Author(s): Toshinori Tabata; Daisuke Hizume; Masayoshi Harada And Akinori Ozaki
Linked Author(s): Toshinori Tabata
Keywords: Yamadazeki Barrage Flood mitigation Numerical hydraulic analysis Irrigation rehabilitation
Abstract: Yamadazeki Barrage (Yamada Weir), located in Asakura City, Fukuoka Prefecture, is an intake structure on the Chikugo River that has been operational since its completion in 1790. Designated as a "World Heritage Irrigation Structure" in 2014, the weir has attracted international attention, particularly as a model for an irrigation project in Afghanistan that has benefited 600,000 people. Its distinctive "oblique weir" design, positioned at an angle to the river flow, effectively reduces water levels during floods and enhances water intake efficiency. While common in Japan, this design has largely been replaced by right-angle weirs in modern construction. Numerical hydraulic analyses using a two-dimensional shallow-water flow model were conducted to simulate flood conditions at Yamada Weir, reaffirming the advantages of oblique weirs and their potential applications in developing countries. These simulations replicated flood events and verified the effectiveness of the oblique weir in lowering water levels through scenario analysis, comparing it with a right-angle weir. The results underscored the flood mitigation benefits of the oblique weir design, highlighting its importance for sustainable water management in diverse contexts.
Year: 2025