Mapping of tide-dominated Hooghly estuary water quality parameters using Sentinel-3 OLCI time-series data

• Main Authors: Bar A.R., Mondal I., Das S., Biswas B., Samanta S., Jose F., Ahmed A.N., Thai V.N.
• Other Authors: 58498187100
• Format: Article
• Published: Springer Science and Business Media Deutschland GmbH 2024
• Subjects: CDOM; Chlorophyll-a; GIS; RS; Sentinel-3; TSM; Chlorophyll A; Environmental Monitoring; Estuaries; Rivers; Water Quality; Atmospheric thermodynamics; Chlorophyll; Geographic information systems; Remote sensing; Water quality; chlorophyll a; chromophoric dissolved organic matter; dissolved organic matter; phosphate; unclassified drug; Chlorophyll a; Chromophoric dissolved organic matter; Pre-monsoon; Shallow estuary; Spatio-temporal variation; Time-series data; Total suspended matter; Water quality parameters; digital mapping; estuarine environment; parameter estimation; time series analysis; trace element; water chemistry; water quality; algorithm; analytical parameters; Article; correlation analysis; data analysis; dredging; estuary; information retrieval; oxygenation; rainy season; remote sensing; satellite imagery; spatiotemporal analysis; suspended particulate matter; total suspended matter; water monitoring; environmental monitoring; river

The study explores the spatio-temporal variation of water quality parameters in the Hooghly estuary, which is considered an ecologically-stressed shallow estuary and a major distributary for the Ganges River. The estimated parameters are chlorophyll-a, total suspended matter (TSM), and chromophoric dissolved organic matter (CDOM). The Sentinel-3 OLCI remote sensing imageries were analyzed for the duration of October 2018 to February 2019. We observed that the water quality of the Hooghly estuaries is comparatively low-oxygenated, mesotrophic, and phosphate-limited. Ongoing channel dredging for maintaining shipping channel depth keeps the TSM in the estuary at an elevated level, with the highest amount of TSM observed during March of 2019 (41.59g m?3) at station A, upstream point. Since the pre-monsoon season, TSM data shows a decreasing trend towards the mouth of the estuary. Chl-a concentration is higher during pre-monsoon than monsoon and post-monsoon periods, with the highest value observed in April at 1.09 mg m?3 in station D during the pre-monsoon period. The CDOM concentration was high in the middle section (January�February) and gradually decreased towards the estuary�s head and mouth. The highest CDOM was found in February at locations C and D during the pre-monsoon period. Every station shows a significant correlation among CDOM, TSM, and Chl-a measured parameters. Based on our satellite data analysis, it is recommended that SNAP C2RCC be regionally used for TSM, Chl-a, and CDOM for water quality product retrieval and in various algorithms for the Hooghly estuary monitoring. � 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.