MONITORING WATER QUALITY PARAMETERS OF LAKE KORONIA BY MEANS OF LONG TIME-SERIES MULTISPECTRAL SATELLITE IMAGES
In this study, a comprehensive 30-year (1984–2016) water quality parameter database for Lake Koronia – one of the most important Ramsar wetlands of Greece – was compiled from Landsat imagery. The reliability of the data was evaluated by comparing water Quality Element (QE) values computed from Landsat data against in situ data. Water quality algorithms developed from previous studies, specifically for the determination of Water Temperature and pH, were applied to Landsat images. In addition, Water Depth, as along with the distribution of floating vegetation and cyanobacterial blooms, were mapped. The performed comprehensive analysis posed certain questions regarding the applicability of single empirical models across multi-temporal, multi-sensor datasets, towards the accurate prediction of key water quality indicators for shallow inland systems. Overall, this assessment demonstrates that despite some limitations, satellite imagery can provide an accurate means of obtaining comprehensive spatial and temporal coverage of key water quality characteristics.