水利水电技术（中英文）

[目的]黄河“几字弯”地区水沙关系不协调，准确模拟不同降雨条件下坡面产流产沙过程，对认识坡面水沙响应机制和支撑水土保持调控具有重要意义。[方法]基于合同沟试验场2023—2024年54组人工模拟降雨试验，设置3种坡度（5°、10°、15°）、3种植被覆盖度〔低（14%～17%）、中（50%～58%）、高（72%～77%）〕和3个雨强（21、50、93 mm/h）组合情景；结合前期土壤含水率与稳定入渗过程，采用贝叶斯方法优化SCS-CN模型参数，并耦合RUSLE模型，模拟坡面水沙过程。[结果]试验揭示植被覆盖度是坡面产流产沙的主导因子，在21mm/h和50 mm/h雨强下贡献率均超过85%，在93mm/h雨强下高于74%；坡度作用随雨强增大而增强，在93mm/h雨强下贡献率升至19.95%。优化后的SCS-CN模型显著提高了径流模拟精度，NSE由0.68提高至0.85，RMSE由3.8mm降至2.1mm；与RUSLE耦合后，能够较好模拟不同条件下的坡面产流产沙过程。[结论]低、中雨强条件下植被覆盖度对坡面减流减沙起主导作用，高雨强条件下坡度对侵蚀动力的促进作用增强。综合考虑前期土壤水分、稳定入渗过程及CN参数优化，提高了SCS-CN模型在研究区坡面尺度上的适用性。

[Objective] The water-sediment relationship in the Ω-shaped bend region of the Yellow River is unbalanced. Accurate simulation of slope runoff and sediment yield under different rainfall conditions is important for understanding slope-scale runoff-sediment responses and supporting soil and water conservation. [Methods] Based on 54 artificial rainfall simulation experiments conducted at the Hetonggou test site during 2023–2024， combined scenarios were designed with three slope gradients (5°， 10°， and 15°)， three vegetation coverage levels [low (14%～17%)， medium (50%～58%)， and high (72%～77%)]， and three rainfall intensities (21， 50， and 93 mm/h). By incorporating antecedent soil moisture content and the stable infiltration process， the key parameters of the SCS-CN model were optimized using a Bayesian approach， and the optimized model was coupled with RUSLE to simulate slope runoff and sediment processes. [Results] The experiments revealed that vegetation coverage was the dominant factor controlling slope runoff and sediment yield， with contribution rates above 85% at rainfall intensities of 21 and 50 mm/h and above 74% at a rainfall intensity of 93 mm/h. The effect of slope increased with rainfall intensity， reaching 19.95% at a rainfall intensity of 93 mm/h. The optimized SCS-CN model substantially improved runoff simulation accuracy， with NSE increasing from 0.68 to 0.85 and RMSE decreasing from 3.8 mm to 2.1 mm. After coupling with RUSLE， the model performed well in simulating runoff and sediment yield under different conditions. [Conclusion] Vegetation coverage plays a dominant role in reducing runoff and sediment under low and moderate rainfall conditions， whereas slope exerts a stronger effect on erosion dynamics under high-intensity rainfall conditions. Considering antecedent soil moisture content， stable infiltration process， and CN parameter optimization can improve the applicability of the SCS-CN model at the slope scale in the study area.