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	Abstract
publications-4331	article	2011	Storey, M.V. and Storey, M.V. and Storey, Michael V. and van der Gaag, Bram and van der Gaag, Bram and Burns, Brendan P. and Burns, Brendan P.	Advances in on-line drinking water quality monitoring and early warning systems.	Water Research	10.1016/j.watres.2010.08.049
publications-4332	article	2011	Ng, Tze Ling and Ng, Tze Ling and Eheart, J. Wayland and Eheart, J. Wayland and Cai, Ximing and Cai, Ximing and Braden, John B. and Braden, John B.	An agentβ€based model of farmer decisionβ€making and water quality impacts at the watershed scale under markets for carbon allowances and a secondβ€generation biofuel crop	Water Resources Research	10.1029/2011wr010399	[1]An agent-based model of farmers' crop and best management practice (BMP) decisions is developed and linked to a hydrologic-agronomic model of a watershed, to examine farmer behavior, and the attendant effects on stream nitrate load, under the influence of markets for conventional crops, carbon allowances, and a second-generation biofuel crop. The agent-based approach introduces interactions among farmers about new technologies and market opportunities, and includes the updating of forecast expectations and uncertainties using Bayesian inference. The model is applied to a semi-hypothetical example case of farmers in the Salt Creek Watershed in Central Illinois, and a sensitivity analysis is performed to effect a first-order assessment of the plausibility of the results. The results show that the most influential factors affecting farmers' decisions are crop prices, production costs, and yields. The results also show that different farmer behavioral profiles can lead to different predictions of farmer decisions. The farmers who are predicted to be more likely to adopt new practices are those who interact more with other farmers, are less risk averse, quick to adjust their expectations, and slow to reduce their forecast confidence. The decisions of farmers have direct water quality consequences, especially those pertaining to the adoption of the second-generation biofuel crop, which are estimated to lead to reductions in stream nitrate load. The results, though empirically untested, appear plausible and consistent with general farmer behavior. The results demonstrate the usefulness of the coupled agent-based and hydrologic-agronomic models for normative research on watershed management on the water-energy nexus.
publications-4333	article	2012	Kiesling, Elmar and Kiesling, Elmar and GΓΌnther, Markus and GΓΌnther, Markus and Stummer, Christian and Stummer, Christian and Wakolbinger, Lea M. and Wakolbinger, Lea M.	Agent-based simulation of innovation diffusion: A review	Central European Journal of Operations Research	10.1007/s10100-011-0210-y	Mathematical modeling of innovation diffusion has attracted strong academic interest since the early 1960s. Traditional diffusion models have aimed at empirical generalizations and hence describe the spread of new products parsimoniously at the market level. More recently, agent-based modeling and simulation has increasingly been adopted since it operates on the individual level and, thus, can capture complex emergent phenomena highly relevant in diffusion research. Agent-based methods have been applied in this context both as intuition aids that facilitate theory-building and as tools to analyze real-world scenarios, support management decisions and obtain policy recommendations. This review addresses both streams of research. We critically examine the strengths and limitations of agent-based modeling in the context of innovation diffusion, discuss new insights agent-based models have provided, and outline promising opportunities for future research. The target audience of the paper includes both researchers in marketing interested in new findings from the agent-based modeling literature and researchers who intend to implement agent-based models for their own research endeavors. Accordingly, we also cover pivotal modeling aspects in depth (concerning, e.g., consumer adoption behavior and social influence) and outline existing models in sufficient detail to provide a proper entry point for researchers new to the field.
