The purpose of this paper is to deal with influence on channel form by regulated river width artificially in small and middle-sized river. Firstly, we surveyed about 100 rivers and evaluated the some parameters related to channel form, width (B), representative grain-diameter (dr), bed slope (I) and so on, with GIS data and survey data. Secondly, we calculated flow discharge(Q), flow depth (H), Froude number (Fr) and so on using the existing formula. Finally, we investigated the relationship between those channel characteristics and channel forms. As a result, there were highly correlations between the sandbar generation area classification (Kuroki et.al. 1984) and channel forms. we found that the types of those river channels can be classified 4 groups by Fr - BI0.2/H.
In conclusion, the results of this study were found to have effects on the ratio of the river width and the depth of water (B/H) which were set up artificially has affected the river channel through change of a stream bed form.
