Abstract
Resent studies have demonstrated that rivers in the western Pacific islands can be very important in affecting global riverine material flux. The Kaoping River is a typical tropical, island-type river with the largest drainage area in Southern Taiwan. Material outputs from the Kaoping River are expected to play a major role in affecting the local coastal environment. Therefore, this study aims at understanding processes and mechanisms for generation, transport and transformation of terrigenous materials in the Kaoping drainage basin. The temporal and spatial distributions of hydrochemical parameters, total suspended matter (TSM), major ions, nutrients, and particulate and dissolved species of C, N and P (DOC, DIN, DIP, DON, DOP, POC and PON) were measured in the Kaoping River from August 1999 to August 2000. The collected data are used to elucidate sources and the influence of external forcing on fluxes of sediment, carbon and nutrients form the Kaoping drainage basin.
Based on the fluxes of TSM and total dissolved solid (TDS) observed in the Kaoping River, the total, physical and chemical weathering rates were estimated about 7,368, 5985 and 1,383 g/m2/yr, respectively. The significant correlation between TSM-load and water discharge suggested that the sediment flux was primarily controlled by the runoff in the drainage basin.
The generation of total carbon (DIC¡ÏDOC¡ÏPIC¡ÏPOC) in the Kaoping drainage basin was about 191g C/m2/yr. The yields of DIC, DOC, PIC and POC were 110 (60%), 2.27 (1.7%), 35.6 (17%) and 42.6 (21%) g C/m2/yr, respectively. These values of carbon yield from the Kaoping drainage basin were very high in comparison with ones obtained from the Lanyang River and the other major rivers in the world. The annual fluxes of riverine DIC, DOC, PIC, POC and TC from the Kaoping River were about 34.5, 0.705, 11.0, 13.2 and 63.2 x 1010 g C, respectively.
Regarding the nutrient results, the riverine fluxes of dissolved and particulate nitrogen were 2.298 x 109 mole/yr and 1.55 x 108 mole/yr, respectively. By taking out the natural input of total dissolved nitrogen, anthropogenic input of total dissolved nitrogen in the Kaoping River was about 5-6 x 104 kg/day that is similar to the one (56,779 kg/day) reported by the EPA. The fluxes of total dissolved phosphate and silicate were 3.378 x 107 and 1.285 x 109 mole/yr, respectively. The high riverine flux of silicate also reflects the high weathering rate in the Kaoping drainage basin. The flux of anthropogenic phosphate from the Kaoping River was about 4 - 8 x 103 kg/day which was similar to that estimated from the Tanshui River. Taking the nutrient content in the Kaoping upstream as background level, the natural fluxes of total nitrogen and phosphate in the Kaoping River were estimated to be 8 x 103 and 4 x 103 kg/day which were equivalent to 16% and 57% of the anthropogenic inputs, respectively. Anthropogenic input appears to be the major source of riverine nutrients in the Kaoping River.
Overall, human activities play a major role on affecting the generation, transport and transformation of terrigenous materials in the Kaoping drainage basin. This study also confirms that rivers in Taiwan may be very important in affecting the local and/or the global fluxes of terrestrial materials.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0913101-170557 |
| Date | 13 September 2001 |
| Creators | Yang, Jang-Yi |
| Contributors | J. J. Hung, J. C. Chen, Y. C. Chen |
| 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-0913101-170557 |
| Rights | unrestricted, Copyright information available at source archive |
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