GIS and Remote Sensing in Hydrology, Water Resources and Environment (Proceedings of ICGRHWE held at the Three Gorges Dam, China, September 2003). IAHS Publ. 289, 2004, 316-321

Abstract Chlorophyll concentration is the most widely used measurement derived from ocean colour remote sensing data. In order to retrieve chlorophyll concentrations in highly turbid waters (case 2 waters) in the Pearl River estuary, a predictive model is proposed, which uses remote sensing (SeaWiFS) and environmental factors. Finally, through analysing the discrimination between the two models, the mean standard error of the model with both environmental variables and remote sensing data is 17.96%, and the single mode only using remote sensing data is 32.48%. The present study suggests that the model significantly overestimated in the Case 2 waters in the Pearl River estuary, but not yet fully reliable in other Case 2 waters. The algorithm for ocean colour needs to be urgently improved for turbid waters.

Key words Case 2 water; chlorophyll; environment variables; Pearl River; remote sensing