| publications-4071 |
article |
1992 |
Lee, Byoung Ho and Deininger, Rolf A. |
Optimal Locations of Monitoring Stations in Water Distribution System |
Journal of Environmental Engineering |
10.1061/(asce)0733-9372(1992)118:1(4) |
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The Safe Drinking Water Act requires that the water quality in water distribution systems is to be sampled at locations that are representative of the system; but the act does not describe how the sampling should be done. In this research, a concept of coverage is defined, and methods on how to locate monitoring stations in a network are described. The best set of stations is one that maximizes the coverage. The problems were formulated as integer programming problems, and were solved on a PC using an integer programming code. Two examples of their application to real systems are shown. |
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| publications-4072 |
article |
2006 |
Skolicki, Zbigniew and Wadda, Moe M. and Houck, Mark H. and Arciszewski, Tomasz |
Reduction of Physical Threats to Water Distribution Systems |
Journal of Water Resources Planning and Management |
10.1061/(asce)0733-9496(2006)132:4(211) |
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The potential threats to U.S. water supply systems have changed fundamentally in the past 4 years. Prior to 2001, the major threats were natural causes, accidents, and some malicious behavior by a small group of individuals. Against these threats, water supply agencies have done a truly remarkable job of ensuring a safe, dependable supply. However, threats posed by an organized group of actors may represent a new and different challenge to the security of water supplies. A tool to assist in identifying possible attacks has been developed. Knowledge of these attack scenarios may help in designing countermeasures. The tool uses evolutionary computation as the optimization method, and EPANET as the system simulator. Examples of its use to identify effective physical attacks against a realistic but hypothetical pipe network and initial corresponding countermeasures are presented. |
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| publications-4073 |
article |
2009 |
Smajgl, Alex and Smajgl, Alex and Heckbert, Scott and Heckbert, Scott and Ward, John and Ward, John and Straton, Anna and Straton, Anna |
Simulating impacts of water trading in an institutional perspective |
Environmental Modelling and Software |
10.1016/j.envsoft.2008.07.005 |
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| publications-4074 |
article |
2013 |
Comboul, Maud and Ghanem, Roger |
Value of Information in the Design of Resilient Water Distribution Sensor Networks |
Journal of Water Resources Planning and Management |
10.1061/(asce)wr.1943-5452.0000259 |
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AbstractThe ability to monitor the flow and how water transforms throughout water networks would greatly improve the management of those distribution systems. The sensor placement problem attempts to find the locations of monitoring devices that would optimally observe water quality and protect consumers from accidents and intrusions of contaminants. In some related critical scenarios, the absence of information about possible contamination events, including knowledge of the injection sources, contaminant types or mass, time of pollution, and the variability of water network input parameters, such as the nodal demands and the pipe roughness coefficients, raises several challenges that must be addressed by the sensor network design process. In this paper, the authors describe a stochastic parameterization and analysis of uncertainty for the design of sensor networks aimed at maximizing the probability of detection of accidents and intrusions in water distribution networks. A challenge with such an approach... |
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| publications-4075 |
article |
2009 |
Chu, Junying and Chu, Junying and Wang, Can and Wang, Can and Wang, Can and Wang, Can and Chen, Jining and Chen, Jining and Wang, Hao and Wang, Hao |
Agent-Based Residential Water Use Behavior Simulation and Policy Implications: A Case-Study in Beijing City |
Water Resources Management |
10.1007/s11269-009-9433-2 |
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Residential water use constitutes a major part of urban water demand, and has be gaining importance in the urban water supply. Considering the complexity of residential water use system, an agent-based social simulation, i.e. the Residential Water Use Model (RWUM), is developed in this paper to capture the behavioral characteristics of residential water usage. By disaggregating total water demands down to constituent end-uses, this model can evaluate heterogeneous consumer responses on water, taking into account the factors of market penetration of water-saving technologies, regulatory policies, economic development, as well as social consciousness and preferences. Also, uncertainty analysis technique is innovatively applied in this agent-based model for parameter calibration and model robust testing. According to the case study in Beijing, this model can provide insights to water management agency in evaluating different water usage polices, as well as estimations for potential water saving for future infrastructure development planning. |
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| publications-4076 |
article |
1998 |
Islam, Mohammad Ashraful and Islam, M. Rashidul and Chaudhry, M. Hanif and Chaudhry, M. Hanif |
Modeling of Constituent Transport in Unsteady Flows in Pipe Networks |
Journal of Hydraulic Engineering |
10.1061/(asce)0733-9429(1998)124:11(1115) |
