| Project/Area Number |
60400009
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
広領域
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| Research Institution | Faculty of science, Shimane University |
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Principal Investigator |
MITSUNASHI Takashi Professor, Faculty of Sci., Shimane Univ., 理学部, 教授 (90127499)
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| Co-Investigator(Kenkyū-buntansha) |
MIYATA Itsuo Professor, Faculty of Sci., Shimane Univ., 理学部, 教授 (90069948)
HASHITANI Hiroshi Professor, Faculty of Sci., Shimane Univ., 理学部, 教授 (00156267)
TAKAYASU Katsumi Associate Professor, Fac. of Sci., Shimane Univ., 理学部, 助教授 (00127490)
ONISHI Ikuo Professor, Faculty of Sci., Shimane Univ., 理学部, 教授 (40032445)
TOKUOKA Takao Professor, Faculty of Sci., Shimane Univ., 理学部, 教授 (30025358)
伊藤 晴明 島根大学, 理学部, 教授 (80032423)
荒木 長男 島根大学, 理学部, 教授 (70028124)
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| Project Period (FY) |
1985 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥27,000,000 (Direct Cost: ¥27,000,000)
Fiscal Year 1988: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1987: ¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 1986: ¥8,000,000 (Direct Cost: ¥8,000,000)
Fiscal Year 1985: ¥9,000,000 (Direct Cost: ¥9,000,000)
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| Keywords | Natural History / Echo-sounding / Lake Sediments / Water quality criteria vegetation / aquatic plant / 植生 / 水草 / 音響探査 / 湖底推積層 / 希土類金属イオン分離 / 底質 / 放射年代 / 環境モニタリング / 廃水処理 / 自然残留磁気 / 中海宍道湖 / 完新世 / 環境変遷 / 鉛同位体年代 / 中海層 |
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| Research Abstract |
In these four years the natural history of the Lake Naka-no-umi and Lake Shinji has been studied from mainly geological, geochemical and plant-ecological points of view. Recent bottom sediments were collected and analyzed at 248 points of Lake Shinji and 27 points of Lake Naka-no-umi. Columnar samples of 1 to 2 m thick have been obtained at several tens points and analysed on the basis of sedimentological and paleontological ( diatom, pollen, foraminifer, ostracoda and molluscs ) methods. Radiometric chronology of C14, Pb210 and Cs137 methods have clarified that the desiometric chronology of c14, pb210 and cs137 methods have clarified that the sedimentation rate is three times larger in Lake Shinji than in Lake Naka-noumi, that is, 0.107gr/cm/y in the former and 0.044gr/cm/y in the latter by pb210 method. The historically-known environmental changes from marine to fresh-water ( 350 years ago), and fresh-water to blackish water (150 years ago ) can be supported by faunal changes in the columnar sections. These ages can be evidenced by the above-mentioned chronologic methods. Surficial and vertical distribution of some elements contained in the sediment of bothlakes have been analyzed geochemically. Aquatic plants in Lake Shinji and vegetation of flora surrounding these lakes have been described areally and were illustrated on the vegetation map.
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