Cultivation

Because of the heterogeneous nature of this habitat type and spectral similarities with other categories (e.g. grassland, shrubby grassland, wetland), the cultivation habitat type cannot be mapped accurately using imagery classification alone. Therefore, 1:20K topographic data (Lands (1997 1:20K)) have been used to identify the areas through manual discrimination of cultivated areas from spectrally similar but non-cultivated areas, and has substantially improved the mapping confidence. The category is mapped with a medium level of confidence and uncertainties exist in some identified areas.

Golf Course/Urban Park

Golf courses and urban parks also cannot be mapped satisfactorily using imagery classification and also relied upon the 1:20K topographic data (Lands (1997 1:20K)) and Lands Department's Countryside Map Series (Lands 1998 1:20K)) to identify these habitats. Both the location and boundary of golf courses and urban parks were clearly identified and the level of mapping confidence is therefore high.

Rural Industrial Storage/Containers

As this category is characterised largely by blocks of multi-coloured containers and/or plain-coloured commercial/industrial materials intermingled with concrete paths, the spectral nature of the habitat is not homogeneous enough to be classified satisfactorily using satellite imagery. These storage areas are generally referred to as "black spot" areas by the Government. The accuracy of the mapping of this category was improved through recourse to the "black spot" databases provided by the Planning Department. As a result, the habitat is mapped with a high level of confidence.

Quarry

This habitat type cannot be distinguished from other spectrally similar categories by imagery classification alone. Manual identification was carried out with the use of existing information (Table 4.3c). The habitat can thus be regarded as mapped with a high level of confidence.

Landfill

Due to its spectral similarity with other habitat categories, landfills were initially classified as the same category as bare rock or soil, rocky shore, artificial rocky/hard shoreline and quarry under imagery classification. However, manual on-screen digitisation using existing information (Table 4.3d) resulting in the mapping of landfills with a high level of confidence.

Other

This category includes mainly those areas which have been identified as bare reclaimed land and construction sites. The areas were mapped primarily through imagery classification supplemented with manual adjustment based on the knowledge of the Study Team. Due to the variability within this habitat type and the potential for the nature of the area to change with time, mapping accuracy of the habitat is considered medium.