Integration of heterogenous land cover maps for forest cover change detection at national scale: The case of Vietnam

The objective of this study was to assess the presence of a forest transition in Vietnam and describe its geographic pattern, by comparing and homogenizing available forest cover datasets for different years. Several datasets of forest cover for Vietnam for the years 1992-1993 and 1999-2000, based on remote sensing, were assembled. The main coregistration errors were corrected, and thematic contents and spatial details of the maps were homogenized. After that, estimates of forest cover in Vietnam were derived for each map, and their spatial pattern were compared in order to evaluate the consistency of the estimates for the years 1992-1993 and for 1999-2000. Using the data which present the highest agreement, one could conclude to a net reforestation in Vietnam for the period 1993-2000. However, the quality of these new forests has yet to be assessed.