Multi-Objective Optimal Allocation of Water Resources Based on the NSGA-2 Algorithm While Considering Intergenerational Equity: A Case Study of the Middle and Upper Reaches of Huaihe River Basin, China

Abstract

With the rapid development of society and the economy, the demand for water resources is increasing. This, combined with the increasing competition for water resources between current and future generations, hinders the sustainable development of society. To alleviate prominent water resources problems, achieve sustainable utilization of water resources and the sustainable development of society and economy, a multi-objective optimal water resources allocation model is proposed, in which different water sources and different water departments are considered to achieve the maximum social and economic benefits of the study area on the premise of water resources sustainability. To meet the needs of future generations, the discount value is introduced to measure intergenerational equity. A case study from seven cities in the upper and middle reaches of the Huaihe River Basin is given to verify the practicality and viability of the model. The non-dominated sorting Genetic Algorithms-2(NSGA-2) was used to find optimal water resources allocation schemes in 2020 and 2050 under the condition of a hydrological drought year (inflow guarantee rate p = 75%). Compared with previous models, the intergenerational equity model considers the sustainability of water resources, has higher social and economic benefits, and ensures the fair distribution of water resources among generations. According to the results, under balanced weight, the water shortage ratio of the seven cities will decrease from 5.24% in 2050 to 1.58% in 2020, and the economic benefit will increase from 79.46(1010CNY) to 168.3(1010CNY), respectively. In addition, the discount value of economic benefit in 2050 is 80.23(1010CNY), which is still higher than that in 2020. This shows that the water resource allocation scheme can eliminate the disparity between supply and demand for water resources and achieve intergenerational equity. Therefore, the intergenerational equity model can alleviate the contradiction of water resources and realize intergenerational equity.

Multi-Objective Optimal Allocation of River Basin Water Resources under Full Probability Scenarios Considering Wet–Dry Encounters: A Case Study of Yellow River Basin

“…Step 1: Parameter selection. According to the research of Jia et al [ 45 ] and Zhang et al [ 3 ], the parameters in the NSGA-II algorithm set the population size (N) to 100, maximum number of iterations to 1000, crossover probability to 0.75, and mutation probability to 0.01, and these parameters, overall, produce excellent results from the model.…”

“…Water resources, as strategic natural and public social resources, are directly related to the interests of the state and its prosperity, people, and related social development [ 1 , 2 ]. As socioeconomic development has sped up, the demand for water resources has increased sharply, with a contradiction gradually appearing between supply and demand thereof, while an uneven spatiotemporal distribution of precipitation has exacerbated the shortage of water resources in some areas [ 3 , 4 , 5 ]. The question of how to allocate water resources scientifically, reasonably, and fairly, while ensuring that limited water resources produce greater economic benefits and promoting sustainable socioeconomic and ecosystem development, has attracted the attention of governments and scholars around the world [ 6 , 7 , 8 ].…”

Multi-objective optimal water resources allocation in the middle and upper reaches of the Huaihe River Basin (China) based on equilibrium theory

“…Objective 1 (Maximization of Efficiency): Based on the principle of balance, efficiency, and equity, the maximum economic benefits is taken as the goal 31 : …”

“…Objective 2 (Maximization of Sustainability): On the basis of sustainability development, take the minimum sum of Chemical Oxygen Demand (COD) emission in the basin as the objective 31 : where represents the discharge of COD in unit sewage of water use department in sub-region (ton/m 3 ) and represents the coefficient of the sewage discharge of water consumption department in sub-region .…”

“…The water resources allocated from each water source to each sub-regions cannot exceed the capacity of each water source 31 . where represents the available water resources quantity of water source .…”