MAPPING OF THE ALGAE DISTRIBUTION TO SUPPORT WATER QUALITY MANAGEMENT IN THE DAU TIENG RESERVOIR

In the last two decades, the development of satellite technology has made it easier and more convenient to apply remote sensing in warning and solving environmental problems, especially the tracking, monitoring, and evaluation of environmental objects. Algae blooms are one of the top environmental issues of concern today. The blooms cause many harmful effects on the water environment and ecosystems in the area, such as reducing dissolved oxygen levels and producing harmful toxins, causing aquatic organisms to lack oxygen and be poisoned and dead. This study presents the research results in monitoring and calculating the concentration of algae in the Dau Tieng Reservoir by remote sensing. By constructing a regression function between monitoring data and qualitative algorithms from Landsat image spectrum reflection, the study conducted quantification and mapping of the distribution of algae concentration in the Dau Tieng Reservoir area. The calculation results show that the qualitative algorithm 3BDA(3) from the spectral bands in the GREEN, RED, and near-infrared NIR wavelength bands shows a reasonable degree of correlation with the monitoring data. Since then, the author has mapped the distribution of algae concentration and the current status of blooming algae on the reservoir at 3-time points. The study's results show the feasibility of applying remote sensing technology in monitoring, evaluating, and analyzing the concentration of algae in Dau Tieng Reservoir. The calculation results are an essential source of advice in managing reservoir water quality to prevent and minimize environmental and ecosystem damage in the area local water bodies.