Tree canopy cover, land use and planning implications in urban Hong Kong

Abstract

The relationships between urban tree cover and land use in the main urban areas of Hong Kong were studied with the aid of aerial photographs. Some relevant terms and concepts were defined and elaborated. The relative proportions of artificial surfaces, tree canopy cover and additional growth spaces in 12 land uses were estimated. Three essential attributes of the tree cover, namely the canopy configuration, tree habitat and tree-building propinquity, were also evaluated. Land uses were divided into three groups according to canopy cover. For each land use, the distribution and characteristics of the tree cover were discussed with reference to urban planning, urban history and urban morphology. The densely built-up city left scarce plantable spaces which are concentrated on remnant slopes embedded within the urban matrix, the parks and open spaces, and the low-density residential districts. Outside these areas, the tree canopies are mainly isolated and discrete entities spatially segregated from the built-up framework. Different land uses furnish plantable spaces of different geometry which to a large extent moulds the canopy configuration. The implications for urban planning and landscaping in new development and renewal areas are discussed. Some measures to augment and rejuvenate amenity greenery are proposed. The methods can be applied to other cities to acquire rapidly synoptic urban-greenery data for planning purposes.