荆江-洞庭湖构成的具有复杂时空变化特点的江湖水系对长江防洪体系有着重要影响。自三峡水库蓄水运用以来,荆江干流以及向洞庭湖三口分流过程发生了新的调整,因此在一定程度上改变了原有的防洪形势。为应对荆江-洞庭湖水系关系的变化,需要能够准确模拟河道、湖泊内各种复杂水流运动过程,建立了荆江-洞庭湖区一、二维嵌套水动力学模型,对荆江和三口河系模拟采用一维河网模型,洞庭湖区采用二维浅水湖泊模型。本嵌套模型是以边界搭接的水量交换方式连接一、二维模型,即一维模型为二维模型的提供上游流量边界;二维模型为一维模型提供下游水位边界,模型之间能互相传递物理量,并依据边界水力因子相等原则,实现互赋边界迭代计算。利用2008年全年荆江干流上监利、螺山站,三口河道的新江口、沙道观站、弥陀寺以及洞庭湖区内的鹿角站的实测水文资料对模型进行率定,利用2012年的实测水文资料对模型进行验证。同时模拟计算了洞庭湖丰、枯水期的流场,湖区主体表层水流流向是从目平湖-南洞庭湖-东洞庭湖,最终由城陵矶流出,接着汇入长江。丰水期水体几乎被置换,而枯水期“死水”现象明显。模型在水位、流量、断面流速过程3方面的验证结果显示,无论是在荆江干流、分洪水系还是洞庭湖区,模拟结果均与实测资料吻合较好,峰谷对应关系明显。嵌套模型选取的糙率等参数准确,技术处理到位,具有较高的精度,能较好反映整个荆江-洞庭湖区的水流运动过程。同时模型可用于荆江-洞庭湖区不同组合类型洪水过程的计算,对三峡调度影响下的荆江防洪预测有着重要参考价值。 The rivers and lakes with the characteristics of complicated space-time changes formed by Jingjiang-Dongting Lake have an important influence on the flood control system in the Yangtze River. Since the impoundment of the Three Gorges Reservoir, the Jingjiang main stream and the tributary to the three Dongting Lake took place a new adjustment, so to some extent, changed the original flood control situation. In order to cope with the change of Jingjiang-Dongting Lake water system, we need to be able to accurately simulate various watercourse flows in rivers and lakes, and to establish one- and two-dimensional nested hydrodynamic models of Jingjiang-Dongting Lake area. Using a one-dimensional river network model, Dongting Lake area using two-dimensional shallow lake model. The nested model is connected to a two-dimensional model with boundary-laden water exchange, that is, the one-dimensional model provides an upstream flow boundary for the two-dimensional model; the two-dimensional model provides the downstream water level boundary for the one-dimensional model, Transfer each other physical quantities, and based on the principle of equal boundary hydraulic factor, mutual endowment boundary iterative computing. Based on the measured hydrological data of Jingjiang River, Luoshan Station, Sanjiang River, Xinjiangkou, Shadaoguan Station, Amitabha Temple and Antlers Station in Dongting Lake in 2008 throughout the year, the model was calibrated by using the measured hydrological data of 2012 Verify the model. At the same time, the flow fields in abundance and dry season of Dongting Lake are simulated and calculated. The main surface water flow in the lake area flows from Muping Lake to South Dongting Lake to East Dongting Lake, finally flows out from Chenglingji, and then flows into the Yangtze River. During the wet season, the water body is almost replaced, while the phenomenon of “stagnant water” in dry season is obvious. The verification results of the model at the water level, the flow rate and the cross-section flow rate process 3 show that the simulation results are in good agreement with the measured data, and the correspondence between the peaks and valleys is obvious, no matter in the mainstream of Jingjiang River, flood diversion system or Dongting Lake. Roughness and other parameters selected by the nested model are accurate, the technology is in place and has high precision, which can better reflect the whole water flow process in Jingjiang-Dongting Lake area. At the same time, the model can be used to calculate the flood process of different combinations in Jingjiang - Dongting Lake area, which is of important reference value for the flood control forecast of Jingjiang under the influence of the Three Gorges Project.