ACCURATE MAPPING OF DATE PALMS AT DIFFERENT AGE-STAGES FOR THE PURPOSE OF ESTIMATING THEIR BIOMASS

摘要

The main objective of the current study was to produce an accurate map of date palm (DP) plantations in the Emirate of Abu Dhabi in United Arab Emirates (UAE) using moderate resolution Landsat-8 (OLI) imagery. The second objective was to be able to create a more detailed map depicting three different categories of date palms at three different age stages: young, medium, and mature. This was achieved using a hierarchical integrated approach: first, Landsat-8 OLI imagery were used to map mature date palms in the study area; second, an object oriented classification (OOC) approach was applied at the plantation level using sub-meter Worldview-2 imagery (WV-2) to depict and map medium and young aged palms. Three age-stage categories of date palms were mapped with acceptable accuracy. The primary outcome of this classification approach was the creation of detailed maps of date palms to be used as input to a remote sensing (RS) based biomass estimation model for the assessment of the above ground biomass (AGB) and carbon sequestered (CS) of date palms. Results were validated using existing ancillary data and field checks. DP were mapped with an overall accuracy of 94.5% which was considered high in similar conditions of drylands, while the overall kappa statistics was estimated at 0.888.