HYPERSPECTRAL REMOTE-SENSING OF TURBIDITY AND CHLOROPHYLL-A AMONG NEBRASKA SAND HILLS LAKES

This study was conducted to establish correlations between reflectance spectra, turbidity and chlorophyll a among 22 fresh to alkaline lakes in Nebraska, U.S.A., sampled in June and July of 1994. Peak reflectan ce ranged from 2-22 per cent between 500 and 600 nm. Turbidity and chl orophyll a ranged from 1-82 NTU and 1-171 mu g l(-1), respectively, wi th significant correlation (P<0.001) between the two. Reflectance firs t-derivatives corresponding to wavelengths 429 and 695 nm, were signif icantly correlated with chlorophyll a (P<0.001), and derivatives at 42 9, 628 and 695 nm were significantly correlated with turbidity (P<0.00 1) despite a wide range in water quality conditions.