| China is a country which is seriously lack of water resources and lagging of water conservancy development. So how to speed up the development of water conservancy reform and rationally utilize water resources to maximum limit are the urgent problems that related to the sustainable development of the society, economy and ecological environment system, and related to the improvement of people’s living standards. As reservoir is the key project that can increase water conservancy support ability and realize the scientific allocation of water resources, improving the level of its operation and management is the important measure to accelerate the development of water conservancy reform in the future. Sediment deposition is synchronous with reservoir operation, which restricts the comprehensive benefits and threats to the service life of reservoir. So in order to give full play to the comprehensive benefits of reservoir, we must study on reservoir water-sediment coordinative operation which take comprehensive consideration of flood control and irrigation and sand sedimentation reduction of reservoir. This is the development direction of reservoir management pattern at present.Compared with the ordinary reservoir operation, reservoir water-sediment coordinative operation should consider not only the reasonable allocation of water, but also making reasonable arrangement of the storage and discharge time of sediment. For cascade reservoirs, operation requirements of upstream and downstream reservoirs and cumulative adjustment effect that upstream cascade do to downstream reservoirs should take into consideration. Reservoir water-sediment coordinative operation refers to the two aspects of reservoir operation and sediment deposition calculation, which mutual contacts and mutual influences. Comprehensive understanding the relationship between sediment deposition and targets such as flood control and power generation and theoretically combining sediment deposition calculation and reservoir operation that realize water-sediment coordinative operation will further enrich the basic theory of reservoir operation and sediment, it has important theoretical significance and practical application value.Reservoir water-sediment coordinative operation is a typical complex large system multi-objective problem. Due to reservoir operation calculation and sediment deposition calculation are two different systems of both properties and decision-making period, and the study on cascade reservoirs coordinative operation itself is a optimal control problem that has a lot of constraint conditions, dynamic and complicated nonlinear systems, whose optimal solution had been affected by the dimension disaster and the problem of local optimal solution, thus it has great difficulty to construct and jointly solve a multi-objective decision model that can comprehensively reflect comprehensive benefits of water-sediment coordinative operation in the optimal problem of water-sediment coordinative operation of reservoir. Based on this, the paper deeply researches on the method and application of reservoir water-sediment coordinative operation in system, the main content respectively contain reservoir operation, sediment deposition calculation, the construction and solution of the multi-objective decision model on the water-sediment coordinative operation, the generation of non inferior solutions, evaluation decision and case study of water-sediment coordinative operation. The major achievements are as following:(1) Research on regulation of reservoir operation and the scouring and silting of sediment deposition. In order to explore the regulation between the scouring and silting and reservoir operation from macro and micro aspects, firstly the influence of four types of macro mode reservoir operation on sediment deposition rate, deposition distribution and type of deposition balance is analyzed, which can give the macro use frame of water and sediment regulation. By studying in impact on sediment by limited water level and storage time adjustment, the conclusion is that storage time only changes the sediment deposition rate but limited water level can change the whole deposition balance. And the sediment ejection mechanism for three types of macro mode on reservoir sediment ejection is analyzed and the efficient way for sediment ejection is discussed. At last, the characteristics of sediment scouring after the initial deposition balance are discussed and the regulation of water storage and sediment ejection according to different characteristics of scouring and silting is summarized.(2) Particle swarm optimization algorithm based on catfish effect for reservoir optimal operation. Aim at the shortcoming of particle swarm optimization algorithm that easy to fall into local optimum and slow convergence when solving reservoir optimal operation problem, catfish effect mechanism is introduced into it. So particle swarm optimization based on catfish effect is proposed and its implementation step of solving reservoir optimal operation problem is given. The catfish device in the algorithm realizes the dynamic tracing of particle diversity and automatically introduction of catfish particle, which can activate particles that get lazy in evolution. And the convergence rate is improved through driven effect and high-quality dynamic regulating of catfish particle. Finally the algorithm’s feasibility and high efficiency are verified through the two examples that are single reservoir flood-control optimal operation and cascade reservoirs power generation optimal operation.(3) The multi-objective optimization of the reservoir water-sediment coordinative operation. In view of reservoir operation related to multiple objectives for comprehensive benefits, such as flood control, irrigation, ecological and sediment regulation, after integrating objectives and decision variables, the multi-objective decision-making model for single reservoir is established that can reflect the comprehensive water-sediment benefits basing on the calculation mathematics model of one-dimensional sediment scouring and silting. By deeply researching on generating technology of multi-objective problem’s non inferior solution and introducing characteristics of weighting method and constraint method in vector optimization theory, multi-objective particle swarm optimization algorithm based on catfish effect is proposed. Compared with the vector optimization theory, it can compute more efficiency and gain multiple non inferior solutions at the same time. Finally, the validity and feasibility of the proposed algorithm are proved through the application of water-sediment optimal operation of Three Gorges Reservoir. And the comparation between the application of storage time optimization on sediment constraints of Three Gorges Reservoir and the above one is discussed.(4) The multi-objective decision-making model of water-sediment coordinative operation of cascade reservoirs and its solving method. In view of the purpose of cascade reservoirs water-sediment coordinative operation, the three calculation sub-models of flood control, power generation and sediment deposition are established. On this basis, the multi-objective decision-making model of water-sediment coordinative operation in cascade reservoirs is constructed, which can better reflect the links between water and sediment and coordination with every objective interest of cascade reservoirs. For the realization of the model solving, the multi-objective decision-making model is transformed into single objective optimization model by using the constraint method. With a given constraint threshold, the single objective optimization model can be solved by particle swarm optimization algorithm based on catfish effect. The non-inferior sets of the multi-objective problem can be achieved by changing constraint threshold level. At last, according to the subjective weight from analytic hierarchy process and objective weight from entropy method, and combined with the ideal point evaluation method, the evaluation model of ideal point based on combination weight is proposed, which remedies the defects of single-weighing to some extent and make evaluation result more objective.(5) The application of water-sediment coordinative operation of Xiluodu-Xiangjiaba cascade reservoirs. Take Xiluodu-Xiangjiaba cascade reservoirs as the research object. First of all, on the basis of analyzing the necessity and prerequisites of cascade reservoirs storage time optimization, the impact on power generation and navigation and sediment deposition for cascade reservoirs by combination storage time adjustment is researched. It shows that staggered cascade reservoirs storage time is beneficial for principles of storage and power generation, and storage time adjustment on cascade reservoirs will change the sediment distribution which means advanced storage time would increase sediment deposition and put-back storage time would decrease sediment deposition. Then, aim at the maximum annual average power generation and minimum storage capacity loss rate about sediment of cascade reservoirs in calculate period, the multi-objective decision model of water-sediment coordinative operation on Xiluodu-Xiangjiaba cascade reservoirs is built, and the non inferior solutions is obtained by constraint method. Finally, the non inferior solution sets are evaluated by using different weights. It shows that evaluation of the optimal solution is different if the weight is different and the optimal solution is a balanced one of of water and sediment multi-objective decision model. Case study verifies the feasibility and effectiveness of the method and model. |
PDF Full Text Request