Author(s): B. Spinewine; C. Carena; Y. Zech
Linked Author(s): Yves Zech
Keywords: River morphology; Ex-post prediction; Long-term river modelling
Abstract: To demonstrate the ability of models to predict long-term evolution of fluvial morphology, an ex-post analysis of the Rhine during the last two centuries was carried out. An advantage of such an analysis is that the result is known and can serve straightforwardly to compare with model outputs. Conversely, ancient data is generally difficult to obtain, and the main work in such an analysis is the selection of a relevant dataset, complementing fragmentary ancient data with more recent data adequately interpreted for reconstructing realistic initial conditions. The Upper German Rhine has been deeply reshaped by large engineering works in the 19th century. The initially braided reach Basle-Maxau was constricted into a unique channel, while the reach Maxau-Mainz was significantly shortened by numerous meander shortcuts. Both types of works resulted in intense erosion upstream and spread deposition downstream. Using some data from the literature, but also satellite and aerial images freely accessible on the Internet, and hydrologic data also from the Internet, it was possible to qualitatively reproduce most of the observed behaviour of the river.