USING THE NDVI DIFFERENCING FOR MAPPING OF DIPTEROCARP FOREST IN SAVANAKET PROVINCE, LAO PDR

摘要

A dipterocarp forest is a dominal type of forest native in Lao PDR, it include Dipterocarpacaeae tree family, which are tall and are known to produce resins and timber with good quality. It is a tipical type of deiduous forest, formed various landscape and ecological system in Lao, especially the elephant ecosystem. Mapping and monitoring of Diterocarp forest is the purpose of the study. Data used is the Landsat image taken in dry season (January) and wet season (August). In the image of dry season, the forest ares is looked as the bareland because trees sheding all of their leaves. Inversely with this, in rainly season, the Diterocarp forest area is looked as the evegreen forest because leaves of trees are ground up with very high canopy index. The NDVI image had been used for determination of the forest areas and then, the NDVI differenced image between two seasons has been used for determination of the Diterocarp forest,where having high diference of the NDVI values are the Diterocarp forest areas. Dending on the threshold of the diference NDVI valus and comparision with other GIS data such as DEM and morphological features, the Diterocarp forest map has been established with differenced type such as homogenous Diterocarp forest, Diterocarp forest mixed with evegreen forest, Diterocarp forest mixed with rice cultivated plant, Diterocarp forest mixed with bush and grass...The map has been checked with high accuracy.