publications-4334	article	2012	Suero, Francisco J. and Suero, Francisco J. and Mayer, Peter and Mayer, Peter W. and Mayer, Peter W. and Rosenberg, David E. and Rosenberg, David E.	Estimating and Verifying United States Households' Potential to Conserve Water	Journal of Water Resources Planning and Management	10.1061/(asce)wr.1943-5452.0000182	AbstractBehavior and technological impacts on residential indoor water use and conservation efforts in the United States are identified. Preexisting detailed end-use data was collected before and after toilets, faucets, showerheads, and clothes washers were retrofitted in 96 owner-occupied, single-family households in Oakland, California; Seattle, Washington; and Tampa, Florida, between 2000 and 2003. Water volume, duration of use, and time of use were recorded and disaggregated by appliance for two weeks before and four weeks after appliances were retrofitted. For each appliance, observed differences in water use before and after retrofits are compared to water savings predicted by simple analytical, regression, and hybrid models. Comparisons identify prediction precision among models. Results show that observed and predicted distributions of water savings are skewed with a small number of households showing potential to save more water. Regression and hybrid model results also show the relative and sign...
publications-4335	article	2013	Beal, Cara and Beal, Cara and Stewart, Rodney Anthony and Stewart, Rodney Anthony and Fielding, Kelly S. and Fielding, Kelly S.	A novel mixed method smart metering approach to reconciling differences between perceived and actual residential end use water consumption	Journal of Cleaner Production	10.1016/j.jclepro.2011.09.007	Studies have shown that householdersβ€™ perceptions of their water use are often not well matched with their actual water use. There has been less research however, investigating whether this bias is related to specific categories of end use and/or specific types of socio-demographic and socio-psychological household profiles. A high resolution smart metering study producing a detailed end use event registry as well as psycho-social and socio-demographic surveys, stock inventory audits and self-reported water diaries was completed for 252 households located in South-east Queensland, Australia. The study examined the contributions of end uses to total water use for each group that self-identified as β€_x009c_lowβ€_x009d_, β€_x009c_mediumβ€_x009d_ or β€_x009c_highβ€_x009d_ water users. A series of univariate tests (i.e. analysis of variance) were conducted to examine a range of variables that characterise each self-identified water usage group including age, income, percentage of water efficient stock (e.g. low-flow taps), family size and composition and water conservation intentions and attitudes. The level of information consumers receive on their water bill as well as the diurnal end use patterns were also examined. The paper concludes with a discussion of the general characteristics (i.e. income, age, gender and family composition) of groups that tended to overestimate or underestimate their water use and how this knowledge can be used to inform demand management policy such as targeted community education programmes and community-based social marketing. Further, the potential for positive economic and sustainable development outcomes from this research is also discussed.
publications-4336	article	2013	Makki, Anas A. and Makki, Anas Ahmad and Stewart, Rodney Anthony and Stewart, Rodney Anthony and Panuwatwanich, Kriengsak and Panuwatwanich, Kriengsak and Beal, Cara and Beal, Cara	Revealing the determinants of shower water end use consumption: enabling better targeted urban water conservation strategies	Journal of Cleaner Production	10.1016/j.jclepro.2011.08.007	Abstract The purpose of this study was to explore the predominant determinants of shower end use consumption and to find an overarching research design for building a residential water end use demand forecasting model using aligned socio-demographic and natural science data sets collected from 200 households fitted with smart water meters in South-east Queensland, Australia. ANOVA as well as multiple regression analysis statistical techniques were utilised to reveal the determinants (e.g. household makeup, shower fixture efficiency, income, education, etc.) of household shower consumption. Results of a series of one-way independent ANOVA extended into linear multiple regression models revealed that females, children in general and teenagers in particular, and the showerhead efficiency level were statistically significant determinants of shower end use consumption. Eight-way independent factorial ANOVA extended into a three-tier hierarchical linear multiple regression model, was used to create a shower end use forecasting model, and indicated that household size and makeup, as well as the showerhead efficiency rating, are the most significant predictors of shower usage. The generated multiple regression model was deemed reliable, explaining 90.2\% of the variation in household shower end use consumption. The paper concludes with a discussion on the significant shower end use determinants and how this statistical approach will be followed to predict other residential end uses, and overall household consumption. Moreover, the implications of the research to urban water conservation strategies and policy design, is discussed, along with future research directions.
