River Lek (IMAGE) Geological Society of America Caption Even long before medieval inhabitants reclaimed land and raised dykes at a large scale, humans have had a strong impact on river behavior in the Dutch delta plain. Physical geographers at Utrecht University, The Netherlands, have demonstrated that two present Rhine branches developed stepwise in the first centuries CE, because of two combined man-induced effects. Credit https://beeldbank.rws.nl, Rijkswaterstaat/Joop van Houdt. Usage Restrictions Credit: https://beeldbank.rws.nl, Rijkswaterstaat / Joop van Houdt. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.