近年來台灣都會地區迅速發展,人口逐漸往都市集中,都會區人口密集,為滿足居民生活需求,都市內興建了大量且密集的建物,而增加之建物會阻隔地表逕流,並改變原本地表水流狀況。 本文主要目的在利用都市淹水模式,考慮建物阻隔及蓄水效應及其對地表水流產生的影響,以可反應細部地形變化但解析度較大之模擬網格,進行都市淹水之快速計算。同時將都市淹水模式結合多重尺度之平行計算,在尺度較大之全流域主網格中進行零慣性波方程式之求解,並在局部細化區域考慮建物效應,進一步求解局部高解析度之淹水分佈情形,並將不同尺度之全區及局部細化區域以平行計算的方式進行同步演算,提升都市淹水模式計算之整體效能,模擬局部細化地區之淹水過程。 本文於以理想案例進行都市淹水模式之檢定,檢定結果顯示都市淹水模式之合理性;同時以台北市中央區納莉颱風事件進行都市淹水模式之驗證,與調查淹水範圍比較,考慮建物效應之淹水模式更能反應實際流況,進一步將模式應用於曾文溪流域之莫拉克颱風事件,並劃分不同解析度之網格進行多重尺度之淹水模擬,其結果顯示局部細化地區之淹水模擬結果,具有良好之準確度,並在演算效率上有大幅度的提昇。
Recently, the highly developed urban area in Taiwan caused the concentrated population and result in densely distributed buildings. Buildings often affect the propagation of overland flow in urban areas. Building walls change the direction and velocity of flow, and can exclude interior spaces from flooding. The study aims to develop an urban inundation model to represent the resistance and the storage effects of buildings and reveal the rapid simulation in urban flood modeling by coarse grids. Meanwhile, the inundation model of local refinement solves the non-inertia overland flow hydraulic equations using the coarse main grids in global domain; whereas the building e effect is applied to the fine grids to reflect the details of flood in high resolution. The computing of global domain and all the local regions were parallelized to different threads by parallel algorithm to improve the efficiency of the multi-scale inundation model An ideal case was used for model calibration. The comparison of the simulation results demonstrated that urbain inundation model has good accuracy. The model was applied on Typhoon Nari event in the central Taipei City for model verification. The results showed that the presented inundation model reproduces the inundation results more comparable with the observed flooding situation.