Lemanscope

Lémanscope: Monitoring Lake Geneva Through Citizen Science with EyeOnWater

Lémanscope is a large-scale citizen science project dedicated to understanding the seasonal and spatial variations in water quality across Lake Geneva (Lac Léman). Led by researchers from EPFL in collaboration with the Association pour la Sauvegarde du Léman (ASL), Eawag, and the University of Lausanne, the project engages hundreds of volunteers to collect observations of water transparency and water colour throughout the lake. Website link: https://lemanscope.org/projet/

By combining observations from citizens with satellite data, Lémanscope helps scientists gain a more complete picture of the lake's ecological dynamics while strengthening public engagement in freshwater stewardship.

EyeOnWater as the Tool for Colour Measurements

To collect water colour observations, Lémanscope relies on the EyeOnWater Colour app. Participants simply take a photograph of the water surface using their smartphone and submit the observation through the app. The system automatically derives a standardized water colour value based on the internationally recognized Forel-Ule colour scale, enabling consistent measurements across different locations and observers.

The EyeOnWater platform was specifically designed to support citizen science and has been used worldwide to monitor rivers, lakes, coastal waters, seas, and oceans. Every observation contributes to a growing global database of water colour measurements that extends historical records dating back more than a century.

How Lémanscope Uses EyeOnWater

Within the Lémanscope project, volunteers navigate Lake Geneva during their regular recreational or professional activities and record observations using the EyeOnWater app. The process is simple:

1. Open the EyeOnWater Colour app.
2. Photograph the lake surface following the app instructions.
3. Submit the observation together with basic contextual information.
4. Instantly contribute to a scientific dataset used by researchers.

The resulting measurements are combined with transparency observations from Secchi disks and compared with satellite imagery to better understand water quality patterns across the lake.

From Local Observations to Global Impact

One of the unique strengths of EyeOnWater is that local measurements become part of a global water quality database. Lémanscope participants can view their observations alongside measurements from lakes, rivers, coastal waters, and oceans around the world. This allows both scientists and citizens to place Lake Geneva's observations within a broader environmental context.

All observations are stored and visualized through the EyeOnWater platform, creating an open and accessible resource for research, education, and environmental awareness.
The success of Lémanscope demonstrates the power of citizen science. By using a simple smartphone app, volunteers generate valuable scientific information while developing a stronger connection with their local environment. Every measurement helps researchers better understand Lake Geneva's ecosystem and supports efforts to protect this unique freshwater resource for future generations.

Join the Global EyeOnWater Community

Whether you are participating in Lémanscope on Lake Geneva or observing waters elsewhere in the world, EyeOnWater makes it possible for everyone to contribute to water science. Together, citizen scientists are creating one of the largest collections of water colour observations available today, helping researchers monitor and understand changing aquatic environments on a global scale.