| publications-4451 |
article |
2002 |
Jain, Ashu and Jain, Ashu and Ormsbee, Lindell and Ormsbee, Lindell |
Short-term water demand forecast modeling techniques: Conventional methods versus AI |
Journal American Water Works Association |
10.1002/j.1551-8833.2002.tb09507.x |
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A variety of forecast modeling techniques, from conventional techniques such as regression and time series analyses to relatively new artificial intelligence (AI) techniques such as expert systems and artificial neural networks (ANNs), were investigated for use in short-term water demand forecasting. Daily water demand, daily maximum air temperature, and daily total rainfall data from Lexington, Ky., for 1982-92 were used to develop and test several forecast models. The performance of each model was evaluated using two standard statistical parameters. On the basis of the measured statistical parameters, the Al models outperformed the conventional models. Both expert system and ANN technologies should be further explored by water utility engineers and managers because these techniques have the potential to enhance the operational performance of various water supply and delivery systems. |
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| publications-4452 |
article |
2003 |
Feuillette, Sarah and Feuillette, Sarah and Bousquet, François and Bousquet, François and Goulven, Patrick Le and Goulven, P. Le |
SINUSE: a multi-agent model to negotiate water demand management on a free access water table |
Environmental Modelling and Software |
10.1016/s1364-8152(03)00006-9 |
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| publications-4453 |
article |
2004 |
Howarth, David Armine and Howarth, D. and BΓΌtler, Sarah and Butler, S. |
Communicating water conservation: how can the public be engaged? |
Water Science & Technology: Water Supply |
10.2166/ws.2004.0041 |
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In 2001 the Environment Agency and Thames Water completed a collaborative research project β€_x009c_The Effectiveness of Marketing Campaigns in Achieving Water Efficiency Savingsβ€_x009d_. The project attempted to assess the effectiveness of a water efficiency campaign in a residential area of 8000 properties. The results showed that the campaign had no significant effect on water demand both at the individual property level and the total flow into the area. Responses to direct questions about the campaign indicated that at most 5\% had noticed it despite the fact that 25\% claimed to read the local newspaper and listen to the local radio station used for the campaign, and the fact that a leaflet was sent to all households. The market research provided some clues as to why the customer response to this campaign was so disappointing, principally because the public regard water as low priority compared to other environmental issues. Other research is reviewed that provide additional reasons for the unwillingness of the public to engage on this issue. This paper reviews β€_x009c_success storiesβ€_x009d_ from Phoenix, Arizona and Singapore and identifies the main learning points from these programs. Article 14 of the Water Framework Directive calls for active involvement in water policy. An assessment is made of what this might mean for public participation in water conservation programs. |
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| publications-4454 |
article |
2004 |
White, Saxon William and White, Stuart and Milne, GR and Milne, George R. and Riedy, Chris and Riedy, Chris |
End use analysis: issues and lessons |
Water Science & Technology: Water Supply |
10.2166/ws.2004.0043 |
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Methodologies for end use analysis have been developed by different researchers in the energy and water fields and in different areas in the world over the last 20 years. While there are core features associated with the methodologies and models used, the differences can provide insight into the ways that they might be improved, as well as the differences that may be required in different regions and when models are used for different purposes. In addition to reviewing the field of end use analysis and appliance stock models, this paper will focus on two case studies. The first is the Sydney Water End Use Model, developed as part of the Sydney Water Least Cost Planning Study. This model has been developed and used to project the demand for water in Sydney over the next 20 years under business as usual scenario, as well as allow the projection of a number of scenarios which include major investment in water efficiency and effluent reuse programs as well as regulatory options to improve the efficiency of water using appliances in stalled in new buildings. Key features of the Sydney Water End Use Model include the fact that it takes into account the fact that the efficiency of toilets in Australia has a much larger range than (say) the US, in that the dual flush toilet was introduced in (to date) three stages. The model also accounts for projections of demographic and land use change which has been particularly dramatic in Sydney, particularly the movement to smaller occupancy rates in dwellings, and towards multi-family residential dwellings. The second case study will demonstrate the linkages between end use modeling of energy using and water using appliances. A model of residential energy use in Australia has been developed as part of a research project to develop greenhouse abatement scenarios for Australia, and many of the appliances modeled overlap with the water end use model, including clothes washing machines, dishwashers, showerheads and taps. This more recent modeling exercise has revealed the importance of key assumptions in standard stock modeling techniques, and highlighted the need for earlier starting dates for stock modeling. The process and results of these two case studies will be presented, and conclusions drawn about further improvements in end use analysis for both water and energy use. The linkage between the use of backcasting as a planning tool, and the use of end use analysis as a pre-requisite for the development of a demand management program is highlighted. |
