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Editorial

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7 pages, 225 KiB

Open AccessEditorial

Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems

by Manuel Herrera, Silvia Meniconi, Stefano Alvisi and Joaquín Izquierdo

Water 2018, 10(4), 440; https://doi.org/10.3390/w10040440 - 8 Apr 2018

Cited by 6 | Viewed by 4133

Abstract

This document is intended to be a presentation of the Special Issue “Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems”. The final aim of this Special Issue is to propose a suitable framework supporting insightful hydraulic mechanisms [...] Read more.

This document is intended to be a presentation of the Special Issue “Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems”. The final aim of this Special Issue is to propose a suitable framework supporting insightful hydraulic mechanisms to aid the decision-making processes of water utility managers and practitioners. Its 18 peer-reviewed articles present as varied topics as: water distribution system design, optimization of network performance assessment, monitoring and diagnosis of pressure pipe systems, optimal water quality management, and modelling and forecasting water demand. Overall, these articles explore new research avenues on urban hydraulics and hydroinformatics, showing to be of great value for both Academia and those water utility stakeholders. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

Research

Jump to: Editorial, Review

17 pages, 3092 KiB

Open AccessArticle

On the Role of Minor Branches, Energy Dissipation, and Small Defects in the Transient Response of Transmission Mains

by Silvia Meniconi, Bruno Brunone and Matteo Frisinghelli

Water 2018, 10(2), 187; https://doi.org/10.3390/w10020187 - 11 Feb 2018

Cited by 45 | Viewed by 3652

Abstract

In the last decades several reliable technologies have been proposed for fault detection in water distribution networks (DNs), whereas there are some limitations for transmission mains (TMs). For TM inspection, the most common fault detection technologies are of inline types—with sensors inserted into [...] Read more.

In the last decades several reliable technologies have been proposed for fault detection in water distribution networks (DNs), whereas there are some limitations for transmission mains (TMs). For TM inspection, the most common fault detection technologies are of inline types—with sensors inserted into the pipelines—and then more expensive with respect to those used in DNs. An alternative to in-line sensors is given by transient test-based techniques (TTBTs), where pressure waves are injected in pipes “to explore” them. On the basis of the results of some tests, this paper analyses the relevance of the system configuration, energy dissipation phenomena, and pipe material characteristics in the transient behavior of a real TM. With this aim, a numerical model has been progressively refined not only in terms of the governing equations but also by including a more and more realistic representation of the system layout and taking into account the actual functioning conditions. As a result, the unexpected role of the minor branches—i.e., pipes with a length smaller than the 1% of the length of the main pipe—is pointed out and a preliminary criterion for the system skeletonization is offered. Moreover, the importance of both unsteady friction and viscoelasticity is evaluated as well as the remarkable effects of small defects is highlighted. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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21 pages, 2890 KiB

Open AccessArticle

Water End Use Disaggregation Based on Soft Computing Techniques

by L. Pastor-Jabaloyes, F. J. Arregui and R. Cobacho

Water 2018, 10(1), 46; https://doi.org/10.3390/w10010046 - 9 Jan 2018

Cited by 36 | Viewed by 7737

Abstract

Disaggregating residential water end use events through the available commercial tools needs a great investment in time to manually process smart metering data. Therefore, it is extremely difficult to achieve a homogenous and sufficiently large corpus of classified single-use events capable of accurately [...] Read more.

Disaggregating residential water end use events through the available commercial tools needs a great investment in time to manually process smart metering data. Therefore, it is extremely difficult to achieve a homogenous and sufficiently large corpus of classified single-use events capable of accurately describe residential water consumption. The main goal of the present paper is to develop an automatic tool that facilitates the disaggregation of the individual water consumptions events from the raw flow trace. The proposed disaggregation methodology is conducted through two actions that are iteratively performed: first, the use of an advanced two-step filter, whose calibration is automatically conducted by the Elitist Non-Dominated Sorting Genetic Algorithm NSGA-II; and second, a cropping algorithm based on the filtered water consumption flow traces. As a secondary goal, yet complementary to the main one, a semiautomatic massive classification process has been developed, so that the resulting single-use events can be easily categorized in the different water end uses in a household. This methodology was tested using water consumption data from two different case studies. The characteristics of the households taken as reference and their occupants were unequivocally dissimilar from each other. In addition, the monitoring equipment used to obtain the consumption flow traces had completely different technical specifications. The results obtained from the processing of the two studies show that the automatic disaggregation is both robust and accurate, and produces significant time saving compared to the standard manual analysis. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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16 pages, 2461 KiB

