scholarly journals An agent-based modeling framework for sociotechnical simulation of water distribution contamination events

2013 ◽  
Vol 15 (3) ◽  
pp. 862-880 ◽  
Author(s):  
M. Ehsan Shafiee ◽  
Emily M. Zechman
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Large Population ◽  
Water Distribution Network ◽  
Contaminant Plume ◽  
Modeling Framework ◽  
Agent Based ◽  
Water Demands ◽  
Demand Patterns

In the event that a contaminant is introduced to a water distribution network, a large population of consumers may risk exposure. Selecting mitigation actions to protect public health may be difficult, as contamination is a poorly predictable dynamic event. Consumers who become aware of an event may select protective actions to change their water demands from typical demand patterns, and new hydraulic conditions can arise that differ from conditions that would be predicted when demands are considered as exogenous inputs. Consequently, the movement of the contaminant plume in the pipe network may shift from its expected trajectory. A sociotechnical model is developed here to integrate agent-based models of consumers with an engineering water distribution system model and capture the dynamics between consumer behaviors and the water distribution system for predicting contaminant transport and public exposure. Consumers are simulated as agents with behaviors, including movement, water consumption, exposure, reduction in demands, and communication with other agents. As consumers decrease their water use, the location of the contaminant plume is updated and the amount of contaminant consumed by each agent is calculated. The framework is tested through simulating realistic contamination scenarios for a virtual city and water distribution system.

Assessment of Lisbon drinking water distribution network biofilm colonization and associated hazards

2008 ◽  
Vol 8 (4) ◽  
pp. 421-426
Author(s):  
J. Menaia ◽  
M. Benoliel ◽  
A. Lopes ◽  
C. Neto ◽  
E. Ferreira ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Storage Tanks ◽  
Water Pipe ◽  
Cultural Methods ◽  
Drinking Water Distribution ◽  
And Storage

Concerns arise from the possible occurrence of pathogens in drinking water pipe biofilms and storage tank sediments. In these studies, biofilm samples from pipes and sediments from storage tanks of the Lisbon drinking water distribution system were analyzed. Protein determinations and heterotrophic counts on pipe biofilm samples were used to assess the Lisbon network sessile colonization intensity and distribution. Indicator and pathogenic microorganisms were analyzed in pipe biofilm samples, as well as in storage tanks biofilm and sediments, by using cultural methods and PCR, to assess risks. Results have shown that the Lisbon network sessile colonization is relatively weak in intensity. In addition, no meaningful hazards were apparent for both the network biofilm and the storage tanks biofilm and sediments.

Study on the impacts of peaking factors on a water distribution system in Germany

2010 ◽  
Vol 10 (2) ◽  
pp. 165-172 ◽  
Author(s):  
K. Diao ◽  
M. Barjenbruch ◽  
U. Bracklow
Keyword(s):  
Energy Consumption ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Design Stage ◽  
Water Age ◽  
Specific System ◽  
Average Water

This paper aims to explore the impacts of peaking factors on a water distribution system designed for a small city in Germany through model-based analysis. As a case study, the water distribution network was modelled by EPANET and then two specific studies were carried out. The first study tested corresponding system-wide influences on water age and energy consumption if the peaking factors used at design stage are inconsistent with ones in real situation. The second study inspected the possible relationship between the choice of peaking factors and budgets by comparing several different pipe configurations of the distribution system, obtained according to variety of peaking factors. Given the analysis results, the first study reveals that average water age will increase if peaking factors estimated at design stage are larger than real values in that specific system, and vice versa. In contrast, energy consumption will increase if peaking factors defined for system design are smaller than ones in real case, and vice versa. According to the second study, it might be possible to amplify peaking factors for design dramatically by a slight increase in the investment on this system. However, further study on budget estimation with more factors and detailed information considered should be carried out.

scholarly journals Management of water distribution systems in PDA conditions using isolation valves: case studies of real networks

2019 ◽  
Vol 22 (4) ◽  
pp. 681-690 ◽  
Author(s):  
A. Fiorini Morosini ◽  
O. Caruso ◽  
P. Veltri
Keyword(s):  
Case Studies ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Optimal Number ◽  
System Management ◽  
System Control

