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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Controls of Trace Metal Distributions in the Kaoping Coastal Zone

Ho, Chuang-yi 24 July 2008 (has links)
This study investigates the distributions of trace metals and their controlling mechanisms in the Kaoping coastal zone. Concentrations of most dissolved metals were generally lower in the wet season than in the dry season in the Kaoping Estuary, showing clearly the effects of river discharge rate and water residence time on metal distributions. Dissolved trace metals (Fe, Mn, Zn, Cu, Cd and Pb) behaved non-conservatively with addition in the estuary. Nevertheless, dissolved Pb was apparently removed from the estuary in the wet season. Particulate Al and Fe were derived mainly from continental weathering and their transports through the estuary depend highly on the distribution of total suspended matter (TSM). During the dry season, the occurrence oxygen-deficit condition in the low salinity region and possible pollution from the San-Wei fishery harbor likely determined the distributions and solid-solution partitions of Mn, Zn, Cu, Cd and Pb in the estuary. Distributions of dissolved trace metals in the Kaoping coastal zone were significantly influenced by terrestrial inputs from the Kaoping River. Seasonal variations were attributed largely from the mixing between river water and sea water in the mixing layer and sediment resuspension from canyon bed. The column integrated dissolved and particulate metals were generally higher in the summer season than in other seasons. The difference was especially pronounced in nearshore stations. Concentrations of dissolved Mn, Zn, Cu and Pb increased generally with depth, reflecting the effects of resuspension and lateral transport of bottom sediment. Dissolved Zn and Cu concentrations correlated well with dissolved Mn concentration, but particulate Zn and Cu correlated poorly with particulate Al, implying that distributions of Zn and Cu were controlled by terrestrial inputs and biogeochemical processes in the Kaoping Canyon. Positive and negative correlations are found between dissolved Cd and nutrients (N+N¡Aorthophosphate) and between dissolved Cd and dissolved organic carbon (DOC), respectively, indicating that Cd is a nutrient-type metal and controlled biogeochemically in the Kaoping Canyon. Specific events such as typhoon and earthquake influenced significantly the distributions of trace metals in the Kaoping coastal zone. The integrated suspended-matter and suspended-metal concentrations showed an order magnitude higher during the typhoon season than in the normal summer season. Under the influence of earthquake, the TSM values of the bottom waters were much higher (2-7 folds) during the post- earthquake cruise (Jan/2007) than in the normal season (Jan/2006). Meanwhile, particulate Al, Fe, and Mn can increase up to 2- to 10-folds after earthquake in the bottom layer of canyon. Metal enrichment factor (EF) is an indicator of metal pollution. The EFs show an order magnitude higher in the dry season than in the wet season both in the estuary and canyon. Such seasonal patterns clearly indicate the impacts of local and river inputs on metal distributions in the estuary and canyon.
2

Seasonal distribution of copepods in relation to environmental factors in Tanshui and Kaoping estuaries

