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 KuhneTucker condition to obtain the noninferior 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.

Introduction

Rivers and lakes are important for the early utilization of water resources, while reservoirs reflect the complex needs of modern human beings. Given the natural erosion and human activities, sediment siltation problem in rivers, lakes and reservoirs has become increasingly prominent. For instance, the Yellow River is the second largest river in China. With the inharmonious relationship between water and sediment and rapid increase in the utilization of hydropower resources, significant changes have taken place in the spatial distribution of sediments in the Yellow River in different periods, resulting in serious sediment disasters and ecological deterioration problems (Hu et al., 2010a). Sediment disasters have seriously affected the production and life of people, as well as the functions of rivers, lakes, and reservoirs (Rashid et al., 2015). Through turning disaster into wealth, making full use of the resource characteristics of sediments has become a potential way to solve the above problems. Disasters caused by sediments have been known. However, the resource characteristics of sediments have been accepted by the public only in recent years. Along the Yellow River, sediment resources are used for flood control and dike reinforcement, soil improvement of waterlogged salineealkali land, building materials, and other approaches, which provide significant ecological, economic, and social benefits (Chen et al., 2017). The main sediment treatment is centralized desilting through the desilting basin for a considerable time. However, with the long-term utilization, dredging sediment accumulates on both sides of desilting basin and channels. This buildup reduces the capacity of water and sediment transport in channels, increases the burden of drainage channels and dredging cost, and causes the desertification of land.