Author(s): Morihiro Harada; Rahma Yanda
Linked Author(s): Morihiro Harada
Keywords: No Keywords
Abstract: This study focuses on "riverbed environment" which is the foundation of the stream ecosystem in the upper and middle reaches. This study aims to develop a numerical simulation model that can directly evaluate habitat of organisms dependent on riverbed at the same time as calculating flow and river bed variation in reach scale by changes in flow rate and sediment supply from upstream. First, the concept of the riverbed environment model is shown. Based on this, this study discusses what kind of function should be implemented in numerical calculation method. Next, the outline and results of numerical simulation model in development are shown. The Nays 2D solver of IRIC which is a general horizontal two-dimensional riverbed variation solver was improved, and the riverbed environment model coupled with the grain size distribution, flow resistance, porosity was implemented. As a result, it became possible to obtain not merely the necessary information for habitat evaluation of the riverbed, but also the precision of riverbed variation calculation itself improved. Then, the concept for evaluating the swimming fish habitat volume by estimating the flow profile including the roughness layer is introduced. By implementing this concept into the improved horizontal two-dimensional model, it will be possible to directly evaluate the volume of the swimming fish and benthic specie’s habitat.
Year: 2018