Abstract: Selection of optimal external transport schemes in hydropower projects is usually difficult because of difficulties in cost and investment estimation, various risk factors, complicated spatial distribution of transport network, and a large body of data to deal with. In addition, a transport scheme must meet the requirements of construction schedule, transport volume of construction materials and so on. This paper presents a staged decision-making method for optimizing transport routes and external transport schemes. First, aimed at multi-source route optimization for allocating and delivering large-quantity cargoes, we use a new concept of equivalent transport expense to reflect material transport costs and construction project investments comprehensively. Based on this concept, an optimal path algorithm is used to select multiple alternatives. Then, to opt for the optimal external traffic schemes from the alternatives, a multi-objective optimization method is adopted to construct a multi-objective optimization model with the objectives of minimizing generalized material transport costs, transport time, and transport risks. This model uses an analytic hierarchy process (AHP) to determine the target weight, and selects external transport schemes by applying the technique for order preference by similarity to an ideal solution (TOPSIS). Finally, a case study demonstrates the application of our method and its advantages in decision-making for external transport schemes in hydropower engineering.

Key words: water conservancy project, external transportation of hydropower project, multi-objective decision-making, routing optimization, equivalent transport expense, TOPSIS