scholarly journals Multi-Objective Optimal Operation of the Inter-Basin Water Transfer Project Considering the Unknown Shapes of Pareto Fronts

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2644 ◽  
Author(s):  
Jianjian Xu ◽  
Dan Bai
Keyword(s):  
Water Supply ◽  
Evolutionary Algorithm ◽  
River Water ◽  
Optimal Operation ◽  
Water Diversion ◽  
Multi Objective ◽  
Study Results ◽  
Water Diversion Project ◽  
Pareto Fronts ◽  
Wei River

Studies have shown that the performance of multi-objective evolutionary algorithms depends to a large extent on the shape of the Pareto fronts of the problem. Although, most existing algorithms have poor applicability in dealing with this problem, especially in the multi-objective optimization operation of reservoirs with unknown Pareto fronts. Therefore, this paper introduces an evolutionary algorithm with strong versatility and robustness named the Multi-Objective Evolutionary Algorithm with Reference Point Adaptation (AR-MOEA). In this paper, we take two water conservancy hubs (Huangjinxia and Sanhekou) of the Hanjiang to Wei River Water Diversion Project as example, and build a multi-objective operation model including water supply, ecology, and power generation. We use the AR-MOEA, the Non-dominated Sorting Genetic Algorithm II (NSGA-II), the Multi-Objective Evolutionary Algorithm based on Decomposition (MOEA/D) and the Indicator-Based Evolutionary Algorithm (IBEA) to search the optimal solutions, respectively. We analyze the performance of four algorithms and the operation rules in continuous dry years. The results indicate that (1) the AR-MOEA can overcome the difficulty of the shape and distribution of the unknown Pareto fronts in the multi-objective model. (2) AR-MOEA can improve the convergence and uniformity of the Pareto solution. (3) If we make full use of the regulation ability of the Sanhekou reservoir in the dry season, the water supply for coping with possible continuous dry years can be guaranteed. The study results contribute to the identification of the relationship among objectives, and is valued for water resources management of the Hanjiang to Wei River Water Diversion Project.

scholarly journals Multi-Objective Optimal Operations Based on Improved NSGA-II for Hanjiang to Wei River Water Diversion Project, China

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1159 ◽  
Author(s):  
Lianzhou Wu ◽  
Tao Bai ◽  
Qiang Huang ◽  
Jian Wei ◽  
Xia Liu
Keyword(s):  
Power Generation ◽  
Search Space ◽  
Water Transfer ◽  
Water Diversion ◽  
Multi Objective Optimization ◽  
Nsga Ii ◽  
Multi Objective ◽  
Water Diversion Project ◽  
Basin Water ◽  
Wei River

It is important to investigate the laws of reservoir multi-objective optimization operations, because it can obtain the best benefits from inter-basin water transfer projects to mitigate water shortage in intake areas. Given the multifaceted demands of the Hanjiang to Wei River Water Diversion Project, China (referred hereafter as “the Project”), an easy-to-operate multi-objective optimal model based on simulation is built and applied to search the multi-objective optimization operation rules between power generation and energy consumption. The Project includes two reservoirs connected by a water transfer tunnel. One is Huangjinxia, located in the mainstream of Hanjiang with abundant inflow but no regulation ability, and the other is Sanhekou, located in the tributary of Hanjiang with multi-year regulation ability but less water. The layout of the Project increases the difficulty of reservoir joint optimization operations. Therefore, an improved Non-dominated Sorting Genetic Algorithm-II (I-NSGA-II) with a feasible search space is proposed to solve the model based on long-term series data. The results show that: (1) The validated simulation model is helpful to obtain Pareto front curves to reveal the rules between power generation and energy consumption. (2) Choosing a reasonable search step size to build a feasible search space based on simulation results for the I-NSGA-II can help find more optimized solutions. Considering the influence of the initial populations of the algorithm and limited computing ability of computers, the qualified rate of Pareto points solved by I-NSGA-II are superior to NSGA-II. (3) According to the characteristics of the Project, water transfer ratio threshold value of two reservoirs are quantified for maximize economic benefits. Moreover, the flood season is a critical operation period for the Project, in which both reservoirs should supply more water to intake areas to ensure the energy balanced of the entire system. The findings provide an easy-to-operate multi-objective operation model with the I-NSGA-II that can easily be applied in optimal management of inter-basin water transfer projects by relevant authorities.

scholarly journals Research on the Dispatching Rules of Inter-Basin Water Transfer Projects Based on the Two-Dimensional Scheduling Diagram

2021 ◽  
Vol 9 ◽  
Author(s):  
Siyu Cai ◽  
Long Sun ◽  
Qingtao Liu ◽  
Yi Ji ◽  
Hao Wang
Keyword(s):  
Water Supply ◽  
Prospect Theory ◽  
Decision Model ◽  
Optimal Operation ◽  
Water Transfer ◽  
Water Diversion ◽  
Two Dimensional ◽  
Multi Objective ◽  
Scheduling Scheme ◽  
Basin Water

Inter-basin water transfer projects play an important role in allocating water resources that vary both in temporal and spatial scale while supporting regional development. In the practical operation of inter-basin water transfer projects, high water level and less inflow runoff would result in water supply destruction, while low water level and more inflow runoff would cause abandoned water. How to play the compensation roles of hydrological characteristics and storage capacities of multi-reservoirs to maximize the utilization efficiency of water resources, the key is to select the basis for the decision-making of starting water transfer process. In this paper, we selected the “Datong-Huangshui” water transfer project as the research subject, analyzed the composition of the inter-basin water transfer system, and constructed a dispatching rule extraction model including water transfer rules, water diversion rules, and water supply rules. Then the NSGA-II was used to solve the multi-objective optimization model to obtain the Pareto frontier solution set of the dispatching rules. Finally, the optimal operation scheme was determined and discussed according to the scheduling scheme decision model. The model itself was based on the gray target model and prospect theory. We found that: (1) The optimal target frontier obtained by the two-dimensional scheduling diagram and the hedging rules for water supply was closer to the theoretical optimal frontier of the multi-objective problem. This result indicated that the two-dimensional scheduling diagram and the hedging rules for water supply could better guide the water diversion operation of inter-basin water transfer projects. (2) Based on the multi-objective optimal operation schemes set, the OPT scheme obtained by the scheduling scheme decision model using gray target model and prospect theory could generate 359 million Kwh. At the same time, it could guarantee 90% of municipal and industrial water supply and 85% of agricultural water supply.

scholarly journals Optimal Regulation of the Cascade Gates Group Water Diversion Project in a Flow Adjustment Period

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2825
Author(s):  
Jie Zhu ◽  
Zhao Zhang ◽  
Xiaohui Lei ◽  
Xia Yue ◽  
Xiaohua Xiang ◽  
...  
Keyword(s):  
Water Level ◽  
Optimal Operation ◽  
Water Diversion ◽  
Decision Variable ◽  
Optimal Regulation ◽  
Multi Objective ◽  
Flow Adjustment ◽  
Water Diversion Project ◽  
Group Water ◽  
Regulation Model

This study focuses on the regulation demand of the cascade gates group water diversion project during the flow adjustment period. A multi-objective optimization regulation model was coupled with the one-dimensional hydrodynamic model and the multi-objective genetic algorithm. Gate opening was used as the decision variable to generate the local operation-oriented cascade gates group regulation scheme. This study considered the Shijiazhuang to Beijing section of the middle route of the South-to-North Water Diversion Project. The optimal operation model has a better control effect than the conventional control method, and the number of gate operations was reduced by 23.38%. The average water level deviation was less than 0.15 m when the feedforward control time of the cascade gates group water diversion project was not more than 24 h. The basic mechanism of maintaining water level stability during the short-term scheduling of the cascade gates group water diversion project makes use of the volume capacity, or the space of the channel pool adjacent to the water demand change position, in advance. The multi-objective optimal regulation model of the cascade gates group that was constructed in this study can quickly generate regulation schemes for different application scenarios.

