Influence of Wind on Suspended Matter in the Water of the Albufera of Valencia (Spain)

Wind is one of the factors that has a great influence on suspended matter in lakes, especially in shallow lagoons. In order to know how wind affects the water in Albufera of Valencia, a shallow coastal lagoon, the measured variables of turbidity and transparency have been correlated with the estimates by processing Sentinel-2 satellite images with the Sen2Cor processor. Data from four years of study show that most of them are light to gentle easterly breezes and moderate to fresh westerly breezes. The results obtained show significant correlations between the measured variables and those obtained from the satellite images for total suspended matter and water transparency and with the average daily wind speed. There is no significant correlation between wind and chlorophyll a. Moderate to fresh breezes resuspend the fine sediment reaching concentration values from 100 to 300 mg L-1 according to satellite data. However, it is necessary to obtain field data for the values of moderate and fresh winds, as for now there are no experimental data to verify the validity of the satellite estimates.

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Influence of Wind on Suspended Matter in the Water of the Albufera of Valencia (Spain)

Journal of Marine Science and Engineering ◽

10.3390/jmse9030343 ◽

2021 ◽

Vol 9 (3) ◽

pp. 343

Author(s):

Juan Soria ◽

Miguel Jover ◽

José Antonio Domínguez-Gómez

Keyword(s):

Experimental Data ◽

Wind Speed ◽

Coastal Lagoon ◽

Suspended Matter ◽

Field Data ◽

Satellite Images ◽

Fine Sediment ◽

Total Suspended Matter ◽

Know How ◽

Sentinel 2

Wind significantly influences suspended matter in lakes, especially in shallow lagoons. To know how wind affects the water in Albufera of Valencia, a shallow coastal lagoon, the measured variables of turbidity and transparency have been correlated with the estimates by processing Sentinel-2 satellite images with the Sen2Cor processor. Data from four years of study of winds show that most of them are light to gentle easterly breezes and moderate to fresh westerly breezes. The obtained results show significant correlations between the measured variables and those obtained from the satellite images for total suspended matter and water transparency, as well as with the average daily wind speed. There is no significant correlation between wind and chlorophyll a. Moderate to fresh breezes resuspend the fine sediment reaching concentration values from 100 to 300 mg L−1 according to satellite data. However, it is necessary to obtain field data for the values of moderate and fresh winds, as for now, there are no experimental data to verify the validity of the satellite estimates.

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A note on a Comparison of Starting Points for the Generation of D-optimal Second-order Designs

African Journal of Applied Statistics ◽

10.16929/ajas/2020.1001.253 ◽

2020 ◽

Vol 7 (2) ◽

pp. 1001-1008

Author(s):

Ngozi Chizoma Umelo-Ibemere

Keyword(s):

Climate Change ◽

Mathematical Analysis ◽

Field Data ◽

Satellite Images ◽

Cultivated Land ◽

Temporal And Spatial ◽

Land Surfaces ◽

Optical Satellite Images ◽

Agricultural Areas ◽

Sentinel 2

Agricultural monitoring has become an absolute necessity in the Sahel countries, especially with climate change which constitutes a real threat for this sector. The aim of this work is to develop a methodology for identifying crops and mapping agricultural areas using Sentinel-2 data from the Copernicus program. The purpose of this work consisted in discriminating the crops of millet, maize and peanuts. This is to analyse the scientific and technical obstacles related to this problem. For this, we have made a mathematical analysis of optical satellite images. High temporal and spatial resolution images (10m to 60m) of Sentinel 2 sensors were used in this work. This unique set of data coupled with field data, has permitted to carry out a diagnosis of land cover and cultivated land surfaces, and evaluating the contribution of this type of data for crop forecast

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Estimating Organic and Inorganic Part of Suspended Solids from Sentinel 2 in Different Inland Waters

Water ◽

10.3390/w13182453 ◽

2021 ◽

Vol 13 (18) ◽

pp. 2453

Author(s):

Bárbara Alvado ◽

Xavier Sòria-Perpinyà ◽

Eduardo Vicente ◽

Jesús Delegido ◽

Patricia Urrego ◽

...

Keyword(s):

Suspended Matter ◽

Inorganic Compounds ◽

Total Concentration ◽

European Space Agency ◽

Total Suspended Matter ◽

Water Bodies ◽

Spatial And Temporal Variation ◽

Inland Waters ◽

Plant Matter ◽

Sentinel 2

Inland waters are very sensitive ecosystems that are mainly affected by pressures and impacts within their watersheds. One of water’s dominant constituents is the suspended particulate matter that affects the optical properties of water bodies and can be detected from remote sensors. It is important to know their composition since the ecological role they play in water bodies depends on whether they are mostly organic compounds (phytoplankton, decomposition of plant matter, etc.) or inorganic compounds (silt, clay, etc.). Nowadays, the European Space Agency Sentinel-2 mission has outstanding characteristics for measuring inland waters’ biophysical variables. This work developed algorithms that can estimate the total concentration of suspended matter (TSM), differentiating organic from inorganic fractions, through the combined use of Sentinel-2 images with an extensive database obtained from reservoirs, lakes and marshes within eastern zones of the Iberian Peninsula. For this, information from 121 georeferenced samples collected throughout 40 field campaigns over a 4-year period was used. All possible two-band combinations were obtained and correlated with the biophysical variables by fitting linear regression between the field data and bands combination. The results determined that only using bands 705 or 783 lead to the obtaining the amount of total suspended matter and their organic and inorganic fractions, with errors of 10.3%, 14.8% and 12.2%, respectively. Therefore, remote sensing provides information about total suspended matter dynamics and characteristics as well as its spatial and temporal variation, which would help to study its causes.

