistent with IPCC Good Practice Guidance by September 2006.
  • A post-inventory evaluation will be undertaken after inventory submission on 15 April to review lessons learned and how to improve processes for the next inventory compilation. This is documented in the schedule of activities in the QA/QC plan.
  • The QA/QC coordinator and responsibilities for this position have been clearly defined in the QA/QC plan.
  • Objectives of the QA/QC programme have been formally documented in the QA/QC plan and performance against these objectives will be regularly reviewed.
  • The QA/QC plan now contains more specific information as cited in the IPCC Good Practice Guidance including a scheduled time frame that follows inventory preparation from its' initial development to final reporting in any given year. It also includes a schedule to review all source categories over a four year period.

A6.3 Methods of QA/QC used by external agencies

Statistics New Zealand: To minimise error, all questionnaires are carefully designed and tested to make them easy for respondents to understand and complete correctly. During the processing of statistics, checks are carried out to ensure the data appears consistent. Checks are also undertaken to ensure responses have been recorded correctly.

Statistics New Zealand aims to ensure all farms and forests are represented in the agriculture surveys. The survey frame is updated with feedback from survey/census respondents. The questionnaire is designed with a view to making it easy for survey respondents to give the information which Statistics New Zealand requires. Questionnaires are tested prior to use in surveys. Statistics New Zealand provides an enquiry service for respondents who need to help completing questionnaires and they follow up respondents to ensure high response rates are achieved. Statistical methodology (sample design, estimation techniques etc) follows international best practice. Data editing and consistency checks are carried out on all data.

A6.4 Future development of the QA/QC system

New Zealand will continue to address the recommendations from the quality management report during 2006. These include:

  • documenting a plan for Tier 2 quality checks
  • investigating ways of performing verification of emissions data
  • continuing to plan and implement a document/records register to improve management of inventory documentation. (The new document management system implemented at the Ministry of the Environment during 2005 is assisting in achieving this improvement.)

A6.5 Example worksheets for QC procedures in 2004

Example worksheets for QC procedures in 2004 [PDF, 23 KB].

A6.6 QA summary worksheet

QA summary worksheet [PDF, 24 KB]