http://117.252.14.250:8080/jspui/handle/123456789/2978 2026-04-05T18:49:26Z http://117.252.14.250:8080/jspui/handle/123456789/3054 Introduction National Institute of Hydrology 2008-01-01T00:00:00Z http://117.252.14.250:8080/jspui/handle/123456789/3053 Contents National Institute of Hydrology 2008-01-01T00:00:00Z http://117.252.14.250:8080/jspui/handle/123456789/3052 40-Application of remote sensing for the assessment of water quality - A case study of Tawa reservoir Choubey, V. K. An attempt has been made to quantify the relationship between the variation in IRS-IALISS- I radiance data and field measured change in secchi disc depth. Secchi disc depth was measured for 47 predetermined sampling locations on reservoir surface water. At extinction depth (secchi depth), water samples were collected from all the sampling locations. Suspended sediments of eight locations representing various reaches of the reservoir were selected for mineralogical, particle size and optical properties analysis. The LISS-I radiance value in band 1 (0.45-0.52pm) band 2 (0-52-0.59 im) and band 3 (0.62-0.68 im) were used in a regression analysis. The coefficient of correlation between observed and estimated values was r= 0.92 for SD, indicating that the equation could accurately predict the water clarity (SD) for this reservoir on new occasions from IRS-IA-LISS-I spectral data. It is shown that mineral composition and optical properties of suspended sediments influence the reflected radiance of water quality. It is concluded that IRS-IA-LISS-I data provide a useful means of mapping water quality in reservoir. 2008-01-01T00:00:00Z http://117.252.14.250:8080/jspui/handle/123456789/3051 41-Sediment analysis of the Hebbal Valley Lakes using scanning electron microscopy and energy Dispersive Spectroscopy Jayaramu, K. C.; Murthy, Usha N. The study examines the lake bed sediments of Hebbal Valley Lake. A rapid population increase accompanied by unplanned developmental works has led to the pollution of surface water, sediments of the lake and also ground water by residential, agricultural, commercial, industrial wastes or effluents. This has declined in the number of water bodies in the urban areas. The Energy Dispersive Spectroscope (EDS) and Scanning Electron Microscopy (SEM) is an advanced tool to characterize the sludge/sediments/soil samples. The EDS spectra reveal that the sediment contains predominant elements like Silica, Calcium, Aluminium, Iron, Potassium and Titanium, are present in the form of salts. The remaining portions may be carbonaceous and inert materials. From the results, it is evident that the lake sediments do not contain the toxic chemicals like Pb, Zn, Cd, Ni, Cu, Cr, and Mg and so sediments can be used as a compost along with the soil in the agricultural fields so that better yield is obtained. It can be concluded that sediment analysis of lake soil from Hebbal valley contains predominant elements and divide of toxic chemical and it can be used as soil supplement for growing crops for better yield. 2008-01-01T00:00:00Z