圖書典藏及影音數位平台

以往相關計畫於計畫期間（民國97年至106年）進行15場颱風之全洪程觀測，完整地掌握入庫泥砂量與過庫泥砂量，以及異重流之運移特性，提供水庫防淤操作之即時資訊、水工模型與數值模擬分析所需輸入與率定資料以及全洪程之泥砂運移行為。由於經驗模式之建立需要累積較多不同規模颱洪事件之觀測資料，且水庫防淤工程建置完成後之減淤操作需要可靠之泥砂觀測資料回饋。因此擬續辦石門水庫之全洪程泥砂運移觀測，累積不同颱洪事件全洪程觀測資料，並配合研擬中之防洪防淤方案位置，改善既有之異重流自動化監測系統，使其達到足夠之空間變化資訊及符合操作運轉所需之準確度與穩定性，並逐步降低全洪程觀測所需之人力。本計畫執行期間自決標日次日(如決標日早於民國107年1月15日則以1月15日為履約起始日)起至民國107年12月15日止。包括入庫羅浮測站岸壁與觀測樁觀測站系統維護、庫區浮台TDR自動化觀測浮台維護、壩頂分層觀測系統、下游各排水口人工測站及自動化觀測系統維護，以及颱洪期間全洪程入庫與出庫泥砂濃度之人工觀測與自動化量測分析等工作。

This project performed ongoing maintenance on long-term monitoring platforms of Shihmen Reservoir to monitor the sediment transport based on former related projects ‘Study of Shihmen Reservoir Water and Sediment Transport Monitoring, and the Development and Application of Density Current Simulation Model’ (2007-2011) and ‘Shihmen Reservoir Long-term Monitoring Project and Desilting Operation Simulation Analysis’(2012-2013) and ‘Sediment Transport Monitoring Facility Maintenance and Flood Event Observations in Shihmen Reservoir’(2014-2015) and ‘Reservoir Sediment Transport Monitoring Technique Development and In-situ Testing Evaluation – A Case Study of Shihmen Reservoir’(2016). This project attained the automated monitoring of sediment transportation in reservoir and real-time data transmission system, in order to instantaneously master the crucial information of sediment transport and density current in reservoir during floods, providing guidelines to the reservoir management operation on water supply, flood control and desiltation. In addition to automated monitoring, this project conducted manual observation on sediment transport during flood events to identify historical hourly reservoir sediment load and reservoir outlet sediment discharge, and also the transport characteristics of density flow in the reservoir region. Current state and silting prevention of the reservoir are hence quantifiable according to these manual measurements, which are used to evaluate the performance of the planning and design on reservoir desiltation operation enhancement. As the extension of previous sediment transport observation operation, this project continued to maintain and improve existing manual and automated monitoring stations, including the hardware maintenance of automated monitoring platform and probe replacement, function enhancement of upstream monitoring station and outlet discharge pipelines at downstream stations. Upgrading of new embedded system, renewal of backup power supplies (12V sealed batteries) and replacement of data transmission method from GPRS to 3G wireless system are performed at all TDR SSC platform monitoring stations. LoRa wireless transmission has also been evaluated for potential backup plan to current data transmission method. Up to current project execution date, the manual monitoring and automated TDR monitoring of sediment transport in reservoir over the flooding periods was performed during typhoon NESAT. This project performed sediment transport monitoring during flood events with both manual observation and automated TDR measurement operation in typhoon events of Typhoon Nepartak, Malakas, and Megi.After the commissioning of desilting tunnel since 2013, the sediment discharge ratio increased to 35% in Typhoon Soulik (2013), 37.2% in Typhoon Trami (2013), 36% in Typhoon Soudelor (2015), 32.6% in Typhoon Dujuan (2015) and 20.9% in Typhoon Megi(2016). Based on observational data from 2008 to 2018, there are three main conditons for density current formation in Shihmen Reservoir: 1.Peak inflow is greater than 1,800 cms. 2.Peak sediment concentration load (ppm) is greater than 17,500 ppm. 3.Inflow load of Q > 300 cms sustained for more than 35 hours.