摘要详情
204 / 2024-02-27 18:03:25
Vegetation management to improve the environment of rock-ramp-type fishway while considering biodiversity
Vegetation management,rock-ramp-type fishway,biodiversity
摘要录用
The fishway at the Miyanaka Intake Dam was built more than 80 years ago and is 134 km from the mouth of the Shinano River. It was renovated in 2012, considering its usefulness as a habitat and passage for bottom-dwelling fish and small fish with weak swimming abilities. A rock-ramp-type fishway that was added as the third fishway in the fishway group, was different from other fishways being made of only concrete, and had the characteristic of having a cobblestone bottom and stagnation around it. The fishways are occasionally submerged by floods, leading to sediment deposition and the creation of new vegetation. Additionally, the vegetation changes owing to the influx of seeds from the upstream and surrounding areas. Important plants that were previously not found near the fishways were identified after the largest flood in 2019. The rock-ramp-type fishway currently has overgrown vegetation. The thick vegetation blocks the main flow and pool areas, and causes poor visibility from the fishway observation deck, raising concerns about the maintenance of the vegetation. In this study, we divided rock-ramp-type fishway into four areas and clarified the vegetation transition in 2012. Specifically, we calculated the number of plant types and measured the areas inhabited by plants. A correlation was found between the results of the fishing catch survey and the vegetation during the same period. Based on these results, we provide suggestions on steadily operating a rock-ramp-type fishway while devising and improving specific management methods. Changes in vegetation, such as an increase in upright vegetation and a decrease in flow-blocking vegetation, could contribute to an increase in the abundance of bottom-dwelling fish, weak swimmers, and juvenile fish. However, predicting and managing vegetation in rock-ramp-type fishway is difficult because of the disruption caused by river-specific flooding and the influx of seeds scattered into the water from upstream and surrounding areas. Maintaining fish corridors for a variety of fish species through the presence and management of appropriate vegetation is essential for the conservation of natural capital and biodiversity.
重要日期
-
会议日期
10月14日
2024
至10月17日
2024
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09月30日 2024
初稿截稿日期
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10月17日 2024
注册截止日期
主办单位
国际水利与环境工程学会亚太地区分会
承办单位
长江水利委员会长江科学院
四川大学
四川大学
联系方式
- Congress Secretariat
- se******@iahr-apd2024.com
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