Optimisation management of multi-purpose reservoir in the dry season: case study of Hoa Binh reservoir, Viet Nam

Reservoir operation is a complicated problem to cope with regarding the complexities and the conflicts among the different stakeholders interest. The study presents the set of operating policies for a multi-purpose reservoir, case study of Hoa Binh reservoir, Viet Nam, focusing on two main objectives: Hydropower and Irrigation demand in the dry season, when the other main target, i.e. the flood control, is less crucial. In addition, another environmental objective under consideration for the dry season is the discharge needed to limit the salinity intrusion into the Red river delta surface water. This is a somehow novel objective to be taken into account when climate change scenarios, observed and projected sea level rise and saline intrusion are considered. The weight of this objective compared to the other ones can be set according to the policy adopted. The study is based on an evolutionary algorithm, namely Genetic Algorithm (GA) to find a Pareto optimal set under different scenarios. The results offer more flexible policies where the reservoir operator may see the trade-off between objectives to decide which is more suitable with the instant interest. Finally, it is shown that the GA model is promising to improve the performance of reservoir operation compared to strict regulations, which are now applied.