Monitoring spatio-temporal variability of the Adour River turbid plume (Bay of Biscay, France) with MODIS 250-m imagery

Abstract

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractIncreased loads of land-based pollutants through river plumes are a major threat to the coastal water quality, ecosystems and sanitary heath. Identifying the coastal areas impacted by potentially polluted freshwaters is necessary to inform management policies and prevent degradation of the coastal environment. This study presents the first monitoring of the Adour River turbid plume (south-eastern Bay of Biscay, France) using multi-annual MODIS data Satellite data are processed using a regional algorithm that allows quantifying and mapping suspended matter in coastal waters. The results are used to investigate the spatial and temporal variability of the Adour River turbid plume and to identify the risk of exposure of coastal ecosystems to the turbid plume waters. Changes in river plume orientation and extent as well as suspended matter concentration rates discharged through the river are correlated to the main hydro-climatic forcings acting in the south-eastern Bay of Biscay. The Adour River turbid plume is shown to be a highly reactive system mainly controlled by the river discharge rates and modulated by the wind changes. Despite the relatively small size of the Adour River, the Adour River turbid plume can have a non-negligible impact on the water quality of the southern Bay of Biscay and the MSM and associated contaminant/nutrients transported within the Adour turbid river plume have the potential to be disseminated far away along the northern shoreline or offshore. The main areas of influence of the river plume are defined over multi-annual (3 years) and seasonal periods. The results presented in this study show the potential of 250-m MODIS images to monitor small river plumes systems and support management and assessment of the water quality in the south-eastern Bay of Biscay.Key words: water quality, River plume, MODIS-Aqua; mineral suspended matters, spatiotemporal variability, Adour estuary. IntroductionAssessment of water quality has become a major issue worldwide and is illustrated in Europe by the implementation of the Water Framework, the Quality of Bathing Waters and the (MSFD, 2008/56/EC), respectively. These directives mainly focus on preventing the degradation of aquatic ecosystems due to anthropogenic pressures. The evaluation of the water quality status is based on the measurement of relevant water quality parameters. Among biological parameters are the composition, abundance and biomass of phytoplankton, the frequency and intensity of blooms and their influences on the water turbidity , Ferreira et al., 2011. Phy...

A Semi-Analytic Model for Estimating Total Suspended Sediment Concentration in Turbid Coastal Waters of Northern Western Australia Using MODIS-Aqua 250 m Data

“…Remote sensing has been used to map a wide array of coastal water's constituents, such as phytoplankton for biomass and primary production [1][2][3][4], coloured dissolved organic matter (CDOM) for its effect on benthic habitats [5][6][7], and total suspended sediments (TSS) concentration as a measure of water quality [8][9][10][11][12]. Many studies have been performed to derive TSS concentration via satellite remote sensing using different platforms: Sea-viewing Wide Field-of-view Sensor (SeaWiFS) [13,14], Landsat series [15][16][17][18][19][20], Medium Resolution Imaging Spectrometer (MERIS) [21][22][23][24][25][26], Moderate Resolution Imaging Spectroradiometer (MODIS) [9,11,25,[27][28][29][30], "Système Pour l'Observation de la Terre" (SPOT) [31], and high resolution sensor IKONOS [32]. Most models are developed to estimate TSS concentration by directly relating the remotely sensed reflectance with in situ measurements of the TSS concentration using statistical analysis, linear and non-linear regression.…”

Have droughts and increased water extraction from the Murray River (Australia) reduced coastal ocean productivity?

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Impacts of Insufficient Observations on the Monitoring of Short- and Long-Term Suspended Solids Variations in Highly Dynamic Waters, and Implications for an Optimal Observation Strategy

“…Considering its widespread application in both environmental protection and scientific research fields [39,42,[51][52][53], it is urgent to assess the uncertainties of MODIS data in SS monitoring, because of the existing temporal gap between MODIS temporal coverage and variations of SS ( Figure 1 and Table 1). Therefore, the assessment of uncertainties in SS monitoring with insufficient remote sensing observations not only provides detailed information on the reliability of the most commonly used data, but also offers guidance for future sampling strategies, for both in situ measurements and remote sensing observations.…”