This research collected surface (<15 cm) sediments from estuarine and coastal zones off southwestern Taiwan. Basic sediment parameters, including grain size, and total organic carbon (TOC) and total inorganic carbon (TIC) concentrations were analyzed. For heavy metals (Fe, Mn, Cd, Cu, Ni, Pb, and Zn), total metal concentrations and metal fractions separated by sequential extraction techniques were determined. This study also obtained several previously collected sediment cores in the Gaoping Canyon area that had been dated by other researchers. Results obtained in this study are used in order to understand the distribution patterns of heavy metals in coastal sediments off southwestern Taiwan, and related to regional environmental changes regarding heavy metals.
The distribution of heavy metal fractions and their geochemical
significances were studied.
Results obtained in this study indicate that physicochemical characteristics of sediments largely affected heavy metal distribution in coastal sediments off southwestern Taiwan. Regional flow patterns contributed to the observed distribution patterns. Higher heavy metal concentrations were found in sediments collected near the Gaoping river mouth, the Gaoping Canyon and its nearby continental slope, and a narrow banded offshore region off the Anping-Tainan urban areas. These results reflect the distribution of fine-grained sediments in the studied area.
Vertical profiles of heavy metals in four dated cores showed drastic increases of heavy metal concentrations since 1995-2000, and some extent of decreases during 2003-2006 in two of the cores. Although actions of environmental protection regarding heavy metal pollution had taken place in this region, decreases in sediment heavy metals were mostly attributed to episodic typhoon and possibly sediment slumping events. With the recently intensified landslides and mud flows in the upper reaches of the river that would bring upstream soils and particles to the estuarine region, leading to the decrease of metal concentrations in the Gaoping estuarine sediments, a more significant decreasing trend in sediment metal concentrations can be speculated for the future.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0208110-200636 |
| Date | 08 February 2010 |
| Creators | Wu, Zhe-yu |
| Contributors | Tsu-Chien Liu, Kuo-Tung Jiann, Hui-Ling Lin, Liang-Saw Wen |
| 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-0208110-200636 |
| Rights | withheld, Copyright information available at source archive |
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