Open AccessArticle

Applications of Graph Spectral Techniques to Water Distribution Network Management

by Armando Di Nardo, Carlo Giudicianni, Roberto Greco, Manuel Herrera and Giovanni F. Santonastaso

Water 2018, 10(1), 45; https://doi.org/10.3390/w10010045 - 9 Jan 2018

Cited by 60 | Viewed by 10369

Abstract

Cities depend on multiple heterogeneous, interconnected infrastructures to provide safe water to consumers. Given this complexity, efficient numerical techniques are needed to support optimal control and management of a water distribution network (WDN). This paper introduces a holistic analysis framework to support water [...] Read more.

Cities depend on multiple heterogeneous, interconnected infrastructures to provide safe water to consumers. Given this complexity, efficient numerical techniques are needed to support optimal control and management of a water distribution network (WDN). This paper introduces a holistic analysis framework to support water utilities on the decision making process for an efficient supply management. The proposal is based on graph spectral techniques that take advantage of eigenvalues and eigenvectors properties of matrices that are associated with graphs. Instances of these matrices are the adjacency matrix and the Laplacian, among others. The interest for this application is to work on a graph that specifically represents a WDN. This is a complex network that is made by nodes corresponding to water sources and consumption points and links corresponding to pipes and valves. The aim is to face new challenges on urban water supply, ranging from computing approximations for network performance assessment to setting device positioning for efficient and automatic WDN division into district metered areas. It is consequently created a novel tool-set of graph spectral techniques adapted to improve main water management tasks and to simplify the identification of water losses through the definition of an optimal network partitioning. Two WDNs are used to analyze the proposed methodology. Firstly, the well-known network of C-Town is investigated for benchmarking of the proposed graph spectral framework. This allows for comparing the obtained results with others coming from previously proposed approaches in literature. The second case-study corresponds to an operational network. It shows the usefulness and optimality of the proposal to effectively manage a WDN. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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731 KiB

Open AccessArticle

A Comparison of Preference Handling Techniques in Multi-Objective Optimisation for Water Distribution Systems

by Gilberto Reynoso-Meza, Victor Henrique Alves Ribeiro and Elizabeth Pauline Carreño-Alvarado

Water 2017, 9(12), 996; https://doi.org/10.3390/w9120996 - 19 Dec 2017

Cited by 8 | Viewed by 4340

Abstract

Dealing with real world engineering problems, often comes with facing multiple and conflicting objectives and requirements. Water distributions systems (WDS) are not exempt from this: while cost and hydraulic performance are usually conflicting objectives, several requirements related with environmental issues in water sources [...] Read more.

Dealing with real world engineering problems, often comes with facing multiple and conflicting objectives and requirements. Water distributions systems (WDS) are not exempt from this: while cost and hydraulic performance are usually conflicting objectives, several requirements related with environmental issues in water sources might be in conflict as well. Commonly, optimisation statements are defined in order to address the WDS design, management and/or control. Multi-objective optimisation can handle such conflicting objectives, by means of a simultaneous optimisation of the design objectives, in order to approximate the so-called Pareto front. In such algorithms it is possible to embed preference handling mechanisms, with the aim of improving the pertinency of the approximation. In this paper we propose two mechanisms to handle such preferences based on the TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) and PROMETHEE (Preference Ranking Organisation METHod for Enrichment of Evaluations) methods. Performance evaluation on two benchmarks validates the usefulness of such approaches according to the degree of flexibility to capture designers’ preferences. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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1793 KiB

Open AccessArticle

Influence of Extreme Strength in Water Quality of the Jucazinho Reservoir, Northeastern Brazil, PE

by Rafael Roney Camara De Melo, Ioná Maria Beltrão Rameh Barbosa, Aida Araújo Ferreira, Alessandra Lee Barbosa Firmo, Simone Rosa Da Silva, José Almir Cirilo and Ronaldo Ribeiro Barbosa De Aquino

Water 2017, 9(12), 955; https://doi.org/10.3390/w9120955 - 7 Dec 2017

Cited by 9 | Viewed by 3744

Abstract

The Jucazinho reservoir was built in the State of Pernambuco, Northeastern Brazil, to water supply in a great part of the population that live in the semi-arid of Pernambuco. This reservoir controls the high part of Capibaribe river basin, area affected several actions [...] Read more.

