从数值波在每一时间步长内传播的距离不超过Courant数个网格点的基础出发 ,采用时间滞后条件 ,构造了虚拟的重叠计算水域 .利用重叠 -投影法 ,在连接 (点 )处建立一、二维耦合模型 ,实现了由一维计算水域向二维计算水域的准确过渡 .采用一、二维耦合模型和全一维模型对上海市淀南片河网的验证计算表明 ,一、二维耦合模型能较好地模拟非恒定水流 ,且具有一定的可靠性和实用性 Based on the time lag condition that the numerical wave propagated within each time step does not exceed the number of Courant grid points, a virtual overlapped computing watershed is constructed. By using the overlap-projection method, A two-dimensional coupling model was established to realize the accurate transition from one-dimensional calculation of water area to two-dimensional calculation of water area.The validation calculation of Shanghai South Dianhe river network using one-dimensional and two-dimensional coupled models and full- Two-dimensional coupling model can simulate unsteady flow well, and has certain reliability and practicability