Updating the Vegetation Layer of the NZLRI National Database Using Satellite Imagery

This paper describes four methods of rapidly mapping vegetation using satellite imagery, for use in updating the vegetation layer of the New Zealand Land Resource Inventory (NZLRI). The visual interpretation method was tested in a 500 km² study area on the North Island west coast where 3 6 NZLRI vegetation classes occurred. Sixteen distinct groups of NZLRI vegetation classes were identified on Landsat Thematic Mapper imagery, and named “image classes”. Classes were identified by correlating ground data with image colour and texture and by using recognisable landform and cultural features. A limited number of vegetation changes have occurred since NZLRI mapping was first carried out. Updating the vegetation layer of the NZLRI requires recognising and mapping changes and modifying the database. Identifying distinctive groups of NZLRI vegetation classes on satellite imagery will facilitate this.