Quasi-simultaneous measurements of suspended sediments concentration (SSC) of very turbid waters at the Yellow River Estuary with the multi-spectral HJ-1 Imageries and in-situ sampling

Evolution of river delta is highly related to the deposition and re-suspension of sediments. At the interacting zone between fresh water of river discharge and seawater, suspended sediments concentration (SSC) varies sharply from a few mg/L to thousands of mg/L; thus, mapping the distribution of SSC will provide the basic information about sediments transportation. The high spatial resolution (30 m) and high revisit frequency (2 day) of CCD imager on board the Chinese environment-monitoring satellite constellation: HJ-1A and HJ-1B, enable an effective observation of the fine dynamics of suspended sediments. In this work, three intensive cruises in the flooding season and dry season of Yellow River were carried out to explore the SSC retrieval algorithms on the basis of HJ-1 CCD imageries. Quasi-simultaneous in-situ SSC data were collected with the pass of HJ-1 over the Yellow River Estuary and its vicinity waters, and a local empirical retrieval algorithm of SSC was established against the TOA (top of atmosphere) reflectance of HJ-1 CCD bands with the correction of Rayleigh scattering. This algorithm can be applied to very turbid waters with thousands of mg/L of SSC.