不同洪水重现期下橡胶坝调控对洪水风险的影响

现有针对河湖水系连通伴生风险分析的方法或不具备物理过程模拟，或缺乏对风险随机性的探讨。以沂沭河水系连通工程为例，在水力学模型的基础上，考虑连通河网不同河流洪峰相关性，创建随机水情条件下河湖水系连通伴生风险分析模型。通过1 200组水情条件，对沂沭河水系上游进行洪水过程模拟，针对橡胶坝可能造成的洪峰叠加问题，提出不同洪水重现期下橡胶坝运行调度风险管控建议。结果表明:① 50年一遇与100年一遇洪水重现期条件下，均呈现出橡胶坝坝址处水位风险极高（概率P>0.8），流速风险较低（P < 0.3）的规律，且每当橡胶坝高度升高25%的设计坝高时，沂河与沭河坝前水位风险皆提高约70%，沭河坝址处流速风险降低约50%。②若在汛前塌坝下泄蓄水，人为洪峰的叠加会使沭河中下游河段产生极高风险。③通过划分水位、流速综合洪水风险安全域，洪水重现期50年一遇时，建议沂沭河橡胶坝在汛前调节至低于50%设计坝高，且控制沭河水深和流速分别在12 m和2.23 m/s以内，可以降低水位和流速风险至低风险（P < 0.4）；洪水重现期100年一遇时，需将橡胶坝调至25%设计坝高以下，或者汛前尽早缓慢塌坝下泄蓄水，才能有效降低沂沭河水系防洪压力。

Impact of regulating rubber dams on the accompanied flood risk during

Existing risk analysis methods have neither the simulation of physical processes nor the discussion of risk randomness. Taking the Interconnected River System Network (IRSN) as an example, the associated risk analysis model of IRSN under random hydrological conditions was established based on the hydraulic model and the correlation of flood peaks. The flooding process in the upper reaches of the Yi and Shu River System is simulated by 1 200 sets of hydrological conditions. Aiming at the problem of flood peak superposition caused by rubber dams, this paper provides risk control suggestions for rubber dam operation and dispatch under different flood return periods. Our results showed that the risk of water level is extremely high (risk probability> 0.8) and the risk of flow rate is lower than 0.3 at the site of the rubber dam under the conditions of the 50-year flood return period and the hundred-year flood return period. When the rubber dam is increased by about 25% of the designed dam height, the risk of water level increases by approximately 70% in front of the dam in the Yi and Shu Rivers, and the risk of flow rate is reduced by about 50% at the dam site of the Shu River. If the dam is collapsed to release water before the flood season, the superposition of man-made flood peaks will cause an extremely high risk in the middle and lower reaches of the Shu River. By dividing the comprehensive flood risk safety area of water level and flood rate, it is suggested that the rubber dams be adjusted to less than 50% of the designed dam height before flood season in the Yi and Shu Rivers, and the depth and velocity the of Shu River be controlled within 12 m and 2.23 m/s respectively, so as to reduce the risk of water level and flow rate to low risk (< 0.4) in the 50-year flood return period. Moreover, to effectively reduce flood control pressure of the Yi and Shu River System in a hundred-year flood return period, it is necessary to adjust the rubber dams to below 25% of the designed dam height or to slowly collapse the dam before the flood season.