Abstract The current paper reports on a case study investigating water distribution system management in emergency conditions when it is necessary to seal off a zone with isolation valves to allow repair. In these conditions, the pressure-driven analysis (PDA) is considered to be the most efficient approach for the analysis of a water distribution network (WDN), as it takes into account whether the head in a node is adequate to ensure service. The topics of this paper are innovative because, until now, previous approaches were based on the analysis of the network behaviour in normal conditions. In emergency conditions, it is possible to measure the reliable functioning of the system by defining an objective function (OF) that helps to choose the optimal number of additional valves in order to obtain adequate system control. The OF takes into account the new network topology by excluding the zone where the broken pipe is located. The results show that the solution did not improve significantly when the number of valves reached a threshold. The procedure applied to other real case studies seems to confirm the efficiency of the methodology even if further examination of other cases in different conditions is necessary.

scholarly journals Promoting equitable water distribution system from Melamchi Water Supply Project in Kathmandu Valley

2020 ◽  
Vol 20 (8) ◽  
pp. 2964-2970
Author(s):  
D. P. Ayadi ◽  
A. Rai ◽  
A. Pandey
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Supply System ◽  
Kathmandu Valley ◽  
Drinking Water Resources ◽  
Key Issues

Abstract The effective and efficient supply of drinking water resources are key to its long-term use and access. In recent decades, the population of Kathmandu Valley has exploded owing to several factors. The water supply system here has also undergone remarkable changes and efforts have been made to enhance its equitable distribution. The major effort, of course, is the Melamchi Water Supply Project (MWSP). As the project approaches completion of its first phase, we would like to point out several key issues for the water distribution system here and express our opinions on promoting equitable water distribution. For this we conducted a thorough literature review and found that improvement in the water distribution network and water tariff in the valley, along with promotion of alternative mitigation options, are the focal issues for promoting an equitable water distribution system in Kathmandu Valley.

Leakage management in a low-pressure water distribution network of Bangkok

2009 ◽  
Vol 9 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Mukand S. Babel ◽  
Md. S. Islam ◽  
A. Das Gupta
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Level Of Service ◽  
Operating Pressure ◽  
Asian Countries ◽  
Pressure Profiles ◽  
Pressure Water

Losses of water due to leakage occur in every distribution network, the only difference is in the amount of leakage. The leakage levels are relatively high in cities of developing Asian countries. Among the several factors, operating pressure is the most important affecting the leakage. This paper describes how the management of pressure can help reduce the leakage in the water distribution network. EPANET is used to develop the hydraulic model to analyse the effect of alternative pressure profiles on the leakage in a pilot area within the water distribution system of Bangkok. One of the alternatives is implemented in the field to verify the applicability of the model. Results indicate that the average reduction in pressure by 2.4 m can reduce the leakage by 12.5% of the system inflow without compromising the level of service.

scholarly journals A bottom-up approach of stochastic demand allocation in water quality modelling

2010 ◽  
Vol 3 (1) ◽  
pp. 43-51 ◽  
Author(s):  
E. J. M. Blokker ◽  
J. H. G. Vreeburg ◽  
H. Beverloo ◽  
M. Klein Arfman ◽  
J. C. van Dijk
Keyword(s):  
Drinking Water ◽  
Water Demand ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Drinking Water Distribution System ◽  
Travel Times ◽  
Bottom Up ◽  
Drinking Water Distribution ◽  
Demand Patterns

Abstract. An "all pipes" hydraulic model of a drinking water distribution system was constructed with two types of demand allocations. One is constructed with the conventional top-down approach, i.e. a demand multiplier pattern from the booster station is allocated to all demand nodes with a correction factor to account for the average water demand on that node. The other is constructed with a bottom-up approach of demand allocation, i.e., each individual home is represented by one demand node with its own stochastic water demand pattern. This was done for a drinking water distribution system of approximately 10 km of mains and serving ca. 1000 homes. The system was tested in a real life situation. The stochastic water demand patterns were constructed with the end-use model SIMDEUM on a per second basis and per individual home. Before applying the demand patterns in a network model, some temporal aggregation was done. The flow entering the test area was measured and a tracer test with sodium chloride was performed to determine travel times. The two models were validated on the total sum of demands and on travel times. The study showed that the bottom-up approach leads to realistic water demand patterns and travel times, without the need for any flow measurements or calibration. In the periphery of the drinking water distribution system it is not possible to calibrate models on pressure, because head losses are too low. The study shows that in the periphery it is also difficult to calibrate on water quality (e.g. with tracer measurements), as a consequence of the high variability between days. The stochastic approach of hydraulic modelling gives insight into the variability of travel times as an added feature beyond the conventional way of modelling.

scholarly journals Hydraulic optimization of the physical parameters of a drinking water distribution system

