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This paper presents the results of an exploratory study on scour occurring around submerged spur-dike. The effect of flow depth and spur-dike dimensions was studied with the help of the experimental data. It was found that the overtopping ratio and the opening ratio are significantly affected on the maximum scour depth. The larger opening ratios (a) caused relatively small scour area and the bank erosion downstream the spur-dike hardly can occur. The longer spur-dike length & the lower flow depth produced scour area wider than the shorter spur-dike length & the higher flow depth. The data collected in this investigation would be useful for the development of numerical models of scour around submerged dikes.

In this paper, the bed variation and sand waves in curved channels are discussed experimentally. In the experiment, the flume is 900 curved open channel and the ratio between width of channel and water depth is less than 10. In this experimental condition, a big sand waves rapidly developed at the outer side in curved channel. The spiral flow occurred behind the wand waves and big scour hole appeared by this spiral flow. Because of this local score, the maximum score depth at the outer side was 1.4 times of the averaged score depth without sand waves condition.In the inner side of the curved channel, the deposition of sand usually occurs. But in this experimental condition, at the downstream region in curved channel, the scour region appeared in the inner side due to the above spiral flow.

This paper presents the results of an experimental study of flow behavior around submerged dikes on rigid bed. The studies of flow behavior including water surface profiles and velocity profiles around a single dike with different cases were carried out with steady uniform flow on smooth rigid bed. It is observed that, the disturbance occurred in the water surface profiles and the velocity profiles for a short distance upstream the dike and for a longer distance downstream the dike. The flow patterns around fullysubmerged dike and just-submerged dike had a different phenomenon such as: A rise in the water surface level upstream the dike and a drop in the water surface level downstream the dike . The separation flow zones were different in each case depending on the kind of the dike.

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