WorldWideScience

Sample records for water demand model

  1. Cache County Water Demand/Supply Model

    OpenAIRE

    Hughes, Trevor C.; Norby, Gregory J.; Thyagarajan, Laxman

    1996-01-01

    This report descibes a municipal water demand forecasting model for use in areas of mixed rural and urban housing types. A series of residential demand functions were derived which forecast water demand based on the ype and density of housing and season. Micro sampling techniques were used to correlate water use data and explanatory variable data for low, medium, and high density housing. The demand functions were...

  2. Modeling water demand when households have multiple sources of water

    Science.gov (United States)

    Coulibaly, Lassina; Jakus, Paul M.; Keith, John E.

    2014-07-01

    A significant portion of the world's population lives in areas where public water delivery systems are unreliable and/or deliver poor quality water. In response, people have developed important alternatives to publicly supplied water. To date, most water demand research has been based on single-equation models for a single source of water, with very few studies that have examined water demand from two sources of water (where all nonpublic system water sources have been aggregated into a single demand). This modeling approach leads to two outcomes. First, the demand models do not capture the full range of alternatives, so the true economic relationship among the alternatives is obscured. Second, and more seriously, economic theory predicts that demand for a good becomes more price-elastic as the number of close substitutes increases. If researchers artificially limit the number of alternatives studied to something less than the true number, the price elasticity estimate may be biased downward. This paper examines water demand in a region with near universal access to piped water, but where system reliability and quality is such that many alternative sources of water exist. In extending the demand analysis to four sources of water, we are able to (i) demonstrate why households choose the water sources they do, (ii) provide a richer description of the demand relationships among sources, and (iii) calculate own-price elasticity estimates that are more elastic than those generally found in the literature.

  3. Accounting for Water Insecurity in Modeling Domestic Water Demand

    Science.gov (United States)

    Galaitsis, S. E.; Huber-lee, A. T.; Vogel, R. M.; Naumova, E.

    2013-12-01

    Water demand management uses price elasticity estimates to predict consumer demand in relation to water pricing changes, but studies have shown that many additional factors effect water consumption. Development scholars document the need for water security, however, much of the water security literature focuses on broad policies which can influence water demand. Previous domestic water demand studies have not considered how water security can affect a population's consumption behavior. This study is the first to model the influence of water insecurity on water demand. A subjective indicator scale measuring water insecurity among consumers in the Palestinian West Bank is developed and included as a variable to explore how perceptions of control, or lack thereof, impact consumption behavior and resulting estimates of price elasticity. A multivariate regression model demonstrates the significance of a water insecurity variable for data sets encompassing disparate water access. When accounting for insecurity, the R-squaed value improves and the marginal price a household is willing to pay becomes a significant predictor for the household quantity consumption. The model denotes that, with all other variables held equal, a household will buy more water when the users are more water insecure. Though the reasons behind this trend require further study, the findings suggest broad policy implications by demonstrating that water distribution practices in scarcity conditions can promote consumer welfare and efficient water use.

  4. Development of Ensemble Model Based Water Demand Forecasting Model

    Science.gov (United States)

    Kwon, Hyun-Han; So, Byung-Jin; Kim, Seong-Hyeon; Kim, Byung-Seop

    2014-05-01

    In recent years, Smart Water Grid (SWG) concept has globally emerged over the last decade and also gained significant recognition in South Korea. Especially, there has been growing interest in water demand forecast and optimal pump operation and this has led to various studies regarding energy saving and improvement of water supply reliability. Existing water demand forecasting models are categorized into two groups in view of modeling and predicting their behavior in time series. One is to consider embedded patterns such as seasonality, periodicity and trends, and the other one is an autoregressive model that is using short memory Markovian processes (Emmanuel et al., 2012). The main disadvantage of the abovementioned model is that there is a limit to predictability of water demands of about sub-daily scale because the system is nonlinear. In this regard, this study aims to develop a nonlinear ensemble model for hourly water demand forecasting which allow us to estimate uncertainties across different model classes. The proposed model is consist of two parts. One is a multi-model scheme that is based on combination of independent prediction model. The other one is a cross validation scheme named Bagging approach introduced by Brieman (1996) to derive weighting factors corresponding to individual models. Individual forecasting models that used in this study are linear regression analysis model, polynomial regression, multivariate adaptive regression splines(MARS), SVM(support vector machine). The concepts are demonstrated through application to observed from water plant at several locations in the South Korea. Keywords: water demand, non-linear model, the ensemble forecasting model, uncertainty. Acknowledgements This subject is supported by Korea Ministry of Environment as "Projects for Developing Eco-Innovation Technologies (GT-11-G-02-001-6)

  5. Modelling Per Capita Water Demand Change to Support System Planning

    Science.gov (United States)

    Garcia, M. E.; Islam, S.

    2016-12-01

    Water utilities have a number of levers to influence customer water usage. These include levers to proactively slow demand growth over time such as building and landscape codes as well as levers to decrease demands quickly in response to water stress including price increases, education campaigns, water restrictions, and incentive programs. Even actions aimed at short term reductions can result in long term water usage declines when substantial changes are made in water efficiency, as in incentives for fixture replacement or turf removal, or usage patterns such as permanent lawn watering restrictions. Demand change is therefore linked to hydrological conditions and to the effects of past management decisions - both typically included in water supply planning models. Yet, demand is typically incorporated exogenously using scenarios or endogenously using only price, though utilities also use rules and incentives issued in response to water stress and codes specifying standards for new construction to influence water usage. Explicitly including these policy levers in planning models enables concurrent testing of infrastructure and policy strategies and illuminates interactions between the two. The City of Las Vegas is used as a case study to develop and demonstrate this modeling approach. First, a statistical analysis of system data was employed to rule out alternate hypotheses of per capita demand decrease such as changes in population density and economic structure. Next, four demand sub-models were developed including one baseline model in which demand is a function of only price. The sub-models were then calibrated and tested using monthly data from 1997 to 2012. Finally, the best performing sub-model was integrated with a full supply and demand model. The results highlight the importance of both modeling water demand dynamics endogenously and taking a broader view of the variables influencing demand change.

  6. Water supply and demand in an energy supply model

    Energy Technology Data Exchange (ETDEWEB)

    Abbey, D; Loose, V

    1980-12-01

    This report describes a tool for water and energy-related policy analysis, the development of a water supply and demand sector in a linear programming model of energy supply in the United States. The model allows adjustments in the input mix and plant siting in response to water scarcity. Thus, on the demand side energy conversion facilities can substitute more costly dry cooling systems for conventional evaporative systems. On the supply side groundwater and water purchased from irrigators are available as more costly alternatives to unappropriated surface water. Water supply data is developed for 30 regions in 10 Western states. Preliminary results for a 1990 energy demand scenario suggest that, at this level of spatial analysis, water availability plays a minor role in plant siting. Future policy applications of the modeling system are discussed including the evaluation of alternative patterns of synthetic fuels development.

  7. Flow based vs. demand based energy-water modelling

    Science.gov (United States)

    Rozos, Evangelos; Nikolopoulos, Dionysis; Efstratiadis, Andreas; Koukouvinos, Antonios; Makropoulos, Christos

    2015-04-01

    The water flow in hydro-power generation systems is often used downstream to cover other type of demands like irrigation and water supply. However, the typical case is that the energy demand (operation of hydro-power plant) and the water demand do not coincide. Furthermore, the water inflow into a reservoir is a stochastic process. Things become more complicated if renewable resources (wind-turbines or photovoltaic panels) are included into the system. For this reason, the assessment and optimization of the operation of hydro-power systems are challenging tasks that require computer modelling. This modelling should not only simulate the water budget of the reservoirs and the energy production/consumption (pumped-storage), but should also take into account the constraints imposed by the natural or artificial water network using a flow routing algorithm. HYDRONOMEAS, for example, uses an elegant mathematical approach (digraph) to calculate the flow in a water network based on: the demands (input timeseries), the water availability (simulated) and the capacity of the transmission components (properties of channels, rivers, pipes, etc.). The input timeseries of demand should be estimated by another model and linked to the corresponding network nodes. A model that could be used to estimate these timeseries is UWOT. UWOT is a bottom up urban water cycle model that simulates the generation, aggregation and routing of water demand signals. In this study, we explore the potentials of UWOT in simulating the operation of complex hydrosystems that include energy generation. The evident advantage of this approach is the use of a single model instead of one for estimation of demands and another for the system simulation. An application of UWOT in a large scale system is attempted in mainland Greece in an area extending over 130×170 km². The challenges, the peculiarities and the advantages of this approach are examined and critically discussed.

  8. Non-residential water demand model validated with extensive measurements

    Directory of Open Access Journals (Sweden)

    E. J. Pieterse-Quirijns

    2012-08-01

    Full Text Available Existing guidelines related to the water demand of non-residential buildings are outdated and do not cover hot water demand for the appropriate selection of hot water devices. Moreover, they generally overestimate peak demand values required for the design of an efficient and reliable water system. Recently, a procedure was developed based on the end-use model SIMDEUM® to derive design rules for peak demand values of both cold and hot water during various time steps for several types and sizes of non-residential buildings, i.e. offices, hotels and nursing homes. In this paper, the design rules are validated with measurements of cold and hot water patterns on a per second base. The good correlation between the simulated patterns and the measured patterns indicates that the basis of the design rules, the SIMDEUM simulated standardised buildings, is solid. Moreover, the SIMDEUM based rules give a better prediction of the measured peak values for cold water flow than the existing guidelines. Furthermore, the new design rules can predict hot water use well. In this paper it is illustrated that the new design rules lead to reliable and improved designs of building installations and water heater capacity, resulting in more hygienic and economical installations.

  9. Evaluating Water Demand Using Agent-Based Modeling

    Science.gov (United States)

    Lowry, T. S.

    2004-12-01

    The supply and demand of water resources are functions of complex, inter-related systems including hydrology, climate, demographics, economics, and policy. To assess the safety and sustainability of water resources, planners often rely on complex numerical models that relate some or all of these systems using mathematical abstractions. The accuracy of these models relies on how well the abstractions capture the true nature of the systems interactions. Typically, these abstractions are based on analyses of observations and/or experiments that account only for the statistical mean behavior of each system. This limits the approach in two important ways: 1) It cannot capture cross-system disruptive events, such as major drought, significant policy change, or terrorist attack, and 2) it cannot resolve sub-system level responses. To overcome these limitations, we are developing an agent-based water resources model that includes the systems of hydrology, climate, demographics, economics, and policy, to examine water demand during normal and extraordinary conditions. Agent-based modeling (ABM) develops functional relationships between systems by modeling the interaction between individuals (agents), who behave according to a probabilistic set of rules. ABM is a "bottom-up" modeling approach in that it defines macro-system behavior by modeling the micro-behavior of individual agents. While each agent's behavior is often simple and predictable, the aggregate behavior of all agents in each system can be complex, unpredictable, and different than behaviors observed in mean-behavior models. Furthermore, the ABM approach creates a virtual laboratory where the effects of policy changes and/or extraordinary events can be simulated. Our model, which is based on the demographics and hydrology of the Middle Rio Grande Basin in the state of New Mexico, includes agent groups of residential, agricultural, and industrial users. Each agent within each group determines its water usage

  10. A fully adaptive forecasting model for short-term drinking water demand

    NARCIS (Netherlands)

    Bakker, M.; Vreeburg, J.H.G.; Schagen, van K.M.; Rietveld, L.C.

    2013-01-01

    For the optimal control of a water supply system, a short-term water demand forecast is necessary. We developed a model that forecasts the water demand for the next 48 h with 15-min time steps. The model uses measured water demands and static calendar data as single input. Based on this input, the m

  11. Importance of demand modelling in network water quality models: a review

    Directory of Open Access Journals (Sweden)

    J. C. van Dijk

    2008-09-01

    Full Text Available Today, there is a growing interest in network water quality modelling. The water quality issues of interest relate to both dissolved and particulate substances. For dissolved substances the main interest is in residual chlorine and (microbiological contaminant propagation; for particulate substances it is in sediment leading to discolouration. There is a strong influence of flows and velocities on transport, mixing, production and decay of these substances in the network. This imposes a different approach to demand modelling which is reviewed in this article.

    For the large diameter lines that comprise the transport portion of a typical municipal pipe system, a skeletonised network model with a top-down approach of demand pattern allocation, a hydraulic time step of 1 h, and a pure advection-reaction water quality model will usually suffice. For the smaller diameter lines that comprise the distribution portion of a municipal pipe system, an all-pipes network model with a bottom-up approach of demand pattern allocation, a hydraulic time step of 1 min or less, and a water quality model that considers dispersion and transients may be needed.

    Demand models that provide stochastic residential demands per individual home and on a one-second time scale are available. A stochastic demands based network water quality model needs to be developed and validated with field measurements. Such a model will be probabilistic in nature and will offer a new perspective for assessing water quality in the drinking water distribution system.

