Bio-optical properties of turbid lakes

Abstract

Nowadays optical remote sensing has become a useful tool for monitoring spatial and temporal properties of the aquatic environment. However, in coastal waters and lakes there are some difficulties concerning the quantitative interpretation of satellite data, consequently, in situ measurements retain their value. Each database (even for 1–2 lakes) helps build a mosaic for describing global variability in the optical properties of lakes and elucidates the connections between types of lakes and environmental as well as climatic conditions. In the present work a database about three turbid Estonian lakes (Peipsi, Võrtsjärv and Harku) was collected and the variations of bio-optical properties in these lakes were studied. For comparing the results with other North-European lakes we analysed the water samples collected from 20 southern Swedish lakes, 14 Estonian lakes and 15 southern Finnish lakes. The inherent and apparent optical properties were also compared with those obtained from two large clear-water Swedish lakes, L. Vänern and L. Vättern. The results obtained in this study definitely have a special importance, because the data of optical properties published for productive lakes are rather few in number and they could be used for the further development of remote sensing algorithms in turbid and humic water bodies.