碩士 / 國立臺灣大學 / 土木工程學研究所 / 92 / Generally, flooding period is the most important time to be considered in the aspect of engineering designs. But in terms of habitats (for example: pool, riffle, run), flow conditions under normal discharge period are more important for the habitat of aquatic species.
In this study, by selecting Gobioidi, Cyprinidae and Homalopteridae as the indicator species, the change of fish habitat in two different kinds of period (flooding & normal discharge period) and the hydraulic diversity in the normal discharge period are discussed.
In addition, the changes of different types of habitats with time and the influences of tides are also analyzed.
A quasi-two-dimensional model, NETSTARS, and a horizontal two-dimensional model, TABS-2, were employed to simulate the hydraulic characteristics of the Lanyang Estuary in the presence and absence of the constructed spur dikes. Both fixed-bed and mobile-bed conditions were investigated.
In the flooding period, installing spur dikes will increase the slow-velocity area that can enlarge the hide area for fish. The effects of sediment transport in the mobile case show that increased sediment deposition would reduce fish habitat area, a finding that is integral to effective long-term habitat management.
On the other hand, the results in the normal discharge period show the fish habitat area will increase without the build of spur dikes. If the flooding risks are not taken into account, the simulation provided the fish habitat area will expand with the less number and the shorter length of spur dikes. But installing spur dikes will increase the hydraulic diversity.
Key words：numerical model, spur dikes, WUA, fish habitat improvement
| Identifer | oai:union.ndltd.org:TW/092NTU05015096 |
| Date | January 2004 |
| Creators | Hui-Ling Yu, 游蕙綾 |
| Contributors | 李鴻源 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 111 |
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