| Summary: | 碩士 === 國立中興大學 === 水土保持學系所 === 96 === In past, two parameters which safety and conveyance were considered while canals improved of agricultural enterprises. As a result of ecological conservation value is getting more and more attention on it. The trend in the future of canals improved is that reach the ecological conservation with keeping original irrigation, drainage and safety functions According that reason, Huludam main canal was used been an large-scale target in this research, and further discussion by the way investigation. Finally, we expect the result will be a follow-up deliberate for canals improved.
Huludam main canal of Tai-chung Irrigation Association is used as an object of this research. Five ecological sites had chosen as follows with investigation monthly: vertical RC revetments, the upstream and downstream of stone-paved grounsill, boulder revetments, still water zone etc. The principal organisms of investigation were fishes and crusts (shrimps and crabs). The environment investigations were keeping with it in the meantime, these environment parameters includes velocity, water depth that simulated by HEC-RAS model; water quality parameters were includes DO, water temperature, EC, pH, SS and NH3- etc. To discuss the distribution of organism resources in Huludam main canal, biodiversity index (species richness, species abundance, and evenness) and IBI index were used in this research.
The results of water quality in the duration of 2007.10 to 2008.04 shows that pH was neutral and alkalinity slightly, EC was about 200~250 μs/cm; DO almost above 7.0 mg/L except 4.1 mg/L occurred in March 2008; NH3- was 0~0.46 mg/L; SS was about 3.0~7.8 mg/L except 22.8 mg/L occurred in November 2007, the water quality of Huludum main canal was good. The results of organisms investigation shows that the species amount was 11 of fishes, shrimps and crabs were both only one species. According to the amount, Acrossocheilus paradoxus was the dominant species and the second species was Pseudorasbora parva. IBI index was used to evaluate the habitat quality of Huludum main canal, the result of IBI was13-25, it means that the habitat quality of Huludum main canal was in the degree of slightly impaired to severely impaired, it also shows that the influence of varied temperatures on habitat quality.
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