The Grain Size Distribution of Bed Materials-A case Study in the Kaoping River Basin

• Main Authors: Yi-ChiehTsai, 蔡宜潔
• Other Authors: Chyan-Deng Jan
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/e2ymak

碩士 === 國立成功大學 === 水利及海洋工程學系 === 103 === The grain size of sediment materials on riverbeds is an important factor of river morphodynamics. In general, sediment materials determine the transport capacity of river flow, leading to the different types of natural river channel networks. Hence, characterizing the grain size distribution is able to refine stream monitoring for the issues of habitat evolution and river management. In this study, we collected 43 standard volumetric samplings in the Kaoping River basin by sampling to clarify its corresponding grain size distribution of bed materials. Here we discuss the spatial distribution of different representative grain size (e.g., D50 and D90) and Manning's n value in each sampling. Then, an exponential grain size distribution (GSD) formula is used to explore relationship between the frequency and size of riverbed sediment materials, and to find the characteristic diameter DC in GSD formula. Furthermore, we used different representative grain size of sediment materials instead of DC leading the formula to relate with sediment transport capacity. Results show that D65 could be a suitable parameter to describe the exponential relationship of sediment frequency with respect to its corresponding size. This study could provide some useful information for the management of rivers and watersheds.