The Jucazinho reservoir was built in the State of Pernambuco, Northeastern Brazil, to water supply in a great part of the population that live in the semi-arid of Pernambuco. This reservoir controls the high part of Capibaribe river basin, area affected several actions that can compromise the reservoir water quality such as disposal of domestic sewage, industrial wastewater and agriculture with use of fertilizers. This study aimed to identify the factors that lead to water quality of the Jucazinho reservoir using a database containing information of nine years of reservoir water quality monitoring in line with a multivariate statistical technique known as Principal Component Analysis (PCA). To use this technique, it was selected two components which determine the quality of the reservoir water. The first principal component, ranging from an annual basis, explained the relationship between the development of cyanobacteria, the concentration of dissolved solids and electrical conductivity, comparing it with the variation in the dam volume, total phosphorus levels and turbidity. The second principal component, ranging from a mensal basis, explained the photosynthetic activity performed by cyanobacteria confronting with the variation in the dam volume. It observed the relationship between water quality parameters with rainfall, featuring an annual and seasonal pattern that can be used as reference to behaviour studies of this reservoir. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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4734 KiB

Open AccessFeature PaperArticle

Implementation of DMAs in Intermittent Water Supply Networks Based on Equity Criteria

by Amilkar E. Ilaya-Ayza, Carlos Martins, Enrique Campbell and Joaquín Izquierdo

Water 2017, 9(11), 851; https://doi.org/10.3390/w9110851 - 3 Nov 2017

Cited by 27 | Viewed by 6268

Abstract

Intermittent supply is a common way of delivering water in many developing countries. Limitations on water and economic resources, in addition to poor management and population growth, limit the possibilities of delivering water 24 h a day. Intermittent water supply networks are usually [...] Read more.

Intermittent supply is a common way of delivering water in many developing countries. Limitations on water and economic resources, in addition to poor management and population growth, limit the possibilities of delivering water 24 h a day. Intermittent water supply networks are usually designed and managed in an empirical manner, or using tools and criteria devised for continuous supply systems, and this approach can produce supply inequity. In this paper, an approach based on the hydraulic capacity concept, which uses soft computing tools of graph theory and cluster analysis, is developed to define sectors, also called district metered areas (DMAs), to produce an equitable water supply. Moreover, this approach helps determine the supply time for each sector, which depends on each sector’s hydraulic characteristics. This process also includes the opinions of water company experts, the individuals who are best acquainted with the intricacies of the network. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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1938 KiB

Open AccessArticle

A Hybrid Water Distribution Networks Design Optimization Method Based on a Search Space Reduction Approach and a Genetic Algorithm

by Juan Reca, Juan Martínez and Rafael López

Water 2017, 9(11), 845; https://doi.org/10.3390/w9110845 - 2 Nov 2017

Cited by 30 | Viewed by 6804

Abstract

This work presents a new approach to increase the efficiency of the heuristics methods applied to the optimal design of water distribution systems. The approach is based on reducing the search space by bounding the diameters that can be used for every network [...] Read more.

This work presents a new approach to increase the efficiency of the heuristics methods applied to the optimal design of water distribution systems. The approach is based on reducing the search space by bounding the diameters that can be used for every network pipe. To reduce the search space, two opposite extreme flow distribution scenarios are analyzed and velocity restrictions to the pipe flow are then applied. The first scenario produces the most uniform flow distribution in the network. The opposite scenario is represented by the network with the maximum flow accumulation. Both extreme flow distributions are calculated by solving a quadratic programming problem, which is a very robust and efficient procedure. This approach has been coupled to a Genetic Algorithm (GA). The GA has an integer coding scheme and variable number of alleles depending on the number of diameters comprised within the velocity restrictions. The methodology has been applied to several benchmark networks and its performance has been compared to a classic GA formulation with a non-bounded search space. It considerably reduced the search space and provided a much faster and more accurate convergence than the GA formulation. This approach can also be coupled to other metaheuristics. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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2389 KiB

Open AccessArticle

A Hybrid Heuristic Optimization Approach for Leak Detection in Pipe Networks Using Ordinal Optimization Approach and the Symbiotic Organism Search

by Chao-Chih Lin

Water 2017, 9(10), 812; https://doi.org/10.3390/w9100812 - 24 Oct 2017

Cited by 15 | Viewed by 5567

Abstract

A new transient-based hybrid heuristic approach is developed to optimize a transient generation process and to detect leaks in pipe networks. The approach couples the ordinal optimization approach (OOA) and the symbiotic organism search (SOS) to solve the optimization problem by means of [...] Read more.

