應用二維數值模式分析攔河堰型式影響河道防洪及輸砂之研究

Application of 2-D numerical model on flood control and sediment transportation for barrage types

李豐佐(Fong-Zuo Lee) ； 黃茂松(Mao-Sung Huang) ； 劉政其(Cheng-Chi Liu) ； 宋德仁(Der-Ren Song) ； 劉桂南(Robert Liu) ； 闕蓓德(Pei-Te Chiueh)

《農業工程學報》 67卷2期 (2021/06) Pp. 32-43

https://doi.org/10.29974/JTAE.202106_67(2).0004

摘要

為探討不同攔河堰型式對於河道防洪及輸砂之影響，本研究以二維數值模式（SRH-2D）建置新店溪碧潭堰上下游河段模型，納入考量全固定堰、全倒伏堰及複合堰等攔河堰改建型式，並設計常流況與200年重現期洪水之水文情境模擬案例。經綜合評估可知複合堰兼具全固定堰蓄水功能和全倒伏堰調節水位能力，二維模擬成果顯示主流通過複合堰時，水位較現況堰體水位有下降情形，複合堰堰體右側設置排砂道可減緩碧潭堰上游約0.5 m的淤積深度，但沖淤影響範圍有限，而複合堰中央的倒伏堰閘門抬升高度自1.5 m至3.0 m，可改善碧潭堰上游靠右岸局部區域約0.5～1.0 m的淤積深度。本研究成果可作為相關管理單位碧潭堰整建工程之參考依據，以期達到防洪減淤及改善現地水域環境之目標。

關鍵字

二維數值模式 ； 攔河堰型式 ； 防洪 ； 輸砂

並列摘要

Flash-flood occurs in the river due to the rainfall the catchment area from events of typhoon and hard rain, the construction of weirs at downstream is required for regulating flow and water elevation. For analyzing the efficiency of flood control and sediment transportation of different weir types, the 2-D numerical model (SRH-2D) is established to simulate the water area of Bitan Weir in the Xindian River. The fixed type barrage, compound type barrage and lodging type barrage are discussed in this study, and the cases of normal and 200-year flood return period are simulated by SRH-2D. The assessment result shows that the compound type barrage has both the water storage function of fixed type barrage and the water elevation regulation function of lodging type barrage. The two-dimensional simulation results show that the performance of flood control is better than original one and desilting outlet on the right side of compound type barrage can reduce the silting depth of about 0.5 meter at the upstream area of Bitan Barrage, but the influence area of scouring and silting is limited. Furthermore, the uplifting height of lodging gate on the central body of compound type barrage raise from 1.5 to 3.0 meters, which can improve the silting situation and reduce of the silting depth about 0.5 to 1.0 meter at the upstream right bank of Bitan Barrage. In order to reach the goal of flood prevention and water environment improvement, the results of this study can provide useful information on management and reconstruction of Bitan Barrage.

並列關鍵字

2-D Numerical model ； Barrage type ； Flood control ； Sediment transportation