Multi-objective optimal allocation of sediment resources based on the subjective trade-off rate method

The rational utilization of the characteristics of sediment resources to achieve the optimal allocation of sediment resources is a key problem that must be solved urgently for ecological governance. On the basis of determining the allocation mode of sediment resources, this study established the multi-objective optimal allocation model of sediment resources, which aimed at the maximum ecological, economic, and social benefits and used the ε-constraint method and Kuhn–Tucker condition to obtain the non-inferior solution. Moreover, the optimal equilibrium solution of the model was obtained by using the subjective trade-off method from the perspective of preference. The Weishan and Bojili irrigation areas in China were then chosen as a case study to verify the feasibility and validity of the model. Results corroborate that, compared with the present situation, the proportions of sediment transport into the field in Weishan and Bojili irrigation areas are significantly increased and that the proportions of the main and branch canal sediment detention in the two irrigation areas are reduced. Compared with the results of the non-inferior solution, ecological and social benefits have been improved, and economic benefit has been decreased. The coordinated optimization of ecological, economic, and social benefits has been realized, instead of blindly pursuing economic benefit.