Land cover

  • Image, Land cover.

    Land cover describes the extent of vegetation, water bodies, built environments, and bare natural surfaces (eg gravel and rock) across New Zealand. Measuring the composition and changes in land cover can help us understand the pressures that different land uses are placing on the biodiversity and functioning of ecosystems.

    We classified Land cover as a national indicator.

    Key findings

     Trend not assessed

    From 1996 to 2012, the largest increases in land cover were in exotic forests (11.5 percent or 208,146ha) and urbanised land (10.1 percent or 20,922ha).

    • Exotic grassland covered 39.8 percent (10.7 million ha) of New Zealand in 2012, a decrease of 1.6 percent (173,388ha) since 1996.
    • Indigenous forest covered 23.8 percent (6.4 million ha) in 2012, a decrease of 0.2 percent (10,518ha) since 1996.
    • From 1996 to 2012, indigenous tussock grassland decreased 1.3 percent (30,049ha) to 2.3 million ha.
    • Over the same period, scrub and broadleaved indigenous hardwoods decreased 3.1 percent (49,266ha) and 1.2 percent (7,353ha), respectively.

    Figure 1

    Note: Data from the reclassified New Zealand Land Cover Database Version 4.0.

    Figure 2

    Land cover, 2012 – interactive map

    Figure 3

    Note: The total area of New Zealand has been calculated to 26,842,403ha. Scrub includes both indigenous and exotic classes. The snow and ice class was calculated in 1996 and has not been updated since.

    Figure 4

    Note: The total area of New Zealand has been calculated to 26,842,403ha. Scrub includes both indigenous and exotic classes. The snow and ice class was calculated in 1996 and has not been updated since.

    Figure 5

    Note: Scrub includes both indigenous and exotic classes. The snow and ice class was calculated in 1996 and has not been updated since.

    Definition and methodology

    The New Zealand Land Cover Database (LCDB) is a national classification of land cover and land use mapped using satellite imagery. We used Version 4.0, which covers mainland New Zealand and the nearshore islands but not the Chatham Islands.

    The LCDB has four major versions (1–4), correlating to the four summer survey periods – 1996/97, 2001/02, 2008/09, and 2012/13. The land cover classification was developed over the first three versions. Classification changes can be tracked to allow comparison between versions.

    The classification starts with seven higher-order classes, which expand to 33 lower-order classes. The data presented here expands the seven higher-order classes to 13 medium-order classes. These provide more detail than the higher-order classes, particularly for indigenous and exotic forests, and grassland classes, but retain a high level of confidence in the allocation accuracy (eg for scrub).

    See the Habitats data in the ‘Related content’ box for more information on the LCDB lower-order classes used.

    Data quality

    We classified Land cover as a national indicator.

    Relevance

    relevance-direct This national indicator is a direct measure of the ‘Vegetation and other land cover’ topic.

    Accuracy

    accuracy-high The accuracy of the data source is of high quality.

    See Data quality information for more detail.

    Supporting information

     

    Published 21 October 2015

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