Scientific Results

This catalogue is obtained by conducting a systematic literature review of scientific studies and reviews related to monitoring, forecasting, and simulating the inland water cycle. The analysis maps scientific expertise across research groups and classifies findings by the type of inland water studied, application focus, and geographical scope. A gap analysis will identify missing research areas and assess their relevance to policymaking.

ID ▲ Type Year Authors Title Venue/Journal DOI Research type Water System Technical Focus Abstract Link with Projects Link with Tools Related policies ID
publications-4001 article 2014 Rathi, Shweta and Gupta, Rajesh and Gupta, Rajesh Sensor Placement Methods for Contamination Detection in Water Distribution Networks: A Review Procedia Engineering 10.1016/j.proeng.2014.11.175 Abstract Several methodologies have been suggested in the past two decades by different researchers to locate sensors in water distribution networks with different objectives. Even though a large number of methodologies have been developed, there is no consensus amongst researchers on the objectives, methodology and other aspects of sensor placements. The methodologies on sensor placement have been broadly classified into two categories as single objective and multi objective sensor location problems and compared on different basis. A critical review of available methodologies is presented to suggest future research needs for sensor network design for real life networks.
publications-4002 article 2012 Liu, Li and Liu, Li and Zechman, Emily M. and Zechman, Emily M. and Mahinthakumar, G. and Mahinthakumar, Gnanamanikam and Ranjithan, S. Ranji and Ranjithan, S. Ranji Identifying contaminant sources for water distribution systems using a hybrid method Civil Engineering and Environmental Systems 10.1080/10286608.2012.663360 The rapid discovery of the contaminant source in a water distribution system (WDS) is vital for generating an efficient control strategy during a contamination event. An inverse problem can be constructed, given sensor measurements in a WDS, to identify the contaminant source characteristics by integrating a WDS simulation model with an optimisation method. However, this approach requires numerous compute-intensive simulation runs to evaluate potential solutions. This paper reports the findings of an investigation by introducing a hybrid method for the real-time characterisation of a contaminant source. This new method integrates a simulation-optimisation approach with a logistic regression and a local improvement method to expedite the convergence and possibly solve the problem quickly. The results of numerical experiments on two example WDS networks demonstrate the efficiency of the proposed hybrid method for contaminant source characterisation. Effects of various hybrid strategies on the algorithm perf...
publications-4003 article 2015 Wagner, David E. and Wagner, David E. and Neupauer, R. M. and Neupauer, Roseanna M. and Cichowitz, Cody and Cichowitz, Cody Adjoint-Based Probabilistic Source Characterization in Water-Distribution Systems with Transient Flows and Imperfect Sensors Journal of Water Resources Planning and Management 10.1061/(asce)wr.1943-5452.0000508 AbstractIf a contamination event occurs in a water distribution system, sensors in the network may observe water quality changes. The data from these sensors can be used to identify the source of the contamination. The sensors can be binary sensors that record the presence or absence of contamination, fuzzy sensors that measure concentration within a set range, or perfect sensors that measure the exact concentration within the bounds of measurement uncertainty. This work presents an adjoint-based probabilistic approach for identifying the source node, source release time, and source strength for an instantaneous release of contamination based on sensor observations and known system hydraulics. In the adjoint approach, information is propagated upgradient from the sensors to the possible source nodes. EPANET is used to simulate the transient hydraulics of the pipe network and the upgradient propagation of the adjoint state through the network. The resulting adjoint states are related to probability density...
publications-4004 article 2011 Preis, Ami and Ostfeld, Avi Hydraulic uncertainty inclusion in water distribution systems contamination source identification Urban Water Journal 10.1080/1573062x.2011.596549 This study presents a methodology for the inclusion of hydraulics uncertainty in contamination source identification. Current research normally considers the system hydraulics as deterministic and the water quality sensors as ideal. In reality however only a small portion of the hydraulic data is known and most likely only Boolean sensor information of a contamination existence. There is a need to incorporate these considerations in contamination source identification models and to explore their influence on the modelling ability to correctly detect the characteristics of a contamination intrusion. This problem is addressed in this manuscript. The proposed method is based on a previous contamination source detection model developed by the authors which is further embedded in a statistical framework for quantifying the uncertainty of a contamination source detection outcome. The methodology is demonstrated on three example applications of increasing complexity through base runs and sensitivity analyses.
publications-4005 article 2010 Hart, William E. and Murray, Regan Review of Sensor Placement Strategies for Contamination Warning Systems in Drinking Water Distribution Systems Journal of Water Resources Planning and Management 10.1061/(asce)wr.1943-5452.0000081 Contamination warning systems (CWSs) are a promising approach for the mitigation of contamination risks in drinking water distribution systems. A critical aspect of the design of a CWS is the strategic placement of online sensors that rapidly detect contaminants. This paper reviews the array of optimization-based sensor placement strategies that have been recently proposed. These strategies are critiqued and several key issues are identified that need to be addressed in future work.
