Performance-based multi-objective design and expansion of water distribution networks considering life cycle costs and future demands

Abstract

Designing the Water Distribution Networks (WDNs) consists of finding out pipe sizes such that the demands are satisfied and the desired performance levels are achieved at minimum cost. However, WDNs are subject to many future changes such as an increase (or decrease) in demand due to population change and migration, changes in water availability due to seasonal and climatic change, etc. Thus, the capacity expansion of WDNs needs to be performed such that the cost of interventions made is minimum while satisfying the demand and performance requirements at various time periods. Therefore, the current study proposed a Dynamic Programming (DP) framework for capacity expansion of WDNs and solved using Multi-Objective Self Adaptive Differential Evolution (MOSADE). The methodology is tested on three benchmark WDNs, namely Two-loop (TL), GoYang, and Blacksburg (BLA) WDNs, and applied to a real case study of the Badlapur region, Maharashtra, India. The results show that the proposed methodology leads to effective Pareto optimal fronts, making it an efficient method for solving WDN expansion problems. Subsequently, an Analytical Hierarchy Process (AHP) based multi-criteria decision-making (MCDM) analysis was performed on the obtained Pareto-optimal solutions to determine the most suitable solution based on three criteria: Life Cycle Cost (LCC) of expansions, hydraulic reliability, and mechanical reliability. The main advantage of the proposed methodology is its capability to consider hydraulic performance as well as structural integrity and demand satisfaction in the face of hydraulic and mechanical failures. HIGHLIGHTS A novel MOSADE-DP framework for solving WDN expansion problems.; Takes into consideration LCC and future water demands.; Pareto-optimal fronts generated between LCC and hydraulic reliability.; Multi-objective multi-criteria decision-making analysis to find out the most suitable option based on LCC, and hydraulic and mechanical reliabilities.; Takes into account hydraulic performance as well as structural integrity.;

Keywords

• future demands
• mcdm analysis
• mosade-dp
• phased expansions
• water distribution network expansion