Nature of suspended solids and IRS1A-LISSI data: A case study of Tawa reservoir (Narmada Basin)

Abstract

IRS1A-LISSI spectral digital data were analyzed to determine the feasibility of quantifying the concentration of suspended solids in the water by this sensor. For this purpose, a small tributary (Tawa) of a major river basin (Narmada Basin) in central India was studied for ground truth evaluation of digital data obtained from the Indian Remote Sensing Satellite-1A Linear Imaging Self-Scanning (IRS1A-LISSI) sensor. Tawa reservoir water samples were collected on 20 October 1988 concurrent with IRS1A overpass. The samples were analyzed to determine the concentration of total suspended matter, grain size, and mineralogy. The results indicate that, in the concentration range between 10 mg/L and 50 mg/L, a positive functional relationship exists between the concentration of suspended solids and the visible wavelength Bands 1, 2, and 3 (0.45–0.68μ m). It has been observed that mineralogy and grain size are the main factors which influence the reflected radiance at lower concentration level (10–50mg/L) of suspended solids. It can be concluded that as the concentration of suspended solids in the 10–50mg/L range increases the spectral response increases. It can be stated that IRS1A-LISSI data provide a good foundation for further development of remote sensing as a practical tool in the estimation of suspended solids.