River channel improvement considered in the response to artificial impacts on Karasu River

Abstract

After gravel quarrying in the 1960s and 70s, the low water channel width has been reduced in Karasu River. To increase the capacity of flood discharge, excavation work has been necessary. Countermeasures for natural width reduction have been needed to cut maintenance costs.

The reduction in the low water channel was presumed by clarifying the correlation between artificial impacts and river responses which Karasu River had in the past, and analyzing the relationship between sedimentation and vegetation after the flood impacts. The excavation design method with less reduction of the width was proposed as a part of the river management strategies.