Abstract: Shuibuya hydropower station suffered a heavy rainfall with 100-year recurrence in 24 hours on July 19, 2016. Continuous heavy rainfall destroyed many parts of the station. The Miaowanggou, located downstream of the Gushubao landslide, was seriously damaged in heavy rainfall due to inadequate slope support and disrepair. The design scheme of Miaowanggou ditch restoration has been partially adjusted due to the restrictions of greening, terrain, cost and other factors. It is necessary to study the exact discharge capacity of the flood drainage ditch after the adjustment. In this paper, the hydraulic characteristics of each ditch after the adjustment are analyzed by channel hydraulic calculation method and the calculation formula of weir flow. The discharge capacity during a heavy rainfall with 100-year recurrence, and the water depth changes in the mutated, gradual, and sloped areas are studied.

Key words: drainage ditch, hydraulic calculation, discharge capacity, water depth

摘要： 2016年7月19日，水布垭水电站于24 h内遭遇了重现期为100年的强降雨，持续强降雨致使厂区多处遭到破坏。位于古树包滑坡体下游的庙王沟由于边坡支护不到位，加上早期排洪沟年久失修，排洪沟几乎完全丧失泄流能力，在暴雨中遭遇巨大破坏。庙王沟排洪沟修复过程中，其设计方案因受厂区绿化、地形、资金等因素的限制做出了局部调整，导致排洪沟泄流能力不明确。以渠道水力计算方法和堰流流量计算式分析了庙王沟设计方案调整后各排洪沟的水力特性，研究了排洪沟在遭遇重现期为100年的强降雨时的泄流能力及各排洪沟在突变、渐变、折坡部位的水深变化。

关键词: 排洪沟, 水力计算, 泄流能力, 水深