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A new computer model is presented to predict the spatial and temporal distribution of residual constituent in a pipe network under slowly varying unsteady flow conditions. Unlike the other available models, which use steady-state or extended-period simulation of steady flow conditions, thus neglecting inertial effects, the presented model is truly dynamic, using a lumped-system approach to compute unsteady flow conditions. This model also includes dispersion and constituent decay in pipes. Slowly varying flow conditions are computed by numerically integrating the governing equations by an implicit finite-difference scheme subject to the appropriate boundary conditions. The transport equation is solved to compute the propagation of a constituent with a first-order decay rate. To avoid numerical diffusion, the advection and dispersion are solved in two steps: The Warming-Kutler-Lomax explicit scheme is used to solve pure advection while an explicit scheme is used to calculate dispersion and decay. Complete ... |
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| publications-4077 |
article |
2003 |
Grigg, Neil S. and Grigg, Neil S. |
Water Utility Security: Multiple Hazards and Multiple Barriers |
Journal of Infrastructure Systems |
10.1061/(asce)1076-0342(2003)9:2(81) |
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In recent years, the United States has learned much from natural disasters about risk to infrastructure systems, and now it faces new threats from malevolent attacks and other human-caused sources. The paper provides a comprehensive report on the experience base with water utility disasters and offers guidance for risk management and analysis. It is based on an American Water Works Association Research Foundation project that included a background study, industry interviews, and a workshop. Methods for risk analysis are in limited use by utilities because of a lack of data and lack of training and priority within utilities. Theories have advanced, but they need to be validated and developed further. Other infrastructure systems have characteristics that are similar to water supply, and water utility experience with risk can strengthen them. Risk management in utilities is more complex and far-reaching than current methods handle. For natural hazards, a great deal is known about threats, but less is known ... |
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| publications-4078 |
article |
2010 |
Kang, Doosun and Lansey, Kevin E |
Real-Time Optimal Valve Operation and Booster Disinfection for Water Quality in Water Distribution Systems |
Journal of Water Resources Planning and Management |
10.1061/(asce)wr.1943-5452.0000056 |
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Historically, a water distribution system’s (WDS) hydraulic performance has been the primary operational concern. Over the past two decades, however, more attention has been paid to water quality behavior in WDS and today, water quality level is an equally important issue for many water utilities. In most cases, maintaining disinfectant levels is usually of interest to avoid the bacteria regrowth and to protect against the potential cross-contamination events. However, disinfectants, such as chlorine, decay over time and produce potentially harmful disinfectant by-products when they react with organic material in the water. Therefore, maintaining a minimum chlorine residual requirement throughout the WDS is a complex but important task. When online booster disinfection is combined with source disinfection, it has been shown that the total chlorine dosage can be reduced while maintaining minimum chlorine residuals across the system. Here, optimal valve operation has been combined with booster disinfection ... |
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| publications-4079 |
article |
1996 |
Rossman, Lewis A. and Boulos, Paul F. |
Numerical Methods for Modeling Water Quality in Distribution Systems: A Comparison |
Journal of Water Resources Planning and Management |
10.1061/(asce)0733-9496(1996)122:2(137) |
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A comparison is made between the formulation and computational performance of four numerical methods for modeling the transient behavior of water quality in drinking-water-distribution systems. Two are Eulerian-based (the finite-difference and discrete-volume methods) and two are Lagrangian-based (the time-driven and event-driven methods). The Eulerian approaches move water between fixed grid points or volume segments in pipes as time is advanced in uniform increments. The Lagrangian methods update conditions in variable-sized segments of water at either uniform time increments or only at times when a new segment reaches a downstream pipe junction. Each method is encoded into an existing distribution-system simulation model and run on several pipe networks of varying size under equal accuracy tolerances. Results show that the accuracies of the methods are comparable. The Lagrangian methods are more efficient for simulating chemical transport. For modeling water age, the time-driven Lagrangian method is the most time-efficient while the Eulerian methods are more memory-efficient. |
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| publications-4080 |
article |
2015 |
ParΓ©, Guy and ParΓ©, Guy and Trudel, Marie Claude and Trudel, Marie-Claude and Jaana, Mirou and Jaana, Mirou and Kitsiou, Spyros and Kitsiou, Spyros |
Synthesizing information systems knowledge: A typology of literature reviews |
Information & Management |
10.1016/j.im.2014.08.008 |
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