Active Remote Sensing for total above ground biomass estimation over tropical forest
Abstract
The work present in this research mainly focuses on up-scalling approach for aboveground biomass (AGB) estimation employing multi-source active remote sensing data (i.e. IfSAR, TerraSAR) combined with in-situ data. The information provided by Synthetic Aperture Radar (SAR) image is useful for forest management which is the measurement of forest properties such as AGB and stem volume can be generated by non-destructive approach with more efficiently, cost-effective, and can be applied over large forest areas. This work considers study sites over tropical rainforest landscape in Pasoh Forest Reserve, Negeri Sembilan, Malaysia. As a beginning, this research was start with a brief introduction and the explaining of recent trends on monitoring and modeling of forest resources using remote sensing data and approach. This research works on the validation of forest parameters predictions and modeling, followed by estimation of AGB using up-scalling approach. Finally, this work evaluates the TAGB estimation based on allometric method and backscatter information. The results show that the different accuracy of forest parameters predictions and modeling of IfSAR data based on up-scalling approach. Moreover, the up-scalling approach also gives the different result of TAGB estimation.
Research Objective
The main objective of this research is to estimate total aboveground biomass based on up-scalling method using active remotely sensed data (i.e. Interferometric Synthetic Aperture Radar) in Pasoh Forest Reserved, Negeri Sembilan.
Study Area
The study area of this research is conducted in Pasoh Forest Reserve which located in Negeri Sembilan of Peninsular Malaysia at latitude 2º 59’N and longitude 102º 19’E. The area an approximately of 2,450 ha (Malaysia, 2012) and 145 km southeast of Kuala Lumpur. The core area 50 ha of the Forest Reserve is covered with primary lowland mixed Dipterocarp forest that includes various species of Shorea and Dipterocarpus (Kosugi et al., 2008).
Up-scalling methods
This method are consists of grid systems in order to estimate the TAGB with different type of kernel sizes. The involved of kernel size are 1) 5m × 5m, 2) 10m × 10m, 3) 20m × 20m, and 4) 50m × 50m. Each of grid have different number of trees which is the larger grid size, the more trees include in the grid. Figure 3.3 shows the grid system or kernel analysis that applied into field data and also the IfSAR data. The blue area shows the available of 25 ha field data collection in year 2009.
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Tree height and DBH evaluation based on up-scalling method
The evaluation of tree height and DBH are done by comparing the sample points of IfSAR and field data. Both of data are verified by using RMSE equation. The accuracy, regression and correlation value of tree height and DBH are shown below:
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