Gräf, J. Share this Send to email Authored by Gräf, J. Publications Browse all Publication 2021 Monitoring of Suspended Sediments in a Tropical Forested Landscape With Citizen Science Publication 2021 Crowdsourced Water Level Monitoring in Kenya’s Sondu-Miriu Basin—Who Is “The Crowd”? Publication 2019 Citizen science in hydrological monitoring and ecosystem services management: State of the art and future prospects