publications-4006 article 2009 Zechman, Emily M. and Zechman, Emily M. and Zechman, Emily M. and Ranjithan, S. Ranji Evolutionary Computation-Based Methods for Characterizing Contaminant Sources in a Water Distribution System Journal of Water Resources Planning and Management 10.1061/(asce)0733-9496(2009)135:5(334) The area of systematic identification of contamination sources in water distribution systems is in its infancy and is rapidly growing. The real water distribution network problem poses many challenges that current methods usually assume away to facilitate manageable method development and testing. Current methods may not readily and efficiently address issues, such as multiple sources, unknown contamination types with different reaction kinetics, use of different types of sensors with varying degree of resolution, dynamically varying demand and sensor information, and uncertainty and errors in the data and measurements. With the aim of addressing these imminent challenges, this paper reports the findings of an ongoing research investigation that develops and tests an evolutionary algorithm-based flexible and generic procedure, which is structured within a simulation-optimization paradigm. This paper describes the specific implementation of the method using evolution strategies (ESs), a population-based he...
publications-4007 article 2014 Yuan, Xiyue and Yuan, Xiao-Chen and Wei, Yi‐Ming and Wei, Yi-Ming and Pan, Su-Yan and Pan, Su-Yan and Pan, Su-Yan and Pan, Su-Yan and Jin, Juliang and Jin, Ju-Liang Urban Household Water Demand in Beijing by 2020: An Agent-Based Model Water Resources Management 10.1007/s11269-014-0649-4 Beijing is faced with severe water scarcity due to rapid socio-economic development and population expansion, and a guideline for water regulation has been released to control the volume of national water use. To cope with water shortage and meet regulation goal, it has great significance to study the variations of water demand. In this paper, an agent-based model named HWDP is developed for the prediction of urban household water demand in Beijing. The model involves stochastic behaviors and feedbacks caused by two agent roles which are government agent and household agent. The government agent adopts economic and propagandist means to make household agent optimize its water consumption. Additionally, the consumption is also affected by the basic water demand deduced from extended linear expenditure system. The results indicate that the total water demand of urban households in Beijing will increase to 317.5 million cubic meters by 2020, while the water price keeps growing at a low level. However, it would drop to 294.9 million cubic meters with high growth of water price and low increment in per capita disposable income. Finally, some policy recommendations on water regulation are made. Copyright Springer Science+Business Media Dordrecht 2014
publications-4008 article 2010 Eliades, Demetrios G. and Polycarpou, Marios M. A Fault Diagnosis and Security Framework for Water Systems IEEE Transactions on Control Systems and Technology 10.1109/tcst.2009.2035515 Water resources management is a key challenge that will become even more crucial in the years ahead. From a system-theoretic viewpoint, there is a need to develop rigorous design and analysis tools for control, fault diagnosis and security of water distribution networks. This work develops a mathematical framework suitable for fault diagnosis and security in water systems; in addition it investigates the problem of determining a suitable set of locations for sensor placement in large-scale drinking water distribution networks such that contaminant detection is optimized. This work contributes to the research by presenting a problem formulation were the state-space representation of the propagation and reaction dynamics is coupled with the impact dynamics describing the β€_x009c_damageβ€_x009d_ caused by a contamination of the water distribution network. We propose a solution methodology for the sensor-placement problem by considering several risk-objectives, and by utilizing various optimization and evolutionary computation techniques. To illustrate the methodology, we present results of a simplified and a real water distribution network.
publications-4009 article 2009 Berry, Jonathan W. and Carr, Robert D. and Hart, William E. and Leung, Vitus J. and Phillips, Cynthia A. and Watson, Jean-Paul Designing Contamination Warning Systems for Municipal Water Networks Using Imperfect Sensors Journal of Water Resources Planning and Management 10.1061/(asce)0733-9496(2009)135:4(253) We consider the problem of designing a contaminant warning system for a municipal water distribution network that uses imperfect sensors, which can generate false-positive and false-negative detections. Although sensor placement optimization methods have been developed for contaminant warning systems, most sensor placement formulations assume perfect sensors, which does not accurately reflect the behavior of real sensor technology. We describe a general exact nonlinear formulation for imperfect sensors and a linear approximation. We consider six general solution strategies, some of which have multiple solution methods. We applied these methods to three test networks, including one with over 10,000 nodes. Our experiments indicate that it is worth deploying a sensor network even when sensors have low detection probability. They also indicate it is worth paying attention to sensor imperfections when placing sensors even when there is a response delay of up to 8 h. The best choice of solution strategy depends upon the user's goals and the problem size. However, for large-scale problems with a moderate number of sensors, using a local search for the linear approximation formulation provides a reasonable-quality solution in a few minutes of computation. Our models assume that sensors can fail via false negatives. Additionally, we discuss ways to model false positives, ways to limit them, and how to trade them off against false negatives. All of our solution methods can handle false positives but our experiments do not explicitly consider them.
publications-4010 article 2010 Propato, Marco and Propato, Marco and Sarrazy, Fanny and Sarrazy, Fanny and Tryby, Michael E. and Tryby, Michael E. Linear Algebra and Minimum Relative Entropy to Investigate Contamination Events in Drinking Water Systems Journal of Water Resources Planning and Management 10.1061/(asce)wr.1943-5452.0000059 A two-step approach is proposed to assist forensic investigation of possible source locations following a contaminant detection in drinking water systems. Typically this identification problem is ill posed as it has more unknowns than observations. First, linear algebra is employed to rule out potential contaminant injections. Second, an entropic-based Bayesian inversion technique, the minimum relative entropy method, solves for the remaining variables. This formulation allows for the less committed prior distribution with respect to unknown information and can include model uncertainties and measurement errors. The solution is a space-time contaminant concentration probability density function accounting for the various possible injections that may be the cause of the observed data. Besides, a probability measure quantifying the odds of being the actual location of contamination is assigned to each potential source. Effectiveness and features of the method are studied on two example networks.