Monitoring water constituents and salinity variations of saltwater using EO-1 Hyperion satellite imagery in the Pearl River Estuary, China

to detect water constituents´ concentrations and salinity of the Pearl River Estuary (PRE), we analyzed the spectral properties of water constituents and investigated the relationships between field water reflectance spectra and water constituents´ concentrations based on the synchronous in-situ hyper-spectral data analysis. Two strong relationships were discovered (two linear fit described respectively the positive correlation), one between in-situ reflectance ratio R₆₈₀/R₅₂₇ and total suspended sediment concentrations (TSS) (R²=65%) and the other between chlorophyll-a concentrations and the reflectance ratio R₇₀₄/R₅₁₃ (R²=78%); however, the result also showed that the absorption coefficient of color dissolved organic matter (CDOM) was not tightly correlated with reflectance. In addition, we also observed the significant relationships (R²=79%) between TSS and surface salinity. Finally, we were able to develop a novel method to detect water constituents´ concentrations and surface salinity of river estuary waters from the calibrated EO-1 Hyperion reflectance data in the PRE. The EO-1 Hyperion derived surface salinity and water constituents´ concentrations were validated using in-situ data that were collected on December 21, 2006, and synchronous with EO-1 Hyperion satellite imagery acquisition. The results showed that the semi-empirical relationships are capable of predicting salinity and water constituents´ concentrations from EO-1 Hyperion imagery.