Testing of a model for the simulation of the volume reflectance of water due to suspended sediment under controlled conditions, for various sediment types

Abstract

Abstract A model that simulates the volume reflectance of water is tested in laboratory conditions with three different sediments of known grain size distribution and spectral reflectance. The model uses, as its main input variables, the grain size distribution of the suspended sediment, the density of the grains and the spectral reflectance of the wet sediment from which the suspension comes. The spectral bands of the model are completely programmable and they have been adapted to correspond to green, red and near-infrared, as in Landsat MSS bands 4, 5 and 6. The grain size distribution, the reflectance in the three spectral bands and the density of the three sediment types had been measured and these measurements were used as input variables for the model to simulate the volume reflectance of the water, in the same spectral bands, for different suspended sediment concentrations. Each sediment type was used to produce several concentration levels in a specially prepared 1101 tank and the volume reflectance of the water was measured. The measurements were compared with the simulated results of the model. Then the model was modified to simulate the volume reflectance of a stratified environment, where the concentration changes with depth, and used to explain some discrepancies in the chromaticity transformation.