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尾瀬ヶ原における河川と池溏の水文地形学
野原, 精一;村田, 智吉;藤原, 英史;福原, 晴夫;萩原, 富司;千賀, 有希子
Permalink : http://hdl.handle.net/2115/85009
JaLCDOI : 10.14943/lowtemsci.80.95
KEYWORDS : 泥炭地湿原;河川;尾瀬ヶ原;水文地形学;池溏;bog pools;environmental change;hydrogeomorphology;Ozegahara mire;rivers
Abstract
尾瀬ヶ原は面積約7.6km2の本州最大の泥炭地・山岳湿原である．気候変動の湿原への影響を探るため湿原における洪水の影響を明らかにすることを目的に研究を実施した．2019年5月に融雪による洪水が発生し，上田代の池溏は滝のような流れを受け，池溏底質の洗堀や湿原への流出が観察された．洪水前後に粒度分析を行った結果，洪水後の池溏には数μmの非常に小さな球形無機粒子や無機粒子があり，水深約1ｍより深い池溏はしばらく濁った．直後にUAVの空撮によって詳細な濁りの分布が明らかになった．研究見本園の表層から約1m深に無機成分の多い層が見られ，過去約1,300年前の洪水履歴とみられた．
Ozegahara mire is the largest peatland (7.6 km2) in the mainland of Japan. The mire is located on the amphitheater-shaped basin surrounded by high mountains of 2,000 m. The heavy snow flooding in torrents was happened in May 2019 at Kamitashiro area. The turbidity of bog pools in Kamitashiro increased in May 2019, by surface water and ground water inflow. After the flooding, distribution of the muddy water in bog pool was taken by air photography of UAV. The high content of inorganic particle was detected from peatland sediment of about 1 m depth layer and estimated by historical flooding about 1,300 years ago. The bog pool KA1-04 had early snowmelt by ground water inflow from middle bog pool.
Ozegahara mire is the largest peatland (7.6 km2) in the mainland of Japan. The mire is located on the amphitheater-shaped basin surrounded by high mountains of 2,000 m. The heavy snow flooding in torrents was happened in May 2019 at Kamitashiro area. The turbidity of bog pools in Kamitashiro increased in May 2019, by surface water and ground water inflow. After the flooding, distribution of the muddy water in bog pool was taken by air photography of UAV. The high content of inorganic particle was detected from peatland sediment of about 1 m depth layer and estimated by historical flooding about 1,300 years ago. The bog pool KA1-04 had early snowmelt by ground water inflow from middle bog pool.
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