scholarly journals Multi-objective optimization for improving equity and reliability in intermittent water supply systems

2020 ◽  
Vol 20 (5) ◽  
pp. 1592-1603 ◽  
Author(s):  
Passwell Pepukai Nyahora ◽  
Mukand Singh Babel ◽  
David Ferras ◽  
Andres Emen
Keyword(s):  
Decision Making ◽  
Water Supply ◽  
Water Distribution ◽  
Investment Decision ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Water Supply Systems ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Intermittent Water Supply

Abstract Intermittent water systems suffer from several drawbacks such as unfair distribution among users, low reliability and poor water quality. Given limited water and financial resources, making decisions for improving intermittent water supply (IWS) becomes a complex process. The paths to continuous supply are a priori undefined, however, the provision of efficient service is crucial. In the scientific literature, limited research addresses how to improve intermittent systems, to enhance the current service while transitioning to continuous supply. A multi-objective optimization (MOO) tool using a genetic algorithm has been developed to assist in investment decision-making. This approach uses multiple cost-effective intervention options to maximize equity and reliability while minimizing cost implications in an IWS system. The costs in such interventions include expenditure on pipe replacement, booster pump and elevated tank installation. The approach was first tested on a benchmark Hanoi synthetic network, and then applied to the water distribution network of Milagro (Ecuador). The developed tool reveals the extent to which equity and reliability can be driving objectives, and how they can be factored into decision-making. The application of the MOO tool in intermittent systems in order to improve existing distribution networks with strategic infrastructure addition can provide greater equity and reliability.

Determination of Neutral Point in Water Distribution Network Pipes with Variable Discharge on Route

2014 ◽  
Vol 909 ◽  
pp. 428-432 ◽  
Author(s):  
Ioan Sarbu ◽  
Gabriel Ostafe
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Neutral Point ◽  
Water Supply Systems ◽  
Proposed Model

Distribution networks are an essential part of all water supply systems. Distribution system costs within any water supply scheme may be equal to or greater than 60% of the entire cost of the project. The reliability of supply is much greater in the case of looped networks. The pipe networks have concentrated outflows or uniform outflow along the length of each pipe. In some pipes with variable discharge of a looped distribution network, water velocity could be reversed between its extremities. Thus, it is a water stall point denominated neutral point in which the discharge is null. In this paper a mathematical model for the determination of water stall point location in the pipes with distributed consumption is developed. This model has been implemented in a computer program for PC microsystems. Numerical example will be presented to demonstrate the accuracy and efficiency of the proposed model.

scholarly journals A multi-objective optimization model for operation of intermittent water distribution networks

2020 ◽  
Vol 20 (7) ◽  
pp. 2630-2647
Author(s):  
Mohammad Solgi ◽  
Omid Bozorg-Haddad ◽  
Hugo A. Loáiciga
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Optimization Model ◽  
Water Distribution ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Intermittent Operation ◽  
Supply Interruption

Abstract Intermittent operation of water distribution networks (WDNs) is an undesirable yet inevitable strategy under some circumstances such as droughts, development, electricity blackouts, and water pollution, mostly in developing countries. Intermittent utilization of WDNs poses several disadvantages encompassing water quality degradation, deterioration of the water-distribution system, and extra operational and maintenance costs due to frequently interrupted supply, unfair water distribution among consumers, and reduction of system serviceability. This paper proposes a multi-objective optimization model to address the negative consequences of intermittent water shortages. The model is intended to maximize the quantitative and qualitative reliability and the fairness in water supply, and to minimize the frequency of supply interruption. The developed model also considers pragmatic limitations, water quality, water pressure, and supply reservoir's constraints to plan the operation of intermittent water distribution systems under water shortage. The model's efficiency is tested with a WDN in Iran and compared with a standard operation policy (SOP) for water distribution. According to the evaluated efficiency criteria concerning reliability, resiliency, and vulnerability of water quality and quantity of water supply, the developed model is superior to the SOP rule and improves the performance of the network under intermittent operation. In addition, the results demonstrate there is a tradeoff between the uniformity of water distribution and the frequency of supply interruption that shows operators’ and customers’ conflicting priorities.

scholarly journals GIS use of Land Use/Land Cover layers and historical data for water losses indices

2019 ◽  
Vol 85 ◽  
pp. 07009
Author(s):  
Alexandru Aldea ◽  
Mihaela Aldea ◽  
Sorin Perju
Keyword(s):  
Water Supply ◽  
Water Distribution ◽  
Historical Data ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Water Supply Systems ◽  
Land Use Land Cover ◽  
Water Losses ◽  
Decision Factors ◽  
Supply Systems

The population growth and/or its use and development of the land is a continuous preoccupation of the decision factors regarding the water supply system in general and the development of the potable water distribution networks in particular. This issue is even more critical especially in the areas of big cities and important urban growing. As the urbanization of land outgrows the existing water supply systems, one of the possible solutions is to expand the water distribution network in order to cover this urban growth. The present paper analyses further the possibilities to define and use certain indices of urban development together with water loss indices in order to determine trends or issues related with the provision of water supply services and connectivity.

