Evaluating the Potentials of Spectral Indices of the MODIS in Estimating the Plant Production in Semirom Pastures

During the last two decades remote sensing scientists have studied the role of resulting vegetation indices through the satellite data in evaluating the natural resources, These indices have shown high correlations with vegetation parameters. The aim of this study was to evaluate the potentials of spectral indices of MODIS sensor for estimating Semirom and Brojen pastures plant production. Different preprocessings including geometric correction were applied using topographic maps of 1:250000 and the RMSe was 0.8 pixels. Also the atmospheric correction was applied through the dark object subtraction. Field data collection was conducted on the vast areas of about 800,000 ha during the June 2005. The vegetation units with similar floristic-physiognomic-ecologic compositions were considered as an exclusive vegetation type and were sampled with stratified random sampling. The plant production was measured using double sampling method. For this study the June 2005 MODIS data was analyzed. Various vegetation indices were examined on the image and the resulting images were classified to 7 pasture production groups. Finally the produced maps and the sampled points were controlled for their accuracies. The results confirmed the high correlations of used SWIR bands with field data (R2 = 0.85). Also the NDVI, SAVI and RVI plus other similar vegetation indices which employ red or NIR bands had relatively intermediate correlations with pasture data (R2 = 0.6). Overall, the findings of this study prove that the pasture plant production can be estimated using SWIR bands of the MODIS sensor.