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| publications-4455 |
article |
2004 |
ArbuΓ©s, Fernando and ArbuΓ©s, Fernando and OrtΓÂ, RamΓ³n BarberΓ΅n and BarberΓ΅n, RamΓ³n and VillanΓΊa, Inmaculada and VillanΓΊa, Inmaculada |
Price impact on urban residential water demand: A dynamic panel data approach |
Water Resources Research |
10.1029/2004wr003092 |
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[1]In this paper, we formulate and estimate a model of residential water demand with the aim of evaluating the potential of pricing policies as a mechanism for managing residential water. The proposed econometric model offers a new perspective on urban water demand analysis by combining microlevel data with a dynamic panel data estimation procedure. The empirical application suggests that residential users are more responsive to a lagged average price specification. Another result of the estimated model is that price is a moderately effective tool in reducing residential water demand within the present range of prices, with the estimated values for income elasticity and β€_x009c_elasticity of consumption with respect to family sizeβ€_x009d_ reinforcing this conclusion. |
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| publications-4456 |
article |
2007 |
Slay, Jill and Slay, Jill and Miller, Michael G. and Miller, Michael |
Lessons Learned from the Maroochy Water Breach |
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10.1007/978-0-387-75462-8_6 |
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Supervisory control and data acquisition (SCADA) systems are widely used to monitor and control operations in electrical power distribution facilities, oil and gas pipelines, water distribution systems and sewage treatment plants. Technological advances over the past decade have seen these traditionally closed systems become open and Internet-connected, which puts the service infrastructures at risk. This paper examines the response to the 2000 SCADA security incident at Maroochy Water Services in Queensland, Australia. The lessons learned from this incident are useful for establishing academic and industry-based research agendas in SCADA security as well as for safeguarding critical infrastructure components.Keywords: SCADA security, Maroochy Water Services breach |
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| publications-4457 |
article |
2008 |
Skadsen, Janice and Janke, Robert and Janke, Robert and Janke, Robert and Grayman, Walter M. and Samuels, William B. and Tenbroek, Mark and Steglitz, Brian and Bahl, Sumedh |
Distribution system on-line monitoring for detecting contamination and water quality changes |
Journal American Water Works Association |
10.1002/j.1551-8833.2008.tb09678.x |
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Concerns about water quality and possible intentional contamination of water distribution systems are making on-line monitoring an increasingly important priority for many water utilities. The city of Ann Arbor (Mich.) evaluated different water quality monitoring parameters, tested multiple manufacturers’ monitoring equipment, and evaluated how to effectively locate monitoring equipment within the distribution system to address these two concerns. A suite of modeling tools was used in this case study. Total chlorine, ultraviolet absorbance at 254 nm, conductivity, and dissolved oxygen were selected for monitoring based on pilot testing. When balancing costs and benefits, four stations for monitoring water quality and four stations for monitoring contamination events were found to be sufficient for the city. Only one location was common between water quality and security sites, and the number of security monitors needed was not affected by system demands. It was confirmed that it is critical to minimize response time in order to mitigate the effects of a contamination event. |
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| publications-4458 |
article |
2009 |
Hasan, Jafrul and States, Stanley and Deininger, Rolf A. |
Safeguarding The Security Of Public Water Supplies Using Early Warning Systems: A Brief Review |
Journal of Contemporary Water Research & Education |
10.1111/j.1936-704x.2004.mp129001007.x |
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Water distribution systems are vulnerable to aquaterrorism (terrorism attacks on the water supply) because they are extensive, relatively unprotected, accessible, and often isolated (USEPA 2002, 2003a, Grayman, 2002; Mays, 2004). An emerging activity in the water security arena is developing methods to minimize the public health and economic impacts of a large-scale attack. An intense effort is currently underway to improve analytical monitoring and detection of biological, chemical, and radiological contaminants in drinking water systems as part of the overall effort to secure drinking water supplies (USEPA, 2003b). One approach for avoiding or mitigating the impacts from contamination of a distribution system is to perform monitoring in the context of an Early Warning System (EWS). At present, federal agencies, academic communities, and private companies are working together to develop practical and effective early warning systems. The goal of an early warning system is to reliably identify lowprobability/high-impact contamination events in a distribution system’s finished water, or in source water, in time to permit an effective local response that reduces or avoids entirely the adverse impacts that may result from such an event. The core of an EWS is a monitoring technology that, ideally, would detect or screen for a variety of toxic substances or infectious microorganisms (Brosnan 1999; USEPA 2002). This article briefly reviews the essential elements of an EWS, the relevant plans for developing and implementing an EWS, and the current status and potential for an EWS to ensure the security of drinking water supplies and systems. |
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| publications-4459 |
article |
2009 |
Uber, James G. and Uber, James G. and Murray, Regan and Murray, Regan and Janke, Robert and Janke, Robert |
