TEC - West Coast Region, New Zealand

The aim of this case study was to identify the status of LENZ environments within the West Coast Regional Council area through the use of the TEC tool. The wider aim was to provide a quantitative assessment of the degree of indigenous cover remaining in the West Coast Region including the Buller, Grey and Westland Districts.

The Threatened Environment Classification Tool (TEC) is a freely available simple and practical GIS too which is an extension of the Land Environments of New Zealand (LENZ) Classification; it has been used in this case study to assess the status of threatened environments on the west coast of New Zealand.  The study has potential to be of value in enhancing future policy development along the West Coast.

In their assessment this study used raster layers in ESRI raster format at 25 meter resolutions which were prepared using New Zealand Map Grid Projection. The following datasets were used in this studies analysis:

  1. Land Environments of New Zealand Level IV (LENZ).
  2. Land Cover Database version 2 was used to determine indigenous cover.
  3. Protection – a national database of protected lands (this database is held and administered by Landcare Research). This was compiled in July 2008 from the most recent available data.
  4. Regional and District boundaries derived from LINZ data via the Meshblock database.

The Raster datasets were analysed to produce an aspatial database by a technique known as Combinatorial Analysis using software developed in C++ by Landcare Research. SQL queries were developed to summarise the data in the database, and the results were exported to Excel spreadsheets using Visual Basic.               

The results illustrated that the West Coast Region has only 2.3% of its area within LENZ Level IV environments that are classified as one of the five ‘threatened environments’ (i.e. either Acutely Threatened, Chronically Threatened, At Risk, Critically Underprotected or Underprotected) against a national mean for regions of 45%. Of the 86 LENZ level IV Environments in the West Coast, 11 would be classified as ‘threatened environments’.

 

There are no LENZ Environments in the West Coast region in the category with the highest level of threat (Acutely Threatened: < 10% indigenous vegetation left). In conclusion, much of the area of the West Coast Region is of LENZ environments classified as “Less Reduced and Better Protected” nationally.

This means that relatively high proportions of the LENZ environments in the West Coast Region retain some form or indigenous cover, and most have legal protection across > 20% of their land area. Within the West Coast Region, the Buller District contains all the remaining (identified) indigenous cover of land that falls within environments that are nationally classified as ‘threatened environments’. There are similar areas of indigenous cover of At Risk environments in each of the districts.

A number of environments of limited extent or vulnerable nationally may warrant further protection. A spatial investigation of the remaining Indigenous Cover in these LENZ environments may be warranted. Data suitable for such a study have been prepared during this study but fell outside the scope of the project.

Associated Models

Threatened Environment Classification (TEC tool)

The Threatened Environment Classification is an interactive GIS tool which helps planners identify and set a value on New Zealand‘s threatened environments.

References

Price, R. & Briggs, C. (2008) Threatened Environment Classification for the West Coast Region, New Zealand. Landcare Research Contract Report: LC0809/076, 16p. Prepared for Envirolink.

Walker, S., R. Price, D. Rutledge, R. T. T. Stephens, and W.G. Lee. (2006). Recent loss of indigenous cover in New Zealand. New Zealand Journal of Ecology 30: 169–177