This research is based on the plan and design of Datang constructed wetland as a storm water wetland system. Qantity of the discharges from Datan community drainage system including its branches surround Dapeng Bay National Scenic Area are estimated. The objectives of this research is to study the possibilities of using the concept of stormwater wetland system for including the Datan constructed wetland and Lin-Bian right-bank wetland as flood detention wetland system and treatment wetlands during the dry season. Generally, flood detention ponds are not functioning except during storm seasons. Rainfall are mostly concentrated from June to September in southern Taiwan (mainly due to southwest monsoon and typhoon), the Datan wetland has therefore planned to treat the domestic sewages and the disposal from aquaculture farms during the dry season, and first flushing drainage during storm season. Besides the flood detention volume, Datan wetland has been designed into four major sections, a) primary settling for settle part of the suspended particles and aeration; b) bio-filtration through 2 sets of bio-filter using crushed bricks and oyster shells as filter media, mainly designed for BOD removal and partly early denitrification; c) followed by shallow weeds pond for reaeration and nutrients uptake by plantation; d) entering a series of open water ponds for stabilization. Landscape has been take good care for recreative function and habitat reserved for variety of birds. Due to the flood detention function will flood the basin few times a year, variable depth environment and plantations are designed. Wetland maintains ordinary water level at EL=-1.1m, maximum flood detention can go as high as EL=+1.5m. The wetland has effective surface approximately 5.5 ha., maximum flood detention quantity approximately 130,000 cubic meters. Since the area is tidally affected, influents contain different levels of salinities. Plantation becomes a difficult issue for the Datan wetland, due to the saline waters. Mangrove is the best choice, so far, for this situation. The mangrove forest has the richest productivity on wetland ecosystem, and can carry on the physical biology multistage degeneration to the sewage and absorb various pollutants. Hydraulic analysis estimates the peak discharge of Datan drainage system¡¦s 10 year flood frequency is 20.17cms, Datan constructed wetland and Linbian right bank constructed wetland can reduces the peak rate of 8.06cms and 4.38 cms, respectively. In addition, most of the branches of the Datan drainage system are thus achieve the ten year return period bench mark from the HEC-RAS evaluation The water quality monitoring results after one month of operation have shown the average elimination rates, TOC=-10%, BOD5=53%, TKN=71%, NH3-N=88%, NO3-N=65, NO2-N=90%, TN=70%, TP=52%, OP=56%, Chl.a=-61%, SS=4%, the turbidity (NTU)=70%. BOD and nutrients are shown effective reductions, while the SS and the chlorophyll-a are correlated mainly due to the plankton growth in the open waters. Long-term monitoring is continuing for the evaluation of the water quality purification function and the operational management model.

<p> In the past decade, sites of hydrothermal activity along the Juan de Fuca Ridge have gained a growing amount of attention. Increased sampling has provided the materials for more detailed studies, including those collected from Axial Seamount, a large shield volcano on the central portion of the ridge. Axial Seamount is host to at least three active vent sites, one of which, along the northwest caldera wall, consists of recently active eruptive-fissures and nearby chimney-like spires. A sampled spire from this location and samples from other vent areas are described using reflected and transmitted light techniques. They have been found to consist of the sulphide phases sphalerite, wurtzite, pyrite, marcasite, chalcopyrite, isocubanite, and galena. Jordanite and tetrahedrite-tennanite are also known to precipitate at these vent sites, but were not observed here. The most dominant non-sulphide minerals are amorphous silica and barite. Native sulfur, Fe and Mn oxides and a variety of sulfosalts may also be present. The complex textures in these samples reflect precipitation and growth from higher temperature fluids that are mixing with local ambient seawater. Fluid inclusions in sphalerite have revealed salinities in the 5.6 to 7.0 weight % NaCl range, with homogenization temperatures ranging from 214.8°C to 269.4°C. Temperatures of homogenization require pressure-corrections between approximately 9.0°C and 13.0°C, to set-up a range of trapping temperatures that lie between 211.8°C and 279.4°C. Fluid inclusions are also found in wurtzite, barite, and amorphous silica however, these would yield no data. Middle Valley is a sedimented rift valley that lies at the extreme north end of the Juan de Fuca Ridge. A number of hydrothermal sulphide mounds that lie atop the sediment pile have been sampled. The mineralogy is similar to that at Axial Seamount; however, the dominant sulphide phase at Middle Valley is pyrrhotite. Textural differences between the two sites are significant, a result of the traversing of hydrothermal fluids through a thick package of hemepelagic sediment at Middle Valley. Samples from Middle Valley are found to contain no measurable fluid inclusions in the sections available for study. Mineralogical and fluid inclusion studies are important methods that can be used to help solve the complex growth history of sulfides that are and have been accumulating at mid-ocean ridge vent sites.</p> / Thesis / Bachelor of Science (BSc)