  12. Importance of demand modelling in network water quality models: a review

    Directory of Open Access Journals (Sweden)

    J. C. van Dijk

    2008-01-01

    Full Text Available Today, there is a growing interest in network water quality modelling. The water quality issues of interest relate to both dissolved and particulate substances, with the main interest in residual chlorine and (microbiological contaminant propagation, respectively in sediment leading to discolouration. There is a strong influence of flows and velocities on transport, mixing, production and decay of these substances in the network. This imposes a different approach to demand modelling which is reviewed in this article.

    For transport systems the current hydraulic models suffice; for the more detailed distribution system a network water quality model is needed that is based on short time scale demands that considers the effect of dispersion and transients. Demand models that provide stochastic residential demands per individual home and on a one-second time scale are available. A stochastic demands based network water quality model needs to be developed and validated with field measurements. Such a model will be probabilistic in nature and will offer a new perspective for assessing water quality in the DWDS.

  13. System dynamics modeling for municipal water demand estimation in an urban region under uncertain economic impacts.

    Science.gov (United States)

    Qi, Cheng; Chang, Ni-Bin

    2011-06-01

    Accurate prediction of municipal water demand is critically important to water utilities in fast-growing urban regions for drinking water system planning, design, and water utility asset management. Achieving the desired prediction accuracy is challenging, however, because the forecasting model must simultaneously consider a variety of factors associated with climate changes, economic development, population growth and migration, and even consumer behavioral patterns. Traditional forecasting models such as multivariate regression and time series analysis, as well as advanced modeling techniques (e.g., expert systems and artificial neural networks), are often applied for either short- or long-term water demand projections, yet few can adequately manage the dynamics of a water supply system because of the limitations in modeling structures. Potential challenges also arise from a lack of long and continuous historical records of water demand and its dependent variables. The objectives of this study were to (1) thoroughly review water demand forecasting models over the past five decades, and (2) propose a new system dynamics model to reflect the intrinsic relationship between water demand and macroeconomic environment using out-of-sample estimation for long-term municipal water demand forecasts in a fast-growing urban region. This system dynamics model is based on a coupled modeling structure that takes into account the interactions among economic and social dimensions, offering a realistic platform for practical use. Practical implementation of this water demand forecasting tool was assessed by using a case study under the most recent alternate fluctuations of economic boom and downturn environments.

  14. Improving the Performance of Water Demand Forecasting Models by Using Weather Input

    NARCIS (Netherlands)

    Bakker, M.; Van Duist, H.; Van Schagen, K.; Vreeburg, J.; Rietveld, L.

    2014-01-01

    Literature shows that water demand forecasting models which use water demand as single input, are capable of generating a fairly accurate forecast. However, at changing weather conditions the forecasting errors are quite large. In this paper three different forecasting models are studied: an Adaptiv

  15. Improving the Performance of Water Demand Forecasting Models by Using Weather Input

    NARCIS (Netherlands)

    Bakker, M.; Van Duist, H.; Van Schagen, K.; Vreeburg, J.; Rietveld, L.

    2014-01-01

    Literature shows that water demand forecasting models which use water demand as single input, are capable of generating a fairly accurate forecast. However, at changing weather conditions the forecasting errors are quite large. In this paper three different forecasting models are studied: an Adaptiv

  16. Data-driven behavioural modelling of residential water consumption to inform water demand management strategies

    Science.gov (United States)

    Giuliani, Matteo; Cominola, Andrea; Alshaf, Ahmad; Castelletti, Andrea; Anda, Martin

    2016-04-01

    The continuous expansion of urban areas worldwide is expected to highly increase residential water demand over the next few years, ultimately challenging the distribution and supply of drinking water. Several studies have recently demonstrated that actions focused only on the water supply side of the problem (e.g., augmenting existing water supply infrastructure) will likely fail to meet future demands, thus calling for the concurrent deployment of effective water demand management strategies (WDMS) to pursue water savings and conservation. However, to be effective WDMS do require a substantial understanding of water consumers' behaviors and consumption patterns at different spatial and temporal resolutions. Retrieving information on users' behaviors, as well as their explanatory and/or causal factors, is key to spot potential areas for targeting water saving efforts and to design user-tailored WDMS, such as education campaigns and personalized recommendations. In this work, we contribute a data-driven approach to identify household water users' consumption behavioural profiles and model their water use habits. State-of-the-art clustering methods are coupled with big data machine learning techniques with the aim of extracting dominant behaviors from a set of water consumption data collected at the household scale. This allows identifying heterogeneous groups of consumers from the studied sample and characterizing them with respect to several consumption features. Our approach is validated onto a real-world household water consumption dataset associated with a variety of demographic and psychographic user data and household attributes, collected in nine towns of the Pilbara and Kimberley Regions of Western Australia. Results show the effectiveness of the proposed method in capturing the influence of candidate determinants on residential water consumption profiles and in attaining sufficiently accurate predictions of users' consumption behaviors, ultimately providing

  17. Integrating the simulation of domestic water demand behaviour to an urban water model using agent based modelling

    Science.gov (United States)

    Koutiva, Ifigeneia; Makropoulos, Christos

    2015-04-01

    The urban water system's sustainable evolution requires tools that can analyse and simulate the complete cycle including both physical and cultural environments. One of the main challenges, in this regard, is the design and development of tools that are able to simulate the society's water demand behaviour and the way policy measures affect it. The effects of these policy measures are a function of personal opinions that subsequently lead to the formation of people's attitudes. These attitudes will eventually form behaviours. This work presents the design of an ABM tool for addressing the social dimension of the urban water system. The created tool, called Urban Water Agents' Behaviour (UWAB) model, was implemented, using the NetLogo agent programming language. The main aim of the UWAB model is to capture the effects of policies and environmental pressures to water conservation behaviour of urban households. The model consists of agents representing urban households that are linked to each other creating a social network that influences the water conservation behaviour of its members. Household agents are influenced as well by policies and environmental pressures, such as drought. The UWAB model simulates behaviour resulting in the evolution of water conservation within an urban population. The final outcome of the model is the evolution of the distribution of different conservation levels (no, low, high) to the selected urban population. In addition, UWAB is implemented in combination with an existing urban water management simulation tool, the Urban Water Optioneering Tool (UWOT) in order to create a modelling platform aiming to facilitate an adaptive approach of water resources management. For the purposes of this proposed modelling platform, UWOT is used in a twofold manner: (1) to simulate domestic water demand evolution and (2) to simulate the response of the water system to the domestic water demand evolution. The main advantage of the UWAB - UWOT model

  18. A new model for long-term global water demand projection

    Science.gov (United States)

    Chen, J.; Xing, B.; Shi, H.; Zhang, B.

    2015-12-01

    Rational projection of water demand is critically important to the future development of society. Achieving the desired accuracy for long-term water demand projection (WDP) is challenging due to the complex and uncertain relationships between water demand and various socio-economic indicators. At the same time, traditional forecasting methods, such as multivariate statistical analysis and time series analysis methods, are not adequate for long-term WDP because of the limitations in modelling structures. In this study, a five-staged WDP model is proposed and applied to the global WDPs. The hypothesis for the new model is that water demand is related to socio-economic development level. From the historic data in the Western Europe and United States, the five stages of water demand can be clearly observed. These stages are marked by evident change in water demand trend, and are categorized by the per capita GDP at that stage. The proposed WDP model is then validated with historic water consumption data in United Kingdom and Hong Kong, and the proposed model can explain the historic water consumption well. The developed five-staged WDP model is applied to the WDPs in Hong Kong and Pearl River Basin. Further, using the newly developed water consumption algorithm, this study investigates the global future water demand.

  19. A bottom-up approach of stochastic demand allocation in water quality modelling

    Directory of Open Access Journals (Sweden)

    E. J. M. Blokker

    2010-04-01

    Full Text Available 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.

  20. A bottom-up approach of stochastic demand allocation in water quality modelling

    Directory of Open Access Journals (Sweden)

    E. J. M. Blokker

    2010-01-01

    Full Text Available An "all pipes" hydraulic model of a DMA-sized 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.

    The stochastic water demand patterns are constructed with an end-use model on a per second basis and per individual home. The flow entering the test area was measured and a tracer test with sodium chloride was performed to measure travel times. The two models were evaluated on the predicted sum of demands and travel times, compared with what was measured in the test area.

    The new bottom-up approach performs at least as well as the conventional top-down approach with respect to total demand and travel times, without the need for any flow measurements or calibration measurements. The bottom-up approach leads to a stochastic method of hydraulic modelling and gives insight into the variability of travel times as an added feature beyond the conventional way of modelling.

  1. Application of short-term water demand prediction model to Seoul.

    Science.gov (United States)

    Joo, C N; Koo, J Y; Yu, M J

    2002-01-01

    To predict daily water demand for Seoul, Korea, the artificial neural network (ANN) was used. For the cross correlation, the factors affecting water demand such as maximum temperature, humidity, and wind speed as natural factors, holidays as a social factor and daily demand 1 day before were used. From the results of learning using various hidden layers and units in order to establish the structure of optimal ANN, the case of 3 hidden layers and numbers of unit with the same number of input factors showed the best result and, therefore, it was applied to seasonal water demand prediction. The performance of ANN was compared with a multiple regression method. We discuss the representation ability of the model building process and the applicability of the ANN approach for the daily water demand prediction. ANN provided reasonable results for time series prediction.

  2. The 3D simulation and optimized management model of groundwater systems based on ecoenvironmental water demand

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Through the study of mutual process between groundwater systems and eco-environmental water demand, the eco-environmental water demand is brought into groundwater systems model as the important water consumption item and unification of groundwater's economic, environmental and ecological functions were taken into account. Based on eco-environmental water demand at Da'an in Jilin province, a three-dimensional simulation and optimized management model of groundwater systems was established. All water balance components of groundwater systems in 1998 and 1999 were simulated with this model and the best optimal exploitation scheme of groundwater systems in 2000 was determined, so that groundwater resource was efficiently utilized and good economic, ecologic and social benefits were obtained.

  3. On inclusion of water resource management in Earth system models - Part 1: Problem definition and representation of water demand

    Science.gov (United States)

    Nazemi, A.; Wheater, H. S.

    2015-01-01

    Human activities have caused various changes to the Earth system, and hence the interconnections between human activities and the Earth system should be recognized and reflected in models that simulate Earth system processes. One key anthropogenic activity is water resource management, which determines the dynamics of human-water interactions in time and space and controls human livelihoods and economy, including energy and food production. There are immediate needs to include water resource management in Earth system models. First, the extent of human water requirements is increasing rapidly at the global scale and it is crucial to analyze the possible imbalance between water demands and supply under various scenarios of climate change and across various temporal and spatial scales. Second, recent observations show that human-water interactions, manifested through water resource management, can substantially alter the terrestrial water cycle, affect land-atmospheric feedbacks and may further interact with climate and contribute to sea-level change. Due to the importance of water resource management in determining the future of the global water and climate cycles, the World Climate Research Program's Global Energy and Water Exchanges project (WRCP-GEWEX) has recently identified gaps in describing human-water interactions as one of the grand challenges in Earth system modeling (GEWEX, 2012). Here, we divide water resource management into two interdependent elements, related firstly to water demand and secondly to water supply and allocation. In this paper, we survey the current literature on how various components of water demand have been included in large-scale models, in particular land surface and global hydrological models. Issues of water supply and allocation are addressed in a companion paper. The available algorithms to represent the dominant demands are classified based on the demand type, mode of simulation and underlying modeling assumptions. We discuss

  4. On inclusion of water resource management in Earth System models – Part 1: Problem definition and representation of water demand

    Directory of Open Access Journals (Sweden)

    A. Nazemi

    2014-07-01

    Full Text Available Human activities have caused various changes in the Earth System, and hence, the interconnections between humans and the Earth System should be recognized and reflected in models that simulate the Earth System processes. One key anthropogenic activity is water resource management that determines the dynamics of human–water interactions in time and space. There are various reasons to include water resource management in Earth System models. First, the extent of human water requirements is increasing rapidly at the global scale and it is crucial to analyze the possible imbalance between water demands and supply under various scenarios of climate change and across various temporal and spatial scales. Second, recent observations show that human–water interactions, manifested through water resource management, can substantially alter the terrestrial water cycle, affect land-atmospheric feedbacks and may further interact with climate and contribute to sea-level change. Here, we divide the water resource management into two interdependent elements, related to water demand as well as water supply and allocation. In this paper, we survey the current literature on how various water demands have been included in large-scale models, including Land Surface Schemes and Global Hydrological Models. The available algorithms are classified based on the type of demand, mode of simulation and underlying modeling assumptions. We discuss the pros and cons of available algorithms, address various sources of uncertainty and highlight limitations in current applications. We conclude that current capability of large-scale models in terms of representing human water demands is rather limited, particularly with respect to future projections and online simulations. We argue that current limitations in simulating various human demands and their impact on the Earth System are mainly due to the uncertainties in data support, demand algorithms and large-scale models. To

  5. Modeling future water demand in California from developed and agricultural land uses

    Science.gov (United States)

    Wilson, T. S.; Sleeter, B. M.; Cameron, D. R.

