Application of remote sensing in the determination of water quality in Nebraska reservoirs

In June, July, and August, 1975, ground truth was collected from Lake McConaughy, a 35,000 acre reservoir in western Nebraska, coincident with the overflights of LANDSAT. Water samples were collected on six different dates and analyzed for turbidity, suspended solids, and chlorophyll, parameters which had correlated well with CCT reflectances. The correlations and regressions reported were derived from data obtained on only three of the six sampling dates. The radiance values from each of the four spectral bands were printed out in the form of a map of Lake McConaughy. Reflectances in the various bands were then obtained from the map at the appropriate sampling sites. The dependent variables chlorophyll, suspended solids, and turbidity were compared to the independent variables - reflectances in the four bands - by regression analysis. Both multiple and univariate regressions were examined. It is concluded that CCT's from LANDSAT can be used to detect and quantify the water quality parameters suspended solids, turbidity, and chlorophyll

The Impact Of Artificial Reduction Of Light On A Eutrophic Farm Pond

A novel technique for reducing growth of aquatic macrophytes and decreasing primary productivity in an eutrophic farm pond was evaluated by the addition of commercial blue and brown aniline dyes to pond water isolated from the surrounding pond in experimental boxes. Blue-dyed water completely eliminated all aquatic macrophytes, while brown-dyed water eliminated only Potamogeton sp. Primary productivity was reduced, and phytoplankton populations similar to those observed in spring and fall pulses in lakes were present in the dyed water during the summer. Intense thermal stratification, anaerobiosis, and chemical changes were recorded in the enclosed waters after dye addition