INFLUENCE OF SUSPENDED PARTICLE SIZE DISTRIBUTION ON THE VARIABILITY OF WATER OPTICAL PROPERTIES OF THE POYANG LAKE, CHINA

The suspended particle size distribution (PSD) provides crucial information for the study of water environment. Based on the in situ data from wet and dry season in 2008-2011, the paper studied the temporal and spatial characteristics of PSD in Poyang Lake and its influence on water optical properties. The median particle size (D-v50) shows more significant variation in dry season between different districts than in wet season. The negative correlation between D-v50 and mass-specific absorption coefficient of total suspended particles (a(p)*(400)) denotes that inorganic particles also has "package effect". Good correlationship is found between spectral slope of PSD and spectral slope of attenuation coefficient and scattering coefficient. Compared to mass concentration, the particle size information can better explain the variability of scattering properties. Furthermore, a retrieval model for cross-sectional area concentration is established by remote sensing reflectance ratio to provide more information about particle size in Poyang Lake.