Above ground biomass mapping of mangrove forest in Vietnam by ALOS PALSAR

This research is investigating the above ground biomass mapping of mangrove forest in Vietnam by ALOS PALSAR measurements. Our test sites are located at four districts of Quang Ninh province in the Northeast of Vietnam. Firstly, a field measurement were carried out in to measure water level, tree species, height, diameter at breast height (DBH) and crown diameter. Secondly, Soil sampling will be further carried out at the laboratory equipment by RCFEE. It was found that the water level has a few meters diurnal changes, the area covered by mainly four species of mangrove forests with homogeneous spatial distribution, height ranges from 0.6m to 5.0m, DBH from 5cm to 30cm and crown diameter from 0.7 to 1.6m. Allometric relationship between DBH and above ground biomass was retrieved via literature survey (Komiyama et al., 2008) and those equations are interpolated supplemented via field survey results. Then ALOS PALSAR HH and HV polarimetric backscatter coefficients are investigated and an above ground biomass of those area are estimated based on an allometric equation. By solving the allometric equations among PALSAR HV polarimetric image, tree height, DBH and above ground tree weight (AGW), AGW was mapped over the mangrove area. Estimated AGW values ranges from 6.4 (t/ha) at 2m-height tree to 16.0 (t/ha) at 5m-height tree.