圖書典藏及影音數位平台

本年度以彰化、雲林及嘉義縣市為計畫區，將現行淹水潛勢模擬之數值模式，進行地文資料之強化更新與各項參數之細緻檢校，以供未來即時淹水模擬演算技術研發與下階段淹水潛勢圖繪製之所需。

The Water Resources Planning Institute, Water Resources Agency of the Ministry of Economic Affairs has completed the “Second Upgrading Potential Inundation Maps” plan of the whole Taiwan from 2014 to 2016. The production method is based on the numerical model of SOBEK. However, in recent years, many governance projects have been completed, and the two-dimensional flooding model that was established in the past has gradually changed from the current situation. In order to maintain the correctness of the basic data of the model and ensure the reliability of the model calculation results, we upgraded and renewed models of Changhua County, Yunlin County, Chiayi County and Chiayi City. The total number of field survey is 797 of cross sections. Through the comprehensive survey, the actual drainage distribution can be better grasped and built into the numerical model to reflect the actual situation. The watershed area is based on digital elevation model of 1 meter by 1 meter to built into the model. We used Arc Hydro tool of ArcGIS for geography analysis, also collected DEM data, road data, and then to divide the sub-catchment area. The number of sub-catchments after the upgrade was enhanced from 6,429 to 10,600. The project performs a series of model adjustments to ensure that the accuracy of the model can be effectively improved. There are two purposes for model adjustment. One is to ensure that the model is in compliance with the specifications of the numerical model itself, such as the arrangement of the calculation points above and below the gate and the bridge, the arrangement of the pumping station. The second is to ensure consistency in the different data of the model, such as cross section elevation and DEM elevation are the same, and sewer manhole elevation and DEM elevation are the same, etc. In summary, the project is updated through the field survey, and the catchment area is updated. After the data renew is completed, we renewed relevant data in the numerical model to ensure that the model has the same trend with current situation.