    2015-12-01

    Municipal and urban land-use intensification in coming decades will place increasing pressure on water resources in California. The state is currently experiencing one of the most extreme droughts on record. This coupled with earlier spring snowmelt and projected future climate warming will increasingly constrain already limited water supplies. The development of spatially explicit models of future land use driven by empirical, historical land use change data allow exploration of plausible LULC-related water demand futures and potential mitigation strategies. We utilized the Land Use and Carbon Scenario Simulator (LUCAS) state-and-transition simulation model to project spatially explicit (1 km) future developed and agricultural land use from 2012 to 2062 and estimated the associated water use for California's Mediterranean ecoregions. We modeled 100 Monte Carlo simulations to better characterize and project historical land-use change variability. Under current efficiency rates, total water demand was projected to increase 15.1% by 2062, driven primarily by increases in urbanization and shifts to more water intensive crops. Developed land use was projected to increase by 89.8%-97.2% and result in an average 85.9% increase in municipal water use, while agricultural water use was projected to decline by approximately 3.9%, driven by decreases in row crops and increases in woody cropland. In order for water demand in 2062 to balance to current demand levels, the currently mandated 25% reduction in urban water use must remain in place in conjunction with a near 7% reduction in agricultural water use. Scenarios of land-use related water demand are useful for visualizing alternative futures, examining potential management approaches, and enabling better informed resource management decisions.

  6. Modeling and Forecasting of Water Demand in Isfahan Using Underlying Trend Concept and Time Series

    Directory of Open Access Journals (Sweden)

    H. Sadeghi

    2016-02-01

    Full Text Available Introduction: Accurate water demand modeling for the city is very important for forecasting and policies adoption related to water resources management. Thus, for future requirements of water estimation, forecasting and modeling, it is important to utilize models with little errors. Water has a special place among the basic human needs, because it not hampers human life. The importance of the issue of water management in the extraction and consumption, it is necessary as a basic need. Municipal water applications is include a variety of water demand for domestic, public, industrial and commercial. Predicting the impact of urban water demand in better planning of water resources in arid and semiarid regions are faced with water restrictions. Materials and Methods: One of the most important factors affecting the changing technological advances in production and demand functions, we must pay special attention to the layout pattern. Technology development is concerned not only technically, but also other aspects such as personal, non-economic factors (population, geographical and social factors can be analyzed. Model examined in this study, a regression model is composed of a series of structural components over time allows changed invisible accidentally. Explanatory variables technology (both crystalline and amorphous in a model according to which the material is said to be better, but because of the lack of measured variables over time can not be entered in the template. Model examined in this study, a regression model is composed of a series of structural component invisible accidentally changed over time allows. In this study, structural time series (STSM and ARMA time series models have been used to model and estimate the water demand in Isfahan. Moreover, in order to find the efficient procedure, both models have been compared to each other. The desired data in this research include water consumption in Isfahan, water price and the monthly pay

  7. Supply-demand 3D dynamic model in water resources evaluation: taking Lebanon as an example

    Science.gov (United States)

    Fang, Hong; Hou, Zhimin

    2017-05-01

    In this paper, supply-demand 3D dynamic model is adopted to create a measurement of a region’s capacity to provide available water to meet the needs of its population. First of all, we draw a diagram between supply and demand. Then taking the main dynamic factors into account, we establish an index to evaluate the balance of supply and demand. The three dimension vector reflects the scarcity of industrial, agricultural and residential water. Lebanon is chosen as the object of case study, and we do quantitative analysis of its current situation. After data collecting and processing, we calculate the 3D vector in 2012, which reveals that agriculture is susceptible to water scarcity. Water resources of Lebanon are “physical rich” but “economic scarcity” according to the correlation chart and other statistical analysis.

  8. A novel domestic electric water heater model for a multi-objective demand side management program

    Energy Technology Data Exchange (ETDEWEB)

    Paull, Liam; Li, Howard; Chang, Liuchen [University of New Brunswick, Department of Electrical Engineering, Fredericton, NB (Canada)

    2010-12-15

    This paper presents a novel domestic hot water heater model to be used in a multi-objective demand side management program. The model incorporates both the thermal losses and the water usage to determine the temperature of the water in the tank. Water heater loads are extracted from household load data and then used to determine the household water usage patterns. The benefits of the model are: (1) the on/off state of the water heater and temperature of the water in the tank can be accurately predicted, and (2) it enables the development of water usage profiles so that users can be classified based on usage behaviour. As a result, the amount of ancillary services and peak shaving that can be achieved are accurately predictable and can be maximized without adversely affecting users. (author)

  9. A Probabilistic Short-Term Water Demand Forecasting Model Based on the Markov Chain

    Directory of Open Access Journals (Sweden)

    Francesca Gagliardi

    2017-07-01

    Full Text Available This paper proposes a short-term water demand forecasting method based on the use of the Markov chain. This method provides estimates of future demands by calculating probabilities that the future demand value will fall within pre-assigned intervals covering the expected total variability. More specifically, two models based on homogeneous and non-homogeneous Markov chains were developed and presented. These models, together with two benchmark models (based on artificial neural network and naïve methods, were applied to three real-life case studies for the purpose of forecasting the respective water demands from 1 to 24 h ahead. The results obtained show that the model based on a homogeneous Markov chain provides more accurate short-term forecasts than the one based on a non-homogeneous Markov chain, which is in line with the artificial neural network model. Both Markov chain models enable probabilistic information regarding the stochastic demand forecast to be easily obtained.

  10. Research on Water Utility Revenue Model and Compensation Policy under Uncertain Demand

    Directory of Open Access Journals (Sweden)

    Shou-Kui He

    2014-03-01

    Full Text Available With the diversification of both water utility investment and property right structure, it is necessary to establish a scientific compensation mechanism of water conservancy benefit to balance the interests among investors, water users and pertinent sectors which suffer loss. This paper analyzes the compensation policies water management authority imposed on water supply enterprises under uncertain demand, establishes a compensation model with risk preference, explains the implications of risk preference on the decision-making behaviors of water supply enterprises by using numerical analysis method, provides the basis for the water management department to formulate reasonable water resources charge standards and compensation policies. At last, the paper discusses how to implement the water compensation policies according to the characteristics of rural water utilities.

  11. Non-residential water demand model validated with extensive measurements and surveys

    NARCIS (Netherlands)

    Pieterse-Quirijns, I.; Blokker, E.J.M.; van der Blom, E.C.; Vreeburg, J.H.G.

    2013-01-01

    Existing Dutch guidelines for the design of the drinking water and hot water system of nonresidential buildings are based on outdated assumptions on peak water demand or on unfounded assumptions on hot water demand. They generally overestimate peak demand values required for the design of an efficie

  12. Modelling global water stress of the recent past: on the relative importance of trends in water demand and climate variability

    Directory of Open Access Journals (Sweden)

    Y. Wada

    2011-12-01

    Full Text Available During the past decades, human water use has more than doubled, yet available freshwater resources are finite. As a result, water scarcity has been prevalent in various regions of the world. Here, we present the first global assessment of past development of water stress considering not only climate variability but also growing water demand, desalinated water use and non-renewable groundwater abstraction over the period 1960–2001 at a spatial resolution of 0.5°. Agricultural water demand is estimated based on past extents of irrigated areas and livestock densities. We approximate past economic development based on GDP, energy and household consumption and electricity production, which are subsequently used together with population numbers to estimate industrial and domestic water demand. Climate variability is expressed by simulated blue water availability defined by freshwater in rivers, lakes, wetlands and reservoirs by means of the global hydrological model PCR-GLOBWB. We thus define blue water stress by comparing blue water availability with corresponding net total blue water demand by means of the commonly used, Water Scarcity Index. The results show a drastic increase in the global population living under water-stressed conditions (i.e. moderate to high water stress due to growing water demand, primarily for irrigation, which has more than doubled from 1708/818 to 3708/1832 km3 yr−1 (gross/net over the period 1960–2000. We estimate that 800 million people or 27% of the global population were living under water-stressed conditions for 1960. This number is eventually increased to 2.6 billion or 43% for 2000. Our results indicate that increased water demand is a decisive factor for heightened water stress in various regions such as India and North China, enhancing the intensity of water stress up to 200%, while climate variability is often a main determinant of extreme events. However, our results also suggest

  13. Modelling global water stress of the recent past: on the relative importance of trends in water demand and climate variability

    Science.gov (United States)

    Wada, Y.; van Beek, L. P. H.; Bierkens, M. F. P.

    2011-12-01

    During the past decades, human water use has more than doubled, yet available freshwater resources are finite. As a result, water scarcity has been prevalent in various regions of the world. Here, we present the first global assessment of past development of water stress considering not only climate variability but also growing water demand, desalinated water use and non-renewable groundwater abstraction over the period 1960-2001 at a spatial resolution of 0.5°. Agricultural water demand is estimated based on past extents of irrigated areas and livestock densities. We approximate past economic development based on GDP, energy and household consumption and electricity production, which are subsequently used together with population numbers to estimate industrial and domestic water demand. Climate variability is expressed by simulated blue water availability defined by freshwater in rivers, lakes, wetlands and reservoirs by means of the global hydrological model PCR-GLOBWB. We thus define blue water stress by comparing blue water availability with corresponding net total blue water demand by means of the commonly used, Water Scarcity Index. The results show a drastic increase in the global population living under water-stressed conditions (i.e. moderate to high water stress) due to growing water demand, primarily for irrigation, which has more than doubled from 1708/818 to 3708/1832 km3 yr-1 (gross/net) over the period 1960-2000. We estimate that 800 million people or 27% of the global population were living under water-stressed conditions for 1960. This number is eventually increased to 2.6 billion or 43% for 2000. Our results indicate that increased water demand is a decisive factor for heightened water stress in various regions such as India and North China, enhancing the intensity of water stress up to 200%, while climate variability is often a main determinant of extreme events. However, our results also suggest that in several emerging and developing economies

  14. Predicting the impact of water demand and river flow regulation over riparian vegetation through mathematical modeling

    Science.gov (United States)

    Garcia-Arias, A.; Pons, C.; Frances, F.

    2013-12-01

    The vegetation of the riversides is a main part of the complex riparian ecosystems and has an important role maintaining the fluvial ecosystems. Biotic and abiotic interactions between the river and the riverbank are essential for the subsistence and the development of both ecosystems. In semi-arid Mediterranean areas, the riparian vegetation growth and distribution is especially controlled by the water accessibility, determining the limit between the lush riparian bands and the sparse upland. Human intervention can alter the river hydrology determining the riparian vegetation wellbeing and its distribution and, in consequence, affecting both riparian and fluvial ecosystems. Predictive models are necessary decision support tools for adequate river management and restoration initiatives. In this context, the RibAV model is useful to predict the impact of water demand and river flow regulation on the riparian vegetation. RibAV is able to reproduce the vegetation performance on the riverside allowing the scenarios analysis in terms of vegetation distribution and wellbeing. In this research several flow regulation and water demand scenarios are proposed and the impacts over three plant functional types (PFTs) are analyzed. The PFTs group the herbaceous riparian plants, the woody riparian plants and the terrestrial vegetation. The study site is the Terde reach at the Mijares River, a 539m length reach located in a semi-arid Mediterranean area in Spain. The scenarios represent river flow alterations required to attend different human demands. These demands encompass different seasonality, magnitude and location. The seasonality is represented as hydroelectric (constant all over the year), urban (increased during the summer period) and agricultural demands (monthly seasonality). The magnitude is varied considering the 20%, the 40% and the 80% of the mean daily flow. Two locations are considered, upstream or downstream the study site. To attend the demands located

  15. Modelling global water stress of the recent past: on the relative importance of trends in water demand and climate variability

    Directory of Open Access Journals (Sweden)

    Y. Wada

    2011-08-01

    Full Text Available During the past decades, human water use more than doubled, yet available freshwater resources are finite. As a result, water scarcity has been prevalent in various regions of the world. Here, we present the first global assessment of past development of water scarcity considering not only climate variability but also growing water demand, desalinated water use and non-renewable groundwater abstraction over the period 1960–2001 at a spatial resolution of 0.5°. Agricultural water demand is estimated based on past extents of irrigated areas and livestock densities. We approximate past economic development based on GDP, energy and household consumption and electricity production, which is subsequently used together with population numbers to estimate industrial and domestic water demand. Climate variability is expressed by simulated blue water availability defined by freshwater in rivers, lakes and reservoirs by means of the global hydrological model PCR-GLOBWB. The results show a drastic increase in the global population living under water-stressed conditions (i.e., moderate to high water stress due to the growing water demand, primarily for irrigation, which more than doubled from 1708/818 to 3708/1832 km3 yr−1 (gross/net over the period 1960–2000. We estimate that 800 million people or 27 % of the global population were under water-stressed conditions for 1960. This number increased to 2.6 billion or 43 % for 2000. Our results indicate that increased water demand is the decisive factor for the heightened water stress, enhancing the intensity of water stress up to 200 %, while climate variability is often the main determinant of onsets for extreme events, i.e. major droughts. However, our results also suggest that in several emerging and developing economies (e.g., India, Turkey, Romania and Cuba some of the past observed droughts were anthropogenically driven due to increased water demand rather than being climate

  16. Modeling and managing urban water demand through smart meters: Benefits and challenges from current research and emerging trends

    Science.gov (United States)

    Cominola, A.; Giuliani, M.; Castelletti, A.; Piga, D.; Rizzoli, A. E.

