圖書典藏及影音數位平台

士文水庫規劃興建於率芒溪支流士文溪上，計畫日供水量約20萬噸，可滿足屏東地區目標年民國120年需水量缺口，並可取代屏東地區地下水源之使用，及減緩地盤下陷、提升用水水質、提高屏東地區自來水普及率等目標。本所近年辦理士文水庫水砂調查相關計畫，並業於民國101年完成自記式水位站建置。為取得寶貴水砂資料，延續歷年水位流量監測成果，應持續進行水位站觀測維護，並蒐集莫拉克後率芒溪及其支流土砂環境變遷等相關資料。故本計畫辦理率芒溪流域相關之產砂評估、河道輸砂分析及對策研擬等，以期建立率芒溪流域完整之水砂環境資料，更新及補充水庫規劃重要參數，利於士文水庫後續規劃及推動。

1.Introduction The Shi-Wen reservoir planned to be built on the tributary of Shuai-Mang Creek named Shi-Wen Creek. The planned daily water supply amount is 200 thousand ton, which is enough for Pingtung area until 2031, and can replace the use of groundwater in that area even ease up land subsidence, increase water quality and the penetration rate of piped water. To acquire the water and sediment data, it is needed to maintain the gauging station and collect the data of environment change in Shuai-Mang Creek and its tributaries after Typhoon Morakot to help the following planning of Shi-Wen reservoir. 2.The maintaining of gauging station and observation of water and sediment in Shi-Wen Creek Besides maintaining the gauging station, this project also set a new current-meter on the right side of Shi-Wen #3 bridge. The observation of Shi-Wen #3 bridge showed that the discharge was 0.20~1.45cms in the dry season, and increased to 18~50cms in the wet season. And this project also measured the discharge of Typhoon Fung-Wong on Shi-Wen bridge and measured the discharge of groundwater and the cross-section of Shi-Wen #3 bridge. 3.The analysis of sediment transport of the river basin This project combined the remote sensing technology and geographic information system to analyze the sediment amount of slope erosion and landslides. According to the results, the sediment transport amount was 844 thousand m3. In addition, this project also analyzed the existing landslides of the potential deep-seated landslides in reservoir area. The result showed that the existing landslides were on the toe of the slopes from 2010 to 2013, and the magnitude were not large. 4.The Simulation of Shuai-Mang Creek and the strategies suggested The 1D river bed simulation of this project was suggested to use the total sediment load equation of Yang’s, because it can display the same erosion and deposition trend in the same section, therefore, it is better than the sediement load equation of Ackers and White, and Meyer-Peter and Muller. According to the simulation results, the whole 6 bridges in this research area area higher than the stage of Q50 discharge. In the river section of Shi-Wen bridge to Shi-Wen #3 bridge, the estuary to Shi-Wen bridge and the upstream of Tsau-Shan Creek, it is needed to take care of the problems of slope toe erosion. 5.The reviews and suggestions of the Watershed Management and Strategy After reviewed of the past projects and the researches in this projects, we suggest the future projects should have more reseach of the subsurface flow. Besides, after a torrential rain event, it is better to have clear signs about closed roads and substitute roads, and even have rainfall warning. In addition, this projects had completed preliminary eco-checklist filling out, and recommend future projects to continue this work. 6.The situation analysis of the water and sediement environment of Shuai-Mang Creek river basin After the researched mentioned before, this project analyzed the situation of the water and sediement environment by separating the river as the upstream watershed, the submerge zone of the reservoir, and the downstream channel. These analyses involving the environment situation, the future environment prediction, the goals of the Watershed Management and the strategies.

本報告由經濟部水利署水利規劃試驗所主辦，逢甲大學執行，旨在進行士文溪水位站的觀測維護及流域水砂調查分析。計畫內容包含水位站設備的定期與不定期維護，以及平時與全洪程的水砂觀測。同時，也進行了流域產砂分析，包括衛星影像蒐集、崩塌地調查與土砂生產量估算。此外，報告還探討了河道沖淤模擬及對策研擬，並對集水區保育治理對策進行了檢討。最後，針對率芒溪流域的水砂環境情勢進行了分析。研究結果將有助於士文水庫的後續規劃與推動。