圖書典藏及影音數位平台

河川治理以往主要以防洪安全為功能，但於著重環境美化、生態保育及休閒遊憩之今日，整合美化區域環境，拓展民眾之生活空間，重視區域環境藍帶之美感與生命力，已是時勢所趨。因而在盡可能降低對河防安全的影響，確保防洪排水之基本目標下，尋求「治水」、「利水」、「親水」及「活水」之機能，並積極對河川流域空間多元化利用。 鱉溪位於花蓮縣境內，因昔日甲魚（鱉）蹤跡隨處可見而得名，其發源於海岸山脈，為秀姑巒溪上游長流性支流，主流沿山谷北流，並於富裏鄉石平橋附近匯入秀姑巒溪。主流長16.91 公里，流域面積47.96平方公里河道蜿蜒曲折，沿線散佈著大小不一的河谷平原，平原區面積合計約4.7 平方公里，佔全流域面積的10%左右。中上游坡度陡峭，週邊林相覆蓋良好，流域土地多屬於山坡地保留區。主流於石門附近進入花東縱谷平原，坡度減緩，河道型態轉為蜿蜒曲折，河幅也較寬。 鱉溪流域終年水量豐沛，水域生態十分豐富，有臺東間爬岩鰍、菊池氏細鯽、大吻?虎等臺灣東部原生魚種。然為滿足農業取水、土地利用，興建不少防砂壩、攔河堰、護岸工程，河道內棲地逐漸退化，鱉類與居民與河川之親密關係不再，且鑒於本流域前業已辦理相關生態調查及復育規劃等作業，為讓理論與實務結合爰辦理本計畫，期透過整體環境營造規劃與檢視，並擇約500公尺河段實際進行生態、景觀及環境營造工程，以實現生態復育，重建社區與鱉溪的日常連繫，削減河道內災害之目的。

This project has the main object to reach the sustainable environmental and ecological developments of the Bie River, hoping to reduce the flood hazard and also welly concerning the river ecological conservation and environmental rehabilitation requirement.The application of ecological engineering methodologies and environmental rehabilitations in river restoration can also fulfill different targets in terms of river sustainable development, natural resources protection and local people expects. Under the abovementioned philosophy, we will combine river restoration and ecological environment rehabilitation to create the safety, diversity, naturality, and water-recreation environment in the river. This project is implemented within two years and this year is the second year’s work. Based on the data collected from the relevant surveys and planning reports over the past years and the data collection and investigations from year 105 to year 106 of this project, fish species distribution is basically unaffected by the artificial structures inside the Bie River, however, the biological diversity is becoming weaker than it was before. The fish way constructed before was mostly destroyed to become useless, this project will thus recommend to improve the river barrage weir configuration and to reconstruct some fish ways to increase the fish species diversity. The habitat environment in the river water bank areas suitable for softshell turtle breeding are basically uninterrupted and there is no damaging factors under the current natural environment also. By increasing quantity of natural rocks and concrete roughness of the water bank will be able to create more river alga resource for fish food. In addition, the major damage factor of softshell turtle comes from human fishing, and education of ecological protection concept shall thus be enhanced. In according with our site investigation and oral communication with the local people, the river natural environment variations caused by artificial engineering works and continuing human fishing in the past cause the main reasons to damage the quantity of softshell turtle. This year, we conducted dry and wet supplementary ecological surveys on the left bank of the downstream of Wen-zi-dong Bridge and the environmental rehabilitation areas on the left bank of Feng-nan community. Mainly for the re-education of the indicator species and key demonstration areas choose to collect environmental and ecological information, on the whole, this year in the waters of ecological species and quantity of the survey results, and the previous survey is not very different. With an area of 47.96 Km2 and a mainstream flow length of 16.91 Km, the flow-making time of the Bie river is short, and the river banks of the two sides have been built into paddy fields. After the torrential rains, the flow of the river suddenly increased and the water quickly returned after the rain stopped. The correlation is not high, but it shows a very significant positive correlation with the change of precipitation in the river.The estimated flow from the 5th bridge to the Fuchi bridge is about 0.026 ~ 0.061cms. The measured flow in this project is the lowest in June, but it is still much higher than the above-mentioned river flow. In order to ensure the ecological environment of rivers in the entire reach of the river, it is not recommended to completely cut off the main flow at the diversion port of irrigation channels and divert flow of at least 0.039cms back into the river. As per the ecological characteristics of migratory fishes, this project develop some optional schemes to mitigate the river barrage weir affection. Three environmental rehabilitation sites are selected, they are Feng-nan Community Site (Chi-feng Bridge to Ji-la-mi-dai River Check Dam), Left High River Bank at downstream of Wen-zi-dong Bridge and the Right High River Bank at at downstream of Yong-feng Bridge. Different rehabilitation objects are adopted to develop different feasible schemes and the best option is selected. Also, at areas nearby the community, a proper ecological observation and experience activities along with some water-recreational facilities are integrated together to increase the natural environmental and ecological value of the Bie River. In order to maintain the ecological environment of Bie river, it is proposed that a 5-year pilot project of protecting the fisheries in this area should be carried out from below the Si Wei Bridge to above Fuxing Bridge so as to protect and conserve the diversified and rich ecological species in Bie river , And consider the Fengnan community is a tribe of Jiramiti, with its traditional aboriginal fishing culture, open fishing in part of the summer every year. In terms of overall project implementation, this project recommends to apply the coming annual budget of Water Resources Agency of Economic Affair and proceeds the two most feasible and effective demonstration projects at Feng-nan Community and Wen-zi-dong sites mentioned above. Whereas in some river bank areas adjacent to the public property, it is proposed to adopt certain environmental measures to cultivate and reduce the embankment slope so as to improve its landscape image, which can then be gradually connected with the planning and implementation of the subsequent hydrophilic recreation networks nearby. In the river longitudinal corridor, building fish ladders at the barrage weirs of 02-A, 14-A, 20-A, 29-A, and 46-A are proposed, and the related engineering design includes cement-rubble masonry work, precast concrete block, gabion protection work, and a double layers geotextile. These projects can be combined with the annual river restoration works after the natural flood disaster in certain years or implement formally as the second engineering phase by applying the related budgets.