Yu, Ren-yao 11 August 2005 (has links)
The seasonal and spatial changes in species composition and abundance of copepods in relation to environment factors in both Tanshui and Kaoping estuaries were investigated in 2003. In total, 99 copepod species belonging to 8 genera and 3 families and 113 species belonging to 25 genera and 4 families were identified in the Tanshui and Kaoping estuaries, respectively; correspondingly each with the mean abundance of 1680 ¡Ó 403 inds/m3 and 3682 ¡Ó 1274 inds/m3. The species composition of copepods was apparently different between Tanshui and Kaoping estuaries. In the Tanshui estuary, the 6 most dominant copepods, Temora turbinata, Euterpina acutifrons, Canthocalanus pauper, Acrocalanus longicornis, Acrocalanus gibber, and Nannocalanus minor, were all marine species; among them, T. turbinata was the most abundant and contributed 11.9% to the total copepod count. While in the Kaoping estuary, many dominant species were freshwater dwellers, such as Pseudodiaptomus annandalei, Neodiaptomus schmackeri, Microcyclops tricolor, and Paracyclops fimbriatus. P. annandalei was the most abundant species and contributed 8.3% to the total copepods. The dominant marine species in the Kaoping estuary were Pseudodiaptomus marius, T. turbinata, Acartia omorii, Cosmocalanus darwini and Paracalanus parvus. The species composition and abundance of the copepods exhibited noticeable seasonal changes in both estuaries, particularly in the Kaoping estuary, probably related to the intensities of monsoon, rainfull and runoff of freshwater. In the Tanshui estuary, copepod assemblages were short of clear seasonal changes; the dominant species, Temora turbinata, Euterpina Acutifrons, and Canthocalanus pauper were found in all sampling months, with the peak abundance of these species as well as of the total copepods in May and lowest in November. In the Kaoping estuary, the peak abundance was found in February and lowest in August, while P. annandalei and Mongolodiaptomus birula were the most dominant species in these two months, respectively. The copepod (with the exception of Acrocalanus longicornis) abundance in the Tanshui estuary showed insignificant correlation with environmental factors, having significant and negative correlation with temperature. In the Kaoping estuary, on the other hand, most copepods were negatively and significantly correlated with both temperature and salinity.
3

Seasonal Distribution of Siphonophores in Tapeng Bay and Kaoping Coastal Waters, Southwestern Taiwan.

Hung, Yu-Pang 04 September 2002 (has links)
This study aims to investigate the spatial and temporal distribution of siphonophores in relation to water temperature, salinity, concentration of chlorophyll a and the abundance of copepods in Tapeng Bay and Kaoping coastal waters from June 1999 to July 2001. In Tapeng Bay, 20 species of siphonophores belonging to 9 genus and 3 families were identified with the mean abundance of 11¡Ó33 ind./100m3. The 5 most dominant siphonophore species in Tapeng Bay were Lensia subtiloides, Chelophyes appendiculata, Lensia subtilis, Bassia bassensis, and Lensia campanella, comprising 85% of the numerical total siphonophores. The siphonophores were mainly found at north station and scarce or even absent at St. N and St. S. Seasonal distribution of siphonophores was inconsistent, but generally had higher abundance in fall and winter. In Kaoping coastal waters, 34 species of siphonophores belonging to 16 genus and 5 families were identified, with the mean abundance of 648¡Ó636 ind./100m3. Seasonal change in numerical abundance of siphonophores was obvious, with higher in spring and autumn. The 5 most dominant species were C. appendiculata, L. subtiloides, Chelophyes contorta, Sulculeolaria chuni and B. bassensis, and comprised 77% of the total counted of siphonophores. The species number, species diversity, and the mean abundance of siphonophores in Kaoping coastal waters were higher than that in Tapeng Bay. The siphonophores found in the present study mostly belong to the widespread oceanic species and widespread coastal species. The distributions of siphonophore were not significantly (p>0.05) correlated to temperature, salinity, concentration of chlorophyll a and the abundance of copepods, except Abylopsis tetragona and Diphyes dispar, that exhibited significant negative correlation with temperature (p<0.01) and chlorophyll a (p<0.01), respectively.
4

Influences of River Fluxes on Biogeochemical Processes of Carbon and Nutrients in the Kaoping Coastal Zone