A new transient-based hybrid heuristic approach is developed to optimize a transient generation process and to detect leaks in pipe networks. The approach couples the ordinal optimization approach (OOA) and the symbiotic organism search (SOS) to solve the optimization problem by means of iterations. A pipe network analysis model (PNSOS) is first used to determine steady-state head distribution and pipe flow rates. The best transient generation point and its relevant valve operation parameters are optimized by maximizing the objective function of transient energy. The transient event is created at the chosen point, and the method of characteristics (MOC) is used to analyze the transient flow. The OOA is applied to sift through the candidate pipes and the initial organisms with leak information. The SOS is employed to determine the leaks by minimizing the sum of differences between simulated and computed head at the observation points. Two synthetic leaking scenarios, a simple pipe network and a water distribution network (WDN), are chosen to test the performance of leak detection ordinal symbiotic organism search (LDOSOS). Leak information can be accurately identified by the proposed approach for both of the scenarios. The presented technique makes a remarkable contribution to the success of leak detection in the pipe networks. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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1867 KiB

Open AccessFeature PaperArticle

Data-Driven Study of Discolouration Material Mobilisation in Trunk Mains

by Gregory Meyers, Zoran Kapelan and Edward Keedwell

Water 2017, 9(10), 811; https://doi.org/10.3390/w9100811 - 24 Oct 2017

Cited by 1 | Viewed by 4538

Abstract

It has been shown that sufficiently high velocities can cause the mobilisation of discolouration material in water distribution systems. However, how much typical hydraulic conditions affect the mobilisation of discolouration material has yet to be thoroughly investigated. In this paper, results are presented [...] Read more.

It has been shown that sufficiently high velocities can cause the mobilisation of discolouration material in water distribution systems. However, how much typical hydraulic conditions affect the mobilisation of discolouration material has yet to be thoroughly investigated. In this paper, results are presented from real turbidity and flow observations collected from three U.K. trunk main networks over a period of two years and 11 months. A methodology is presented that determines whether discolouration material has been mobilised by hydraulic forces and the origin of that material. The methodology found that the majority of turbidity observations over 1 Nephelometric Turbidity Units (NTU) could be linked to a preceding hydraulic force that exceeded an upstream pipe’s hydraulically preconditioned state. The findings presented in this paper show the potential in proactively managing the hydraulic profile to reduce discolouration risk and improve customer service. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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4892 KiB

Open AccessArticle

Transient Wave Scattering and Its Influence on Transient Analysis and Leak Detection in Urban Water Supply Systems: Theoretical Analysis and Numerical Validation

by Huan-Feng Duan

Water 2017, 9(10), 789; https://doi.org/10.3390/w9100789 - 13 Oct 2017

Cited by 6 | Viewed by 5761

Abstract

This paper investigates the impacts of non-uniformities of pipe diameter (i.e., an inhomogeneous cross-sectional area along pipelines) on transient wave behavior and propagation in water supply pipelines. The multi-scale wave perturbation method is firstly used to derive analytical solutions for the amplitude evolution [...] Read more.

