中国水利

2021年郑州“7·20”特大暴雨灾害后，郑州市实施系列工程与非工程措施，防洪能力得到系统性提升。为检验现状工况应对极端暴雨洪水的成效，本研究基于逐小时降雨、地形及现状工况数据，依托郑州市防洪“五预”（预报、预判、预警、预演、预案）系统，采用三水源新安江模型、水工程调度模型与一维河道水动力模型耦合技术开展洪水复盘模拟与风险分析，全过程融入预判功能实现洪水风险超前研判与工程联合调度优化，经与郑州“7·20”灾害实况对比验证了模型方法的适用性与模拟结果的可靠性。结果表明：现状工况下15座水库按批复调度规则运行可充分发挥拦洪作用，按郑州“7·20”水位起调最高水位未超设计水位，按现状汛限水位起调最高水位未超校核水位；主城区河道经综合治理排涝能力显著提升，贾鲁河（科学大道—京港澳高速段）、金水河全段达100年一遇防洪标准，潮河、七里河局部河段存在漫溢险情；贾峪河、贾鲁河两处南水北调中线工程交叉建筑物洪水漫溢入渠风险大幅度降低，可有效保障南水北调中线工程输水安全。研究成果可为郑州市极端降水防御、非常规暴雨洪水预报预警及防洪体系优化完善提供技术支撑。

After the “7·20” extreme rainstorm flood in Zhengzhou City in 2021, a series of engineering and nonengineering measures were implemented in Zhengzhou City, and the flood control capacity was systematically improved. In order to test the actual effect of the current working conditions to deal with extreme rainstorm floods, this study was based on the hourly rainfall, topography, and current working conditions data of rainstorm, relying on the “five pre”(forecasting, pre-assessment, early-warning, rehearsal and contingency planning) system of flood control in Zhengzhou City, using the coupling technology of three-source Xin'anjiang model, water engineering dispatching model, and one-dimensional river hydrodynamic model to carry out flood retrospective simulation and risk analysis. The whole process was integrated into the pre-judgment function to realize the advanced research and judgment of flood risk and the optimization of engineering joint dispatching. The applicability of the model method and the reliability of the simulation results were verified by comparing with the actual situation of the “7·20” disaster. The results show that the operation of 15 reservoirs under the current operating conditions can give full play to the role of flood storage and regulation. The highest water level adjusted according to the “7·20” actual water level does not exceed the design water level, and the highest water level adjusted according to the current flood limit water level does not exceed the check water level. The river channel in the main urban area has been significantly improved through comprehensive management and drainage capacity. The Jialu River(from Science Avenue to Beijing-Hong Kong-Macao Expressway section) and the whole section of the Jinshui River have reached the flood control standard of 100-year return period, and only the local sections of the Chaohe River and Qilihe River have overflow danger. The risk of flood overflowing into the channel of the two cross-buildings of the middle line of the South-to-North Water Diversion Project in Jiayu River and Jialu River is greatly reduced, which can effectively guarantee the water conveyance safety of the middle line of the South-to-North Water Diversion Project. The research results can provide technical support for extreme precipitation defense, unconventional rainstorm flood forecasting and early warning, and flood control system optimization and improvement in Zhengzhou City.