    2015-12-01

    Urban population growth, climate and land use change are expected to boost residential water demand in urban contexts in the next decades. In such a context, developing suitable demand-side management strategies is essential to meet future water demands, pursue water savings, and reduce the costs for water utilities. Yet, the effectiveness of water demand management strategies (WDMS) relies on our understanding of water consumers' behavior, their consumption habits, and the water use drivers. While low spatial and temporal resolution water consumption data, as traditionally gathered for billing purposes, hardly support this understanding, the advent of high-resolution, smart metering technologies allowed for quasi real-time monitoring water consumption at the single household level. This, in turn, is advancing our ability in characterizing consumers' behavior, modeling, and designing user-oriented residential water demand management strategies. Several water smart metering programs have been rolled-out in the last two decades worldwide, addressing one or more of the following water demand management phases: (i) data gathering, (ii) water end-uses characterization, (iii) user modeling, (iv) design and implementation of personalized WDMS. Moreover, the number of research studies in this domain is quickly increasing and big economic investments are currently being devoted worldwide to smart metering programs. With this work, we contribute the first comprehensive review of more than 100 experiences in the field of residential water demand modeling and management, and we propose a general framework for their classification. We revise consolidated practices, identify emerging trends and highlight the challenges and opportunities for future developments given by the use of smart meters advancing residential water demand management. Our analysis of the status quo of smart urban water demand management research and market constitutes a structured collection of information

  17. Development of Extended Period Pressure-Dependent Demand Water Distribution Models

    Energy Technology Data Exchange (ETDEWEB)

    Judi, David R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mcpherson, Timothy N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-20

    Los Alamos National Laboratory (LANL) has used modeling and simulation of water distribution systems for N-1 contingency analyses to assess criticality of water system assets. Critical components considered in these analyses include pumps, tanks, and supply sources, in addition to critical pipes or aqueducts. A contingency represents the complete removal of the asset from system operation. For each contingency, an extended period simulation (EPS) is run using EPANET. An EPS simulates water system behavior over a time period, typically at least 24 hours. It assesses the ability of a system to respond and recover from asset disruption through distributed storage in tanks throughout the system. Contingencies of concern are identified as those in which some portion of the water system has unmet delivery requirements. A delivery requirement is defined as an aggregation of water demands within a service area, similar to an electric power demand. The metric used to identify areas of unmet delivery requirement in these studies is a pressure threshold of 15 pounds per square inch (psi). This pressure threshold is used because it is below the required pressure for fire protection. Any location in the model with pressure that drops below this threshold at any time during an EPS is considered to have unmet service requirements and is used to determine cascading consequences. The outage area for a contingency is the aggregation of all service areas with a pressure below the threshold at any time during the EPS.

  18. Evaluating Outdoor Water Use Demand under Changing Climatic and Demographic Conditions: An Agent-based Modeling Approach

    Science.gov (United States)

    Kanta, L.

    2016-12-01

    Outdoor water use for landscape and irrigation constitutes a significant end use in residential water demand. In periods of water shortages, utilities may reduce garden demands by implementing irrigation system audits, rebate programs, local ordinances, and voluntary or mandatory water use restrictions. Because utilities do not typically record outdoor and indoor water uses separately, the effects of policies for reducing garden demands cannot be readily calculated. The volume of water required to meet garden demands depends on the housing density or lawn size, type of vegetation, climatic conditions, efficiency of garden irrigation systems, and consumer water-use behaviors. Many existing outdoor demand estimation methods are deterministic and do not include consumer responses to conservation campaigns. In addition, mandatory restrictions may have a substantial impact on reducing outdoor demands, but the effectiveness of mandatory restrictions depends on the timing and the frequency of restrictions, in addition to the distribution of housing density and consumer types within a community. This research investigates a garden end-use model by coupling an agent-based modeling approach and a mechanistic-stochastic water demand model to create a methodology for estimating garden demand and evaluating demand reduction policies. The garden demand model is developed for two water utilities, using a diverse data sets, including residential customer billing records, records of outdoor conservation programs, frequency and type of mandatory water use restrictions, lot size distribution, population growth, and climatic data. A set of garden irrigation parameter values, which are based on the efficiency of irrigation systems and irrigation habits of consumers, are determined for a set of conservation ordinances and restrictions. The model parameters are then validated using customer water usage data from the participating water utilities. A sensitivity analysis is conducted for

  19. A Stepwise Time Series Regression Procedure for Water Demand Model Identification

    Science.gov (United States)

    Miaou, Shaw-Pin

    1990-09-01

    Annual time series water demand has traditionally been studied through multiple linear regression analysis. Four associated model specification problems have long been recognized: (1) the length of the available time series data is relatively short, (2) a large set of candidate explanatory or "input" variables needs to be considered, (3) input variables can be highly correlated with each other (multicollinearity problem), and (4) model error series are often highly autocorrelated or even nonstationary. A step wise time series regression identification procedure is proposed to alleviate these problems. The proposed procedure adopts the sequential input variable selection concept of stepwise regression and the "three-step" time series model building strategy of Box and Jenkins. Autocorrelated model error is assumed to follow an autoregressive integrated moving average (ARIMA) process. The stepwise selection procedure begins with a univariate time series demand model with no input variables. Subsequently, input variables are selected and inserted into the equation one at a time until the last entered variable is found to be statistically insignificant. The order of insertion is determined by a statistical measure called between-variable partial correlation. This correlation measure is free from the contamination of serial autocorrelation. Three data sets from previous studies are employed to illustrate the proposed procedure. The results are then compared with those from their original studies.

  20. Modeling and Dynamical Analysis of the Water Resources Supply-Demand System: A Case Study in Haihe River Basin

    Directory of Open Access Journals (Sweden)

    Chongli Di

    2014-01-01

    Full Text Available The relationship between water resources supply and demand is very complex and exhibits nonlinear characteristics, which leads to fewer models that can adequately manage the dynamic evolution process of the water resources supply-demand system. In this paper, we propose a new four-dimensional dynamical model to simulate the internal dynamic evolution process and predict future trends of water supply and demand. At the beginning, a new four-dimensional dynamical model with uncertain parameters is established. Then, the gray code hybrid accelerating genetic algorithm (GHAGA is adopted to identify the unknown parameters of the system based on the statistic data (1998–2009. Finally, the dynamical analysis of the system is further studied by Lyapunov-exponent, phase portraits, and Lyapunov exponent theory. Numerical simulation results demonstrate that the proposed water resources supply-demand system is in a steady state and is suitable for simulating the dynamical characteristics of a complex water supply and demand system. According to the trends of the water supply and demand of several nonlinear simulation cases, the corresponding measures can be proposed to improve the steady development of the water resources supply-demand system.

  1. Importance of demand modelling in network water quality models: a review

    NARCIS (Netherlands)

    Blokker, E.J.M.; Vreeburg, J.H.G.; Buchberger, S.G.; Van Dijk, J.C.

    2008-01-01

    Today, there is a growing interest in network water quality modelling. The water quality issues of interest relate to both dissolved and particulate substances. For dissolved substances the main interest is in residual chlorine and (microbiological) contaminant propagation; for particulate substance

  2. Importance of demand modelling in network water quality models: a review

    NARCIS (Netherlands)

    Blokker, E.J.M.; Vreeburg, J.H.G.; Buchberger, S.G.; Van Dijk, J.C.

    2008-01-01

    Today, there is a growing interest in network water quality modelling. The water quality issues of interest relate to both dissolved and particulate substances. For dissolved substances the main interest is in residual chlorine and (microbiological) contaminant propagation; for particulate substance

  3. Stochastic water demand modelling for a better understanding of hydraulics in water distribution networks

    NARCIS (Netherlands)

    Blokker, E.J.M.

    2010-01-01

    In the water distribution network water quality process take place influenced by de flow velocity and residence time of the water in the network. In order to understand how the water quality changes in the water distribution network, a good understanding of hydraulics is required. Specifically in

  4. Modeling and clustering water demand patterns from real-world smart meter data

    Directory of Open Access Journals (Sweden)

    N. Cheifetz

    2017-08-01

    Full Text Available Nowadays, drinking water utilities need an acute comprehension of the water demand on their distribution network, in order to efficiently operate the optimization of resources, manage billing and propose new customer services. With the emergence of smart grids, based on automated meter reading (AMR, a better understanding of the consumption modes is now accessible for smart cities with more granularities. In this context, this paper evaluates a novel methodology for identifying relevant usage profiles from the water consumption data produced by smart meters. The methodology is fully data-driven using the consumption time series which are seen as functions or curves observed with an hourly time step. First, a Fourier-based additive time series decomposition model is introduced to extract seasonal patterns from time series. These patterns are intended to represent the customer habits in terms of water consumption. Two functional clustering approaches are then used to classify the extracted seasonal patterns: the functional version of K-means, and the Fourier REgression Mixture (FReMix model. The K-means approach produces a hard segmentation and K representative prototypes. On the other hand, the FReMix is a generative model and also produces K profiles as well as a soft segmentation based on the posterior probabilities. The proposed approach is applied to a smart grid deployed on the largest water distribution network (WDN in France. The two clustering strategies are evaluated and compared. Finally, a realistic interpretation of the consumption habits is given for each cluster. The extensive experiments and the qualitative interpretation of the resulting clusters allow one to highlight the effectiveness of the proposed methodology.

  5. Modeling and clustering water demand patterns from real-world smart meter data

    Science.gov (United States)

    Cheifetz, Nicolas; Noumir, Zineb; Samé, Allou; Sandraz, Anne-Claire; Féliers, Cédric; Heim, Véronique

    2017-08-01

    Nowadays, drinking water utilities need an acute comprehension of the water demand on their distribution network, in order to efficiently operate the optimization of resources, manage billing and propose new customer services. With the emergence of smart grids, based on automated meter reading (AMR), a better understanding of the consumption modes is now accessible for smart cities with more granularities. In this context, this paper evaluates a novel methodology for identifying relevant usage profiles from the water consumption data produced by smart meters. The methodology is fully data-driven using the consumption time series which are seen as functions or curves observed with an hourly time step. First, a Fourier-based additive time series decomposition model is introduced to extract seasonal patterns from time series. These patterns are intended to represent the customer habits in terms of water consumption. Two functional clustering approaches are then used to classify the extracted seasonal patterns: the functional version of K-means, and the Fourier REgression Mixture (FReMix) model. The K-means approach produces a hard segmentation and K representative prototypes. On the other hand, the FReMix is a generative model and also produces K profiles as well as a soft segmentation based on the posterior probabilities. The proposed approach is applied to a smart grid deployed on the largest water distribution network (WDN) in France. The two clustering strategies are evaluated and compared. Finally, a realistic interpretation of the consumption habits is given for each cluster. The extensive experiments and the qualitative interpretation of the resulting clusters allow one to highlight the effectiveness of the proposed methodology.

