SPATIOTEMPORAL VARIABILITY OF TURBIDITY OBSERVED FROM SENTINEL 2-A/B IN MARKERMEER LAKE INFLUENCED BY THE CONSTRUCTION OF THE MARKER WADDEN ISLANDS

The Netherlands has a long history of land reclamation and marine engineering. The Markermeer lake was separated from the Zuiderzee bay (North Sea) and was planned to be reclaimed but was indefinitely postponed in the 80’s for financial reason and then become an ecological and recreational area. Currently, the lake is a 680 km², shallow body of water with a mean water depth of 3.6 m that and it’s limited by the Houtribdijk dam. The Markermeer Lake has thick blanket of silt on the bottom and turbid water affects the food web and ecosystem. A group of islands called Marker Wadden were created at the lake using the bottom silt in 2016. One of the goals of the islands was to geoengineering the region and use the islands as sediment-capture system to improve the water quality of the lake and its habitat. Optically, the Markermeer Lake is a case 2 waters. The lake presents a complex optical properties that is influenced by turbidity, total suspended sediments, dissolved matter, organic matter, microorganisms and inorganic particulates matter from minerals. For this study, we used available data from Sentinel-2A/B satellites imagery from 2015 to the present to understand the impact of the Marker Wadden in the water quality of the lake. The cloud-less selected imagery was processed using ACOLITE (application of Sentinel-2 imagery for coastal and inland waters) for atmospheric correction and effect from the bottom. After the image correction, then the multispectral remote sensing reflectances of the region were obtain and water quality parameters (turbidity, suspended particle matter and chlorophyll) were calculated. A total of 115 images were analyzed to measure the parameters: before, during and after the Marker Wadden construction. A spatial-temporal analysis of turbidity for the lake was used to understand the impact of the Marken Wadden islands. Natural events such as rainfall, wind and storms had an additional impact to the turbidity of the lake, but considering the island goal, as sediment-capture system, results shows that is not effective as expected.