Woody Aboveground Biomass Estimation using Radar Data in the mixed Hyrcanian Forest (Case Study: Khayroud Forest of Nowshahr, Mazandaran)

This study investigates the capability of ALOS-2 full polarimetric radar data for estimating woody aboveground biomass (AGB) in a mixed Hyrcanian forest. For collecting ground data, the low slope areas selected and measured for a total of 127 square sample plots with an area of 900-m2. Tree height and Diameter at Breast Height (DBH) were measured for each tree with DBH of larger than 7.5-cm and the volume of each tree was calculated using these two characteristics. We used volume to biomass equation (multiplying the volume by the wood-critical density) to calculate AGB in each sample plot. The average of observed AGB was 318.04-tons per hectare for the study area. To process ALOS-2 data, the polarization channels were calibrated and multi-looked. We used a Box-Car filter with window size of 5×5 pixels to reduce the noise. Finally, the extracted features were geometrically corrected. They are Backscattering intensity components in the form of gamma naught, Freeman-Durden target decompositions components and variables derived from mathematical relationships betw