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 â–² Type Year Authors Title Venue/Journal DOI Research type Water System Technical Focus Abstract Link with Projects Link with Tools Related policies ID
publications-4311 article 1980 Billings, R. Bruce and Billings, R. Bruce and Billings, R B and Agthe, Donald E. and Agthe, Donald E. and Agthe, D.E. Price elasticities for water: a case of increasing block rates Land Economics 10.2307/3145831 A model for estimating the price elasticity of demand for water when increasing block rates and for availability of service charges appear in the rate schedule is described. The model requires the use of two price-related variables - the marginal price of water and the difference between the actual payment for water and what the payment would be if all units of water were sold at the marginal price. Biased estimates of the price elasticity of demand result if the difference variable is omitted. The price variables are measured for the typical consumer, using actual water consumption and the rate schedule. The use of this model should make predictions of consumer response to rate structure changes more accurate when block rates or availability of servie charges appear in the rate schedule. 16 references.
publications-4312 article 1995 Boulos, Paul F. and Boulos, Paul F. and Altman, Tom and Altman, Tom and Jarrige, Pierre-Antoine and Jarrige, Pierre-Antoine and Collevati, Francois and Collevati, Francois DISCRETE SIMULATION ApPROACH FOR NETWORK-WATER-QUALITY MODELS Journal of Water Resources Planning and Management 10.1061/(asce)0733-9496(1995)121:1(49) An efficient system simulation methodology that solves the contaminant-transport problem in drinking-water-distribution systems is developed. The method can be effectively used for modeling the time-varying interaction of water quality and hydraulic behavior within the distribution-system environment. The solution of the time-varying water-quality problem is obtained in an event-oriented system-simulation framework. This allows for dynamic water-quality modeling that is less sensitive to the structure of the network and to the length of the simulation process itself than previously proposed methods. In addition, numerical dispersion of concentration front profile resolution is nearly eliminated. The resulting method can be applied to every type of water-distribution system while requiring the least number of calculations necessary to carry out the simulation process. The performance of the method is demonstrated by application to an example water-distribution network. The method should prove to be a valuable tool for managing water quality in drinking-water-distribution systems.
publications-4313 article 1995 Buchberger, Steven G. and Buchberger, Steven G. and Wu, Lin and Wu, Lin Model for Instantaneous Residential Water Demands Journal of Hydraulic Engineering 10.1061/(asce)0733-9429(1995)121:3(232) Residential water use is visualized as a customer-server interaction often encountered in queueing theory. Individual customers are assumed to arrive according to a nonhomogeneous Poisson process, then engage water servers fro random lengths of time. Busy servers are assumed to draw water at steady but random rates from the distribution system. These conditions give rise to a time-dependent Markovian queueing system having servers that deliver random rectangular pulses of water. Expressions are derived for the mean, variance, and probability distribution of the flow rate and the corresponding pipe Reynolds number at points along a dead-end trunk line. Comparison against computer-simulated results shows that the queueing model provides an excellent description of the temporal and spatial variations of the flow regime through a dead-end trunk line supplying water to a block of heterogeneous homes. The behavior of the local flow field given by the queueing model can be coupled with water-quality models that require ultra-fine temporal and spatial resolutions to predict the fate of contaminants moving through municipal distribution systems.
publications-4314 article 1998 Vairavamoorthy, Kalanithy and Vairavamoorthy, Kalanithy and Lumbers, J. P. and Lumbers, Jeremy Leakage Reduction in Water Distribution Systems: Optimal Valve Control Journal of Hydraulic Engineering 10.1061/(asce)0733-9429(1998)124:11(1146) The reduction of leakage is an important objective of the United Kingdom water industry. The inclusion of pressure-dependent leakage terms in network analysis allows the application of formal optimization techniques to identify the most effective means of reducing water losses in distribution systems. The development of an optimization method to minimize leakage in water distribution systems through the most effective settings of flow reduction valves is described. The method shows a significant advantage compared with previously published techniques in terms of robustness and computational efficiency. A particular feature of the approach is the use of an objective function that allows minor violations in the targeted pressure requirements. This allows a much greater improvement in the exceedance of minor pressure requirements than would otherwise be achieved.
