It is an important subject to evaluate sediment transport bubfet in river management works. In this paper sediment transport output from the Ishikari River is investigated as primitive example for this subject. Relationship between turbidity data and suspend sediment concentration data is investigated and a formula to evaluate wash load transport rate is proposed. Using the daily discharge data of the past 20 yeas, the annual sediment runoff from the Ishikari River mouth is calculated. The annual runoff of the bed material is also calculated by a numerical model for bed load and suspended load transport, bed deformation and grain size distribution of bed material. The results of wash load runoff and bed material load runoff are compared and it is found that wash load runoff can be explained as a part of bed material load.
Eighty years have passed since systematic improvement of the Ishikari River started in 1910. Before the improvements, the Ishikari River was in a completely natural state, and caused floods every year due to its meandering stream. The goal of the improvements was to further the development of Hokkaido by rcelaiming the vast marshes along the Ishikari River. The improvement work involved channel improvement of river, mainly by (1) excavating short-cuts to shorten the river and lower the flood stage, and (2) construction of continuous embankments to prevent floods.As a result, flood protection has improved remarkably and allowed the development of new residential areas. Flood prevention and reduction in water-levelsby the short-cuts have changed the Ishikari Marshes to fertile arable land.This study will clarify how channel improvements in the Ishikari River executed for regional development contributed to a change in flood flows and decreases in floods.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.