The primary objective of the joint project conducted by the Global Land Analysis and Discovery Lab (GLAD) from University of Maryland and SERVIR-Mekong is to provide regionally consisted time-series of woody vegetation structure data suitable for land cover change monitoring at the national and regional scales. The GLAD team has developed an automated system for the Landsat data processing and characterization. Using temporally and spatially consistent Landsat data, the GLAD team derived a series of products depicting annual dynamics of woody vegetation structure and primary forest extent. The products are consistent at the regional level and provided at spatial resolution relevant for the national analysis. Presented data may be useful for assessing the national forest management policy effects, international forest resources reporting, and greenhouse gases emission estimation. SERVIR regional land cover monitoring portal (https://rlcms-servir.adpc.net/en/forest-monitor/) provides capacity for online data visualization and analysis.
Technical Data Description
All data layers provided in the geographic coordinates using WGS84 reference system. Pixel size is 0.00025 x 0.00025 degree. Annual data provided in 8-bit GeoTiff format suitable for visualization and analysis in most GIS software. Other datasets (including annual Landsat data composites as 16-bit data) are available by request.
Dr. Peter Potapov: email@example.com
Landsat cloud-free annual data composites
The composites of median annual normalized surface reflectance value for SWIR (1,600 nm), NIR (850 nm), and red (660 nm) Landsat spectral bands provided for a spatial reference. The Landsat data was composited by the GLAD automatic data processing system. The data processing include clouds and cloud shadows screening and reflectance normalization to reduce effects of surface anisotropy and atmospheric scattering.
Tree canopy cover
A proportion of canopy cover from woody vegetation taller than 5 meters within the mapping unit (Landsat data pixel, approximately 30x30 meters). The map value represents percent tree canopy cover for each year. The regional tree canopy cover model was calibrated using tropical airborne lidar data and applied annually. Forest change detection results were integrated with the annual tree canopy cover time-series data.
Tree cover height
The median height of the top of the tree canopy above the ground within the mapping unit (Landsat data pixel, approximately 30x30 meters). The map value represents canopy height in meters for each year. The regional tree height model was calibrated using tropical airborne lidar data and applied annually. Forest change detection results were integrated with the annual tree height time-series data.
The primary forests defined as long-lived natural forests that have no indication of disturbance or regrowth since 1985 and which spectral signature corresponds to a mature forest stand. The map value “1” corresponds to the primary forest extent for a certain year. The regional primary forest extent for the year 2000 was mapped through supervised classification approach, and the map was annually updated using the forest change detection product.