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Sentinel-2 Reveals Abrupt Increment of Total Suspended Matter While Ever Given Ship Blocked the Suez Canal

Water ◽

10.3390/w13223286 ◽

2021 ◽

Vol 13 (22) ◽

pp. 3286

Author(s):

Milad Niroumand-Jadidi ◽

Francesca Bovolo

Keyword(s):

News Media ◽

Suspended Matter ◽

Time Window ◽

Total Suspended Matter ◽

Suez Canal ◽

Trade Routes ◽

The North ◽

The Impact ◽

North And South ◽

Sentinel 2

The blockage of the Suez Canal, one of the world’s key trade routes, by a giant container ship in March 2021 was in the spotlight of news media worldwide, mainly because of its economic impacts. In this study, we look at this event from an environmental perspective by analyzing the impact of the artificial barrier made by the ship over the channel and of operations like dredging on the concentration of total suspended matter (TSM). In this context, multitemporal Sentinel-2 images are used to study short-term variations of TSM within a time window spanning before, during, and after the blockage event. A well-established neural network-based processor called Case 2 Regional CoastColour (C2RCC) is employed to derive remote sensing reflectance (Rrs) and then TSM concentrations from Sentinel-2 imagery. The results indicate that the stuck ship acted as an artificial barrier leading to very different TSM conditions north and south of the canal. Furthermore, the blockage of the Suez Canal and subsequent dredging caused an abrupt increment (+400%) in the concentration of TSM moving north from the ship’s location. We also identified a very high contrast between the TSM concentration in the north and south of the vessel during the blockage event.

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Spatiotemporal Distribution of Total Suspended Matter Concentration in Changdang Lake Based on In Situ Hyperspectral Data and Sentinel-2 Images

Remote Sensing ◽

10.3390/rs13214230 ◽

2021 ◽

Vol 13 (21) ◽

pp. 4230

Author(s):

Zuoyan Gao ◽

Qian Shen ◽

Xuelei Wang ◽

Hongchun Peng ◽

Yue Yao ◽

...

Keyword(s):

Water Quality ◽

Suspended Matter ◽

Hyperspectral Data ◽

Total Suspended Matter ◽

Lake Water Quality ◽

Concentration Data ◽

Temporal And Spatial Distribution ◽

Inversion Model ◽

Sentinel 2

The concentration of total suspended matter (TSM) is an important parameter for evaluating lake water quality. We determined in situ hyperspectral data and TSM concentration data for Changdang Lake, China, to establish a TSM concentration inversion model. The model was applied using 60 Sentinel-2 images acquired from 2016 to 2021 to determine the temporal and spatial distribution of TSM concentration. Remote sensing images were also utilized to monitor the effect of ecological dredging in Changdang Lake. The following results were obtained: (1) Compared with four existing models, the TSM concentration inversion model established in this study exhibited higher accuracy and was suitable for Changdang Lake. (2) TSM concentrations obtained for the period 2016–2021 were higher in spring and summer, and lower in autumn and winter. (3) The dredging process influenced a small area of the surrounding water body, resulting in higher TSM concentrations. However, a subsequent reduction in TSM concentrations indicated that the ecological dredging project might improve the water quality of Changdang Lake to a considerable extent. Therefore, it was inferred that the use of Sentinel-2 images was effective for the long-term monitoring of water quality changes in small and medium-sized lakes.

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PRELIMINARY INVESTIGATION ON CHLOROPHYLL-A AND TOTAL SUSPENDED MATTER CONCENTRATION IN MANILA BAY USING HIMAWARI-8 AHI AND SENTINEL-3 OLCI C2RCC

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlvi-4-w6-2021-303-2021 ◽

2021 ◽

Vol XLVI-4/W6-2021 ◽

pp. 303-311

Author(s):

R. B. Torres ◽

A. C. Blanco

Keyword(s):

Water Quality ◽

Linear Regression ◽

Chlorophyll A ◽

Suspended Matter ◽

Satellite Images ◽

Preliminary Investigation ◽

Quality Parameters ◽

Total Suspended Matter ◽

Water Quality Parameters ◽

Chl A

Abstract. Water quality monitoring is important in maintaining the cleanliness and health of water bodies. It enables us to identify sources of pollutions and study trends. While modern methods include the use of satellite images to estimate water quality parameters, commonly used satellite systems, such as Landsat and Sentinel, only generate images with temporal resolution of 2 to 16 days on the average. Himawari-8 satellite system, on the other hand, generates full-disk images every 10-minutes, making it possible to generate water quality parameters concentration maps more frequently. This paper presents the preliminary analysis of the generation of yearly and seasonal Chlorophyll-a (Chl-a) and Total Suspended Matter (TSM) estimation models using Himawari-8 satellite images and linear regression. Correlation analysis shows that the single spectral bands and band ratios involving Red band have the strongest relationship with Chl-a and TSM. Generated linear regression yearly and seasonal models resulted to R2 values of 0.4 to 0.5 with RMSE values around 3 micrograms/cm3 for Chl-a and 9.5 grams/m3 for TSM. Results also indicate that the seasonal models are better than the yearly models in terms of fit and error. Results from the preliminary investigation will be used to generate a more robust global model in future studies.

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