ON MODELS FOR ESTIMATION OF SUBMERGED SEAGRASS ABOVEGROUND BIOMASS IN SHALLOW COASTAL WATER

摘要

Recent works have seen satellite remotely sensed images be used in estimation of the aboveground seagrass biomass. This can be accomplished in coastal area where the seagrass are fully exposed during the lowest low tide for satellite data acquisition. However to acquire satellite images of fully exposed seagrass is very rare and not all coastal areas with seagrass occurrence ever experiences an exposed lowest low tides. In shallow submerged seagrass, model for deriving for the aboveground biomass using satellite image is not well-established and finely reported yet. Hence, this article introduces a few models for retrieval of submerged seagrass biomass based on empirical analysis, and experimental-based allometric approaches using samples of E. acoroides (giant), T. hemprichii (medium) and H. ovalis (small), common seagrass species with significant different in size in Malaysian coastal water. Using medium resolution scale (30m pixel resolution) of Landsat 8 Operational Land Imager (OLI), seagrass biomass can be quantified in various scales by integrating the empirical model with allometric model. Preliminary results indicated empirical analysis is viable through the plant densities (0% to 100%) with dry biomass weights. Refining these densities and biomass weights with allometric approach has preliminary shown improved accuracy. It is therefore concluded that physical model for retrieval of submerged seagrass biomass using remote sensing data require further elaborations and expected to produce more promising results for seagrass in natural as well as complex coastal environment.