This paper investigates the impacts of non-uniformities of pipe diameter (i.e., an inhomogeneous cross-sectional area along pipelines) on transient wave behavior and propagation in water supply pipelines. The multi-scale wave perturbation method is firstly used to derive analytical solutions for the amplitude evolution of transient pressure wave propagation in pipelines, considering regular and random variations of cross-sectional area, respectively. The analytical analysis is based on the one-dimensional (1D) transient wave equation for pipe flow. Both derived results show that transient waves can be attenuated and scattered significantly along the longitudinal direction of the pipeline due to the regular and random non-uniformities of pipe diameter. The obtained analytical results are then validated by extensive 1D numerical simulations under different incident wave and non-uniform pipe conditions. The comparative results indicate that the derived analytical solutions are applicable and useful to describe the wave scattering effect in complex pipeline systems. Finally, the practical implications and influence of wave scattering effects on transient flow analysis and transient-based leak detection in urban water supply systems are discussed in the paper. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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6421 KiB

Open AccessArticle

Energy Dissipation in Circular Drop Manholes under Different Outflow Conditions

by Feidong Zheng, Yun Li, Jianjun Zhao and Jianfeng An

Water 2017, 9(10), 752; https://doi.org/10.3390/w9100752 - 30 Sep 2017

Cited by 16 | Viewed by 8992

Abstract

Circular drop manholes have been an important device for energy dissipation and reduction of flow velocities in urban drainage networks. The energy dissipation in a drop manhole depends on the manhole flow patterns, the outflow regimes in the exit pipe and the downstream [...] Read more.

Circular drop manholes have been an important device for energy dissipation and reduction of flow velocities in urban drainage networks. The energy dissipation in a drop manhole depends on the manhole flow patterns, the outflow regimes in the exit pipe and the downstream operation conditions, and is closely related to the hydraulic and geometric parameters of the manhole. In the present work, the energy dissipation of a drop manhole with three drop heights was experimentally investigated under free outflow conditions and constrained outflow conditions. The results demonstrate that the local head loss coefficient is solely related to the dimensionless drop parameter for free surface outflow without a downstream backwater effect, whereas it depends on the dimensionless submerge parameter for constrained outflow. Moreover, it is concluded that the energy dissipation is largely promoted when outlet choking occurs. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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7936 KiB

Open AccessArticle

Enabling Efficient and Sustainable Transitions of Water Distribution Systems under Network Structure Uncertainty

by Jonatan Zischg, Michael Mair, Wolfgang Rauch and Robert Sitzenfrei

Water 2017, 9(9), 715; https://doi.org/10.3390/w9090715 - 18 Sep 2017

Cited by 15 | Viewed by 5471

Abstract

This paper focuses on the performance of water distribution systems (WDSs) during long-term city transitions. A transition describes the pathway from an initial to a final planning stage including the structural and functional changes on the infrastructure over time. A methodology is presented [...] Read more.

This paper focuses on the performance of water distribution systems (WDSs) during long-term city transitions. A transition describes the pathway from an initial to a final planning stage including the structural and functional changes on the infrastructure over time. A methodology is presented where consecutive WDSs under changing conditions are automatically created, simulated and then analyzed at specific points in time during a transition process of several decades. Consequential WDS analyses include (a) uncertain network structure, (b) temporal and spatial demand variation and (c) network displacement. With the proposed approach, it is possible to identify robust WDS structures and critical points in time for which sufficient hydraulic and water quality requirements cannot be ensured to the customers. The approach is applied to a case study, where a WDS transition of epic dimensions is currently taking place due to a city relocation. The resulting necessity of its WDS transition is modelled with automatically created planning options for consecutive years of the transition process. For the investigated case study, we tested a traditional “doing-all-at-the-end” approach, where necessary pipe upgrades are performed at the last stages of the transition process. Results show that the sole design of the desired final-stage WDS is insufficient. Owing to the drastic network deconstruction and the stepwise “loss of capacity”, critical pipes must be redesigned at earlier stages to maintain acceptable service levels for most of the investigated future scenarios. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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1459 KiB

Open AccessArticle

PEPSO: Reducing Electricity Usage and Associated Pollution Emissions of Water Pumps

by S. Mohsen Sadatiyan A. and Carol J. Miller

Water 2017, 9(9), 640; https://doi.org/10.3390/w9090640 - 26 Aug 2017

Cited by 9 | Viewed by 5726

Abstract

Using metaheuristic optimization methods has enabled researchers to reduce the electricity consumption cost of small water distribution systems (WDSs). However, dealing with complicated WDSs and reducing their environmental footprint remains a challenge. In this study a multi-objective version of Pollution Emission Pump Station [...] Read more.

