Pastoral Intensification

How we monitor

• Where and how we collect the data

  Waikato Regional Council obtains information on the number and type of stock on each farm in the Waikato region from the AgriBase® database. AsureQuality Limited developed, and now maintains, AgriBase®.

  We estimate the area of pastoral land on each farm and the changes in pastoral and pine forest land cover from the Land Cover Database version 5.0 (LCDB v5.0).
• Monitoring frequency

  AsureQuality Limited maintains AgriBase® records through:

  • routine contact with farmers
  • monthly updates of property changes from Quotable Value New Zealand.

  Waikato Regional Council purchases AgriBase® with data updates every six months.

  The LCDB is generally updated every 5 years by Landcare Research New Zealand Ltd. LCDB v5.0 was funded by a consortium of central government agencies, including the Ministry for the Environment, the Ministry for Primary Industries, and the Department of Conservation. Waikato Regional Council’s monitoring of pastoral area depends on the release of updated LCDB datasets.
• Monitoring history

  Development of the AgriBase® system began in late 1988. National data capture began in 1993. Waikato Regional Council has purchased a snapshot of the AgriBase® database every six months since 2008.

  The New Zealand Land Cover Database (LCDB) is a multi-temporal digital thematic map of land cover and land use. The LCDB version 5.0 data was created by Landcare Research New Zealand Ltd and is primarily derived from satellite imagery. Various more recent mapping data sources and spectral methods were used to assess the changes in land over time and improve the data. LCDB version 5.0 was released in January 2020 and includes corrections to all time steps 1997/97, 2001/02, 2008/09, 2012/13 and 2018/19. More detailed information is available at Land Cover Database.
• Measurement technique

  Plantation forest conversion to pastoral land, pastoral land use area, intensity and change are estimated using spatial analysis methods to examine existing spatial datasets held by Waikato Regional Council’s Geographic Information System (GIS).

   Waikato Regional Council uses:

  • AgriBase® data on stock numbers to calculate the number of stock units on each farm, the land area of the farm, and identify changes in the number of stock units from 2012 to 2019.
  • Landcover data (LCDB version 5.0) to calculate the area of pastoral land on each farm and identify changes between pasture and pine forest from 2012 to 2019.
• Calculating stock density

  Waikato Regional Council calculates stock density for each farm by dividing the total stock units on the farm by the total area of pastoral land. Following this process for the whole region requires a series of steps, outlined below.

  Due to the way in which the AgriBase® dataset is constructed, we first pre-process the data using GIS tools to avoid overestimating stocking rates using a 'flattening' process to area proportion AgriBase® recorded stock numbers to the available LCDB v5.0 pastoral extent. This is necessary because AgriBase® records the total area of each farm, which may include non-pastoral land.

  We work out the total stock units for each farm by converting the animals into common stock units and calculating a farm total.

  We use the AgriBase® stock data and the AsureQuality stock unit conversion factors for this task. We also use information from AsureQuality about the typical distribution of stock classes expected on a ‘standard’ farm. This allows us to estimate stock density in more detail for each farm type.

  We use predefined stock unit density classes to classify farm types (including pine forest) into one of the five classes shown below.
• Stock unit density classes and farm types

   

  Stock unit density class (stock units/ha)	Farm type where stock unit density typically observed
  0 (no stock units)	Pine forest
  Less than 10.5	Sheep farms
  10.5 to 17.5	Beef farm and lower stocked dairy farms
  17.5 24.5	Mid-range dairy farms
  Greater than 24.5	Higher stocked dairy farms
• Calculating pine forest conversion to pastoral land use

  LCDB version 5.0 includes time step data for 2012/13 and 2018/19. Spatial analysis of the Landcover data is used to calculate the area of pastoral land on each farm in each of the years and identify changes between pasture and pine forest from 2012 to 2019.
• Pastoral land use change

  Using the stock unit density class defined farm types as a base, pastoral intensity changes from 2012 to 2019 are identified and a measure of the magnitude of change in terms of typical farm system breaks is made. The magnitude and direction of change is classified as shown below.

  Pastoral stock unit density class change	Pastoral land use change class
  Two or more class increase	Major intensification
  One class increase	Moderate intensification
  No class change	No change
  One class decrease	Moderate destocking
  Two or more class decrease	Major destocking
  No reliable stock data	No data

  We identify which of the eight major catchment management zones in the Waikato region that each farm fits into. This helps us determine how pastoral intensification might be affecting water quality in different parts of the region.

  We identify which of the eight Land Use Capability (LUC) classes in the Waikato region that each farm fits into. This helps us determine how pastoral intensification might be affecting water quality on different types of land in the region.

  We create a map showing the distribution of pastoral intensification, no change, and de-stocking for the Waikato region.
• Guidelines and standards

  To calculate stock density from AgriBase® data, Waikato Regional Council uses the AsureQuality stock unit conversion factors. These factors are used to work out feed budgets in the agricultural industry.

  To identify land cover and calculate changes between years Waikato Regional Council uses the most recent version of LCDB which includes corrections to all time steps and maintains backward compatibility.
• Limitations

  AgriBase® data cannot be used to calculate farm-based stock densities for all farms in the Waikato Region. This is because not all land parcels in the database are linked to a specific farm.

  The AgriBase® data purchased by Waikato Regional Council does not discriminate between the age classes of the animals. The equation used to calculate total stock units is a generalised one that uses typical stock classes on farms.

   

  Quality control procedures

  For information on the Land Cover Database data quality (lineage, positional accuracy, attribute accuracy, logical consistency, and completeness) see the updated LCDB metadata.

  Sophisticated quality assurance procedures (including statistical, SQL query, visual/spatial inspection) have been developed by AsureQuality Limited to verify the incoming data for AgriBase®.

   

  Footnotes

  The LCDB version 5.0 dataset is a "public good" dataset created by Landcare Research New Zealand Limited and supplied under Creative Commons Attribution V4.0 International Licensing.

  AgriBase® data is a product of AsureQuality.

• Changes in pastoral intensity across catchment management zones of the Waikato region from 2012 to 2019

  

  Main Points

  • Most of the pastoral land in all catchment management zone showed no change.
  • Net pastoral intensification occurred in all catchment management zones across the region, except in the West Coast zone (+0%).
  • The greatest net pastoral intensification occurred in the Upper Waikato catchment management zone (+12%).
• Changes in pastoral intensity across Land Use Capability (LUC) classes of the Waikato region from 2012 to 2019

  

  Main Points

  • Most of the pastoral land in all LUC classes showed no change.
  • The greatest net pastoral intensification occurred on LUC class 4 pastoral land (+6%).
  • The greatest net de-stocking occurred on LUC class 1 pasture (+1.5%).