Incorporating Topography into Landscape Continuity Analysis—Hong Kong Island as a Case Study

The increase in population and the expansion of built-up areas into natural and agricultural areas results in more than just loss of open spaces surrounding cities. Reduced accessibility to nature, visual intrusion of buildings into natural viewsheds, and changes in runoff requires us to assess these impacts on open spaces. Our aim in this paper was to examine and demonstrate how topography can be incorporated into modeling and analyzing environmental impacts of cities. Taking Hong Kong Island as a case study, we used historical topographic maps to map changes in the built-up areas between 1930 and 2006. We analyzed changes in three variables representing different kinds of human impacts: landscape continuity, visibility of built-up areas, and runoff from built-up areas. We show that consideration of topography (both natural and artificial) is critical to understand spatial patterns of land use and of human impacts on open spaces. The methods employed here can be applied to examine and visualize the potential effects of future and proposed development plans.