为研究三峡建库后复杂多变的江湖关系，建立了一维恒定流全沙数学模模型，对江湖主要控制站的年径流量、三口分流量、三口分流过程、三口分沙量均进行了计算与分析。结果表明，该数学模型计算的长江及洞庭湖主要水沙情况与实测情况相近，可用于江湖关系的定量分析。

For studying complicated riverlake relationship change after completion of TGP,a 1D steady flow wholesand mathematic model was setup. The calculations and analyses on the annual runoff at several main control stations, diverted discharges,their processes and diverted sediment at three Outlets were performed. The computed results of watersand status of Changjiang and Dongting Lake obtained from mathematic model approach to the observed data at several main hydrometric stations. This mathematic model may be used for the quantitative analysis of riverlake relationship.