2014 Fiscal Year Final Research Report
Preliminary Study to Reconstruct the History of Water Quality Change of Recent Past
Project/Area Number |
24650605
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Research Category |
Grant-in-Aid for Challenging Exploratory Research
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Allocation Type | Multi-year Fund |
Research Field |
Geography
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Research Institution | The University of Shiga Prefecture |
Principal Investigator |
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Co-Investigator(Kenkyū-buntansha) |
MARUO Masahiro 滋賀県立大学, 環境科学部, 准教授 (80275156)
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Project Period (FY) |
2012-04-01 – 2015-03-31
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Keywords | 河川堆積物 / 柱状試料 / 年層 / 環境復元 / 湛水域 |
Outline of Final Research Achievements |
The river mouth of Kitagawa Brook is normally stagnant because it is easily closed by sand and gravel transported by littoral currents of Biwa Lake, Japan. A new urban area exists in the basin and sewerage works were constructed in the early 1990s, so contaminated water with a bad odour had flowed into the brook before the sewerage works. To reduce the smell, the river mouth was excavated to narrow the channel in the early 1980s. Thus, river-bed sediment after this excavation only occurs at the river mouth. From the upper 24 cm of a sediment core, we found 19 strata of leaves which were supplied from deciduous trees in autumn. We also found several gravel layers which were supplied from the lake during severe storms. The combination of veins and gravel layers were reconstructed for about 20 years of sediment records with an error of two to three years.
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Free Research Field |
地形学
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