Question: Can recent satellite imagery of coarse spatial resolution support forest cover assessment and mapping at the regional level?
Location: Continental southeast Asia.
Methods: Forest cover mapping was based on digital classification of SPOT4-VEGETATION satellite images of 1 km spatial resolution from the dry seasons 1998/1999 and 1999/2000. Following a geographical stratification, the spectral clusters were visually assigned to land cover classes. The forest classes were validated by an independent set of maps, derived from interpretation of satellite imagery of high spatial resolution (Landsat TM, 30 m). Forest area estimates from the regional forest cover map were compared to the forest figures of the FAO database.
Results: The regional forest cover map displays 12 forest and land cover classes. The mapping of the region's deciduous and fragmented forest cover remained challenging. A high correlation was found between forest area estimates obtained from this map and from the Landsat TM derived maps. The regional and sub-regional forest area estimates were close to those reported by FAO.
Conclusion: SPOT4-VEGETATION satellite imagery can be used for mapping consistently and uniformly the extent and distribution of the broad forest cover types at the regional scale. The new map can be considered as an update and improvement on existing regional forest cover maps.
Abbreviations: ASEAN = Association of Southeast Asian Nations; FAO = Food and Agriculture Organization of the United Nations; IUCN = International Union for Conservation of Nature; LCCS = Land Cover Classification System; MRC = Mekong River Commission; NDVI = Normalized Difference Vegetation Index; NIR = Near infrared; S10 = Ten day standard composites; SWIR = Short wave infrared; VGT = SPOT4-VEGETATION.