Testing Sentinel 3 Algorithms for Chlorophyll a Trend Assessment in Different Reservoir Conditions

Published: Jan. 1, 2025

The volume of water stored in reservoirs needs to be regularly monitored ensure that quality parameters meet the necessary standards for their intended uses. At other times surveillance is control new impacts may arise when solving primary needs, example, case eutrophication. Public administrations frequently monitor chlorophyll a (chl-a). It an indicator phytoplankton biomass, and increase its level alarm signal. Typically, chl-a levels below 2.5 mg/m3 are considered good quality, above 25 bad quality. However, frequency situ sampling usually monthly or less. In this work, we test capacity CHL_OC4ME CHL_NN algorithms OLCI Level 2 Sentinel-3 with daily resolution. We chose two representative Spain different uses characteristics. Tous reservoir mainly used urban irrigation supply it characterized by low (<1 mg/m3). Bellús was built prevent flooding problems, eutrophic average 15 mg/m3, maximum 100 mg/m3. Our results indicate Sentinel 3 algorithm performance depends on trophic conditions. For oligotrophic conditions (chl-a < 2.6 mg/m3) both overestimate concentration. more accurate than CHL_OC4ME. intermediate -20 (> 20 best performing algorithm. also observed conditioned size mass pixel number calculate them. recommendation CHL Concentration based could monitoring chl-a. Monitoring continuously detect deviations from baseline, which significant value itself.

Language: Английский

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Metabolomic Analysis of Both Microcystin-Producing and Microcystin-Free Microcystis aeruginosa Strains in Response to Exogenous Microcystin Exposure

Water, Journal Year: 2025, Volume and Issue: 17(7), P. 993 - 993

Published: March 28, 2025

Microcystis aeruginosa (M. aeruginosa), a key species in cyanobacterial blooms, is notably concerning due to its production of harmful microcystins (MCs). In this study, the differences ability MC-producing and MC-free strains M. respond exogenous MCs (MC-LR) were compared. The results showed that at higher concentrations, MC-LR affected cell morphology, growth, photosynthetic efficiency, induced oxidative stress aeruginosa. Under high concentration exposure, 14.7% reduction density, accompanied by 32% elevation Vj 63.1% decline FV/FM. density decreasing 22.5%, increasing 2-fold, FV/FM dropping 69.5%. inhibitory effect concentrations was found be stronger compared strains. addition, reduced efficiency photosystem II blocking electron transfer from QA QB; for strains, may have acted as signaling molecule affecting targeting QB on D1 protein, thus leading detachment protein complex. Metabolomics analysis affects arginine synthesis release MCs.

Language: Английский

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Spatial modeling of chlorophyll-a parameter by Landsat-8 satellite data and deep learning techniques: The case of Lake Mogan

Ömer Halisdemir Üniversitesi Mühendislik Bilimleri Dergisi, Journal Year: 2025, Volume and Issue: 14(2), P. 615 - 629

Published: April 15, 2025

Water is essential for the sustainability of life and healthy functioning ecosystems. Increasing pollution poses a serious threat to world's waters, making monitoring protection water quality strategic imperative. Chlorophyll-a one most important indicators ecosystem health, as it measure photosynthetic activity phytoplankton density, lifeblood aquatic Remote sensed data provide unique opportunity analyse chlorophyll-a changes in lake In this study, concentration was modelled by machine deep learning techniques using measurements, Landsat-8 surface reflectance values spectral indices Lake Mogan between 2018 2024. The RF, ANN, CNN models achieved R² 0.84, 0.85, 0.92, respectively. With its ability learn relationships, identify patterns complex datasets, superior process remote sensing imagery, thematic maps were generated model, which performed best study. results study demonstrate potential sensing-based approaches chlorophyll-a. produce highly accurate results, provides literature with an effective tool future studies.

Language: Английский

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Removal of Cyanobacterial Harmful Algal Blooms (HABs) from Contaminated Local Park Lake using Ganoderma lucidum Mycelial Pellets

Heliyon, Journal Year: 2024, Volume and Issue: 11(1), P. e41205 - e41205

Published: Dec. 15, 2024

Eutrophication and hypereutrophication in lakes foster harmful blue-green algal blooms, which pose a significant threat to the ecological health of freshwater reservoirs. This study investigated effectiveness bio-flocculation approach using Ganoderma lucidum fungus strain BGF4A1 remove these specifically targeting cyanobacterial species like Microcystis PCC-7914. Key flocculation parameters, concentrations, adsorption kinetics, pellet morphology were explored this research. Our results demonstrate that G. can effectively up 93.70 % cyanobacteria (measured as chlorophyll-a absorbance), 75.28 chemical oxygen demand (COD), 92.09 total suspended solids (TSS) under optimal conditions: an initial pH 4, 1 fungal volume (w/v), 48 h contact time, 100 rpm agitation at room temperature. Microscopic examination water samples before after treatment confirmed reduction colonies, indicating death or decline targeted organisms. Morphological analysis field emission scanning electron microscopy (FESEM) revealed cells deposited on hyphae pellets, contrast smooth surface control pellets. These novel culture technologies show great promise bio-flocculating agents for removing algae potentially be adapted microalgae harvesting biodiesel production.

Language: Английский

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Temporal and spatial variation patterns of chlorophyll a in marine ranching under global interannual events

Marine Environmental Research, Journal Year: 2024, Volume and Issue: 202, P. 106760 - 106760

Published: Sept. 19, 2024

Language: Английский

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Combining radiative transfer model with statistical model for distinguishing heavy metal stress level in rice from Sentinel-2 satellite images

Journal of Applied Remote Sensing, Journal Year: 2024, Volume and Issue: 18(04)

Published: Nov. 12, 2024

Heavy metal stress can lead to morphological and physiological variations in crops. We aimed distinguish heavy levels based on the of parameters from radiative transfer statistical models. Sentinel-2 satellite images situ measured data were collected metal-contaminated soils rice growing areas Zhuzhou City, Hunan Province, China. The chlorophyll content (chlorophyll a + b, Cab) leaf area index (LAI) calculated using PROSAIL model multilayer perceptron algorithm. A two-dimensional feature space was established Cab-LAI. Furthermore, normalized (HMSI) Cab-LAI theoretical triangular explored rice. results indicated that (i) artificial neural network algorithm successful at deriving with high estimation accuracy. Pearson's correlation coefficient between predicted Cab 0.85; (ii) concentration cadmium soil HMSI 0.84, indicating it is good indicator damage caused by stress, maximum occurring subjected pollution; (iii) pollution occurred both sides Xiangjiang River, whereas moderate mainly existed around heavily polluted areas. Areas non-pollution mild distributed over most study area. Combining LAI feasible method determine distribution large

Language: Английский

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Comprehensive Assessment of Trophic Status and Chlorophyll-a Dynamics in the Jhelum River Basin: Implications for River Ecosystem Management

International Journal of Environmental Research, Journal Year: 2024, Volume and Issue: 19(2)

Published: Dec. 23, 2024

Language: Английский

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