環境保護署 - 策略性環境評估

研究報告

Chapter 4 PRELIMINARY HABITAT MAP

4.2

Methodology

4.2.2

Satellite Imagery Classification

Post-classification discrimination

Post classification discrimination uses decision rules to refine the classification by re-assigning classified pixels by reference to other sources of information. For example, pixels classified as Bare/Modified and falling within the boundary of a known quarry, would be re-assigned as the Quarry habitat. The post classification discrimination process is summarised in Table 4.2b below.

Table 4.2b Post-classification Discrimination
Class from Imagery Classification (Table 4.2)	Derived Habitat	Processing and Data Source
Bare/Modified	Bare Rock or Soil	Within the Bare/Modified class, bare rock or soil features were identified from visual interpretation of aerial photos.
	Quarry	Within the Bare/Modified class, quarry features were identified from Lands (1997 1:20K) and Mouchel (1998).
	Landfill	Within the Bare/Modified class, landfill features were identified from Mouchel (1998).
	Other (Urban or Other Highly Modified Area)	Bare/Modified class less Bare Rock/Soil, Quarry and Landfill.
Grassland, Shrubby Grassland, Low Mixed Shrub and Tall Mixed Shrub	Cultivation	Within any of these four classes, areas that coincided with the Cultivation layer of Lands (1997 1:20K) were identified as the Cultivation habitat.
Grassland	Grassland	The Grassland class less the Cultivation habitat.
Shrubby Grassland	Shrubby Grassland	The Shrubby Grassland class less the Cultivation habitat
Low Mixed Shrub	Mixed Shrubland	Merging of the Low Mixed Shrub and Tall Mixed Shrub classes less the Cultivation habitat.
Tall Mixed Shrub Baeckia Shrubland Mangrove	(see above) Baeckia Shrubland	(see above) nil
Mangrove	Mangrove	Within the Mangrove class, areas that coincided with Tam and Wong (1997) were identified as the Mangrove habitat.
Wetland	Freshwater/Brackish Wetland	Within the Wetland class, areas that coincided with the Cultivation layer of Lands (1997 1:20K) or data from Dudgeon and Chan (1996) were identified as the Freshwater/Brackish Wetland habitat.
Forest	Montane Forest	Within the Forest class, areas that are above 600 metres as determined from the Contours data of Lands (1997 1:20K) were identified as the Montane Forest habitat.
Forest	Lowland Forest	Forest class less the Montane Forest habitat.

2005

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最近修訂日期: 二零零五年十二月二十二日