Spectral characterization of suspended sediments generated from two texture classes of clay soil

Abstract

Using natural sunlight and a wide range of suspended sediment concentrations, this research examined surface spectral responses to various concentrations of suspended sediments with different textures. Reflectivities at each of 170 individual channels between 400 and 900 nm, as well as the relationship between the integral of reflectance and the suspended sediment concentrations (SSC), were analysed. The results showed that as SSC increased, the reflectance from the finer soil increased faster than that from the coarser soil. The overall correlation between SSC and reflectance for the finer soil was higher than the one for the coarser soil. As SSC increased, the peak-reflectance wavelength of both sediments shifted toward longer wavelengths. The coarser soil suffered an early shift at 250mgl⁻ while the finer soil experienced the shift later at 500mgl-1. Finally, the integral of reflectance at 800-900 nm interval was found to be useful for the estimation of SSC.