【摘要】 【目的】为明晰极端暴雨下洪峰流量形成的驱动要素，对北京“23·7”极端暴雨洪峰进行调查，从而揭示洪峰流量的变化规律，为区域灾后重建规划与防灾减灾工作提供科学依据。【方法】在2023年北京“23·7”极端暴雨发生后，对位于暴雨中心的门头沟区56条沟道140个洪痕点位开展调查，在明晰沟道洪峰流量空间变化基础上，使用随机森林模型定量分析各要素对沟道洪峰流量的驱动规律。【结果】（1）门头沟区沟道洪峰流量大小分布与降雨中心分布有较强一致性，整体由北向南递增，洪峰流量范围在27.5～1 072.0 m~3/s之间，超过10、20、50年一遇洪峰流量水平的沟道分别占总数的82%、71%、41%。（2）本次降雨条件下，影响门头沟区沟道洪峰流量差异的前5个因素依次为流域面积、沟道长度、平均起伏度、径流系数和淤积量，其相对重要值依次为1.000、0.524、0.471、0.382、0.346，表明地形因素对此次暴雨条件下门头沟区沟道洪峰流量影响最大。（3）各要素与洪峰流量存在复杂的非线性关系。【结论】根据最重要的5个驱动因素，建议灾后恢复重建工作中，以沟道为基本单位，实施“一沟一策”管理策略。合理布设防洪措施，提高工程防洪标准，重点关注淤积量、径流系数等关键可控因素。同时完善应急预案，整治侵占沟道行洪空间等问题，以提升区域的抗洪能力。未来研究需扩展至土地使用模式、水利设施建设等人为因素，因地制宜地分析洪峰流量影响机制，为不同地区的防灾减灾工作提供精准的指导。更多还原

【Abstract】 [Objective] To clarify the driving factors of peak discharge formation under extreme rainstorms,an investigation of the extreme rainstorm peak discharge in Beijing’s “23·7” event was conducted, thereby revealing the patterns of peak discharge variation, and providing a scientific basis for regional post-disaster reconstruction planning and disaster prevention and mitigation work. [Method] To analyze the drivers of peak discharge under extreme rainfall conditions, after the extreme rainfall event in Beijing in July, 2023, a research team surveyed 140 flood mark points across 56 gullies in the Mentougou District. Then, the random forest model was used to analyze the factors driving peak discharge based on the spatial changes.[Result](1) In the Mentougou District, the peak discharge of gullies increased from north to south, with values ranging from 27.5 to 1 072.0 m~3/s. Gullies exceeding the peak discharge levels for 10-year, 20-year,and 50-year events accounted for 82%, 71%, and 42% of the total, respectively.(2) The main factors influencing peak discharge differences in Mentougou District under rainfall conditions were basin area, gully length, mean relief amplitude, runoff coefficient and sediment accumulation, with importance values of1.000, 0.524, 0.471, 0.382, 0.346, respectively. The topographic factors had the greatest influence on peak discharge in the gullies of Mentougou District under current heavy rainfall conditions.(3) These factors exhibited a complex nonlinear relationship with peak discharge. [Conclusion] Based on the five key driving factors, it is recommended to implement a “One Gully, One Strategy” management approach for postdisaster recovery and reconstruction, using gullies as the basic unit. The strategy should include rational flood control measures and higher engineering standards, focusing on key controllable factors such as sediment accumulation and runoff coefficient. Additionally, emergency plans should be improved, and actions should be taken to address encroachments on gully flow areas to enhance flood resistance. Future research should expand to include human factors such as land use patterns and water infrastructure construction, analyzing the impact mechanisms of peak discharge in different regions to provide more precise guidance for disaster prevention and reduction efforts.更多还原