Research on the Design and Practice of Flood Control Projects for Mountain Torrent Gullies: A Case Study of Mountain Torrent Gully Treatment in Southern Anhui
山洪沟防洪工程设计与实践研究--以皖南地区山洪沟治理为例

摘要

山洪沟灾害是威胁我国山区城镇与乡村安全的主要自然灾害类型，其防治工作兼具紧迫性与复杂性。 本文以安徽省广德市白马河山洪沟为典型范例，系统构建并实践了一套集“水文地质精准评估、工程措施差 异化设计、生态友好型材料应用、施工运维全过程优化及综合效益科学评价”于一体的综合治理技术体系。 研究通过高精度水文分析（结合“84办法”与历史洪水调查）、精细化地质勘察、多方案工程比选及MIKE11 水动力模拟，确立了以“护岸固脚、清淤畅流、生态优先”为核心的治理方案。工程措施包括清淤疏浚6.08 km （清淤量4.48万m³）、差异化新建护岸5.31km（涵盖格宾石笼、浆砌石与钢筋混凝土三种型式）。数值模 拟结果表明，工程实施后河道10年一遇设计洪水位平均降低0.15 m，最大降幅达0.52 m，行洪能力显著提 升。基于极限平衡法的稳定性计算与局部冲刷深度分析验证了所有护岸结构的安全可靠性（抗滑安全系数 Kc ≥1.29，抗倾安全系数K0≥2.53）。全生命周期经济评价显示，项目经济内部收益率（EIRR）为8.4%， 效益费用比（EBCR）达1.25，具有显著的经济合理性。本研究不仅为白马河提供了直接的技术解决方案，更 旨在形成一套可复制、可推广的南方丘陵区山洪沟系统治理方法论，为提升区域洪灾韧性与推进水生态文明 建设提供关键技术支撑与实践案例。

Abstract

Mountain torrent gully disasters are a major type of natural disaster threatening the safety of towns and villages in mountainous areas of China, and their prevention and control are both urgent and complex. Taking the Baima River mountain torrent gully in Guangde City, Anhui Province as a typical case, this paper systematically constructs and applies a comprehensive treatment technical system integrating accurate hydrogeological assessment, differentiated design of engineering measures, application of eco-friendly materials, whole-process optimization of construction and operation and maintenance, and scientific evaluation of comprehensive benefits. Through high precision hydrological analysis combining the “84 Method” and historical flood investigation, refined geological investigation, multi-scheme engineering comparison, and MIKE11 hydrodynamic simulation, a treatment scheme centered on “bank protection and foundation reinforcement, dredging for smooth flow, and ecological priority” is established. The engineering measures include dredging of 6.08 km, with a dredging volume of 44,800 m³, and differentiated construction of 5.31 km of new revetments, covering three structural forms: gabion cages, mortared masonry, and reinforced concrete. The numerical simulation results show that, after project implementation, the design flood level under a 10-year return period is reduced by an average of 0.15 m, with a maximum reduction of 0.52 m, indicating a significant improvement in flood discharge capacity. Stability calculation based on the limit equilibrium method and local scour depth analysis verify the safety and reliability of all revetment structures, with an anti-sliding safety coefficient Kc ≥ 1.29 and an anti-overturning safety coefficient K0 ≥ 2.53. The whole-life-cycle economic evaluation shows that the project has an economic internal rate of return (EIRR) of 8.4% and an economic benefit-cost ratio (EBCR) of 1.25, demonstrating clear economic rationality. This study not only provides a direct technical solution for the Baima River, but also aims to form a replicable and promotable methodology for systematic mountain torrentgully treatment in hilly areas of southern China, providing key technical support and a practical case for improving regional flood disaster resilience and promoting water ecological civilization construction.