The thesis " main studies and achievements are as follows : 1 . under the assumption of double - layer computational mode , the governing equations for the horizontal 2 - d stratified density current is derived by integrating the 3 - d fundamental equations along the flow depth . 2 在异重流双层计算模式下，从三维水沙基本方程出发，利用数学工具沿垂线积分，推导得出了平面二维异重流上、下两层水体的水沙运动基本方程。
