碩士 / 國立臺灣大學 / 生物環境系統工程學系暨研究所 / 92 / The Hsintien Stream is one of the major branches of the Danshuei River system, which runs through the metropolitan capital city of Taipei and receives large amount of wastewater. The dissolved oxygen is generally low in the tidal portion of the Hsintien Stream. Hypoxia/anoxia occurs often, particularly during the low flow period when the Feitsui Reservoir, Chingtan Dam and Chihtan Dam impound the freshwater for municipal water supply. Fish kills happen from time to time.
The purpose of this study is to apply a numerical hydrodynamic and water quality model to the Danshuei River, with special attention to the tidal portion of the Hsintien Stream. The model is calibrated with the prototype conditions of the year 2000. The hydrodynamic portion of the model is recalibrated with measured surface elevation and velocity at various stations in the river system. The water quality portion of the model is calibrated with respect to the field data provided by Taiwan EPA. We also estimate the related input data of point and nonpoint sources. The model can simulate the concentrations of various forms of nutrients, CBOD and dissolved oxygen.
In this study, we use the design monthly flow of Q90 and Q75 to demonstrate that the low flow does result in low DO conditions endangering the fish survival. The model simulation results suggest that the conditions may be mitigated by the combination of pollutant reduction and flow augmentation. If the point source loading is reduced by 75%, then the maintenance of Q75 flow in the Hsintien Stream will ensure DO higher than 1 mg/L. The Feitsui Reservoir, Chingtan Dam and Chihtan Dam may impound water during the flood periods and release some to maintain Q75 flow in Hsintien Stream during the drought periods.
| Identifer | oai:union.ndltd.org:TW/092NTU00404008 |
| Date | January 2004 |
| Creators | Liu, Shin-Yi, 劉欣宜 |
| Contributors | Ming-Hsi Hsu, 許銘熙 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 114 |
Page generated in 0.0022 seconds