A preliminary study shows that Submarine Groundwater Discharge (SGD) exists around Taiwan even though groundwater overdrawing is serious. Only five of the 20 sites studied did not record any SGD signal. Two nearly fresh SGD samples were obtained, providing strong and direct evidence for the existence of SGD in Taiwan.
SGD is the submarine seepage of all fluids from coastal sediments into the overlying coastal areas. It has been well documented that SGD may contribute much nutrients to the coasts (Burnett et al.,2001, 2003; Church, 1996; Taniguchi et al., 2002; Zhang and Satake, 2002). Because of its difficulty in measurement, there are few reports on the characteristics of groundwater seepage, such as the flow rate and the water chemistry. In Taiwan, the only report was published in the Japanese journal Geochemistry (Chen et al. , 2005 ).
In this study, samples were collected monthly from May, 2004 to June, 2006 at Xiziwan and Caishan in Kaohsiung. A flux chamber was also used in the observation of the SGD seepage rates. Further, samples were collected from 20 different places around Taiwan.
The SGD collecting device, the SGD-Flux chamber and the Lee type seepage meter (Zhang et al., 2005) were used in this study, the latter being the first time used to explore the SGD flux in Taiwan. Salinity, dissolved oxygen saturation (%), nutrients (NO3, NO2, PO4, SiO2, NH3), total alkalinity, pH and major ions were analyzed.
We averaged all seepage rate data at Xiziwan and Caishan to estimated the SGD seepage rate at about 1.32¡Ó1.57 L/m2/hr. The average concentrations of inorganic nitrogen (NO3+NO2+NH3), PO4 and SiO2 are, respectively, 48.6¡Ó86.3 (n=85), 0.78¡Ó1.26 (n=110) and 55.1¡Ó39.8
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0910107-170327 |
| Date | 10 September 2007 |
| Creators | Lin, Yi-jie |
| Contributors | Chon-Lin Lee, Tsung-Ren Peng, Saulwood Lin, Chen-Tung Arthur Chen, Chiu-Long Chou |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0910107-170327 |
| Rights | unrestricted, Copyright information available at source archive |
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