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A suitable algorithm for estimating chlorophyll- a using field data and satellite images in the waters of the Persian Gulf (Hormozgan Province)
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Fereshteh Saraji *   , Zahra Mansoori , Yousef Mousivand , Ali Salarpouri , Golamali Akbarzadeh , Hadi Kookan |
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Abstract: (719 Views) |
Introduction: This research was conducted to estimate the concentration of chlorophyll a using field data and satellite images and finding the appropriate algorithm.
Materials & Methods: In this research, 22 stations in the waters of the Persian Gulf of Hormozgan province, located on the coast and far from the coast, during December 2019 to December 2014, were examined monthly. Sampling of water to measure chlorophyll a was done using a Rotner bottle from half a meter below the water surface. Sentinel 3 (Sentinel 3) satellite images, which can be downloaded daily from international sites with a delay of up to 3 hours for free, were used. In this research, the difference between the collected ground chlorophyll values and the values obtained from different algorithms was estimated for each pixel.
Results: In the present study, the concentration of chlorophyll a in the coastal waters of Bandar Abbas was 3/391±0/118 and in the areas away from the coast 2/087±0/115 mg/m3, respectively. In coastal waters, chlorophyll a had a higher concentration. According to the field results and comparing different chl a estimation algorithms (OC4, OC5, OC6, OC4ME) and also comparing the results with the chlorophyll products of the European Space Organization OL_2_WFT among the discussed algorithms, the OC4ME algorithm has the highest coefficient of determination (R2) of 0/224 was for chlorophyll a. Based on the available results, the amount of chlorophyll a was estimated for a significant percentage of pixels with a difference of less than 2 mg/m3 compared to the actual values. In the OC4ME method, the values of chlorophyll a were recorded for more than 78% of the pixels with a difference of less than 2 mg/m3 with the actual values, so they had a good relative accuracy. The results showed that the OC4ME algorithm and satellite images received from Sentinel 3 are suitable for determining the density of microalgae through chlorophyll a for the waters of the Persian Gulf (Hormozgan).
Conclusion: It is possible to monitor microalgae blooms with chlorophyll a satellite data and images with greater speed and less cost in coastal management, warning and preventing damages caused by microalgae blooms in the inlet waters of shrimp farms, the waters around fish cages and desalination water are used. |
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| Keywords: Chlorophyll a, Satellite Images, Algorithm, Hormozgan Province |
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Full-Text [PDF 872 kb]
(256 Downloads)
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Type of Study: Research |
Subject:
Special
Received: 2025/11/8 | Accepted: 2025/09/1 | Published: 2025/12/2
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