Ho, Cheng-Ming 29 July 2004 (has links)
This study aims to understand the influence of external forcing (i.e. climate, human influences) changes on the inputs of terrigenous materials from the Kaoping River as well as the biogeochemical responses of carbon and nutrients to riverine fluxes in the Kaoping coastal zone. The Kaoping River exhibits contrasting patterns in water discharge and material fluxes between wet and dry seasons. In general, river discharge is about 12 times higher in the wet season than in the dry season. Riverine fluxes of terrigenous materials (DOC¡BPOC¡BDSi¡BDIN¡BDIP¡BTDN and TDP) are about 3 to 10 times higher in the wet season than in the dry season. Consequently, distribution patterns of carbon, nutrients and hydrochemical parameters are significant difference among four seasons in the Kaoping coastal zone. Distributions of DOM (dissolved organic matter), POM (particulate organic matter) and nutrients in the Kaoping coastal zone show that the highest concentration is generally found in the area close to the Kaoping estuary, and the concentration decreases with the distance away from the land. The riverine fluxes also affect the ratios of DOC/TOC and £GPOC/£GPN in the coastal zone. The characteristics of DIN and DIP distributions and their ratios imply that the primary productivity may be largely limited by nitrogen (DIN < 1£gM¡AN/P < 10) rather than phosphorus (DIP < 0.2£gM¡AN/P < 30) in the Kaoping coastal zone. The occurring probability of nitrogen limitation varies from season to season during the study period, roughly ranging from 4% to 42% (winter, summer > spring, autumn). The GP (gross production) ranges from 708-19819 mg C m-2 d-1 in spring, from 2451-16230 mg C m-2 d-1 in summer, and from 844-5549 mg C m-2 d-1 in winter. The DCR (dark community respiration) ranges from 970-6284 mg C m-2 d-1 in spring, from 861-12418 mg C m-2 d-1 in summer, and from 997-5781 mg C m-2 d-1 in winter. Both GP and DCR display the highest value in summer, indicating the significant influence of terrigenous fluxes on biological production and respiration during summer. Meanwhile, correlations are significantly positive between GP (DCR) and temperature and nutrients, but significantly negative between GP (DCR) and salinity, also indicating the impacts of terrigenous inputs on GP and DCR. In the Kaoping coastal zone, the BCD (bacterial carbon demand) is about 15% GP and 64% GP, respectively, in winter and summer, inplying that the contribution of GP to BCD is more important in winter than in summer. Judging from the ratio of GP/DCR in different seasons and sampling stations, we conclude that the study area near the Kaoping estuary is likely to be autotrophic throughout the study period, the other stations are also likely to be autotrophic during summer. Nevertheless, the offshore stations appear to be heterotrophic during the winter season.
5

Spatial and temporal distribution of Thaliacea in relation to water masses in the Kaoping coastal waters, southweatern Taiwan.

Sun, Zhi-Hua 29 August 2003 (has links)
Abstract The species composition, distribution and generations of the thaliacea in relation to the sea surface temperature, salinity and chlorophyll a were studied in the Koaping coastal waters, southwestern Taiwan, from June 2001 to October 2002. In all, 16 species of the thaliacea belonging to 3 families and 11 genera were identified. Among these, Doliolum denticulatum was the most dominant species and comprised 62.2% of the numerical total of thaliacea, other common species including: Thalia orientalis (22.8%), Thalia democratica (7.5%), Thalia rhomboids (2.4%) and Dolioliletta gegenbauri (2.3%). The mean numerical abundance of thaliacea was 690.6 1601.4 ind./100m3. Most species showed apparently seasonal changes, with the highest abundance in March 2002 and the lowest was in November 2001. Higher abundances of thaliacea were generally found in the 100m oblique tows when compared with the surface tows, except in March and October 2002 that bulk abundances were found in the surface waters. The variation of thaliacean species composition and abundance among stations and mouths was larger in 2002 than in 2001. Higher similarity in community structure of thaliacea was found between August and November 2001, while larger variations among stations were found in March and July 2002. In general, the abundance of thaliacea species showed significantly negative correlation with water temperature but significantly positive correlations with salinity and chlorophyll a. Blastozooid(phorozooids and gonozooids) of the Doliolum denticulatum and Dolioletta gegenburia dominated in the study area and comprised 99.2% of total doliolids. Blastozooid(gonozooids) was also dominated in Salpida species and comprised 84.3% of total Salpida, except Thalia rhomboids that blastozooid occupied only 40.1%.
6

Seasonal distribution of chaetognaths in relation to environmental factors in Tamshui and Kaoping estuaries and adjacent costal waters