publications-4315 article 1999 Tucciarelli, Tullio and Tucciarelli, Tullio and Criminisi, Antonio and Criminisi, Antonio and Termini, Donatella and Termini, Donatella Leak Analysis in Pipeline Systems by Means of Optimal Valve Regulation Journal of Hydraulic Engineering 10.1061/(asce)0733-9429(1999)125:3(277) Estimation of water loss at small leaks and openings in different areas of a pipe network is handled by means of an iterative two-step procedure. The first step is estimation of the parameters in the network simulation model. It is achieved with the maximization of a likelihood function, equal to the sum of the squares of the difference between the observed water heads and flow rates and their computed values in a given number of nodes and pipes. The estimated parameters include the loss factors and the loss exponent. They provide the water loss per unit time in each area of the network, called zone. The second step is optimization of the openings of the valves included in the network. It is constrained by the minimum pressure head allowed in the nodes. Closure of the valves enhances the different response of the network with respect to the water loss and the load in each node. The robustness of the procedure is tested with numerical experiments by relaxing most of the assumptions made in the model. The water loss estimation in a real network with fictitious measures also shows the robustness of the procedure.
publications-4316 article 2000 Zhou, Senlin and Zhou, S.L and McMahon, Thomas A. and McMahon, Thomas A. and Walton, Andrea and Walton, A. and Lewis, Jeffrey and Lewis, J. Forecasting daily urban water demand: a case study of Melbourne Journal of Hydrology 10.1016/s0022-1694(00)00287-0
publications-4317 article 2000 VΓ­tkovskΓ½, John P. and VΓ­tkovskΓ½, John P. and Simpson, Angus R. and Simpson, Angus R. and Lambert, Martin F. and Lambert, Martin F. Leak Detection and Calibration Using Transients and Genetic Algorithms Journal of Water Resources Planning and Management 10.1061/(asce)0733-9496(2000)126:4(262) Leak detection and calibration of pipe internal roughnesses in a water distribution network are significant issues for water authorities around the world. Computer simulation of water distribution systems to determine the location and size of leaks is emerging as an important tool. A major uncertainty in developing computer models is the condition of the interior of the pipes in the network, especially if they are old. An innovative technique for leak detection and calibration called the inverse transient technique has been recently developed. This paper uses the genetic algorithm (GA) technique in conjunction with the inverse transient method to detect leaks and friction factors in water distribution systems. A continuous variable representation has been developed for the GA coding scheme in this paper. Two new GA operators for crossover and mutation are also introduced. The inverse transient method using the GA technique is effective at finding leakage locations and magnitudes while simultaneously findi...
publications-4318 article 2000 Arora, Geeta and Powell, James C. and Kansal, Mitthan Lal and West, John R. and Minocha, Vijay K. and Powell, Jennifer and Hallam, Nicholas B. and Forster, C.F. and West, John R. and Hallam, Nicholas B. and Simms, John and Forster, C.F. and Simms, John Performance of Various Kinetic Models for Chlorine Decay Journal of Water Resources Planning and Management 10.1061/(asce)0733-9496(2001)127:5(349) A number of computer packages have been developed for modeling chlorine decay in water distribution networks. However, there is uncertainty as to the kinetic model that they should use for the decay mechanism. This paper explores the performance of six different kinetic models for the decay of free chlorine in over 200 bulk water samples from a number of different sources. The paper also presents the results of surveying the longitudinal decay profile of free chlorine in two \Iin situ\N pipe stretches. It concludes that for network modeling purposes, it is generally reasonable to assume first-order kinetics for bulk and overall decay.
publications-4319 article 2004 Prasad, T. Devi and Prasad, T. Devi and Park, Nam-Sik and Park, Namsik Multiobjective Genetic Algorithms for Design of Water Distribution Networks Journal of Water Resources Planning and Management 10.1061/(asce)0733-9496(2004)130:1(73) This paper presents a multiobjective genetic algorithm approach to the design of a water distribution network. The objectives considered are minimization of the network cost and maximization of a reliability measure. In this study, a new reliability measure, called network resilience, is introduced. This measure mimics a designer's desire of providing excess head above the minimum allowable head at the nodes and of designing reliable loops with practicable pipe diameters. The proposed method produces a set of Pareto-optimal solutions in the search space of cost and network resilience. Genetic algorithms are observed to be poor in handling constraints. To handle constraints in a better way, a constraint handling technique that does not require a penalty coefficient and is applicable to water distribution systems is presented. The present model is applied to two example problems, which are widely reported. Comparison of the present method with other methods revealed that the network resilience based approach gave better results.
publications-4320 article 2005 Allmann, Ytimothy P. and Allmann, Ytimothy P. and Carlson, Kenneth and Carlson, Kenneth Expanded Summary: Modeling intentional distribution system Contamination and Detection Journal American Water Works Association 10.1002/j.1551-8833.2005.tb10803.x The vulnerability of drinking water distribution systems, combined with the heightener risk of an attack designed to producce mass casualities, has stirred a great amount of interest in designing adequate defenses for these resources.