Effect of three types of geology on the morphology and habitat characteristics of mountain streams

2014 Fiscal Year Final Research Report

• Project/Area Number: 25889042
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Hydraulic engineering
• Research Institution: Kyushu University
• Principal Investigator: SATO Tatsuro 九州大学, 持続可能な社会のための決断科学センター, 助教 (20711849)
• Project Period (FY): 2013-08-30 – 2015-03-31
• Keywords: 山地渓流 / ステッププール / 流域地質

Outline of Final Research Achievements

The purpose of the present study was to reveal how the morphology of mountain streams change with geology for improving nature friendly river management. We surveyed 53 sites of mountain streams in north central region of the Kyushu Island, focusing on three main geology there; granite, pelitic schist and welded tuff. As the results, bed material and step-pool morphology were different depending on geology. As for the streams of granite, boulders and sand occupied large percentage of bed material, and step height and pool depth were greater than the other streams with different geology. At the streams of welded tuff, bedrock were exposed in the large part of river bed. In addition, we revealed that step height is passively correlated the stream power index, an index for the sediment transport potential and product of drainage area and gradient, whose relationship are different depending on geology.

Free Research Field

河川応用生態