Effects of Bamboo forest expansion and climate change on flood and drought runoff in forested catchments

2018 Fiscal Year Final Research Report

• Project/Area Number: 15H05632
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Rural environmental engineering/Planning
• Research Institution: Ishikawa Prefectural University
• Principal Investigator: FUJIHARA Yoichi 石川県立大学, 生物資源環境学部, 准教授 (10414038)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 気候変動 / 竹林拡大 / 土壌物理性 / 積雪 / 融雪 / シミュレーション / 森林水文 / 洪水・渇水

Outline of Final Research Achievements

We investigated the effects of the expansion of Bamboo forest and climate change on flood and drought runoff of forested catchments. As root mass increased, volumetric soil water content at the same soil matric potential decreased. Therefore, we concluded that soil water retention was reduced as the Bamboo forest expanded. Dye tracer experiments demonstrated that water moves through roots and soil cracks, and the dye was observed in the soil from the surface to a depth of 30cm. As climate change and Bamboo forest expansion continue, long wave radiations emitted from trees increase, resulting in earlier snow disappearance than that of current conditions in conjunction with temperature increases.

Free Research Field

水文学

Academic Significance and Societal Importance of the Research Achievements

竹林と針葉樹林における雨水流出経路に違いが見られることから、竹林拡大によって洪水・渇水緩和機能にも影響が現れる可能性が高い。さらに、気候変動にともなう気温上昇によって流域内に蓄えられる積雪が減少するだけでなく、樹体からの長波放射が増加することによって融雪が促進され消雪が早まることを示した。これらの情報は、災害に強い森林づくりを進めるのに際して活用されることが期待される。