  6. Enhancing user comfort models for Demand Response solutions for domestic water heating systems

    NARCIS (Netherlands)

    Belov, Alexander; Vasenev, Alexandr; Havinga, Paul J.M.; Meratnia, Nirvana

    2016-01-01

    Demand Side Management (DSM) solutions for domestic Water Heaters (WHs) can assist consumers benefit financially by optimizing their energy usage. However, users’ dissatisfaction caused by negative impact of DSM on their comfort may force them to reject the provided solutions. To facilitate DSM adop

  7. Enhancing user comfort models for Demand Response solutions for domestic water heating systems

    NARCIS (Netherlands)

    Belov, A.; Vasenev, Alexandr; Havinga, Paul J.M.; Meratnia, Nirvana

    2016-01-01

    Demand Side Management (DSM) solutions for domestic Water Heaters (WHs) can assist consumers benefit financially by optimizing their energy usage. However, users’ dissatisfaction caused by negative impact of DSM on their comfort may force them to reject the provided solutions. To facilitate DSM

  8. Demand Modelling in Telecommunications

    Directory of Open Access Journals (Sweden)

    M. Chvalina

    2009-01-01

    Full Text Available This article analyses the existing possibilities for using Standard Statistical Methods and Artificial Intelligence Methods for a short-term forecast and simulation of demand in the field of telecommunications. The most widespread methods are based on Time Series Analysis. Nowadays, approaches based on Artificial Intelligence Methods, including Neural Networks, are booming. Separate approaches will be used in the study of Demand Modelling in Telecommunications, and the results of these models will be compared with actual guaranteed values. Then we will examine the quality of Neural Network models

  9. Water demands for electricity generation in the U.S.: Modeling different scenarios for the water–energy nexus

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lu; Hejazi, Mohamad I.; Patel, Pralit L.; Kyle, G. Page; Davies, Evan; Zhou, Yuyu; Clarke, Leon E.; Edmonds, James A.

    2015-05-01

    Water withdrawal for electricity generation in the United States accounts for approximately half the total freshwater withdrawal. With steadily growing electricity demands, a changing climate, and limited water supplies in many water-scarce states, meeting future energy and water demands poses a significant socio-economic challenge. Employing an integrated modeling approach that can capture the energy-water interactions at regional and national scales is essential to improve our understanding of the key drivers that govern those interactions and the role of national policies. In this study, the Global Change Assessment Model (GCAM), a technologically-detailed integrated model of the economy, energy, agriculture and land use, water, and climate systems, was extended to model the electricity and water systems at the state level in the U.S. (GCAM-USA). GCAM-USA was employed to estimate future state-level electricity generation and consumption, and their associated water withdrawals and consumption under a set of six scenarios with extensive details on the generation fuel portfolio, cooling technology mix, and their associated water use intensities. Six scenarios of future water demands of the U.S. electric-sector were explored to investigate the implications of socioeconomics development and growing electricity demands, climate mitigation policy, the transition of cooling systems, electricity trade, and water saving technologies. Our findings include: 1) decreasing water withdrawals and substantially increasing water consumption from both climate mitigation and the conversion from open-loop to closed-loop cooling systems; 2) open trading of electricity benefiting energy scarce yet demand intensive states; 3) within state variability under different driving forces while across state homogeneity under certain driving force ; 4) a clear trade-off between water consumption and withdrawal for the electricity sector in the U.S. The paper discusses this withdrawal

  10. Travel Demand Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, Frank [ORNL; Garrow, Dr. Laurie [Georgia Institute of Technology

    2011-01-01

    This chapter describes the principal types of both passenger and freight demand models in use today, providing a brief history of model development supported by references to a number of popular texts on the subject, and directing the reader to papers covering some of the more recent technical developments in the area. Over the past half century a variety of methods have been used to estimate and forecast travel demands, drawing concepts from economic/utility maximization theory, transportation system optimization and spatial interaction theory, using and often combining solution techniques as varied as Box-Jenkins methods, non-linear multivariate regression, non-linear mathematical programming, and agent-based microsimulation.

  11. Climate policy implications for agricultural water demand

    Energy Technology Data Exchange (ETDEWEB)

    Chaturvedi, Vaibhav [Joint Global Change Research Inst., College Park, MD (United States); Hejazi, Mohamad I. [Joint Global Change Research Inst., College Park, MD (United States); Edmonds, James A. [Joint Global Change Research Inst., College Park, MD (United States); Clarke, Leon E. [Joint Global Change Research Inst., College Park, MD (United States); Kyle, G. Page [Joint Global Change Research Inst., College Park, MD (United States); Davies, Evan [Univ. of Alberta, Edmonton, AB (Canada); Wise, Marshall A. [Joint Global Change Research Inst., College Park, MD (United States); Calvin, Katherine V. [Joint Global Change Research Inst., College Park, MD (United States)

    2013-03-01

    Energy, water and land are scarce resources, critical to humans. Developments in each affect the availability and cost of the others, and consequently human prosperity. Measures to limit greenhouse gas concentrations will inevitably exact dramatic changes on energy and land systems and in turn alter the character, magnitude and geographic distribution of human claims on water resources. We employ the Global Change Assessment Model (GCAM), an integrated assessment model to explore the interactions of energy, land and water systems in the context of alternative policies to limit climate change to three alternative levels: 2.5 Wm-2 (445 ppm CO2-e), 3.5 Wm-2 (535 ppm CO2-e) and 4.5 Wm-2 (645 ppm CO2-e). We explore the effects of two alternative land-use emissions mitigation policy options—one which taxes terrestrial carbon emissions equally with fossil fuel and industrial emissions, and an alternative which only taxes fossil fuel and industrial emissions but places no penalty on land-use change emissions. We find that increasing populations and economic growth could be anticipated to almost triple demand for water for agricultural systems across the century even in the absence of climate policy. In general policies to mitigate climate change increase agricultural demands for water still further, though the largest changes occur in the second half of the century, under both policy regimes. The two policies examined profoundly affected both the sources and magnitudes of the increase in irrigation water demands. The largest increases in agricultural irrigation water demand occurred in scenarios where only fossil fuel emissions were priced (but not land-use change emission) and were primarily driven by rapid expansion in bioenergy production. In these scenarios water demands were large relative to present-day total available water, calling into question whether it would be physically possible to produce the associated biomass energy. We explored the potential of improved

  12. Scheduling of Domestic Water Heater Power Demand for Maximizing PV Self-Consumption Using Model Predictive Control

    DEFF Research Database (Denmark)

    Sossan, Fabrizio; Kosek, Anna Magdalena; Martinenas, Sergejus

    2013-01-01

    to predict the future temperature of the water and it manages its state (on and off) according to the forecasted PV production, which are computed starting from forecast of the solar irradiance. Simulations for the proof of concept and for validating the proposed control strategy are proposed. Results......This paper presents a model predictive control (MPC) strategy for maximizing photo-voltaic (PV) selfconsumption in a household context exploiting the flexible demand of an electric water heater. The predictive controller uses a water heater model and forecast of the hot Water consumption in order...... of the control approach are compared with a traditional thermostatic controller using historical measurements of a 10 kW PV installation. Economic results based on the Italian self consumption tariffs are also reported. The model of the water heater complex is a mixed grey and white box and its parameters have...

  13. Inclusion of climatic and touristic factors in the analysis and modelling of the municipal water demand in a Mediterranean region

    Science.gov (United States)

    Toth, Elena; Bragalli, Cristiana; Neri, Mattia

    2017-04-01

    In Mediterranean regions, inherently affected by water scarcity conditions, the gap between water availability and demand may further increase in the near future due to both climatic and anthropogenic drivers. In particular, the high degree of urbanization and the concentration of population and activities in coastal areas is often severely impacting the water availability also for the residential sector. It is therefore crucial analysing the importance of both climatic and touristic factors as drivers for the water demand in such areas, to better understand and model the expected consumption in order to improve the water management policies and practices. The study presents an analysis referred to a large number of municipalities, covering almost the whole Romagna region, in Northern Italy, representing one of the most economically developed areas in Europe and characterized by an extremely profitable tourist industry, especially in the coastal cities. For this region it is therefore extremely important to assess the significance of the drivers that may influence the demand in the different periods of the year, that is climatic factors (rainfall depths and occurrence, temperature averages and extremes), but also the presence of tourists, in both official tourist accommodation structures and in holidays homes (and the latter are very difficult to estimate). Analyses on the Italian water industry at seasonal or monthly time scale has been so far, extremely limited in the literature by the scarce availability of data on the water demands, that are made public only as annual volumes. All the study municipalities are supplied by the same water company, who provided monthly consumption volumes data at the main inlet points of the entire distribution network for a period of 7 years (2009-2015). For the same period, precipitation and temperature data have been collected and summarised in indexes representing monthly averages, days of occurrence and over threshold values

  14. Water Demand Under Alternative Price Structures

    OpenAIRE

    Sheila Olmstead; W. Michael Hanemann; Robert N. Stavins

    2007-01-01

    We estimate the price elasticity of water demand with household-level data, structurally modeling the piecewise-linear budget constraints imposed by increasing-block pricing. We develop a mathematical expression for the unconditional price elasticity of demand under increasing-block prices and compare conditional and unconditional elasticities analytically and empirically. We test the hypothesis that price elasticity may depend on price structure, beyond technical differences in elasticity co...

  15. Water Demand Under Alternative Price Structures

    OpenAIRE

    Sheila Olmstead; W. Michael Hanemann; Robert N. Stavins

    2007-01-01

    We estimate the price elasticity of water demand with household-level data, structurally modeling the piecewise-linear budget constraints imposed by increasing-block pricing. We develop a mathematical expression for the unconditional price elasticity of demand under increasing-block prices and compare conditional and unconditional elasticities analytically and empirically. We test the hypothesis that price elasticity may depend on price structure, beyond technical differences in elasticity co...

  16. A hydraulic model is compatible with rapid changes in leaf elongation under fluctuating evaporative demand and soil water status.

    Science.gov (United States)

    Caldeira, Cecilio F; Bosio, Mickael; Parent, Boris; Jeanguenin, Linda; Chaumont, François; Tardieu, François

    2014-04-01

    Plants are constantly facing rapid changes in evaporative demand and soil water content, which affect their water status and growth. In apparent contradiction to a hydraulic hypothesis, leaf elongation rate (LER) declined in the morning and recovered upon soil rehydration considerably quicker than transpiration rate and leaf water potential (typical half-times of 30 min versus 1-2 h). The morning decline of LER began at very low light and transpiration and closely followed the stomatal opening of leaves receiving direct light, which represent a small fraction of leaf area. A simulation model in maize (Zea mays) suggests that these findings are still compatible with a hydraulic hypothesis. The small water flux linked to stomatal aperture would be sufficient to decrease water potentials of the xylem and growing tissues, thereby causing a rapid decline of simulated LER, while the simulated water potential of mature tissues declines more slowly due to a high hydraulic capacitance. The model also captured growth patterns in the evening or upon soil rehydration. Changes in plant hydraulic conductance partly counteracted those of transpiration. Root hydraulic conductivity increased continuously in the morning, consistent with the transcript abundance of Zea maize Plasma Membrane Intrinsic Protein aquaporins. Transgenic lines underproducing abscisic acid, with lower hydraulic conductivity and higher stomatal conductance, had a LER declining more rapidly than wild-type plants. Whole-genome transcriptome and phosphoproteome analyses suggested that the hydraulic processes proposed here might be associated with other rapidly occurring mechanisms. Overall, the mechanisms and model presented here may be an essential component of drought tolerance in naturally fluctuating evaporative demand and soil moisture.

  17. Multi-model projections and uncertainties of irrigation water demand under climate change

    NARCIS (Netherlands)

    Wada, Y.; Wisser, D.; Eisner, S.; Flörke, M.; Gerten, D.; Haddeland, I.; Hanasaki, N.; Masaki, Y.; Portmann, F.T.; Stacke, T.; Tessler, Z.; Schewe, J.

    2013-01-01

    Crop irrigation is responsible for 70% of humanity’swater demand. Since the late 1990s, the expansion ofirrigated areas has been tapering off, and this trend isexpected to continue in the future. Future irrigation waterdemand (IWD) is, however, subject to large uncertaintiesdue to anticipated climat

  18. An integrated communications demand model

    Science.gov (United States)

    Doubleday, C. F.

    1980-11-01

    A computer model of communications demand is being developed to permit dynamic simulations of the long-term evolution of demand for communications media in the U.K. to be made under alternative assumptions about social, economic and technological trends in British Telecom's business environment. The context and objectives of the project and the potential uses of the model are reviewed, and four key concepts in the demand for communications media, around which the model is being structured are discussed: (1) the generation of communications demand; (2) substitution between media; (3) technological convergence; and (4) competition. Two outline perspectives on the model itself are given.

  19. Influence of biological oxygen demand degradation patterns on water-quality modeling for rivers running through urban areas.

    Science.gov (United States)

    Fan, Chihhao; Wang, Wei-Shen

    2008-10-01

    Water-quality modeling has been used as a support tool for water-resources management. The Streeter-Phelps (SP) equation is one often-used algorithm in river water-quality simulation because of its simplicity and ease in use. To characterize the river dissolved oxygen (DO) sag profile, it only considers that the first-order biological oxygen demand (BOD) degradation and atmospheric reaeration are the sink and source in a river, respectively. In the river water-quality calculation, the assumption may not always provide satisfactory simulation due to an inappropriate description of BOD degradation. In the study, various patterns of BOD degradation were combined with the oxygen reaeration to simulate the DO sag profile in a river. Different BOD degradation patterns used include the first-order decay, mixed second-order decay, and oxygen-inhibition decay. The results shows that the oxygen-inhibition SP equation calculates higher BOD and DO concentration, while the mixed second SP equation calculates the least among the three tested models. In river-water calculation of Keelung River, the SP and oxygen-inhibition SP equations calculate similar BOD and DO concentrations, and the mixed second SP equation calculates the least BOD and DO concentration. The pollution loading of BOD and atmospheric reaeration constant are the two important factors that have significant impacts on aqueous DO concentration. In the field application, it is suggested that the mixed second SP equation be employed in water-quality simulation when the monitoring data exhibits a faster trend in BOD decay. The oxygen-inhibition SP equation may calculate the water quality more accurately when BOD decay is slower.

  20. Disaggregating residential water demand for improved forecasts and decision making

    Science.gov (United States)

    Woodard, G.; Brookshire, D.; Chermak, J.; Krause, K.; Roach, J.; Stewart, S.; Tidwell, V.

    2003-04-01

    Residential water demand is the product of population and per capita demand. Estimates of per capita demand often are based on econometric models of demand, usually based on time series data of demand aggregated at the water provider level. Various studies have examined the impact of such factors as water pricing, weather, and income, with many other factors and details of water demand remaining unclear. Impacts of water conservation programs often are estimated using simplistic engineering calculations. Partly as a result of this, policy discussions regarding water demand management often focus on water pricing, water conservation, and growth control. Projecting water demand is often a straight-forward, if fairly uncertain process of forecasting population and per capita demand rates. SAHRA researchers are developing improved forecasts of residential water demand by disaggregating demand to the level of individuals, households, and specific water uses. Research results based on high-resolution water meter loggers, household-level surveys, economic experiments and recent census data suggest that changes in wealth, household composition, and individual behavior may affect demand more than changes in population or the stock of landscape plants, water-using appliances and fixtures, generally considered the primary determinants of demand. Aging populations and lower fertility rates are dramatically reducing household size, thereby increasing the number of households and residences for a given population. Recent prosperity and low interest rates have raised home ownership rates to unprecented levels. These two trends are leading to increased per capita outdoor water demand. Conservation programs have succeeded in certain areas, such as promoting drought-tolerant native landscaping, but have failed in other areas, such as increasing irrigation efficiency or curbing swimming pool water usage. Individual behavior often is more important than the household's stock of water

  1. Exploring Tradeoffs in Demand-side and Supply-side Management of Urban Water Resources using Agent-based Modeling and Evolutionary Computation

    Science.gov (United States)

    Kanta, L.; Berglund, E. Z.

    2015-12-01

    Urban water supply systems may be managed through supply-side and demand-side strategies, which focus on water source expansion and demand reductions, respectively. Supply-side strategies bear infrastructure and energy costs, while demand-side strategies bear costs of implementation and inconvenience to consumers. To evaluate the performance of demand-side strategies, the participation and water use adaptations of consumers should be simulated. In this study, a Complex Adaptive Systems (CAS) framework is developed to simulate consumer agents that change their consumption to affect the withdrawal from the water supply system, which, in turn influences operational policies and long-term resource planning. Agent-based models are encoded to represent consumers and a policy maker agent and are coupled with water resources system simulation models. The CAS framework is coupled with an evolutionary computation-based multi-objective methodology to explore tradeoffs in cost, inconvenience to consumers, and environmental impacts for both supply-side and demand-side strategies. Decisions are identified to specify storage levels in a reservoir that trigger (1) increases in the volume of water pumped through inter-basin transfers from an external reservoir and (2) drought stages, which restrict the volume of water that is allowed for residential outdoor uses. The proposed methodology is demonstrated for Arlington, Texas, water supply system to identify non-dominated strategies for an historic drought decade. Results demonstrate that pumping costs associated with maximizing environmental reliability exceed pumping costs associated with minimizing restrictions on consumer water use.

  2. Long-term trends in field level irrigation water demand in Mahanadi delta districts - a hydrological modeling approach for coping with climate change

    Science.gov (United States)

    Raju Pokkuluri, Venkat; Rao, Diwakar Parsi Guru; Hazra, Sugata; Srikant Kulkarni, Sunil

    2017-04-01

    India uses its 85 percent of available water resources for irrigation making it the country with largest net irrigated area in the world. With one of the largest delta plains, sustaining the needs of irrigation supplies is critical for food security and coping with challenges of climate change. The extensive development of upstream river basins/catchments is posing serious challenge and constrains to the water availability to delta regions, which depend on the controlled/regulated flows from the upstream catchments. The irrigation water demands vary due to changes in agricultural practices, cropping pattern and changing climate conditions. Estimation of realistic irrigation water demand and its trend over time is critical for meeting the supplementary water needs of productive agricultural lands in delta plains and there by coping the challenges of extensive upstream river basin development and climate change. The present study carried out in delta districts of Mahanadi river in Odisha State of India, wherein the long-term trends in field level irrigation water requirements were estimated, both on spatial & temporal scales, using hydrological modeling framework. This study attempts to estimate field level irrigation water requirements through simulation of soil water balance during the crop growing season through process based hydrological modeling framework. The soil water balance computations were carried out using FAO-56 framework, by modifying the crop coefficient (Kc) proportional to the water stress coefficient (Ks), which is a function of root zone depletion of water. Daily meteorological data, spatial cropping pattern, terrain are incorporated in the soil water balance simulation in the model. The irrigation water demand is derived considering the exclusion of soil water stress for each model time step. The field level irrigation water requirement at 8 day interval had been estimated for the each Rabi season (post-monsoon) spanning over 1986 to 2015. The

  3. Job demands-resources model

    NARCIS (Netherlands)

    A.B. Bakker (Arnold); E. Demerouti (Eva)

    2013-01-01

    markdownabstract* The question of what causes job stress and what motivates people has received a lot of research attention during the past five decades. In this paper, we discuss Job Demands-Resources (JD-R) theory, which represents an extension of the Job Demands-Resources model (Bakker &

  4. Job demands-resources model

    NARCIS (Netherlands)

    A.B. Bakker (Arnold); E. Demerouti (Eva)

    2013-01-01

    markdownabstract* The question of what causes job stress and what motivates people has received a lot of research attention during the past five decades. In this paper, we discuss Job Demands-Resources (JD-R) theory, which represents an extension of the Job Demands-Resources model (Bakker & Demerout

  5. Job demands-resources model

    NARCIS (Netherlands)

    A.B. Bakker (Arnold); E. Demerouti (Eva)

    2013-01-01

    markdownabstract* The question of what causes job stress and what motivates people has received a lot of research attention during the past five decades. In this paper, we discuss Job Demands-Resources (JD-R) theory, which represents an extension of the Job Demands-Resources model (Bakker & Demerout

  6. Fundamental Travel Demand Model Example

    Science.gov (United States)

    Hanssen, Joel

    2010-01-01

    Instances of transportation models are abundant and detailed "how to" instruction is available in the form of transportation software help documentation. The purpose of this paper is to look at the fundamental inputs required to build a transportation model by developing an example passenger travel demand model. The example model reduces the scale to a manageable size for the purpose of illustrating the data collection and analysis required before the first step of the model begins. This aspect of the model development would not reasonably be discussed in software help documentation (it is assumed the model developer comes prepared). Recommendations are derived from the example passenger travel demand model to suggest future work regarding the data collection and analysis required for a freight travel demand model.

  7. Modelling global water stress of the recent past: on the relative importance of trends in water demand and climate variability

    NARCIS (Netherlands)

    Wada, Y.; Beek, L.P.H. van; Bierkens, M.F.P.

    2011-01-01

    During the past decades, human water use has more than doubled, yet available freshwater resources are finite. As a result, water scarcity has been prevalent in various regions of the world. Here, we present the first global assessment of past development of water stress considering not only climate

  8. Modelling global water stress of the recent past: on the relative importance of trends in water demand and climate variability

    NARCIS (Netherlands)

    Wada, Y.; Beek, L.P.H. van; Bierkens, M.F.P.

    2011-01-01

    During the past decades, human water use has more than doubled, yet available freshwater resources are finite. As a result, water scarcity has been prevalent in various regions of the world. Here, we present the first global assessment of past development of water stress considering not only climate

  9. Future land-use related water demand in California

    Science.gov (United States)

    Wilson, Tamara; Sleeter, Benjamin M.; Cameron, D. Richard

    2016-01-01

    Water shortages in California are a growing concern amidst ongoing drought, earlier spring snowmelt, projected future climate warming, and currently mandated water use restrictions. Increases in population and land use in coming decades will place additional pressure on already limited available water supplies. We used a state-and-transition simulation model to project future changes in developed (municipal and industrial) and agricultural land use to estimate associated water use demand from 2012 to 2062. Under current efficiency rates, total water use was projected to increase 1.8 billion cubic meters(+4.1%) driven primarily by urbanization and shifts to more water intensive crops. Only if currently mandated 25% reductions in municipal water use are continuously implemented would water demand in 2062 balance to water use levels in 2012. This is the first modeling effort of its kind to examine regional land-use related water demand incorporating historical trends of both developed and agricultural land uses.

  10. Future land-use related water demand in California

    Science.gov (United States)

    Wilson, Tamara S.; Sleeter, Benjamin M.; Cameron, D. Richard

    2016-05-01

    Water shortages in California are a growing concern amidst ongoing drought, earlier spring snowmelt, projected future climate warming, and currently mandated water use restrictions. Increases in population and land use in coming decades will place additional pressure on already limited available water supplies. We used a state-and-transition simulation model to project future changes in developed (municipal and industrial) and agricultural land use to estimate associated water use demand from 2012 to 2062. Under current efficiency rates, total water use was projected to increase 1.8 billion cubic meters (+4.1%) driven primarily by urbanization and shifts to more water intensive crops. Only if currently mandated 25% reductions in municipal water use are continuously implemented would water demand in 2062 balance to water use levels in 2012. This is the first modeling effort of its kind to examine regional land-use related water demand incorporating historical trends of both developed and agricultural land uses.

  11. 'Waterstreams': A model for estimation of crop water demand, water supply, salt accumulation and discharge for soilless crops

    NARCIS (Netherlands)

    Voogt, W.; Swinkels, G.L.A.M.; Os, van E.A.

    2012-01-01

    Abstract: Closed growing systems are obligatory for soilless grown greenhouse crops in The Netherlands. It requires water sources of high quality as sodium (Na) accumulation is a potential risk and necessitates frequent discharge, which causes undesirable emission of nutrients and plant protection p

  12. Future United States Domestic Water Demand

    Data.gov (United States)

    U.S. Environmental Protection Agency — Population projections, estimated per capita consumption rate, and estimated total annual water demand to 2100 for four future projections based off the IPCC SRES...

  13. Household water demand and welfare loss for future Europe

    Science.gov (United States)

    Bernhard, Jeroen; Reynaud, Arnaud; Lanzanova, Denis; de Roo, Ad

    2015-04-01

    Matching the availability of water to its demand in Europe is a major challenge for the future due to expected economic and demographic developments and climate change. This means there is a growing need to estimate future water demand and to optimize the water allocation to all end users to counteract welfare loss. At the European scale it is currently not possible to assess the impact of social and economic changes on future water demand or to prioritize water allocation amongst different sectors based on economic damage without extensive use of assumptions and generalizations. Indeed, our review of existing regional optimization models for Europe reveals that the social-economic component of the water use system needs to be improved by complementing them with detailed water use estimates and cost/benefit functions in order to determine the optimal situation. Our study contributes to closing this knowledge gap for the European household sector by quantifying future water demand and the effect of water pricing, as well as providing a method for the calculation of monetary damage due to unmet demand at the highest spatial resolution possible. We used a water demand function approach in which household water consumption depends upon some exogenous drivers including water price, household income, population and household characteristics and climate conditions. For each European country, the annual water consumption per capita was calculated at regional level (NUTS3) and subsequently disaggregated to five kilometer grid level based on a population density map. In order to produce estimates of water demand, the evolution of the explanatory variables of the water demand functions and population density map were simulated until 2050 based on related variables such as GDP and demographic projections. The results of this study will be integrated into the JRC hydro-economic modelling framework for an assessment of the Water-Agriculture-Energy-Ecosystems Nexus.

