Antarctic Environmental Domains
Between 2003 and 2008, Landcare Research, with funding from a number of New Zealand government agencies, undertook an environmental domains analysis (EDA) for the Antarctic Continent.
Based on a variety of climate, land cover and geological information, the resulting classification provides a data-derived, spatially explicit delineation of environmental character in Antarctica to be used for a range of management activities. The classification is built on the experience Landcare Research scientists have gained in developing a classification of New Zealand’s terrestrial environments called Land Environments of New Zealand.
The classification process
Using publicly available data, a number of spatial data layers were created that differentiated the physical environment within Antarctica. For this classification, mean annual air temperature, seasonal air temperature range, mean annual wind speed, estimated solar radiation at top of atmosphere, period of year with normal diurnal pattern, slope, land (ice) cover and geologic information were used. The data layers covered the continent at a uniform cell size with the same spatial projection. After the layers were complete, a systematic sample of data points was exported to be analysed in two sequential stages that form the basis of the environmental domains analysis.
The first stage used a non-hierarchical classification to group together points that are located close to one another based on their environmental character. This process used the Gower Metric, a range-standardised distance measure, to measure environmental distance between each point. Each point was then clustered into groups based on its environmental distance to the points closest to it. This process defined a range of environments for the Antarctic Continent.
The second stage used a hierarchical classification to define interenvironmental relationships between the centroid for each of the environments identified by the non-hierarchical classification. The outputs from this classification were then imported into a database to create a hierarchy definition. From this, specific group centroids could be exported using purpose-written codes that allowed lookup tables to be joined to the classification raster data layer. Taking into account the end-user requirements of the final classification, the numerous environments created in the non-hierarchical classification were agglomerated down to 21 distinct environments identified as the Environmental Domains of Antarctica classification (Figure 1).
Application of the EDA
The use of a computerised classification procedure allows similar environments, including small, distinctive environments that are otherwise easily overlooked at the continental scale, to be grouped based on their environmental character regardless of their geographical location. The resulting classification is currently being used for a range of management activities including identification of priority sites for protection, environmental monitoring, and assessment of risks associated with human activities.
Download Final report:
Morgan F, Barker G, Briggs C, Price R, Keys H. 2007. Environmental Domains of Antarctica Version 2.0 Final Report. Landcare Research Contract Report: LC0708/055. 2.9MB