Journal of Water Resources Planning and Management

In recent decades, the effects of climate change, rapid urbanization, and the burdens of economic development have confronted cities with challenges in urban water management. This has resulted in mounting pressures on water resources and contributed to water scarcity and extreme flood events. Water-sensitive cities (WSCs) are cites that are resilient, sustainable, and livable and that offer a range of social, economic, and environmental benefits through water-sensitive urban design (WSUD). This paper bridges the gap between theoretical research and practical applications in stormwater management, presenting new methodologies that can be integrated into current engineering practices. By explicitly defining the concepts of WSC and WSUD, this study provides a clear framework for practitioners and engineers to enhance urban water resilience. The research establishes a set of environmental, social, policy, and economic (ESPE) indicators to evaluate the performance of WSUD projects within urban areas to achieve WSCs. Such indicators apply in three specific phases of WSUD projects: planning and design, implementation, and management and maintenance. The data were collected using a survey that received global responses from 388 water management experts from the aforementioned sectors. Structural equation modeling (SEM) was employed to identify the key factors in achieving WSCs. The outcomes of this analysis provide insights to enable water authorities, academics, and practitioners to evaluate the ability of WSUD projects to achieve sustainable water management.

Abstract

The present study introduces a novel penalty-free hybrid metaheuristic, differential evolution–krill herd algorithm (DE-KHA) a multiobjective algorithm (MOA) for the reliability-based optimal design of water distribution networks (WDNs). The selection mechanism of the DE-KHA MOA is equipped with nondominated sorting and density estimation schemes to obtain a Pareto front with diverse trade-off solutions. The introduced penalty-free scheme allows the algorithm to search for hydraulically functional nondominant solutions. With this implemented framework of the DE-KHA MOA, the WDN design problem is formulated with two conflicting objectives, (1) minimizing pipe investment cost; and (2) maximizing network’s reserve through flow entropy (${\mathrm{S}}_{\mathrm{F}}$), a surrogate reliability measure. The application and computational efficiency of the proposed MOA are demonstrated by employing two well-established benchmark case studies. Parallelly a trial-based approach for conducting sensitivity analysis for MOAs is demonstrated. The computational results manifest the efficacy of the penalty-free DE-KHA MOA in resulting in the Pareto front comprising the hydraulic feasible nondominant solutions of disparate trade-off relationships. As well, the results highlight the applicability of the proposed sensitivity analysis approach in improving the convergence behavior of the MOA. Following the reliability-based design, to assess the flexibility of the solved nondominant solutions under critical scenarios above design standards, the study performed a posterior performance investigation using pressure-driven analysis. The results demonstrate the effectiveness of the proposed approach with supported subjective knowledge in selecting robust design alternatives that are mechanically and hydraulically reliable. Moreover, the proposed approach eases the effort and perplexing state of handling increased nondominant design options with larger-size WDNs.

Practical Applications

The present study introduces a computationally efficient multiobjective algorithm for the economical and reliable design of water distribution networks. By considering the reliability measure (flow entropy) in the design framework, the study focuses on proposing design alternatives for water utilities with inherent redundancy and tolerance to failures (mechanical). Following optimal design, the study proposes a performance investigation model that is useful in assessing the network’s integrity, detailing the quantitative and qualitative performance of alternate designs in the face of uncertainties. This particular framework is notably more useful in proposing water utilities, a set of economical yet robust (flexible) design alternatives, which quickly adapt to uncertainties. As well, the proposed design approach eases the effort of designers in handling the increased design options with larger-size networks.

Abstract

The escalating global water scarcity crisis has propelled an increasing dependence on nonconventional water sources, particularly desalination and treated wastewater. Assessments of the United Nations’ water-related sustainable development goals on a global scale have brought to light a paradoxical trend of localized water decisions that have exacerbated long-term water scarcity issues. This study employs a water-energy-food (WEF) nexus framework to evaluate nonconventional water resources, fostering an understanding of interconnected water dynamics and promoting enhanced resource utilization and sustainability. Utilizing a multicriteria mathematical model grounded in life cycle assessment (LCA), this study optimizes water usage across the WEF nexus. The augmented simplex lattice mixture (ASLM) design is employed to identify WEF optimal frontiers under varying priorities within the hyperarid region of Kuwait. The findings underscore the significant influence of hidden virtual water on overall outcomes. Specifically, for wastewater permeate treated by reverse osmosis (WWROP), each cubic meter of permeate utilizes $1.78{\mathrm{m}}^3$, with 90% consumed virtually for chemical production. Within the water-for-food nexus, the results reveal that tertiary-level treated wastewater (WWTTE) contains 67% of the required phosphate for fodder cultivation, leading to an additional $24.89\mathrm{t}/\mathrm{ha}$ of fodder compared with WWROP and desalinated water. An evaluation of the energy-for-water nexus indicates that WWTTE and WWROP exhibit the lowest cumulative energy demand. Consequently, these results advocate for the utilization of WWTTE over WWROP and desalinated water to enhance the overall WEF nexus.

Practical Applications

Research suggests that a misrepresentation of the local context in WEF solutions may contribute to the slow adoption of WEF concepts in governance and political reform. This study addresses the pressing issue of water scarcity through the application of LCA. This analysis involves the evaluation of commercially available nonconventional water technologies concerning demand requirements across municipal, agricultural, and industrial sectors. A mathematical model is employed to assess and optimize the demand and supply assignment problem considering various impacts associated with WEF frontier priorities. The primary focus of this research is on the critical water scarcity challenges faced by hyperarid regions. Specifically, this study delves into the interrelationships among water, energy, and food consumption and their collective impact on these precious resources. Employing LCA, sensitivity analysis, and optimization models, this research scrutinizes the existing state of water, energy, and food in Kuwait. The aim is to provide specific recommendations that contribute to enhancing the equilibrium among these three vital resources.

Leakages are very prevalent in water distribution networks in China, particularly in urban areas. District metering areas (DMAs) provide a practical approach for monitoring the operation of water supply systems and a robust scientific basis for controlling leakages. Therefore, in this study, we assessed leakages in the water distribution network at the city scale using DMAs, with Wuhu, Anhui Province, China as an example. Residential districts in the urban area were divided into four DMA levels. The minimum night flow (MNF) method was used to investigate the extent of the leakages from the urban water distribution network in Wuhu. Finally, we summarize how DMAs could support the management of the urban water supply network during the planning, implementation, and evaluation stages. The results from this case study showed that DMAs and MNF could be integrated to assess the water network leakages in Wuhu.