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Deducing Salinity from Chlorophyll-a using Envisat MERIS Satellite Imagery: A Case Study in Modaomen and Shawan Waterway, Pearl River Estuary, South China

Shuisen Chen(1), Wenrui Huang(2) and Ligang Fang(3)

(1) Guangzhou Institute of Geography, No. 100 Guangzhou Institute of Geography, Guangzhou 510070, China
(2) Florida A&M University - Florida State University, 2525 Pottsdamer Street, Tallahassee, FL 32310-6046, United States
(3) Suzhou Vocational University, Suzhou 215104, Suzhou 215104, China


Because of increasing marine intrusion into the Pearl River Estuary (PRE) of South China, the salinity has become one of the important and necessary hydrological and water quality monitoring parameters. In this research, we examined the relationships between the reflectance from Envisat MERIS satellite imagery and water surface salinity based on the in-situ spectra analysis model of the river water color component, in an attempt to deduce salinity from Chlorophyll-a using remote sensing technique. The study sites were the Modaomen and ShawanWaterway in the Pearl River Estuary, Guangdong Province, South China. We found an indicator of salterwater intrusion location(at 0.45‰, a drinkable water quality stardard) with sharp Chlorophyll-a concentration drop. Therefore, we were able to develop a new method of deducing surface salinity of the river estuary from the calibrated Envisat MERIS reflectance data. The Envisat MERIS derived surface salinities were validated using pointing observation data that were collected on January 31, 2006, and synchronous with Envisat MERIS satellite imagery acquisition. The methodology of deducing salinity from Chlorophyll-a concentration provides potential to monitor coastal saltwater intrusion and provides the water supply and conservancy authorities with referenced spatial information to understand and manage the esturine marine intrusion.


Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry