圖書典藏及影音數位平台

海堤前的水域屬海水與工程結構物交界且交互作用的區域，水文條件極為複雜。此一區域也是防汛期間的溢淹預警與防治的關鍵區域。複雜的自然環境因素致使此一區域的水文環境調查以及治水工作相對更為困難。檢討現有海域調查技術之適用範圍，當前長期作業化近海水文觀測技術主要都是使用在超過5m水深之海域，然而本署所管轄之堤前水域僅至水深5m或是海堤堤肩線向外150m處，為免除觀測人之作業風險，仍需持續發展海堤堤前水域非接觸式觀測新興技術以及透過數值模式技術解析海堤前的水理特徵，藉此整合現有近海水文觀測技術，並透過更完整的資料來評估海堤之安全性與可能的淹水潛勢，發揮水文觀測資料應有之價值。本計畫之工作內容將聚焦於海堤前水域非接觸式觀測技術以及近岸波浪於海堤上溯升越波預測技術之開發，以期能夠更有效地掌握該地區最直接的水文環境特徵，藉以提供本署進行更縝密的海堤後方溢淹預警與海堤構造物維護管理等工作。

The sea states in front of the seawall is highly random and complex due to wave-structure interaction. To ensure the safety of seawall, it is necessary to explore the wave features within the area where is close to the seawall. The aim of this project is to study the innovated technology of remote sensing and to develop the wave runup detection and prediction system. To achieve this aim, this project will be finished within two years. This year is the second year. The works in last year are to (1) collect the present data in the study site, (2) study the remote sensing technology based on the coherent radar, (3) set up the wave run-up measurement system, (4) apply Coastal Engineering Manual to predict wave run-up height and overtopping rate, and (5) develop the 2D hydraulic numerical model for considering the effects of permeable structure. The works in this year are to (1) improve the accuracy of the radar measurements during rainfall, (2) improve the function of wave runup detection system, and (3) improve the accuracy of wave runup prediction based on the ensemble prediction associated with the results from wind wave models, tidal model or remote sensed data.For the development of current and wave monitoring based on the coherent radar, the tests of radar hardware and signals have been finished. Field experiments and data analysis have been implemented too. After a series of field tests and experiments, we confirm that the accuracies of nearshore current and wave observation using the coherent X-band radar. Besides, the developed real-time wave runup detection system was deployed on the seawall to record the wave runup and wave pressure during the typhoons. The recorded data during two typhoons are compared with the ensemble prediction results of Coastal Engineering Manual and the numerical results of self-developed hydraulic numerical model, separately.Through this project, the technologies of remote sensing and hydraulic wave model are improved. It is efficiency for Water Resources Agency to prevent the climate change impacts in the future. These recoded data are important for the safety of seawall and the warning of flooding disaster.