Use of Systems Analysis to Assess and Minimize Water Security Risks |
Journal of Contemporary Water Research & Education |
10.1111/j.1936-704x.2004.mp129001008.x |
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Drinking water systems are vulnerable to contamination by toxic substances, whether the contaminants are introduced intentionally during a terrorist attack, or unintentionally through accidental cross-connections or backflow incidents. In this paper, we discuss the particular characteristics of distribution systems that make a β€_x009c_systems modelingβ€_x009d_ approach useful and effective in assessing, preventing, and mitigating water security threats, and we outline the research needed to develop robust models for water security. |
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| publications-4460 |
article |
2010 |
Davis, Michael and Davis, Michael J. and Davis, Michael J. and Janke, Robert and Janke, Robert and Taxon, Tom and Taxon, T. N. and Evs and EVS |
Assessing potential impacts associated with contamination events in water distribution systems : a sensitivity analysis. |
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10.2172/1009336 |
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An understanding of the nature of the adverse effects that could be associated with contamination events in water distribution systems is necessary for carrying out vulnerability analyses and designing contamination warning systems. This study examines the adverse effects of contamination events using models for 12 actual water systems that serve populations ranging from about 104 to over 106 persons. The measure of adverse effects that we use is the number of people who are exposed to a contaminant above some dose level due to ingestion of contaminated tap water. For this study the number of such people defines the impact associated with an event. We consider a wide range of dose levels in order to accommodate a wide range of potential contaminants. For a particular contaminant, dose level can be related to a health effects level. For example, a dose level could correspond to the median lethal dose, i.e., the dose that would be fatal to 50\% of the exposed population. Highly toxic contaminants may be associated with a particular response at a very low dose level, whereas contaminants with low toxicity may only be associated with the same response at a much higher dose level. This report focuses onmoreΒ» the sensitivity of impacts to five factors that either define the nature of a contamination event or involve assumptions that are used in assessing exposure to the contaminant: (1) duration of contaminant injection, (2) time of contaminant injection, (3) quantity or mass of contaminant injected, (4) population distribution in the water distribution system, and (5) the ingestion pattern of the potentially exposed population. For each of these factors, the sensitivities of impacts to injection location and contaminant toxicity are also examined. For all the factors considered, sensitivity tends to increase with dose level (i.e., decreasing toxicity) of the contaminant, with considerable inter-network variability. With the exception of the population distribution (factor 4 above), sensitivity to the various factors tends to be highest at lower impact levels (e.g., impacts below the 80th percentile). Conversely, for the population distribution factor, sensitivity is lowest at the lower impact levels. For injection duration, impacts generally are higher for longer duration injections. Definite patterns are present in the sensitivity of impacts to injection time, but these vary substantially across the networks. As would be expected, impacts are larger for larger mass injections, but the sensitivity can vary dramatically depending on dose level and the network. Estimated impacts can be sensitive to assumptions about how population is distributed in a network, particularly at high impact levels and high dose levels, again with considerable variability across networks. Finally, impacts can be sensitive to assumptions about ingestion patterns in the potentially exposed population, with sensitivities varying across networks and tending to be highest for high dose levels. When considered in combination with the other factors (but not including the ingestion model used), impacts at low dose levels (levels at which the effects of highly toxic contaminants can be significant) are most sensitive to injection duration. Similarly, when considered in combination, impacts at higher dose levels (levels required for significant effects from contaminants with low toxicity) are most sensitive to injection mass. At low dose levels, for a likely range in injection masses, impacts are not particularly sensitive to injection mass. The influence of the various factors on the location of high percentile injection locations can be as important or more important than their influence on the magnitudes of impacts. In addition, the choice of contaminant has a major influence on which nodes are high impact injection locations. The sharing (overlap) of the same high-percentile injection nodes for different values of a factor can vary substantially by contaminant and impact level (percentile of impact). Overlap tends to decrease with decreasing toxicity of the contaminant and increasing impact level for all the factors considered, with considerable variability among the networks. Our results demonstrate the great variability in the impacts and the sensitivity of impacts to various factors that can occur in different water systems during a contamination event. Although definite patterns exist in the nature and magnitude of impacts and sensitivities for the diverse set of water systems examined, these results also show that substantial inter-network variability limits the ability to predict or extrapolate these results to other systems. Therefore, although water systems do exhibit some similarities in the magnitude and pattern of impacts during contamination events, each individual water system should be treated as unique.Β«less |
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