QUANTIFYING CYANOBACTERIA CONCENTRATION IN THE SOUTHERN CASPIAN SEA USING MODIS SATELLITE IMAGERY

Cyanobacterial blooms in the earth are considered as one cause of water poisoning and a threat to the environment and human health. The Caspian Sea has experienced this phenomenon several times during the past decade. Since this phenomenon is associated with harmful environmental impacts, it is essential to predict, identify and monitor it to manage its impacts. In recent years, remote sensing techniques have been considered as the fastest and cost-effective method for identifying, monitoring, and even predicting this phenomenon. However, most of the studies conducted in this regard have detected, identified, and mapped this phenomenon, and quantitative evaluation of this phenomenon has been less considered. The main aim of this study is to provide an indicator for quantitative estimation of the concentration of cyanobacteria in the South Caspian Sea. For this purpose, MODIS-Aqua and MODIS-Terra satellite imagery and two series of field data measured in the September 2015 and August 2016 simultaneous with satellite overpass were used. Using 2015 data for each sensor, a model was defined based on bands affected by this phenomenon. Then, this model was evaluated using 2016 data. The accuracy of modeling of data related to 2015 for MODIS-Aqua and MODIS-Terra were 0.0006 and 0.0010mg/m3, respectively, and the results of the evaluation for data of 2016 were 0.0018 and 0.0032 mg/m3, respectively.