碩士 / 國立臺灣大學 / 環境工程學研究所 / 92 / Water quality in reservoirs is an important issue of concern interms of water supply nowadays. Abnormally high amount of phytoplankton in water, is one of the causes of water quality deterioration. Concentration of phytoplankton may increase greatly in a short period of time once the conditions in water are suitable for its growth. Light, temperature, nutrients and mixing conditions are key factors controlling algae growth. How they affect the growth of phytoplankton was studied by the method of dynamic modeling in this study. A conceptual stratified system was established to mimic the reservoir water column which showed gradients of environmental factors. Modeling tool, STELLA, was utilized to simulate the variation of the total volume of phytoplankton, and the volume of each of the three algal groups. Field data were collected in the surface water near the dam in Feitsui Reservoir. Data in 2001 were used for calibration and data in 2000, 2002 and 2003 were used for validation.
Calibration of the dynamic model was successful but the validation of the model was not satisfying. The results of sensitivity analyses are helpful to the understanding of the relationship between algae growth and the environmental factors. One of the sensitive factors is phosphorus supply, a process controlled by mixing and the concentration underneath the euphotic layer. Due to the lack of field investigation and available data, poorly calibrated mixing coefficient might account for the unsuccessful validation. There was co-existence of three different algal species under non-steady state condition and competitive exclusion was not necessarily to happen. The analyses of the stratified model and the completely mixing model indicate that the variation on time and space may help to the co-existence of multible species. This may be one of the reasons why biodiversity is maintained in the real world.
To improve the simulation results, different approaches of segmentation of the water column as well as the experiments to investigate the influences of growth parameters of phytoplankton under non-steady state deserve a try in the future.
| Identifer | oai:union.ndltd.org:TW/092NTU05515014 |
| Date | January 2004 |
| Creators | Ming-Yu Lin, 林明郁 |
| Contributors | Shian-Chee Wu, 吳先琪 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 121 |
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