publications-4337	article	2015	Jung, Donghwi and Jung, Donghwi and Jung, Donghwi and Lansey, Kevin and Lansey, Kevin E	Water distribution system burst detection using a nonlinear Kalman filter	Journal of Water Resources Planning and Management	10.1061/(asce)wr.1943-5452.0000464	AbstractA water distribution system burst from a sudden pipe failure results in water loss and disruption of customer service. Artificial neural networks, state estimation, and statistical process control (SPC) have been applied to detect bursts. However, system operational condition changes such as the set of operating pumps and valve closures greatly complicates the detection problem. Thus, to date applications have been limited to networks that are supplied by gravity or under consistent operation conditions. This study seeks to overcome these limitations using a nonlinear Kalman filter (NKF) method to identify system condition, estimate system state, and detect bursts.
publications-4338	article	2000	Deb, Kalyanmoy and Agrawal, Samir and Pratap, Amrit and Meyarivan, T.	A Fast Elitist Non-dominated Sorting Genetic Algorithm for Multi-objective Optimization: NSGA-II		10.1007/3-540-45356-3_83	Multi-objective evolutionary algorithms which use non-dominated sorting and sharing have been mainly criticized for their (i) O(MN3) computational complexity (where M is the number of objectives and N is the population size), (ii) non-elitism approach, and (iii) the need for specifying a sharing parameter. In this paper, we suggest a non-dominated sorting based multi-objective evolutionary algorithm (we called it the Non-dominated Sorting GA-II or NSGA-II) which alleviates all the above three difficulties. Specifically, a fast non-dominated sorting approach with O(MN2) computational complexity is presented. Second, a selection operator is presented which creates a mating pool by combining the parent and child populations and selecting the best (with respect to fitness and spread) N solutions. Simulation results on five difficult test problems show that the proposed NSGA-II, in most problems, is able to find much better spread of solutions and better convergence near the true Pareto-optimal front compared to PAES and SPEA--two other elitist multi-objective EAs which pay special attention towards creating a diverse Pareto-optimal front. Because of NSGA-II's low computational requirements, elitist approach, and parameter-less sharing approach, NSGA-II should find increasing applications in the years to come.
publications-4339	article	2000	Renwick, Mary E. and Renwick, Mary E. and Green, Richard D. and Green, Richard D.	Do Residential Water Demand Side Management Policies Measure Up? An Analysis of Eight California Water Agencies	Journal of Environmental Economics and Management	10.1006/jeem.1999.1102	Abstract To assess the potential of price and alternative demand side management (DSM) policies as an urban water resource management tool, an econometric model of residential demand is formulated and estimated. This econometric model incorporates alternative DSM policy instruments (such as water allocations, use restrictions, public education) and increasing block pricing schedules. The analysis relies on cross-sectional monthly time-series data for eight water agencies in California representing 24\% of the state's population (7.1 million people). Results suggest that both price and alternative DSM policies were effective in reducing demand. However, the magnitude of the reduction in demand varied among policy instruments.
publications-4340	article	2002	Tryby, Michael E. and Boccelli, Dominic L. and Uber, James G. and Rossman, Lewis A.	Facility Location Model for Booster Disinfection of Water Supply Networks	Journal of Water Resources Planning and Management	10.1061/(asce)0733-9496(2002)128:5(322)	Secondary or postdisinfection is widely used to maintain protective levels of disinfectant within water distribution systems. In contrast to conventional methods that apply disinfectant only at the treatment works, booster disinfection reapplies disinfectant at strategic locations within the distribution system to compensate for the losses that occur as it decays over time. Building on the writers' previous work, this paper addresses the problem of locating disinfectant booster stations that minimize the dosage required to maintain residuals throughout the supply network, and introduces a useful parameterization for disinfectant source types. The model is related to the general fixed-charge facility location problem and is formulated as a mixed integer linear programming problem. Results for an example network show that disinfectant dosage savings are achievable with the adoption of booster disinfection, and that the rate of savings decreases as the number of booster stations utilized increases. Furthermore, booster disinfection may provide a more even distribution of disinfectant concentrations throughout the network, and has the potential to reduce aggregate exposure of the population to chlorine (and its by-products) while simultaneously improving residual coverage in the periphery of the distribution system.