  14. Exploring Tradeoffs in Demand-Side and Supply-Side Management of Urban Water Resources Using Agent-Based Modeling and Evolutionary Computation

    Directory of Open Access Journals (Sweden)

    Lufthansa Kanta

    2015-11-01

    Full Text Available Urban water supply systems may be managed through supply-side and demand-side strategies, which focus on water source expansion and demand reductions, respectively. Supply-side strategies bear infrastructure and energy costs, while demand-side strategies bear costs of implementation and inconvenience to consumers. To evaluate the performance of demand-side strategies, the participation and water use adaptations of consumers should be simulated. In this study, a Complex Adaptive Systems (CAS framework is developed to simulate consumer agents that change their consumption to affect the withdrawal from the water supply system, which, in turn influences operational policies and long-term resource planning. Agent-based models are encoded to represent consumers and a policy maker agent and are coupled with water resources system simulation models. The CAS framework is coupled with an evolutionary computation-based multi-objective methodology to explore tradeoffs in cost, inconvenience to consumers, and environmental impacts for both supply-side and demand-side strategies. Decisions are identified to specify storage levels in a reservoir that trigger: (1 increases in the volume of water pumped through inter-basin transfers from an external reservoir; and (2 drought stages, which restrict the volume of water that is allowed for residential outdoor uses. The proposed methodology is demonstrated for Arlington, Texas, water supply system to identify non-dominated strategies for an historic drought decade. Results demonstrate that pumping costs associated with maximizing environmental reliability exceed pumping costs associated with minimizing restrictions on consumer water use.

  15. Mining residential water and electricity demand data in Southern California to inform demand management strategies

    Science.gov (United States)

    Cominola, A.; Spang, E. S.; Giuliani, M.; Castelletti, A.; Loge, F. J.; Lund, J. R.

    2016-12-01

    Demand side management strategies are key to meet future water and energy demands in urban contexts, promote water and energy efficiency in the residential sector, provide customized services and communications to consumers, and reduce utilities' costs. Smart metering technologies allow gathering high temporal and spatial resolution water and energy consumption data and support the development of data-driven models of consumers' behavior. Modelling and predicting resource consumption behavior is essential to inform demand management. Yet, analyzing big, smart metered, databases requires proper data mining and modelling techniques, in order to extract useful information supporting decision makers to spot end uses towards which water and energy efficiency or conservation efforts should be prioritized. In this study, we consider the following research questions: (i) how is it possible to extract representative consumers' personalities out of big smart metered water and energy data? (ii) are residential water and energy consumption profiles interconnected? (iii) Can we design customized water and energy demand management strategies based on the knowledge of water- energy demand profiles and other user-specific psychographic information? To address the above research questions, we contribute a data-driven approach to identify and model routines in water and energy consumers' behavior. We propose a novel customer segmentation procedure based on data-mining techniques. Our procedure consists of three steps: (i) extraction of typical water-energy consumption profiles for each household, (ii) profiles clustering based on their similarity, and (iii) evaluation of the influence of candidate explanatory variables on the identified clusters. The approach is tested onto a dataset of smart metered water and energy consumption data from over 1000 households in South California. Our methodology allows identifying heterogeneous groups of consumers from the studied sample, as well as

  16. Modeling Impact of Climate Change on Water Resources and Agriculture Demand in the Volta Basin and other Basin Systems in Ghana

    Directory of Open Access Journals (Sweden)

    Barnabas A. Amisigo

    2015-05-01

    Full Text Available An assessment of the impacts of projected climate change on water availability and crop production in the Volta Basin and the southwestern and coastal basin systems of Ghana has been undertaken as a component of the impacts and adaptation study for Ghana by UNU-WIDER and the University of Ghana. Four climate change scenarios were considered in addition to a reference (no change scenario—two dry and two wet scenarios. To conduct the analysis, a portion of a special framework using three water models was used; the framework is called the Strategic Analysis of Climate resilient Development (SACReD. First, the CliRun water balance model was used to simulate catchment runoffs using projected rainfall and temperature under the scenarios. Second, climate impacts on yields of the economically important Ghana crops were modeled using the AquaCrop software. Third, the Water Evaluation and Planning (WEAP software was used for the water allocation modeling. The results show that all water demands (municipal, hydropower, and agriculture cannot be simultaneously met currently, or under any of the scenarios used, including the wet scenarios. This calls for an evaluation of groundwater as an additional source of water supply and an integrated water resources management plan in the catchments to balance demand with supply and ensure sustainable socio-economic development. In addition, the AquaCrop model forecasts negative impacts for the crop yields studied, with some crops and regions seeing larger impacts than others.

  17. Forecasting urban water demand: A meta-regression analysis.

    Science.gov (United States)

    Sebri, Maamar

    2016-12-01

    Water managers and planners require accurate water demand forecasts over the short-, medium- and long-term for many purposes. These range from assessing water supply needs over spatial and temporal patterns to optimizing future investments and planning future allocations across competing sectors. This study surveys the empirical literature on the urban water demand forecasting using the meta-analytical approach. Specifically, using more than 600 estimates, a meta-regression analysis is conducted to identify explanations of cross-studies variation in accuracy of urban water demand forecasting. Our study finds that accuracy depends significantly on study characteristics, including demand periodicity, modeling method, forecasting horizon, model specification and sample size. The meta-regression results remain robust to different estimators employed as well as to a series of sensitivity checks performed. The importance of these findings lies in the conclusions and implications drawn out for regulators and policymakers and for academics alike. Copyright © 2016. Published by Elsevier Ltd.

  18. China's rising hydropower demand challenges water sector

    NARCIS (Netherlands)

    Liu, J.; Zhao, D.; Gerbens-Leenes, P.W.; Guan, D.

    2015-01-01

    Demand for hydropower is increasing, yet the water footprints (WFs) of reservoirs and hydropower, and their contributions to water scarcity, are poorly understood. Here, we calculate reservoir WFs (freshwater that evaporates from reservoirs) and hydropower WFs (the WF of hydroelectricity) in China b

  19. China's rising hydropower demand challenges water sector

    NARCIS (Netherlands)

    Liu, J.; Zhao, D.; Gerbens-Leenes, Winnie; Guan, D.

    2015-01-01

    Demand for hydropower is increasing, yet the water footprints (WFs) of reservoirs and hydropower, and their contributions to water scarcity, are poorly understood. Here, we calculate reservoir WFs (freshwater that evaporates from reservoirs) and hydropower WFs (the WF of hydroelectricity) in China

  20. America's water: Agricultural water demands and the response of groundwater

    Science.gov (United States)

    Ho, M.; Parthasarathy, V.; Etienne, E.; Russo, T. A.; Devineni, N.; Lall, U.

    2016-07-01

    Agricultural, industrial, and urban water use in the conterminous United States (CONUS) is highly dependent on groundwater that is largely drawn from nonsurficial wells (>30 m). We use a Demand-Sensitive Drought Index to examine the impacts of agricultural water needs, driven by low precipitation, high agricultural water demand, or a combination of both, on the temporal variability of depth to groundwater across the CONUS. We characterize the relationship between changes in groundwater levels, agricultural water deficits relative to precipitation during the growing season, and winter precipitation. We find that declines in groundwater levels in the High Plains aquifer and around the Mississippi River Valley are driven by groundwater withdrawals used to supplement agricultural water demands. Reductions in agricultural water demands for crops do not, however, lead to immediate recovery of groundwater levels due to the demand for groundwater in other sectors in regions such as Utah, Maryland, and Texas.

  1. Water demand management research: A psychological perspective

    Science.gov (United States)

    Russell, Sally; Fielding, Kelly

    2010-05-01

    The availability of fresh water for human consumption is a critical global issue and one that will be exacerbated by the impacts of climate change. Water demand management has an important role to play in reducing the vulnerability of freshwater supplies to climate change impacts. In this paper, we argue that the field of psychology and environmental psychology in particular can make a vital contribution in understanding further the drivers of residential water demand. A growing body of literature in environmental psychology has examined the determinants of water conservation behavior, and this research has many potential applications for water demand policy. In this paper we offer a review of current psychological research that examines the five broad causes of residential water conservation behaviors: attitudes, beliefs, habits or routines, personal capabilities, and contextual factors. We assess how psychologists have studied water conservation behavior to date, identify shortcomings, and indicate how this research can be used to further promote residential water conservation and to inform evidence-based policy and practice.

  2. Application of stakeholder-based and modelling approaches for supporting robust adaptation decision making under future climatic uncertainty and changing urban-agricultural water demand

    Science.gov (United States)

    Bhave, Ajay; Dessai, Suraje; Conway, Declan; Stainforth, David

    2016-04-01

    Deep uncertainty in future climate change and socio-economic conditions necessitates the use of assess-risk-of-policy approaches over predict-then-act approaches for adaptation decision making. Robust Decision Making (RDM) approaches embody this principle and help evaluate the ability of adaptation options to satisfy stakeholder preferences under wide-ranging future conditions. This study involves the simultaneous application of two RDM approaches; qualitative and quantitative, in the Cauvery River Basin in Karnataka (population ~23 million), India. The study aims to (a) determine robust water resources adaptation options for the 2030s and 2050s and (b) compare the usefulness of a qualitative stakeholder-driven approach with a quantitative modelling approach. For developing a large set of future scenarios a combination of climate narratives and socio-economic narratives was used. Using structured expert elicitation with a group of climate experts in the Indian Summer Monsoon, climatic narratives were developed. Socio-economic narratives were developed to reflect potential future urban and agricultural water demand. In the qualitative RDM approach, a stakeholder workshop helped elicit key vulnerabilities, water resources adaptation options and performance criteria for evaluating options. During a second workshop, stakeholders discussed and evaluated adaptation options against the performance criteria for a large number of scenarios of climatic and socio-economic change in the basin. In the quantitative RDM approach, a Water Evaluation And Planning (WEAP) model was forced by precipitation and evapotranspiration data, coherent with the climatic narratives, together with water demand data based on socio-economic narratives. We find that compared to business-as-usual conditions options addressing urban water demand satisfy performance criteria across scenarios and provide co-benefits like energy savings and reduction in groundwater depletion, while options reducing

  3. China's rising hydropower demand challenges water sector.

    Science.gov (United States)

    Liu, Junguo; Zhao, Dandan; Gerbens-Leenes, P W; Guan, Dabo

    2015-07-09

    Demand for hydropower is increasing, yet the water footprints (WFs) of reservoirs and hydropower, and their contributions to water scarcity, are poorly understood. Here, we calculate reservoir WFs (freshwater that evaporates from reservoirs) and hydropower WFs (the WF of hydroelectricity) in China based on data from 875 representative reservoirs (209 with power plants). In 2010, the reservoir WF totaled 27.9 × 10(9) m(3) (Gm(3)), or 22% of China's total water consumption. Ignoring the reservoir WF seriously underestimates human water appropriation. The reservoir WF associated with industrial, domestic and agricultural WFs caused water scarcity in 6 of the 10 major Chinese river basins from 2 to 12 months annually. The hydropower WF was 6.6 Gm(3) yr(-1) or 3.6 m(3) of water to produce a GJ (10(9) J) of electricity. Hydropower is a water intensive energy carrier. As a response to global climate change, the Chinese government has promoted a further increase in hydropower energy by 70% by 2020 compared to 2012. This energy policy imposes pressure on available freshwater resources and increases water scarcity. The water-energy nexus requires strategic and coordinated implementations of hydropower development among geographical regions, as well as trade-off analysis between rising energy demand and water use sustainability.

  4. Energy demand modeling for Uzbekistan

    Directory of Open Access Journals (Sweden)

    Bobur Khodjaev

    2012-05-01

    Full Text Available The paper is devoted to energy demand forecasting in Uzbekistan. Studies show that in spite of the abundant reserves of hydrocarbons, low energy efficiency can have an adverse impact on energy security in Uzbekistan in the future. Oil and gas are the main primary energy source and they ensure energy security of Uzbekistan. Energy demand forecasting is essential in order to develop an effective energy policy. Such forecast can be useful to plan oil and gas production volumes, to identify priorities for the industrial modernization and to create favorable conditions for sustainable economic development in the future. Author proposes model based on translog function for developing medium-and long-term development programs in energy sector and the modernization and technological re-equipment of industry.

  5. Agent-Based Modelling of Agricultural Water Abstraction in Response to Climate, Policy, and Demand Changes: Results from East Anglia, UK

    Science.gov (United States)

    Swinscoe, T. H. A.; Knoeri, C.; Fleskens, L.; Barrett, J.

    2014-12-01

    Freshwater is a vital natural resource for multiple needs, such as drinking water for the public, industrial processes, hydropower for energy companies, and irrigation for agriculture. In the UK, crop production is the largest in East Anglia, while at the same time the region is also the driest, with average annual rainfall between 560 and 720 mm (1971 to 2000). Many water catchments of East Anglia are reported as over licensed or over abstracted. Therefore, freshwater available for agricultural irrigation abstraction in this region is becoming both increasingly scarce due to competing demands, and increasingly variable and uncertain due to climate and policy changes. It is vital for water users and policy makers to understand how these factors will affect individual abstractors and water resource management at the system level. We present first results of an Agent-based Model that captures the complexity of this system as individual abstractors interact, learn and adapt to these internal and external changes. The purpose of this model is to simulate what patterns of water resource management emerge on the system level based on local interactions, adaptations and behaviours, and what policies lead to a sustainable water resource management system. The model is based on an irrigation abstractor typology derived from a survey in the study area, to capture individual behavioural intentions under a range of water availability scenarios, in addition to farm attributes, and demographics. Regional climate change scenarios, current and new abstraction licence reforms by the UK regulator, such as water trading and water shares, and estimated demand increases from other sectors were used as additional input data. Findings from the integrated model provide new understanding of the patterns of water resource management likely to emerge at the system level.