Chen, Wei-shi 04 September 2004 (has links)
Seventeen species of chaetognaths belonging to nine genera and three families were recognized from the samples collected in estuaries of Tamshui River and Kaoping River from February 2003 to November 2003. In Tamshui River estuary, eleven species belonging to eight genera and three families were recorded, with the mean abundance of 807 ¡Ó 1154 ind./100m3, while in Kaoping River estuary, fourteen species belonging to nine genera and three families were identified, with the mean abundance of 1601 ¡Ó 2796 ind./100m3. The three most dominant species in both estuaries were Flaccisagitta enflata, Aidanosagitta crassa and A. neglecta, and together they comprised ¡Ö95¢Mof the total chaetognaths. The abundance of chaetognaths showed apparent seasonal changes, higher abundance in February in Tamshui River estuary and in May in Kaoping River estuary. The abundance of chaetognaths showed no significant correlation with temperature in both estuaries, but displayed higher relationships to salinity and copepods. The body length¡]BL¡^ of Flaccisagitta enflata showed significant seasonal and spatial differences, with larger in both February and May in Tamshui River estuary but only in May in Kaoping River estuary. Aidanosagitta crassa showed significantly larger in BL in February than in other months in Tamshui River estuary, but it was not in Kaoping River estuary. The stage I of chaetognaths dominated in this study area and occupied ¡Ö80¢Mof the total count. Other stages mostly presented in February in Tamshui River estuary and in May in Kaoping River estuary. Only Fl. enflata was found to have gut content, all copepods, in February and May. The estimated daily predation impact on the standing stock of copepods ( by number ) was insignificant, only ¡Õ1¢H in both estuaries.
7

Denudation and Transport of Terrestrial Materials from the Kaoping River Watershed

Yang, Jang-Yi 13 September 2001 (has links)
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.
8

Temporal and spatial distribution of Chaetognaths in relation to environmental factors in Kaoping coastal waters, southwestern Taiwan

Wang, Shih-Hung 13 August 2003 (has links)
Abstract The species composition, abundance, body lengths and stages of chaetognaths in relation to environmental factors at nine stations in Kaoping coastal waters were investigated during June 2001 to March 2002. In the surface tows, 20 species of chaetognaths, belonging to 10 families and 4 orders, were found, with the mean abundance of 17753 ¡Ó14593 ind./ 100m3. The 4 most dominant species, Flaccisagitta enflata, Aidanosagitta crassa, Sagitta bipuncata and Ferosagitta ferox, comprised > 80% of total chaetognaths. Flaccisagitta enflata was the most common and abundant species and occupied 53% of total chaetognaths. In 100m oblique tows, 21 species of chaetognaths, belonging to 11 families and 4 orders were found, with the mean abundance of 23535 ¡Ó 18696 ind./ 100m3. The 4 most dominant species were Flaccisagitta enflata, Aidanosagitta regularis, Serratosagitta pacifica and Aidanosagitta crassa, and comprised 77% of total chaetognths. Pseudosagitta lyra was the species found only in the 100m oblique tows. The abundance of chaetognaths changed with seasons and had the highest abundance in summer and the lowest in late autumn. The relation between abundance of chaetognaths showed significantly negative relationship with salinity but not for temperature, and had larger variation when salinity > 32 o/oo. Multi-Dimensional Scaling (MDS) method was used to elucidate the variation of chaetognaths community among seasons and stations. The community structure of chaetognaths had somewhat difference among seasons, with higher similarity between August and November, but these two months showed apparently different from June and March. The variation of chaetognaths community among stations was different seasonally, with higher in August and lower in March and June. Furthermore, three species groups were distinguished and their distribution patterns were herein disscussed. The Stage¢¹of chaetognaths dominated in this study area and occupied > 70 % of total count, and the number decreased rapidly following the developmental stages. The most dominant species, Flaccisagitta enflata, was also dominated by stage¢¹throughout the year, implied it might breed in the whole year. The body length of chaetognaths increased apparently with increasing of developmental stages, but overlapped among stages due to the wider variation in each stage.
9

Geochemistry of Major and Trace Elements in the Kaoping River:Weathering and Human Influences.

