DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 7-8/2015 str. 70     <-- 70 -->        PDF

In the study area, 344 samples with different stand closures between 400 m2, 600 m2 and 800 m2 were chosen. Figure 3 shows the 344 sample plots chosen within the Camyazi Forest Directorate shown on the RapidEye satellite image.
Topographical maps, the stand maps and the RapidEye satellite image are located on the ArcGIS database. Carbon stock amounts of the 344 sample plots shown on Figure 3 were calculated using the field data. For all tree species in the sample plots, BEF1 coefficient from NIR Turkey for Turkey’s forests generated by Asan (2006) was used. Volume measurements of the trees acquired with the measurements in the sample plot are multiplied by calculated coefficients for each tree species groups in Turkey´s forests (0.640 for deciduous, 0.473 for coniferous) and then converted to oven dry weight. After that, it is multiplied with coefficients (1.22 in coniferous and 1.24 in deciduous) that is the conversion factor to convert biomass that corresponds to 1 m3 of standing volume and converted to above ground biomass (AGB) weight. Carbon amount of the above-ground biomass (AGB) was calculated by multiplying the AGB value with the coefficient of 0.50.
AGB (coniferous) = Standing volume x 0.473 × 1.22
AGB (deciduous) = Standing volume x 0.640 ×1.24
Carbon Amount of Above-ground Biomass = AGB × 0.50                The carbon value for each sample plot is converted to tones/pixel size (25 m2) depending on the reflectance value coming from “5 × 5m2” RapidEye pixels.
Geometrical corrected RapidEye satellite image was first divided into bands so that the operations can be performed. Reflection values of the separate areas allocated for each band were calculated. To calculate the reflection values of the satellite image, pixel digital numbers had to be converted to radiance values. To this Lλ=(DNλ.gainλ)+biasλ equation is used. Then each pixel´s value to be converted to digital numbers radiance values were converted to reflection values using the below formula:
 
where “p” is reflection value of each pixel; “λ” represents image bands; “L” is radiance of each pixel; “d” is the distance between the Sun and Earth; “Esun” represents solar atmospheric radiance; “θ” is solar angle; “DN” is digital number of each pixel; gain represents the gain value of each band, and bias is the bias value of each band.