Maximizing Sustainability in Reservoir Operation under Climate Change Using a Novel Adaptive Accelerated Gravitational Search Algorithm

Sahar Kamran,Mohammad H Golmohammadi,Farshad Rezaei,Agostino Forestiero,Songfeng Lu,Mohamed Abd Elaziz,Hamid R Safavi

doi:10.3390/w14060905

Abstract

Holding a lasting balance between the water resources and water demands has become a challenging task for water resources managers, especially in recent years with the looming global warming crisis and its resulting climatic change effects. This paper focuses on modeling the optimized operation of the Zayandehrud Reservoir, located in west-central Iran, under two fifth-generation climate change scenarios called RCP4.5 and RCP8.5. A novel variant of the gravitational search algorithm (GSA), named the adaptive accelerated GSA (AAGSA) is proposed and adopted as the optimizer of the reservoir operation in this paper. The major advancement of the AAGSA against the original GSA is its high exploration capability, allowing the proposal to effectively tackle a variety of difficulties any complex optimization problem can face. The goal of the optimization process is the maximization of the sustainability of supplying the downstream water demands by the reservoir. The optimal results obtained by the original GSA and the proposed AAGSA algorithms suggest that the AAGSA can achieve much more accurate results with much less computational runtime, such that the proposed AAGSA is able to achieve the reservoir operation sustainability index of 98.53% and 99.46%, under RCP4.5 and RCP8.5 scenarios, respectively. These figures are higher than those obtained by the original GSA by 23.5% and 16% under RCP4.5 and RCP8.5, respectively, while the runtime of the proposal is reduced by over 80% in both scenarios, as compared to the GSA, suggesting the high competence of the proposed AAGSA to solve such a high-dimensional and complex real-world engineering problem.

Highlights

In recent years, climate change has turned into a critical phenomenon as it takes considerable effects on decreased available water resources
accelerated GSA (AAGSA) is 56 times (98.2%) less than that offered by the gravitational search algorithm (GSA), while for RPC8.5, this value is 44 times (97.7%) less than that evaluated by the GSA
A future period beginning from 2020–2021, ending in 2032–2033, was assumed as a 13-year long-term planning period whose data necessary to simulate its climatic conditions were obtained as the outputs of the RCP4.5 and RCP8.5 climate change scenarios

Summary

Introduction

Climate change has turned into a critical phenomenon as it takes considerable effects on decreased available water resources. The variations in the time, intensity, and type of precipitation, the increased frequency of the extreme phenomena such as floods and droughts, the decreased snowfall, and the intensified ice melting, are among the major and tangible consequences of climate change [3–5]. These events may take negative and irreversible effects on human health and the environment if no planning is suggested to adapt the water management policies to climate change [6]. As a result of the increased water demands, conflicts between users of any water resources will arise and this is the more valuable water users’ demand which would have the decision-makers consider reallocation policies to avoid over-exploitation of water resources [10]

Objectives

Methods

Results

Conclusion