MONITORING THE WATER QUALITY OF LAKE KORONIA USING LONG TIME-SERIES OF MULTISPECTRAL SATELLITE IMAGES

摘要

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, pH, Transparency/Secchi Disk Depth (SDD), Chlorophyll a and Conductivity, were applied to Landsat images. In addition, Water Depth, as well as 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. This assessment demonstrates that satellite imagery can provide an accurate method for obtaining comprehensive spatial and temporal coverage of key water quality characteristics.