Lake Poyang catchment, a large scale system with high spatial variability in land surface characteristics, was chosed to be the study area in this paper. Catchment hydrological and lake hydrodynamic processes are the main processes in the system. To represent the interaction of hydrological and hydrodynamic processes between the lake-catchment and reflect the mechanisms for different processes, an integrated model was set up. The integrated model used three sub-models with different functions to perform spatial linkage and it included a catchment distributed hydrological model WATLAC, a lakeside plain area runoff model and a lake hydrodynamic model MIKE 21. The integrated model used an input-output linkage approach and involved sequential execution of individual sub-model, i. e. , the discharges of major rivers and runoff of plain area were used as input conditions to drive the lake hydrodynamic model, and thus simulate the lake water level in response to catchment discharges. We used the river discharges of six hydrological stations and average base flow index as well as water levels of four lake stations as state variables to calibrate the integrated model. The Nash-Sutcliffe efficiency ( Em ) and determination coefficients ( R2 ) of daily river discharges vary from 0.71-0. 84 and 0.70 -0. 88, respectively and vary from 0.88 -0.98 and 0. 96 -0.98 for lake water levels. Results indicate that the integrated model can ideally reproduce the response of lake water level to the catchment rainfall-runoff process. The simulated lake levels further demonstrate that the integrated model has the ability to obtain the detailed hydrodynamic characteristics in space and time. The proposed model can be used as an effective tool to quantitatively reveal the hydrological and hydrodynamic processes of lake-catchment system in response to climate change and human activities in the catchment.%本文以鄱阳湖湖泊流域系统为研究对象,鉴于该湖泊流域系统尺度较大,下垫面自然属性呈现高度空间异质性且具有流域-平原区-湖泊不同机制的水文水动力过程,为了真实描述湖泊流域间的水文水动力联系及反映不同过程间的作用机制,构建了鄱阳湖湖泊流域联合模拟模型.该模型基于自主研发的流域分布式水文模型WATLAC和湖滨平原区产流模型以及水动力模型MIKE 21 3个不同功能子模型的连接来实现该复杂系统的模拟.模型的联合采用输入-输出驱动及子模型的顺序执行进程,即将五大子流域与平原区入湖径流量作为输入条件来驱动湖泊水动力模型,模拟湖泊水位对流域入湖径流量的响应.以2000-2005年鄱阳湖流域6个水文站点的河道径流量、流域基流指数以及湖泊4个站点的水位资料来率定模型,其中各站点日径流量拟合的纳希效率系数Ens为0.71 ～0.84,确定性系数R2介于0.70 ～ 0.88之间,而湖泊各站点水位拟合的纳希效率系数Ens变化为0.88 ～0.98,确定性系数R2为0.96 ～0.98,均取得令人满意的率定结果.本文提出的鄱阳湖湖泊流域系统水文水动力联合模拟模型能较为理想再现湖泊水位对流域降雨-径流过程的响应.水位模拟结果进一步表明,该联合模型能用来获取重要的水动力空间变化特征.该模型可作为有效工具定量揭示湖泊流域系统水文水动力过程对气候变化和流域人类活动的响应.
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