Optimal Control of Sedimentation in Navigation Channels

Abstract

Many hydraulic engineering projects concern the control of sedimentation. For some large engineering projects, such as construction of a navigation channel over many kilometers in a shallow estuary, comprehensive control of sedimentation is extremely costly. An optimal-control approach is presented. It determines optimal locations and scheduling of dredging to minimize total cost and to obtain a channel where water depths are not less than specified values. The optimal-control problem is formulated and a method is developed. The optimization problem is solved by the conjugate gradient method, and the gradient of the cost function is calculated by solving the adjoint problem. A simulation study is conducted using a 2D numerical model to demonstrate the method. The significance of the adjoint problem is also illustrated in sensitivity analysis experiments.