Santiago Yepez // From Spectral Signatures to Territory: Hyperspectral Remote Sensing Applications

Speaker:

Dr. Prof. Santiago Yépez, University of Concepcion, Chile

This webinar is offered as part of Santiago Yépez' stay in Lyon (February to July 2026) at the Collegium de Lyon - H2O'Lyon Chair.

From Spectral Signatures to Territory: Applications of Hyperspectral Remote Sensing in Water Quality, Sediment Transport, Forests, and Aquatic Macrophytes

«Advanced hyperspectral remote sensing has been the central focus of my research over the last twenty years, integrating airborne hyperspectral imagery, multispectral satellite data, and field radiometric measurements to study aquatic and forest ecosystems in Chile, Venezuela, and France. My work has addressed key environmental challenges related to water quality, suspended sediment transport, aquatic vegetation dynamics, and tree species discrimination through the development of empirical, spectral, and machine learning approaches.
In southern Chilean lakes, I have developed remote sensing methodologies based on Landsat-8/9, Sentinel-2, and ASD FieldSpec-4 measurements to estimate chlorophyll-a concentrations and monitor eutrophication processes and seasonal phytoplankton biomass increases. In parallel, research conducted in the Orinoco River demonstrated the potential of Landsat-8 OLI imagery for estimating suspended sediment concentrations and understanding hydrosedimentological variability in large tropical rivers using surface reflectance models.
My research has also focused on forest ecosystems, where airborne HySpex VNIR-1800 hyperspectral imagery combined with LiDAR data and advanced machine learning techniques enabled the discrimination and mapping of native tree species in the Valdivian temperate rainforest of southern Chile.
Current work in the Rhône River focuses on the spectral characterization of aquatic macrophytes and algal communities using ASD FieldSpec-4 measurements. Particular attention is given to optical attenuation effects associated with water depth and turbidity, and their implications for remote sensing-based classification of aquatic vegetation. The integration of field spectral libraries and very high-resolution Pléiades Neo imagery provides new opportunities for monitoring anthropized river systems and understanding the spatiotemporal dynamics of macrophytes in the Rhône River.»

Professor Santiago Yépez is a geologist and associate researcher at the University of Concepción, with nearly 25 years of experience in university teaching and scientific research. His academic background includes a PhD in hydro-sedimentology and satellite remote sensing from Université Paul Sabatier III Toulouse. He also completed postdoctoral studies supported by the Collège de France and the IRD (Institut de Recherche pour le Développement).
His research focuses mainly on hydrology, fluvial geomorphology, hyperspectral remote sensing, and water quality. He has developed extensive field and research experience on river systems in Venezuela, Colombia, Brazil, the Republic of Congo, and Chile, collaborating with universities and international scientific centers.
He currently serves as Regional Coordinator of the FRIEND-WATER Program for Latin America and the Caribbean (LAC) under UNESCO’s Intergovernmental Hydrological Programme (IHP), contributing to international scientific cooperation and the sustainable management of water resources. His scientific work and publications address hydrological regimes, river dynamics, and the application of advanced remote sensing technologies for environmental monitoring
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The presentation lasts 45 minutes, followed by a 15-minute Q&A session. 
Registration is free and mandatory.

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