scholarly journals Survival analysis of water distribution network under intermittent water supply conditions

2020 ◽  
Vol 20 (8) ◽  
pp. 3531-3541
Author(s):  
Ali Mohammadi ◽  
Mohammadreza Jalili-Ghazizadeh ◽  
Iman Moslehi ◽  
Ehsan Yousefi-Khoshqalb
Keyword(s):  
Survival Analysis ◽  
Water Supply ◽  
Water Distribution ◽  
Supply And Demand ◽  
Demand Management ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Probability Of Failure ◽  
Failure Rates ◽  
Intermittent Water Supply

Abstract Intermittent water supply (IWS) is established temporarily or continuously in many water distribution networks (WDNs) worldwide due to prolonged drought, low rainfall periods, water scarcity and high level of leakage. IWS causes several adverse consequences on the network operation, resulting in ineffective supply and demand management. This paper presents a survival analysis of the network elements, including water mains, service connections, and valves using the Kaplan-Meier approach to determine the survival probability and the probability of failure rates of events of interest. The objective is to explore the changes in failure rates of network elements after implementing an IWS scheme. The non-parametric survival method is applied to the large zone (Zone-5) of the WDN in Tehran (Iran) based on the frequency of failures before, during, and after the implementation of an IWS regime. The results show that the probability of failure rates significantly increase after implementing the IWS scheme, and can remain for several years after, even when the network returns to continuous water supply (CWS). The results of this study can assist utility managers to understand the detrimental effects of IWS systems on increasing failure rates.

scholarly journals Identifying Critical Isolation Valves in a Water Distribution Network: A Socio-Technical Approach

2021 ◽  
Author(s):  
Noha Abdel-Mottaleb ◽  
Payman Ghasemi Saghand ◽  
Mathews Wakhungu ◽  
Hadi Charkhgard ◽  
E. Christian Wells ◽  
...  
Keyword(s):  
Water Distribution ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Decision Makers ◽  
Multi Objective Optimization ◽  
Technical Approach ◽  
Dual Representation ◽  
Multi Objective ◽  
Additional Information ◽  
Single Objective

Abstract Isolation valves are critical for reliable functioning of water distribution networks (WDNs). However, it is challenging for utilities to prioritize valve rehabilitation and replacement given it is often unclear if certain valves are operable in a given WDN. This study uses the Gomory-hu tree of the segment-valve representation (or dual representation) of WDNs to obtain logical implications of inoperable valves (i.e., which segments would be isolated and merged unnecessarily due to valve inoperability). Multi-objective optimization is then used to identify the critical valves based on selected attributes (e.g., social vulnerability, flow volume) of segments that would be unnecessarily isolated as a result. This study developed three multi-objective formulations: first, deterministic; second, accounting for uncertainty; and third, accounting or both uncertainty and likelihood of failure of pipes within segments. Identified critical valves are compared between the three developed formulations and a method considering only a single objective. Results demonstrated that the multi-objective optimization provided additional information that can be used to discern valve importance for utilities in comparison with using a single objective. Further, though there was overlap between the results from the three formulations, the third formulation provided the most insight without overwhelming decision-makers with a large number of identified valves.

A study on appropriate investment of pipeline rehabilitation for water distribution network

2005 ◽  
Vol 5 (2) ◽  
pp. 31-38
Author(s):  
A. Asakura ◽  
A. Koizumi ◽  
O. Odanagi ◽  
H. Watanabe ◽  
T. Inakazu
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Water Supply ◽  
Water Distribution ◽  
Ad Hoc ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Optimal Basis ◽  
Model Case

In Japan most of the water distribution networks were constructed during the 1960s to 1970s. Since these pipelines were used for a long period, pipeline rehabilitation is necessary to maintain water supply. Although investment for pipeline rehabilitation has to be planned in terms of cost-effectiveness, no standard method has been established because pipelines were replaced on emergency and ad hoc basis in the past. In this paper, a method to determine the maintenance of the water supply on an optimal basis with a fixed budget for a water distribution network is proposed. Firstly, a method to quantify the benefits of pipeline rehabilitation is examined. Secondly, two models using Integer Programming and Monte Carlo simulation to maximize the benefits of pipeline rehabilitation with limited budget were considered, and they are applied to a model case and a case study. Based on these studies, it is concluded that the Monte Carlo simulation model to calculate the appropriate investment for the pipeline rehabilitation planning is both convenient and practical.

Multi-objective optimization of water distribution networks using particle swarm optimization

2021 ◽  
Vol 218 ◽  
pp. 18-31
Author(s):  
Douglas F. Surco ◽  
Diogo H. Macowski ◽  
Flávia A.R. Cardoso ◽  
Thelma P.B. Vecchi ◽  
Mauro A.S.S. Ravagnani
Keyword(s):  
Particle Swarm Optimization ◽  
Water Distribution ◽  
Particle Swarm ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Multi Objective Optimization ◽  
Swarm Optimization ◽  
Multi Objective
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