长江防洪实体模型是利用世界银行贷款兴建的重大水利科研项目。通过理论分析与试验研究，建立了适合长江防洪实体模型的非恒定流条件下荆江三口分流模拟控制方式。恒定流和非恒定流条件下的验证试验研究表明，该模拟控制方式下荆江三口模型分流流量与分流过程均与原型相似，基本满足试验精度要求。验证后，该模拟控制方式被应用于长江防洪实体模型荆江河段洪水演进特性试验研究。

The Yangtze River Flood Protection Physical Model is built under the financial support of World Bank loan. Based on theoretical analysis and experimental study, a modeling method of flow diversion of the three outlets in Jingjiang Reach under unsteady flow conditions was established for the model. Validation tests under both steady and unsteady flow conditions manifested that with this modeling method, the experimental flow diversion proves to be consistent with that of the prototype and therefore meets the requirements for precision. Being validated, this modeling method has been applied to Yangtze River Flood Protection Physical Model to study the flood routing features in Jingjiang reach.