2021 ◽  
Vol 2139 (1) ◽  
pp. 012013
Author(s):  
C A Bonilla-Granados ◽  
N J Cely-Calixto ◽  
G A Carrillo Soto
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Hydraulic Modeling ◽  
Physical Parameters ◽  
Drinking Water Distribution System ◽  
Drinking Water Distribution

Abstract Drinking-water distribution systems are generally designed with methodologies based on trial-and-error tests, which generate feasible results. However, these trials are not the most economical and reliable solution since they do not consider the optimization of the network. For the present work, the hydraulic model of the drinking water distribution network of San José de Cúcuta, Colombia, was optimized by applying the concept of resilience rate and minimum cost. The development of the work consisted of the hydraulic modeling of the physical components of the network in EPANET software, as well as the application of calculations of the connectivity coefficient and the unitary power of each section. With the data obtained from the modeling and calculations, the physical parameters were optimized, and the cost-benefit ratio was estimated. It was found that the current drinking water distribution system does not have a power surplus to overcome a system failure. The optimization increased the total energy surplus of the network (261%) and the resilience rate (585%). Also, the connectivity coefficient was improved with an average value of 0.95. The hydraulic optimization methodology applied resulted in a network resilient to system failures.

scholarly journals The Impacts of Spatially Variable Demand Patterns on Water Distribution System Design and Operation

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 567 ◽  
Author(s):  
Kegong Diao ◽  
Robert Sitzenfrei ◽  
Wolfgang Rauch
Keyword(s):  
Water Quality ◽  
System Design ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Service Failure ◽  
Design Flow ◽  
Level Of Service ◽  
Demand Patterns

Resilient water distribution systems (WDSs) need to minimize the level of service failure in terms of magnitude and duration over its design life when subject to exceptional conditions. This requires WDS design to consider scenarios as close as possible to real conditions of the WDS to avoid any unexpected level of service failure in future operation (e.g., insufficient pressure, much higher operational cost, water quality issues, etc.). Thus, this research aims at exploring the impacts of design flow scenarios (i.e., spatial-variant demand patterns) on water distribution system design and operation. WDSs are traditionally designed by using a uniform demand pattern for the whole system. Nevertheless, in reality, the patterns are highly related to the number of consumers, service areas, and the duration of peak flows. Thus, water distribution systems are comprised of distribution blocks (communities) organized in a hierarchical structure. As each community may be significantly different from the others in scale and water use, the WDSs have spatially variable demand patterns. Hence, there might be considerable variability of real flow patterns for different parts of the system. Consequently, the system operation might not reach the expected performance determined during the design stage, since all corresponding facilities are commonly tailor-made to serve the design flow scenario instead of the real situation. To quantify the impacts, WDSs’ performances under both uniform and spatial distributed patterns are compared based on case studies. The corresponding impacts on system performances are then quantified based on three major metrics; i.e., capital cost, energy cost, and water quality. This study exemplifies that designing a WDS using spatial distributed demand patterns might result in decreased life-cycle cost (i.e., lower capital cost and nearly the same pump operating cost) and longer water ages. The outcomes of this study provide valuable information regarding design and operation of water supply infrastructures; e.g., assisting the optimal design.

Application of Artificial Neural Network for Reducing of Chlorine Residual Concentration in Water Distribution Network

2008 ◽  
Vol 3 (2) ◽  
Author(s):  
Jayong Koo ◽  
Toyono Inakazu ◽  
Akira Koizumi ◽  
Yasuhiro Arai ◽  
Kyoungpil Kim ◽  
...  
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Residual Chlorine ◽  
Trial And Error ◽  
Ann Model ◽  
Residual Concentration ◽  
Dead End

It is difficult to estimate residual chlorine at the dead-end area of the water distribution network because chlorine consumption is influenced by various factors. Therefore, there are many water utilities that control the amounts of chlorine in reservoirs using empirical trial-and-error methods to maintain safe levels of residual chlorine in the distribution system. In this study, an ANN model of residual chlorine concentration is proposed which could be used to reduce in chlorine use in water distribution system. The ANN model with best performance was selected by training and verification. The five scenarios for the reduction in chlorine use were analyzed by setting the input chlorine as low as 0.05~0.25 mg/L compared with the input chlorine observed in the time series. Case 4 is the best to be satisfied with the input condition (0.4 mg/L or more) and output condition (0.34 mg/L or more) at the same time. It is possible to reduce chlorine in use up to 0.2 mg/L in the maximum amount.

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