碩士 / 國立中興大學 / 水土保持學系所 / 94 / In Taiwan, recent researches have developed several types of fishways. The Endemic Species Research Institute has been conducted experiment on indigenous fish with various types of fishways since 1998. It has been proved that the fish-bone-type fishways are suitable for the migration of all fish species in Taiwan. However, the water current tends to flow turbulently on the fish-bone-type fishways. Accordingly, in an attempt to stabilize the water current, to make fish migration easy, and to help shrimp to crawl over the check dams to upstream to breed, it is considered to add a porosity filtering on the main body of fishway (hereuinafter referred as improved fish-bone-type fishway).
In an attempt to find out the best location of fish-bone-type fishways and their function of providing migration channel for aquatic animals, and to offer some referential statistics for the design of the check dams attached with fishways in Taiwan, this research aims to explore a way to improving the turbulent current condition on the fish-bone-type fishways and to discussr the possibilities of the migration for fish and crustaceans. The improved fish-bone-type fishway adopts three flow rates in the hydraulic experiment—0.016cms, 0.032cms, and 0.048cms. In the sediment transport test, the tested flow rates are 0.032cms and 0.048cms. Two average granule diameters of adding sediment are 9.27mm and 10.77mm. The total experimental time is 200 minutes, with 100 minutes for adding sediment and another 100 minutes for water cleaning. In the test of fish migration, the goal is to find out the migration rate of 30 Zacco Pachycephalus within 3 hours, with the flow rates at 0.016cms and 0.032cms. In the test of shrimp migration, the flow rate is 0.001cms with thin layer current.
Several findings have been found in this research. In the aspect of hydraulic experiment, the water level in the improved fish-bone-type fishways is higher than that in the original one; however, the water flow in the former is less than that in the latter. This finding shows that porosity filtering can effectively improve the current condition. In the aspect of sediment test, sediment in the improved fish-bone-type fishways can reach to a balance of transporting in 30 minutes, the rate of sediment removal is above 97/%, and the residual sediment is below 3%. The test indicates that the adoption of porosity filtering has no effect on the rate of sediment removal. In the aspect of fish migration experiment, the migration rate of the tested Zacco Pachycephalus can reach over 73% during the experimental time, which is higher than that in the original fishways. The result suggests that the improved fish-bone-type fishway is more suitable for fish migration. In the aspect of shrimp migration test, the finding reports that shrimp would use the porosity filtering to crawl towards upstream when the flow rate is at 0.001cms, and do so on the bottom of the fishway when the flow is even less. With all the results, this research finds that the improved fish-bone-type fishways have great effects on the reduction of flow velocity, on the current stabilization, on the increase of sediment removal, and on the migration of fish and crustaceans. Moreover, the improved fish-bone-type fishways are more suitable to be applied to the check dams on the rivers in Taiwan
| Identifer | oai:union.ndltd.org:TW/094NCHU5080013 |
| Date | January 2006 |
| Creators | Cheng-Shang Hung, 洪正賢 |
| Contributors | 陳樹群 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 97 |
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