台南高雄海堤溢淹越波預警系統驗證及建置(1/2)(附光碟)

為提供經濟部水利署第六河川局(以下簡稱六河局)轄管臺南及高雄沿岸海堤災害預測資訊，本計畫建置海堤作業化海岸防災資訊系統，展示海堤區域波潮演變與溢堤越波預測資訊。主要工作為基本資料蒐集，整理轄區 36 處海堤斷面幾何參數，並根據國際公認氣象組織所發布之氣象條件，模擬臺灣沿海波潮變化，作業化產出臺南及高雄海堤區域的波潮資訊，並將外海波浪預測結果推算至海堤前，同時應用國際通用海岸工程手冊，估算臺南及高雄海堤在颱風侵臺期間的最大溯升高度與平均越波量，並選定一處強化波潮觀測與三處實測溯升高度，以驗證颱風期間的溯升高度。本計畫實際完成之工作成果進一步說明如下： 1. 蒐集過去各單位於臺南與高雄海岸所進行之海氣象相關調查及研究等文獻資料，除轉化為本計畫進行溯升越波預測所需之參數外，亦可作為波、潮、溯升觀測系統架設之重要依據。六河局轄區內曾有及現有長期海氣象觀測站有海上觀測樁一座、海上資料浮標2座、潮位站3座以及岸邊氣象站一座。 2. 透過大尺度數值波潮模式，並根據國際公認氣象組織所發布之風場條件，每日2次作業化預測未來48小時臺南及高雄海堤堤前波潮資訊，作為溯升預測之輸入條件。其中堤前50-200m處之波高係利用Goda (1985)所提出的波浪淺化經驗公式計算。 3. 採用國際常見之海岸工程手冊內相關方法，根據前述之堤前波潮預測資訊，以及本計畫所整理的36處海堤斷面幾何參數，推估臺南及高雄海堤未來48小時之堤面最大溯升高度與平均越波量資訊。與前述作業化波潮模式之計算時間搭配，同樣每日2次產出溯升高度及平均越波量資訊。 4. 為提高預測系統準確性，於六月份起陸續完成灣裡海堤外堤前波潮演變一處及七股、灣裡與彌陀海堤堤面溯升高度共三處觀測系統，用以校驗颱風期間之數值波潮模式與堤面溯升高度估算結果。 5. 引用本計畫實測之七股、灣裡與彌陀實測溯升資料及灣裡浮標實測波潮資料，加上水利署七股、彌陀兩資料浮標及四草、永安兩潮位站，實測波潮資料，能校驗蘇迪勒颱風中心進入陸地期間溯升高度預測失準原因。 6. 蘇迪勒颱風期間溯升預測誤差較大之原因為風場預測無法跟上實際颱風變化。而杜鵑颱風預測僅灣裡海堤略微高估，七股、彌陀則有不錯的結果。 7. 完成「海岸防災預警系統」網頁，透過視窗網頁作業化展示臺南及高雄海堤各區段波潮資訊，包含七股、灣裡與彌陀實測與預測資訊，並有36處堤面溯升高度以及越波量預測結果，以作為規劃海岸防災治理之參考。

To provide Sixth River Management Office the run-up and overtopping prediction information along the seawall in Tainan and Koahsiung, this project builds an operational coastal disaster prevention information system. The goals are to estimate the largest run-up and overtopping at seawalls in Tainan and Kaohsiung during the period of typhoon warning and to validate the predicted run-up at 3 seawalls. All the works within this project are completed on schedule. These works and the corresponding achievements include:
1. Collecting the past data and research reports to obtain the information on the deployment of the instrument and the fundamentals of modeling for coast in the Tainan and Kaohsiung.
2. Using the numerical models to predict the waves and tides information gerationally 48 hours in Tainan and Kaohsiung. According to the forecasted waves, Goda’s equation is utilized to calculate the wave heights near the seawall.
3. Estimate operationally the largest run-up and the overtopping at 36 seawalls by using the formulas in the CEM in Tainan and Kaohsiung for the future 48 hours during the period of typhoon warning.
4. To estabilish 1 GPS data buoy observing the wave and tide and 3 run-up stations. The measure data of the GPS buoy is used to validate the forcast of the wave and tide models. The measure data of run-up stations is utilized to validate the forcaseted run-up.
5. The measured data from the GPS buoy, the other 2 data buoys, and the other 2 tide stations is used for finding the reason of large errors of the forcasted run-up for typhoon SOUDELOR.
6. The major reason of prediction error of run-up is the wind field error when typhoon SOUDELOR is affected by the land. The run-up prediction agrees well with the measurement during typhoon DUJUAN.
7. Construct the operational “Coastal Disaster Prvention Information System” to display the information on the wave, tide, run-up, and overtopping.