THE POTENTIAL FOR REMOTE-SENSING OF LOESS SOILS SUSPENDED IN SURFACE WATERS

The potential for detecting the concentration and type of soils suspen ded in surface water through remote sensing techniques was investigate d by studying the spectral reflectance of two types of soils in suspen sion. In a large tank filled with 7510 liters of water, 20 levels of s uspended sediment (soil) concentration (SSC), ranging from 50 to 1000 mg/l were prepared. A high resolution spectroradiometer was used to me asure the reflectance at each SSC level. The reflectance spectra of tw o contrasting soils were distinct in the visible and near infrared (NI R) portions of the electromagnetic spectrum. The wavelength range betw een 580-690 nm (visible) was found to be optimal for indicating the ty pe of soil, whereas, the wavelength range between 714-880 (NIR) was fo und to be appropriate for estimating the concentration of sediment sus pended in surface waters.