捷水路による洪水氾濫と洪水流の変化

抄録

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.