This study is designed to update the existing Hong Kong-wide vegetation map, to expand the coverage to include new categories, and to present the results in an interactive Geographic Information System (GIS). The scope of the survey encompasses all terrestrial habitats including all habitats above the low tide mark. The map and mapping system will be produced with reference to the latest available satellite images and aerial photographs of Hong Kong, available results of the ongoing Biodiversity Survey, and dedicated field investigations conducted by the Study Team.

This Study is also designed to develop a system for ranking the conservation value of areas of Hong Kong, to supplement compilation of existing conservation data through field surveys, and to present the results in a Geographic Information System (GIS). Conservation value is defined based on terms used in the EIA Technical Memorandum (TM) and includes measures of ecological value, as well as recreational, heritage and landscape functions. This option is not designed to provide a decision-making system for development planning but rather to provide an overall measure of a site's conservation value which can be easily incorporated as a component of the decision-making process.

The most useful habitat information available to date is derived from a 1992 digitised vegetation map of Hong Kong prepared by the Worldwide Fund for Nature (WWF). This map, based on vegetation photographs from 1989, plots 34 different categories of vegetation or land use in addition to height contours, drainage and road data, country park boundaries, special areas and Sites of Special Scientific Interest (SSSIs). The vegetation data has been converted to Arc/Info by WWF, however all other information is still in the original GENAMAP GIS format and is not available in Arc/Info.

The ongoing Biodiversity Survey being conducted by researchers from Hong Kong University (HKU) intends to utilise the WWF map as the basis for an updated habitat map. The Biodiversity Survey study has combined the WWF information with its own data and that of other recent, reliable studies. However, as the latter two data sources only focus on selected areas of Hong Kong, the coverage will not be updated for all areas.

At present, there is no established system for ranking the conservation value of all areas within Hong Kong. Although individual ranking exercises have been conducted under various specific studies and planning initiatives (eg site selection exercises) in the past, these are of limited use in designing a system applicable to all of Hong Kong. A number of different categories of conservation status currently exist in Hong Kong including Country Parks, Special Areas and Sites of Special Scientific Interest (SSSIs). Although these areas cover a large percentage of Hong Kong's land area, they cannot be assumed to encompass all of the areas of conservation value. Certain areas previously designated in these categories may no longer have the same habitat value as when they were designated, and conversely, other undesignated areas may warrant further conservation efforts. However, recommendation on allocation of further conservation efforts on particularly habitats is outside the scope of this Study.

The HKU Biodiversity Survey will also contribute considerably to the existing body of knowledge concerning the conservation value of areas of Hong Kong. One of its objectives is to update existing information on the ecological values and functions of various areas of Hong Kong and highlight those of ecological importance. This information will fill a large number of existing data gaps but will not specifically rank areas and will only address ecological issues. Furthermore, as the Biodiversity Survey will not cover all areas of Hong Kong, geographic data gaps will remain even after the survey is completed.