| Project/Area Number |
17403002
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 海外学術 |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | Research Institute for Humanity and Nature |
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Principal Investigator |
TANIGUCHI Makoto Research Institute for Humanity and Nature, Research Department, Associate Professor (80227222)
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| Co-Investigator(Kenkyū-buntansha) |
GAMO Toshitaka Tokyo University, Ocean Research Institute, Professor (70143550)
TOKUNAGA Tomohika Tokyo University, Graduate school of Frontier Sciences, Associate Professor (70237072)
MIYAOKA Kunihide Mie University, Faculty of Education, Associate Professor (70296234)
ZIN Chang Toyama University, Faculty of Science, Associate Professor (20301822)
ONODERA Shinichi Hiroshima University, Graduate School of Integrated Arts and Sciences, Associate Professor (50304366)
嶋田 純 熊本大学・理学部 (80206169)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥9,800,000 (Direct Cost: ¥8,900,000、Indirect Cost: ¥900,000)
Fiscal Year 2007: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2006: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2005: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | Environmental change / Physical Oceanography and limnology / Groundwater hydrology / Hydrosphere / Conservation of ocean / Material transport / Coastal Ecology |
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| Research Abstract |
Submarine groundwater discharge (SGD) is recognized as an important pathway from land to ocean, not only for water and dissolved material transports but also for ecosystem in the coastal zone. The seepage meters (for SGD flux), piezometers (for groundwater potential and dissolved material transports), optic fiber cable (for sea bottom temperature) and resistivity (fresh-salt water distribution) measurements had been made to evaluate the flux and quality of the SGD in several palaces in East Asia, including, Korea, Taipei, Bangkok, Manila, Osaka.
A multidisciplinary approach was recently taken to assess the potential importance of groundwater seepage to nutrient inputs into Manila Bay, The Philippines. Three lines of seepage meters were installed in transects along the coast at Mariveles, Bataan Province during the period between 8-10 January 2005. The seepage rates along the northern most line showed the highest submarine groundwater discharge (SGD) at rates of 7.1-10.9 cm day^<-1>. The overall average seepage flux was 5.1±5.4 cm/day with a range of 0-26cm/day. Additional methodologies employed included automatic seepage meters, resistivity measurements, and use of natural radon as a groundwater tracer. Seepage meter and tracer results provided consistent results of estimates of SGD into Manila Bay. Both methods also showed that seepage fluxes are not steady-state but are modulated by the tides. Resistivity profiles show that the saline-freshwater interface moves on a tidal time scale. Our results show that dissolved inorganic nitrogen (DIN) fluxes via SGD are comparable in magnitude to DIN fluxes from each of the two major rivers that drain into Manila Bay
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