2022 Fiscal Year Final Research Report
Exploring hydrological functions of wetlands and glacial lakes in the downstream areas of tropical glaciers and their impacts on water resources
| Project/Area Number |
20K04712
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 22040:Hydroengineering-related
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| Research Institution | Nihon University |
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Principal Investigator |
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | 氷河融解 / 衛星観測 / Sentinel-1 / Cバンド合成開口レーダ / 後方散乱係数 / WorldView / 正規化植生指数 / ボリビア多民族国 |
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| Outline of Final Research Achievements |
This study showed the distribution of wetlands and glacial lakes which are formed in the downstream area of tropical glaciers. Monthly water bodies of the wetlands were extracted by combining backscatter coefficients derived from the C-band synthetic aperture radar of the Sentinel-1 satellite, and normalized vegetation index and normalized water index derived from the optical sensors of the WorldView satellite. Backscatter coefficients was also used to extract glacial lakes. We estimated that the occupancy of wetland waters was from 9.7% (dry season) to 22.3% (rainy season) of the catchment area of the Tuni reservoir in Bolivia. We also showed that the area of wetlands is possibly to be associated with the area of glaciers which distribute in their upstream.
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| Free Research Field |
水文学
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| Academic Significance and Societal Importance of the Research Achievements |
本研究は氷河下流の湿地や氷河湖の分布を推定する手法を開発した。複数の衛星データ（Cバンド合成開口レーダと光学センサ）を組み合わせて天候の影響を受けずに推定可能である。また、熱帯氷河下流の湿地水域の変動を示した研究事例は少なく、湿地水域の変動を月単位で推定したことは大きな成果といえる。氷河・湿地・氷河湖の分布する流域の水循環理解に向けて重要情報になりうる。アンデス高地では山岳都市の多くが熱帯氷河の融解水を主要な水資源の１つとして利用している。気候変動下の水資源管理において氷河・湿地・氷河湖を考慮した水循環の理解は社会的にも有益と考えられる。
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