Author(s): M. Roth; M. Weber; G. R. Bezzola
Linked Author(s):
Keywords: River deltas; Sediment transport; Physical models; River restoration
Abstract: The Alpenrhein River has been artificially extended into Lake Constance through the lengthening of its levees. The goal of this extension is to prohibit the premature sedimentation of the bays surrounding the delta. Currently, an investigation on how during floods a part of the flow and transported sediment can be diverted through levee breaches in a controlled manner is under way. These breaches would allow for a more natural delta development. The processes at such a breach were studied with a physical model. For the sediment in the model, an expandable polystyrene grain material with a density of 1030 kg/m3 was used. This density is far smaller than that of the actual sediment found in nature (Lightweight Model). The horizontal model scale was 1:70 and the vertical scale was 1:32, such that the model was geometrically distorted by a factor of approximately 2.2. Only the sand portion of the total suspended sediment load was modeled. Sand is the bed material of the Alpenrhein channel extension and also comprises the most important depositional zones on the lake side of the levee breaches.
Year: 2001