Multi‑objective optimization of water resources allocation in Han River basin

Multi‑objective optimization of water resources allocation in Han River basin

Multi‑objective optimization of water resources allocation in Han River basin (China) integrating efciency, equity and sustainability Lele Deng1 , ShenglianGuo1*, JiaboYin1 , Yujie Zeng1 & Kebing Chen2

The hydrological cycle, afected by climate change and rapid urbanization in recent decades, has been altered to some extent and further poses great challenges to three key factors of water resources allocation (i.e., efciency, equity and sustainability). However, previous studies usually focused on one or two aspects without considering their underlying interconnections, which are insufcient for interaction cognition between hydrology and social systems. This study aims at reinforcing water management by considering all factors simultaneously. The efciency represents the total economic interests of domesticity, industry and agriculture sectors, and the Gini coefcient is introduced to measure the allocation equity. A multi-objective water resources allocation model was developed for efciency and equity optimization, with sustainability (the river ecological fow) as a constraint. The Non-dominated sorting genetic algorithm II (NSGA-II) was employed to derive the Pareto front of such a water resources allocation system, which enabled decision-makers to make a scientifc and practical policy in water resources planning and management.

The proposed model was demonstrated in the middle and lower Han River basin, China. The results indicate that the Pareto front can refect the conficting relationship of efciency and equity in water resources allocation, and the best alternative chosen by cost performance method may provide rich information as references in integrated water resources planning and management. Water resources play key roles in feeding human beings and maintaining sustainable development of a socioeconomic system, which also serve as public resources for the whole society.

All members share equal rights to access the resources; whereas, the contradictory relationship between limited resources and increasing demand has gradually come to the fore1,2 , which gives rise to the water resources allocation issue of efciency, equity and sustainability3 . Water resources allocation strategies should not only pursue water consumption efciency but also consider the equity of water distribution between upstream and downstream, lef and right bank as well as water consumption sectors4 . Meanwhile, facilitating sustainable development is urgent for our social community. Balancing these three factors is the fundamental premise for optimal allocation of water resources, which can efectively maintain healthy social development. Te concepts of efciency, equity and sustainability are extensively involved in water resources allocation. Efciency generally refers to achieving highest monetary value for a certain amount of human and material resources as well as capital. From a socio-economic development perspective, highest efciency is achieved when utilizing limited resources to produce more social wealth and to satisfy human needs5 . Following sustainable development, the efciency of water allocation includes economic efciency, ecological efciency and social efciency6 . However, it’s very difcult to quantify ecological efciency and social efciency in water resources systems. Terefore, the safe minimum standard7 is adopted to estimate the minimum ecological water demands. Equity, as another vital index in sustainable socioeconomic development, advocates a fair access to certain living standards and natural resources. Tis issue has been extensively discussed in social science felds like healthcare and education8,9 . For instance, Lane et al.9 proposed a framework by incorporating an operational defnition of equity in healthcare resource allocation, which can facilitate decision-making.