Beijing water resources and the south to north water diversion project

2005 ◽  
Vol 32 (1) ◽  
pp. 159-163 ◽  
Author(s):  
Duan Wei
Keyword(s):  
Water Resources ◽  
Water Supply ◽  
Water Demand ◽  
Socioeconomic Development ◽  
Water Environment ◽  
Water Saving ◽  
Water Diversion ◽  
The South ◽  
Water Diversion Project ◽  
North Water

Beijing is located in a semiarid region, and water shortage is a common problem in the city. Along with the rapid increase in water demand, due to fast socioeconomic development and an increase in population, a shortage of water resources and a deterioration of the water environment have become obstacles to sustainable socioeconomic development in Beijing. In the long run, sustainable water resources management, water conservation, and completion of the south to north water diversion project will solve the problem. This paper introduces the water resources situation in Beijing; analyzes future water demand; and discusses the actions of water saving, nontraditional water resources exploitation, wetland construction, and water environment protection. The paper also explains the importance of the south to north water diversion project and the general layout of the water supply strategy, water distribution system, and methods to efficiently use the diverted water in Beijing.Key words: water resources, water supply, water saving, water recycling, water diversion.

A multi-objective evolutionary algorithm based on niche selection in solving irregular Pareto fronts

2021 ◽  
pp. 1-21
Author(s):  
Xin Li ◽  
Xiaoli Li ◽  
Kang Wang
Keyword(s):  
Evolutionary Algorithm ◽  
Optimization Problems ◽  
Optimal Solution ◽  
Benchmark Problems ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Environmental Selection ◽  
Optimal Solution Set ◽  
Pareto Fronts

The key characteristic of multi-objective evolutionary algorithm is that it can find a good approximate multi-objective optimal solution set when solving multi-objective optimization problems(MOPs). However, most multi-objective evolutionary algorithms perform well on regular multi-objective optimization problems, but their performance on irregular fronts deteriorates. In order to remedy this issue, this paper studies the existing algorithms and proposes a multi-objective evolutionary based on niche selection to deal with irregular Pareto fronts. In this paper, the crowding degree is calculated by the niche method in the process of selecting parents when the non-dominated solutions converge to the first front, which improves the the quality of offspring solutions and which is beneficial to local search. In addition, niche selection is adopted into the process of environmental selection through considering the number and the location of the individuals in its niche radius, which improve the diversity of population. Finally, experimental results on 23 benchmark problems including MaF and IMOP show that the proposed algorithm exhibits better performance than the compared MOEAs.

scholarly journals Multi-Objective Joint Optimal Operation of Reservoir System and Analysis of Objectives Competition Mechanism: A Case Study in the Upper Reach of the Yangtze River

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2542 ◽  
Author(s):  
Mufeng Chen ◽  
Zengchuan Dong ◽  
Wenhao Jia ◽  
Xiaokuan Ni ◽  
Hongyi Yao
Keyword(s):  
Power Generation ◽  
Water Supply ◽  
Yangtze River ◽  
Water Resource Management ◽  
Flood Control ◽  
Optimal Operation ◽  
Total Power ◽  
The Yangtze River ◽  
Multi Objective ◽  
Reservoir System

The multi-objective optimal operation and the joint scheduling of giant-scale reservoir systems are of great significance for water resource management; the interactions and mechanisms between the objectives are the key points. Taking the reservoir system composed of 30 reservoirs in the upper reaches of the Yangtze River as the research object, this paper constructs a multi-objective optimal operation model integrating four objectives of power generation, ecology, water supply, and shipping under the constraints of flood control to analyze the inside interaction mechanisms among the objectives. The results are as follows. (1) Compared with single power generation optimization, multi-objective optimization improves the benefits of the system. The total power generation is reduced by only 4.09% at most, but the water supply, ecology, and shipping targets are increased by 98.52%, 35.09%, and 100% at most under different inflow conditions, respectively. (2) The competition between power generation and the other targets is the most obvious; the relationship between water supply and ecology depends on the magnitude of flow required by the control section for both targets, and the restriction effect of the shipping target is limited. (3) Joint operation has greatly increased the overall benefits. Compared with the separate operation of each basin, the benefits of power generation, water supply, ecology, and shipping increased by 5.50%, 45.99%, 98.49%, and 100.00% respectively in the equilibrium scheme. This study provides a widely used method to analyze the multi-objective relationship mechanism, and can be used to guide the actual scheduling rules.

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