Author(s)

G. Akbari

Abstract

The overall aim of this study was to investigate stability of flow-sediment regime upstream from a dam, to develop and calibrate a one-dimensional flow-sediment transport numerical model to deal with the many river-reservoir sedimentation problems including river reservoir dredging upstream from a dam. The basic physical principles of the conservation of mass and momentum are used to describe the fluid flow. The conservation of mass and semi-empirical equations governing sediment particle movement are adopted to establish the interaction between the sediment movement and fluid flow. The resulting mathematical formulation is highly non-linear and complex. It is impractical, if not impossible, to solve them analytically. Therefore the three governing equations of water continuity, sediment continuity, and momentum were solved numerically. The three governing equations were solved in an approximate linear form as well as in the more complete non-linear form. Also, by ignoring certain terms, the sediment continuity equation was uncoupled from the other two. Algorithms were developed for linear or non-linear and coupled or uncoupled solutions. Keywords: dredging upstream, linear, non-linear, coupled, uncoupled, watersediment phases. 1 Introduction In recent years, many major projects have caused serious difficulties as proper account has not been taken of their relationship with the surrounding environment. It has been estimated that nearly 14000 mega tonnes of sediment is carried annually by rivers worldwide and is deposited in man made reservoirs. This reduces the capacity of reservoirs which leads to an equivalent loss of 6 billion dollars per annum [5]. Dredging river reservoir upstream a dam is a

Keywords

dredging upstream, linear, non-linear, coupled, uncoupled, watersediment phases.