Print Email Facebook Twitter Field experiment on alternate bar development in a straight sand-bed stream Title Field experiment on alternate bar development in a straight sand-bed stream Author Eekhout, J.P.C. Hoitink, A.J.F. Mosselman, E. Faculty Civil Engineering and Geosciences Department Hydraulic Engineering Date 2013-12-13 Abstract Alternate bars in rivers and streams develop as a result of differences in length scales involved in the adjustment of flow and sediment transport to irregularities of the bed. The amount of field evidence supporting theoretical insights is highly limited. Here, we present results from a large-scale field experiment in a 600 m long straight reach. Over a period of almost 3 years, the channel was allowed to evolve autogenously from initially flat bed conditions, subject to discharge variation. Alternate bars developed within 8 months from the start of the experiment. The initial stages of bar development included bar growth, both in wavelength and amplitude, and bar migration. The latter was too limited to classify the bars as being migrating bars; therefore, we classify the bars as nonmigrating bars. Toward the end of the experiment, the regular alternate bar pattern evolved into an irregular pattern and bar amplitude started to decrease. From the start of the experiment we observed a declining channel slope, from 1.8 m km?1 initially to 0.9 m km?1 halfway the experiment, after which it stabilized. We applied two bar theories to establish their predictive capacity. Both bar theories predicted the development of alternate bars under the constructed channel conditions. In response to the declining channel slope, both theories predicted a decreasing likelihood for the development of alternate bars. Our study shows that under field conditions, the applied bar theories may predict the initial stages of bed development. Subject river morphologyalternate barsbar theoryfield experimentstream restoration To reference this document use: http://resolver.tudelft.nl/uuid:80be8bd0-b8fe-4b7c-9700-c32a3a644d73 DOI https://doi.org/10.1002/2013WR014259 Publisher American Geophysical Union Embargo date 2014-06-13 ISSN 0043-1397 Source Water Resources Research, 49 (12), 2013 Part of collection Institutional Repository Document type journal article Rights © 2013 American Geophysical Union Files PDF Mosselman_2013.pdf 3.18 MB Close viewer /islandora/object/uuid:80be8bd0-b8fe-4b7c-9700-c32a3a644d73/datastream/OBJ/view