Using metaheuristic optimization methods has enabled researchers to reduce the electricity consumption cost of small water distribution systems (WDSs). However, dealing with complicated WDSs and reducing their environmental footprint remains a challenge. In this study a multi-objective version of Pollution Emission Pump Station Optimization tool (PEPSO) is introduced that can reduce the electricity cost and pollution emissions (associated with the energy consumption) of pumps of WDSs. PEPSO includes a user-friendly graphical interface and a customized version of the non-dominated sorting genetic algorithm. A measure that is called “Undesirability Index” (UI) is defined to assist the search for a promising optimization path. The UI also ensures that the final results are desirable and practical. The various features of PEPSO are tested under six scenarios for optimizing the WDS of Monroe City, MI, and Richmond, UK. The test results indicate that in a reasonable amount of time, PEPSO can optimize and provide practical results for both WDSs. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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1276 KiB

Open AccessArticle

Estimation of Water Demand in Water Distribution Systems Using Particle Swarm Optimization

by Lawrence K. Letting, Yskandar Hamam and Adnan M. Abu-Mahfouz

Water 2017, 9(8), 593; https://doi.org/10.3390/w9080593 - 21 Aug 2017

Cited by 32 | Viewed by 9222

Abstract

Demand estimation in a water distribution network provides crucial data for monitoring and controlling systems. Because of budgetary and physical constraints, there is a need to estimate water demand from a limited number of sensor measurements. The demand estimation problem is underdetermined because [...] Read more.

Demand estimation in a water distribution network provides crucial data for monitoring and controlling systems. Because of budgetary and physical constraints, there is a need to estimate water demand from a limited number of sensor measurements. The demand estimation problem is underdetermined because of the limited sensor data and the implicit relationships between nodal demands and pressure heads. A simulation optimization technique using the water distribution network hydraulic model and an evolutionary algorithm is a potential solution to the demand estimation problem. This paper presents a detailed process simulation model for water demand estimation using the particle swarm optimization (PSO) algorithm. Nodal water demands and pipe flows are estimated when the number of estimated parameters is more than the number of measured values. The water demand at each node is determined by using the PSO algorithm to identify a corresponding demand multiplier. The demand multipliers are encoded with varying step sizes and the optimization algorithm particles are also discretized in order to improve the computation time. The sensitivity of the estimated water demand to uncertainty in demand multiplier discrete values and uncertainty in measured parameters is investigated. The sensor placement locations are selected using an analysis of the sensitivity of measured nodal heads and pipe flows to the change in the water demand. The results show that nodal demands and pipe flows can be accurately determined from a limited number of sensors. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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2766 KiB

Open AccessArticle

Non-Dominated Sorting Harmony Search Differential Evolution (NS-HS-DE): A Hybrid Algorithm for Multi-Objective Design of Water Distribution Networks

by Jafar Yazdi, Young Hwan Choi and Joong Hoon Kim

Water 2017, 9(8), 587; https://doi.org/10.3390/w9080587 - 7 Aug 2017

Cited by 29 | Viewed by 4793

Abstract

We developed a hybrid algorithm for multi-objective design of water distribution networks (WDNs) in the present study. The proposed algorithm combines the global search schemes of differential evolution (DE) with the local search capabilities of harmony search (HS) to enhance the search proficiency [...] Read more.

We developed a hybrid algorithm for multi-objective design of water distribution networks (WDNs) in the present study. The proposed algorithm combines the global search schemes of differential evolution (DE) with the local search capabilities of harmony search (HS) to enhance the search proficiency of evolutionary algorithms. This method was compared with other multi-objective evolutionary algorithms (MOEAs) including NSGA2, SPEA2, MOEA/D and extended versions of DE and HS combined with non-dominance criteria using several metrics. We tested the compared algorithms on four benchmark WDN design problems with two objective functions, (i) the minimization of cost and (ii) the maximization of resiliency as reliability measure. The results showed that the proposed hybrid method provided better optimal solutions and outperformed the other algorithms. It also exhibited significant improvement over previous MOEAs. The hybrid algorithm generated new optimal solutions for a case study that dominated the best-known Pareto-optimal solutions in the literature Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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2107 KiB

Open AccessFeature PaperArticle

A Probabilistic Short-Term Water Demand Forecasting Model Based on the Markov Chain

by Francesca Gagliardi, Stefano Alvisi, Zoran Kapelan and Marco Franchini

Water 2017, 9(7), 507; https://doi.org/10.3390/w9070507 - 12 Jul 2017

Cited by 44 | Viewed by 6791

Abstract

This paper proposes a short-term water demand forecasting method based on the use of the Markov chain. This method provides estimates of future demands by calculating probabilities that the future demand value will fall within pre-assigned intervals covering the expected total variability. More [...] Read more.

