圖書典藏及影音數位平台

台灣位處板塊交界，地質結構破碎，且地勢陡峭，坡陡流急，河川由上游帶下來的土砂，成為海岸漂砂沙源主要提供來源之一，而河口與海岸漂砂機制，則影響沙灘的侵淤變化，同時也攸關位於沙灘後側的海岸防護設施安全。惟河口及海岸逐時漂砂觀測不易，且儀器損壞及遺失風險極高，以致資料量不足，無法深入探討漂砂運移機制及推估海岸地形變遷趨勢。 故本計畫將先探討國內外，有關河口及海岸漂砂觀測技術發展現況，依據台灣河川與出海口環境特性，研擬可行的河口及海岸漂砂觀測技術，建構作業化方式自動量測系統，有效觀測河川出海口附近各項資料，尤其是颱洪或豪大雨事件全洪程逐時漂砂資料。而漂沙觀測系統相關儀器、設備與系統，將先於試驗室內完成校驗率定工作，再選擇適宜河口海岸區域進行儀器布設與測試工作，驗證觀測系統的可行性。並透過數值模式，利用本系統觀測資料，探討案例區域漂砂運移機制及海岸地形變遷趨勢。

The purpose of this research project is to develop a technique to apply in the estuary and coastal area by integrating following instruments into a data buoy: Global Positioning System (GPS) of elevation measurement equipped with two high precision channel receiver, current meter, Time Domain Reflectometry (TDR). Through operational technique, the real-time measurements of wave, tidal elevation, current, and concentration of sediment will be transmitted to the server. The research project covers three years from 2015 to 2017. To achieve the purpose mentioned above, the main progress achieved in year 2015 include: (1) reviewing the development of sediment monitoring techniques in the estuary and coastal area to evaluate and select data buoy as the platform and instruments to observe wave, tidal elevation, current and sediment concentration in this project; (2) preparing the prototype of monitoring system with all the necessary instruments for installing into an data buoy, as well as the system test; (3) Calibrating for the wave meter, current meter, GPS, and the evaluation of accuracy TDR measurement; and (4) selecting the estuary of Kao-Ping River as the location for in-situ testing of the prototype data buoy for the next year. The pre-designated progress for the second year 2016 are (1) planning the procedure of deployment and retrieve of the prototype of monitoring system; (2) proceeding the in-situ test; (3) applying an numerical model for simulating hydrodynamic process of the designed estuary. The pre-designated progress for the third year 2017 are (1) confirming the design of the prototype of the monitoring system; (2) revising the procedure of deployment and retrieve of the prototype of monitoring system; (3) confirming in-situ measuring parameters and process; (4) discuss the mechanism of sediment transport and morphology for the designed estuary; (5) training courses. The observations obtained from the technique developed in this project are expected to provide the boundary condition at the estuary for the numerical model and Water Resource Agency (WRA) flooding monitoring system. Combining with the predicted rainfall from Central Weather Bureau (CWB), automatically water level and sediment measurements of the river administered by central government, these information is great helpful to numerical simulating the water elevation, velocity, and the variation of bed for the river, as well as the morphology changes in the estuary and the coastal area nearby. The observations of water elevation, wave, current and sediment concentration in real-time can benefit the WRA in the management of river and resolver. Either in evaluating the effect of hydraulic desilting of a resolver to the downstream in the river; or in flooding disaster assessment during the typhoon and rainstorm.