Multisensor-based Surface Water Quality Monitoring: A Case Study for the Chalkidiki, Greece

This study investigates the application of multisource and multiscale Earth Observation (EO) technologies for monitoring water quality in the Kassandra Mining District, Chalkidiki, Greece. We integrate spectral data from various platforms: high-resolution water spectral libraries from an OceanOptics STS-VIS-VIS spectrometer (337–823 nm) on a DJI Phantom 3 UAV, multispectral imagery from a Parrot Sequoia camera (4 bands) on a DJI Phantom 4 Pro UAV, and 8-band multispectral Planet Labs satellite data at 3-meter resolution. These datasets are combined with in situ surface water samples from f ield campaigns and long-term monitoring by Hellas Gold (HG). Initial results indicate that Total Suspended Solids (TSS), serving as a proxy for estimating arsenic high/ medium/low (As) levels, can be predicted at high accuracy using Partial Least Square Regression (PLSR) on the water spectral libraries (R² = 0.85). Modified spectral indices based on the most important wavelengths identified by PLSR achieved an R² of 0.82, while original multispectral indices from PlanetScope imagery yielded an R² of 0.78. T hese findings suggest strong potential for utilizing these data and methods in water quality monitoring at local and regional scales.

Acknowledgments:

The presented analysis was conducted under the support of the EC grant MultiMiner. The MultiMiner project is funded by the European Union’s Horizon Europe research and innovation actions programme under Grant Agreement No. 10109137474.