In the past decade, severe algal blooms have been occurring in the Blankaart (Belgium) and La Loggia (Italy), two surface water reservoirs acting as a first biologic treatment step before further processing to drinking water. Since these algal blooms hamper the water production, strategies (e.g., injection of algaecide) have been looked at to prevent these from happening or try to control them. In this context, the HYperspectral Pointable System for Terrestrial and Aquatic Radiometry (HYPSTAR), installed since early 2021, helps in monitoring the effectiveness of these strategies. Indeed the HYPSTAR provides, at a very high temporal resolution, bio-optical parameters related to the water quality, i.e., Chlorophyll-a (Chla) concentrations and Suspended Particulate Matter (SPM). In addition, to catch the spatial variability of the water quality, we investigated the potential to provide more advanced water quality maps using Sentinel-2 MSI images. The optimized atmospheric correction method, ACOLITE-GLAD, taking into account adjacency effect and sunglint, was therefore used together with improved algorithms for water quality products, e.g., semi-empirical, semi-analytical, and, neural network based approaches. In the frame of the H2020-CALLISTO project, the resulting water quality data is ingested in a data portal allowing managers of drinking water reservoirs to access continuous and accurate water quality assessment.

Primary Presenter: Clemence Goyens, RBINS (cgoyens@naturalsciences.be)

Authors:

Clémence Goyens, RBINS OD-NATURE  (cgoyens@naturalsciences.be)

Héloise Lavigne, RBINS OD-NATURE  (hlavigne@naturalsciences.be)

Antoine Dille, RBINS OD-NATURE  (adille@naturalsciences.be)

Alexandros Oikonomidis, Centre for Research & Technology Hellas (CERTH)  (aleoikon@iti.gr)

Anastasia Moumtzidou, Centre for Research & Technology Hellas (CERTH)  (moumtzid@iti.gr)