Lai, I-Chen 14 August 2003 (has links)
Abstract This study aims to understand the influence of weathering and human perturbation on spatial and temporal variability of major and trace element distributions in the Kaoping River basin. The collected data are used to elucidate the production, transport and export of major and trace elements from the Kaoping River basin. Experimental results show that the weathering index of the Kaoping River basin is rather high. The significant loss of major ions and enrichment of iron and aluminum from river suspended matter indicate the characteristic of high weathering rate in most tropical rivers. Particulate Si/Al mole ratios range from 1 to 2 showing that the distributions of dissolved and particulate matter are largely controlled by the weathering process of kaolinite and /or smectite formation. During the study period (2002), the physical and chemical weathering rates were estimated about 655.8 and 416.2 g/m2/yr, respectively. Both physical and chemical weathering rates are much lower than those estimated by Yang (2001) during the period of 1999-2000 [3601 g/m2/yr (physical weathering rate), 1146 g/m2/yr (chemical weathering rate)], due to significant difference in river discharge. However, the estimated physical and chemical weathering rates are still much higher than the world averages of physical (150 g/m2/yr) and chemical (33-40 g/m2/yr) weathering rates. The marked difference between this and Yang¡¦s estimates is caused from large difference in river discharge. Silicate weathering was estimated about 97.09 ¡Ó 2.41% of total chemical weathering in the Kaoping River basin. The temporal variations of enrichment factor (EF) for most particulate trace metals (Mn, Zn, Cu, Cr, Pb, Cd, and Hg) reveal a greater pollution status in the dry season than in the wet season. Spatial variations of EF also reveal a greater pollution in the downstream zone than in the upstream zone. Time-series observation showed that concentrations of particulate trace elements were inversely correlated with discharge. The significant correlation between the fluxes of dissolved and particulate trace elements and discharge suggesting that river discharge controlled largely the fluxes of major and trace elements. The annual variations of elemental fluxes were determined critically by the annual difference of river discharge. The distributions of particulate organic carbon (POC) and particulate nitrogen (PN) were similar between suspended matter in the Kaoping River and surface sediments in the Kaoping Canyon. The data of £_13Corg show that about 77.2% of organic matter derived from the Kaoping River basin deposit in the Kaoping Canyon. The Kaoping Canyon appears to play an important role on the transport and deposition of organic matter from the Kaoping River basin.
10

Numerical simulation of topography and stratification effects to the internal tide in Gaoping Submarine Canyon

Lee, Ying-Tsao 10 September 2009 (has links)
It is generally understood that tidal currents ominated the flow field in many submarine canyons, and internal tide may be an order of magnitude more energetic than that of barotropic. The internal tide can be generated and amplified in a marine environment with the strong vertical density interface. The barotropic tides were known to play the dominant role in driving the internal tides at the topographic relief or shelf break.This research tries to look at the mechanisms of internal tides generation and propagation in the Kaoping Submarine Canyon off southwestern Taiwan, using Princeton Ocean Model (POM) with different settings. The model was tested with bottom topography of flat, a slope and real water depth, with and without vertical stratifications. The model settings are grid size 500m, simulate period days, radiation boundary condition at 4 sides. The model forcings are sea level variations at the west side, both semidiurnal tide (M2) and mixed tide (M2+K1) based on OSU tidal model TPXO 6.2. The results suggest that the offshore M2 tidal forcing can generate large internal tidal currents within the canyon with vertical density stratification. The internal tidal currents at the upper-layer of the canyon lag that of lower-layer 3~5 hours. There is no time lag and no amplification of current in the canyon if there is no stratification. There is a transition zone of minimum flow at depth of about 100-200m. Below the interface, the amplitude of semidiurnal internal tidal current increased with water depth in the canyon. The simulated density contours suggest a 120m amplitude vertical fluctuation center at 150m depth, with 5¢J temperature fluctuation. The computed baroclinic energy flux indicates that the energy in lower layer of the canyon is stronger than that of upper layer. The high energy flux appears at the canyon foot and rim, and propagates along the canyon axis landward.

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