Development of Initial Design-Width Formulas for Small Streams: Case Study in Western Gangwon Province

Abstract

The initial design-width formulas of small streams should be determined differently according to the hydrologic and geographical characteristics of the local area. However, the currently applied design-width formula of the design criteria used in water resource design practices does not consider recent rainfall trends and the characteristics of local small streams. Because the extent of the variation in the flood level of small stream is large according to the calculation of the initial design-width, the optimal design-width should be determined through repeated calculation by the trial and error method. Thus, the initial design-width calculation considering regional characteristics is crucial for efficiency and economic analyses of small stream design. In this study, initial design-width formulas were developed by performing regression analysis through univariate and multivariate analysis of design floods, drainage area, and bed slope considering the characteristics in western Gangwon. The proposed initial design-width formulas will be used as a basic design practice data for determining the initial design-width or for verifying the determined design-width of a small stream in this region. Keywords: Initial Design-Width, Small Stream, Design-Floods, Drainage Area, Bed Slope