- 期刊
河川堤防沖蝕機制及堤內洪氾之耦合模擬分析
Coupled Simulation Analysis of River Levee Erosion Mechanisms and Internal Levee Flooding
摘要
為維護河川沿岸的生命財產，河川堤防為重要的保護設施。河川堤防之結構包含不同形式，如土堤、混凝土堤或是外表以混凝土保護之土堤等。近年來，因河川堤防破壞而造成的嚴重淹水事件頻頻發生，如2009年臺灣的莫拉克颱風事件、2019年東日本的哈吉貝風災等事件，皆因豪雨而使強烈高漲的河川挾帶龐大的沖擊力對堤防造成重大的損壞，而漫溢的水體造成鄰近城鎮大規模的淹水。臺灣的河川因山陡坡急而使得洪水的集流時間相當短，且臺灣位處於環太平洋颱風帶中，在颱風或強烈對流所造成的暴雨期間，河川堤防所受到的考驗相當大，因此有必要深入研究河堤的破壞機制，以便於未來有助於河岸防護的永續利用。本研究應用河川水理動床數值模式來模擬河川、堤防與高灘地等之互動，結合河堤破壞機制，探討河堤破壞相關參數之敏感度，並進行不同類型的河堤與致災情境的模擬，以此探討河堤之破壞機理，藉此瞭解河堤的防護能力與其可能失效的情景，可做為評估河堤破壞後導致堤內淹水風險的參考。
並列摘要
To protect lives and property along riverbanks, levees serve as critical protective structures. River levees come in various forms, such as earthen levees, concrete levees, or earthen levees reinforced with concrete. In recent years, severe flooding events caused by levee failures have occurred frequently. Notable incidents include Taiwan's Typhoon Morakot in 2009 and Typhoon Hagibis in East Japan in 2019. Both events resulted from heavy rainfall, causing rivers to swell dramatically, exerting immense force on the levees and leading to significant damage. The overflowed waters caused large-scale flooding in nearby towns. In Taiwan, the short concentration time of floodwaters due to steep river gradients, combined with its location in the Pacific typhoon belt, means that levees face immense challenges during typhoons or intense convective rainstorms. Therefore, it is essential to study the mechanisms of levee failure to ensure the sustainable use of riverbank protection. This study applies a river hydrodynamic and mobile-bed numerical model to simulate interactions between rivers, levees, and floodplains. By integrating levee failure mechanisms, it explores the sensitivity of factors related to levee failure. Simulations of different levee types and disaster scenarios are conducted to investigate levee failure mechanisms. This will help understand levee protection capacity and potential failure scenarios, providing a basis for assessing the flood risk caused by levee breaches.