This paper proposes a short-term water demand forecasting method based on the use of the Markov chain. This method provides estimates of future demands by calculating probabilities that the future demand value will fall within pre-assigned intervals covering the expected total variability. More specifically, two models based on homogeneous and non-homogeneous Markov chains were developed and presented. These models, together with two benchmark models (based on artificial neural network and naïve methods), were applied to three real-life case studies for the purpose of forecasting the respective water demands from 1 to 24 h ahead. The results obtained show that the model based on a homogeneous Markov chain provides more accurate short-term forecasts than the one based on a non-homogeneous Markov chain, which is in line with the artificial neural network model. Both Markov chain models enable probabilistic information regarding the stochastic demand forecast to be easily obtained. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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Review

Jump to: Editorial, Research

103 pages, 2594 KiB

Open AccessEditor’s ChoiceReview

Lost in Optimisation of Water Distribution Systems? A Literature Review of System Design

by Helena Mala-Jetmarova, Nargiz Sultanova and Dragan Savic

Water 2018, 10(3), 307; https://doi.org/10.3390/w10030307 - 13 Mar 2018

Cited by 112 | Viewed by 15317

Abstract

Optimisation of water distribution system design is a well-established research field, which has been extremely productive since the end of the 1980s. Its primary focus is to minimise the cost of a proposed pipe network infrastructure. This paper reviews in a systematic manner [...] Read more.

Optimisation of water distribution system design is a well-established research field, which has been extremely productive since the end of the 1980s. Its primary focus is to minimise the cost of a proposed pipe network infrastructure. This paper reviews in a systematic manner articles published over the past three decades, which are relevant to the design of new water distribution systems, and the strengthening, expansion and rehabilitation of existing water distribution systems, inclusive of design timing, parameter uncertainty, water quality, and operational considerations. It identifies trends and limits in the field, and provides future research directions. Exclusively, this review paper also contains comprehensive information from over one hundred and twenty publications in a tabular form, including optimisation model formulations, solution methodologies used, and other important details. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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780 KiB

Open AccessReview

Overview, Comparative Assessment and Recommendations of Forecasting Models for Short-Term Water Demand Prediction

by Amos O. Anele, Yskandar Hamam, Adnan M. Abu-Mahfouz and Ezio Todini

Water 2017, 9(11), 887; https://doi.org/10.3390/w9110887 - 13 Nov 2017

Cited by 50 | Viewed by 7817

Abstract

The stochastic nature of water consumption patterns during the day and week varies. Therefore, to continually provide water to consumers with appropriate quality, quantity and pressure, water utilities require accurate and appropriate short-term water demand (STWD) forecasts. In view of this, an overview [...] Read more.

The stochastic nature of water consumption patterns during the day and week varies. Therefore, to continually provide water to consumers with appropriate quality, quantity and pressure, water utilities require accurate and appropriate short-term water demand (STWD) forecasts. In view of this, an overview of forecasting methods for STWD prediction is presented. Based on that, a comparative assessment of the performance of alternative forecasting models from the different methods is studied. Times series models (i.e., autoregressive (AR), moving average (MA), autoregressive-moving average (ARMA), and ARMA with exogenous variable (ARMAX)) introduced by Box and Jenkins (1970), feed-forward back-propagation neural network (FFBP-NN), and hybrid model (i.e., combined forecasts from ARMA and FFBP-NN) are compared with each other for a common set of data. Akaike information criterion (AIC), originally proposed by Akaike (1974) is used to estimate the quality of each short-term forecasting model. Furthermore, Nash–Sutcliffe (NS) model efficiency coefficient proposed by Nash–Sutcliffe (1970), root mean square error (RMSE) and mean absolute percentage error (MAPE) are the forecasting statistical terms used to assess the predictive performance of the models. Lastly, as regards the selection of an accurate and appropriate STWD forecasting model, this paper provides recommendations and future work based on the forecasts generated by each of the predictive models considered. Full article

(This article belongs to the Special Issue Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems)

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Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems

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