  6. Optimal Node Grouping for Water Distribution System Demand Estimation

    Directory of Open Access Journals (Sweden)

    Donghwi Jung

    2016-04-01

    Full Text Available Real-time state estimation is defined as the process of calculating the state variable of interest in real time not being directly measured. In a water distribution system (WDS, nodal demands are often considered as the state variable (i.e., unknown variable and can be estimated using nodal pressures and pipe flow rates measured at sensors installed throughout the system. Nodes are often grouped for aggregation to decrease the number of unknowns (demands in the WDS demand estimation problem. This study proposes an optimal node grouping model to maximize the real-time WDS demand estimation accuracy. This Kalman filter-based demand estimation method is linked with a genetic algorithm for node group optimization. The modified Austin network demand is estimated to demonstrate the proposed model. True demands and field measurements are synthetically generated using a hydraulic model of the study network. Accordingly, the optimal node groups identified by the proposed model reduce the total root-mean-square error of the estimated node group demand by 24% compared to that determined by engineering knowledge. Based on the results, more pipe flow sensors should be installed to measure small flows and to further enhance the demand estimation accuracy.

  7. Have Chinese water pricing reforms reduced urban residential water demand?

    Science.gov (United States)

    Zhang, B.; Fang, K. H.; Baerenklau, K. A.

    2017-06-01

    China continues to deal with severe levels of water scarcity and water pollution. To help address this situation, the Chinese central government initiated urban water pricing reforms in 2002 that emphasized the adoption of increasing block rate (IBR) price structures in place of existing uniform rate structures. By combining urban water use records with microlevel data from the Chinese Urban Household Survey, this research investigates the effectiveness of this national policy reform. Specifically, we compare household water consumption in 28 cities that adopted IBR pricing structures during 2002-2009, with that of 110 cities that had not yet done so. Based on difference-in-differences models, our results show that the policy reform reduced annual residential water demand by 3-4% in the short run and 5% in the longer run. These relatively modest reductions are consistent with the generous nature of the IBR pricing structures that Chinese cities have typically chosen to implement. Our results imply that more efforts are needed to address China's persistent urban water scarcity challenges.

  8. Water demand forecasting: review of soft computing methods.

    Science.gov (United States)

    Ghalehkhondabi, Iman; Ardjmand, Ehsan; Young, William A; Weckman, Gary R

    2017-07-01

    Demand forecasting plays a vital role in resource management for governments and private companies. Considering the scarcity of water and its inherent constraints, demand management and forecasting in this domain are critically important. Several soft computing techniques have been developed over the last few decades for water demand forecasting. This study focuses on soft computing methods of water consumption forecasting published between 2005 and 2015. These methods include artificial neural networks (ANNs), fuzzy and neuro-fuzzy models, support vector machines, metaheuristics, and system dynamics. Furthermore, it was discussed that while in short-term forecasting, ANNs have been superior in many cases, but it is still very difficult to pick a single method as the overall best. According to the literature, various methods and their hybrids are applied to water demand forecasting. However, it seems soft computing has a lot more to contribute to water demand forecasting. These contribution areas include, but are not limited, to various ANN architectures, unsupervised methods, deep learning, various metaheuristics, and ensemble methods. Moreover, it is found that soft computing methods are mainly used for short-term demand forecasting.

  9. A Water Demand Curve for Rice Paddy Field

    OpenAIRE

    佐藤, 豊信

    1989-01-01

    Demand for water use in rice paddy fields in Japan has traditionally been measured according to a unit known as "Gensuishin" However, it does not consider farmer decisions on how much water to use in rice production, while the quantity of water measured by "Gensuishin" takes into account biologocal and physical conditions. This paper reports that analysis of water demand in rice production ought to incorporate a farmer's subjective equilibrium and water demand quantity. The water demand cu...

  10. Assessment of water availability and demand in Lake Guiers , Senegal.

    Science.gov (United States)

    Sambou, D.; Weihrauch, D.; Hellwing, V.; Diekkrüger, B.; Höllermann, B.; Gaye, A. T.

    2015-12-01

    Assessment of water availability and demand in Lake Guiers, SenegalWater resources are critical to economic growth and social development. In most African countries, supply of drinking water to satisfy population needs is a key issue because of population growth and climate and land use change. During the last three decades, increasing population, changing patterns of water demand, and concentration of population and economic activities in urban areas has pressurize Senegal's freshwater resources. To overcome this deficit, Senegal turned, to the exploitation of the Lake Guiers. It is the sole water reservoir which can be used extensively as a stable freshwater. Its water is use for irrigating crops and sugar refinery and as a drinking water resource for urban centres, including Dakar, the capital city of Senegal, as well as for the local population and animal herds. To ensure sustainability, a greater understanding of Lake Guiers's water resources and effective management of its use will be required. In this study we developed and quantified future water situation (water availability and demand) in Lake Guiers under scenarios of climate change and population growth until 2050, using the water management model WEAP (Water Evaluation And Planning system). The results show that the pressure on Lake Guiers's water resources will increase, leading to greater competition between agriculture and municipal demand site. Decreasing inflows due to climate change will aggravate this situation. WEAP results offer basis to assister lake Guiers water resources manager for an efficient long-term planning and management. Keywords: climate change, population growth , IWRM, Lake Guiers, Senegal

  11. Linking global water demand and supply using remote sensing products

    Science.gov (United States)

    Poortinga, A.; Thanh Ha, L.; Phuong Vu, N.; Saah, D. S.; Cutter, P. G.; Troy, A.; Ganz, D.

    2016-12-01

    Due to increasing pressures on water resources and changing population dynamics, there is a need to monitor regional water resource availability in a spatially and temporally explicit manner. However, for many parts of the world, there is insufficient data to quantify stream flow in river basins or potential ground water infiltration rates. Often water resource managers use sophistic hydrology models that require complex data sets to generate estimations, but the results of these efforts lack confidence due to the absence of accurate input data or validation methods. Global open access remote sensing derived data products offer exciting new opportunities to study spatial-temporal water dynamics in a way directly relevant to managers. We present the results of an elegant pixel-based water balance formulation to partition rainfall into evapotranspiration, surface water runoff and potential ground water. The method provides a rapid, accurate, and cost-effective solution to mapping water resource availability in basins with no gauges or monitoring infrastructure. The presented method provides important new insights into the spatial and temporal water supply and demand dynamics. The preliminary result of an application of the model build for the Mekong region will be presented, where quantitative water supply estimations are linked with demand patterns. It will be demonstrated that global freely available remote sensing products can be used to produce significant and operational results for water resource managers. We demonstrate that space based technologies and their applications play a key role to optimize the planning, implementation, and monitoring of projects.

  12. Simulation analysis of domestic water demand and its future uncertainty in water scarce areas

    Institute of Scientific and Technical Information of China (English)

    Shouke WEI; Albrecht GNAUCK; Alin LEI

    2009-01-01

    This paper demonstrates a practical simulation approach to analyze domestic water demand and its future uncertainty in water scarce areas through a case study of Beijing, China. Analytic models and a forecasting model were constructed using statistic and econometric regres-sion approaches. The analytic models were used to analyze the interrelationships between domestic water demand and some socio-economic factors of Beijing. The forecasting model was applied to predict domestic water demand from 2009 to 2015, and this model was validated by comparing the prediction values with the observations. Scenario analysis was applied to simulate uncertainty and risks in domestic water demand in the future. The simulation results proved that domestic water demand will increase from 13.9×108 m3 to 16.7×108 m3 from 2009 to 2015. Three more sustainable strategies were also found through scenario analysis. The simulation and modeling approaches and results would be very supportive for water decision makers in allocating water efficiently and making sustainable water strategies.

  13. A Framework for Sustainable Urban Water Management through Demand and Supply Forecasting: The Case of Istanbul

    Directory of Open Access Journals (Sweden)

    Murat Yalçıntaş

    2015-08-01

    Full Text Available The metropolitan city of Istanbul is becoming overcrowded and the demand for clean water is steeply rising in the city. The use of analytical approaches has become more and more critical for forecasting the water supply and demand balance in the long run. In this research, Istanbul’s water supply and demand data is collected for the period during 2006 and 2014. Then, using an autoregressive integrated moving average (ARIMA model, the time series water supply and demand forecasting model is constructed for the period between 2015 and 2018. Three important sustainability metrics such as water loss to supply ratio, water loss to demand ratio, and water loss to residential demand ratio are also presented. The findings show that residential water demand is responsible for nearly 80% of total water use and the consumption categories including commercial, industrial, agriculture, outdoor, and others have a lower share in total water demand. The results also show that there is a considerable water loss in the water distribution system which requires significant investments on the water supply networks. Furthermore, the forecasting results indicated that pipeline projects will be critical in the near future due to expected increases in the total water demand of Istanbul. The authors suggest that sustainable management of water can be achieved by reducing the residential water use through the use of water efficient technologies in households and reduction in water supply loss through investments on distribution infrastructure.

  14. Global monthly water stress: 2. Water demand and severity of water stress

    OpenAIRE

    Wada, Yoshihide; Van Beek, L. P. H.; Viviroli, Daniel; Dürr, Hans H.; Weingartner, Rolf; Bierkens, Marc F. P.

    2011-01-01

    This paper assesses global water stress at a finer temporal scale compared to conventional assessments. To calculate time series of global water stress at a monthly time scale, global water availability, as obtained from simulations of monthly river discharge from the companion paper, is confronted with global monthly water demand. Water demand is defined here as the volume of water required by users to satisfy their needs. Water demand is calculated for the benchmark year of 2000 and contras...

  15. Global monthly water stress: 2. Water demand and severity of water stress

    OpenAIRE

    Wada, Yoshihide; Beek, L. P. H.; Viviroli, Daniel; Dürr, Hans H; Weingartner, Rolf; Bierkens, Marc F.P.

    2011-01-01

    This paper assesses global water stress at a finer temporal scale compared to conventional assessments. To calculate time series of global water stress at a monthly time scale, global water availability, as obtained from simulations of monthly river discharge from the companion paper, is confronted with global monthly water demand. Water demand is defined here as the volume of water required by users to satisfy their needs. Water demand is calculated for the benchmark year of 2000 and contras...

  16. Residential water demand with endogenous pricing: The Canadian Case

    Science.gov (United States)

    Reynaud, Arnaud; Renzetti, Steven; Villeneuve, Michel

    2005-11-01

    In this paper, we show that the rate structure endogeneity may result in a misspecification of the residential water demand function. We propose to solve this endogeneity problem by estimating a probabilistic model describing how water rates are chosen by local communities. This model is estimated on a sample of Canadian local communities. We first show that the pricing structure choice reflects efficiency considerations, equity concerns, and, in some cases, a strategy of price discrimination across consumers by Canadian communities. Hence estimating the residential water demand without taking into account the pricing structures' endogeneity leads to a biased estimation of price and income elasticities. We also demonstrate that the pricing structure per se plays a significant role in influencing price responsiveness of Canadian residential consumers.

  17. High Resolution Modelling of Climate Change Impacts on Water Supply and Demand, Crop Nutrient Usage and GHG emissions, Similkameen Watershed, British Columbia, Canada

    Science.gov (United States)

    Mirmasoudi, S.; Byrne, J. M.; Kroebel, R.; MacDonald, R. J.; Johnson, D. L.; McKenzie, R. H.

    2015-12-01

    The Similkameen watershed in southern British Columbia, Canada is expected to warm substantially in the coming decades. A higher proportion of winter rain to snow and an earlier onset of spring snowmelt are likely to result in lower spring stream flow peaks. The reduction in winter water storage, combined with longer, warmer, and drier summers, poses a challenge for water resources in an irrigation-based agricultural watershed. There are already substantial irrigation developments, and water demands are expected to increase to maintain current agricultural production, further stressing a shrinking summer water supply. Agriculture releases significant amounts of CO2, CH4 and N2O to the atmosphere, accounting for approximately 8% of anthropogenic greenhouse gas (GHG) emissions in Canada, excluding CO2 emissions from fuels. Agricultural GHG fluxes are complex but the active management of agricultural systems offers possibilities for mitigating GHG emissions. Although GHG emissions derived from soil have been researched for several decades, there are still geographic regions and agricultural systems that have not been well characterized. This work will address a series of questions for the Similkameen watershed. For a range of climate scenarios, we will: (i) use the GENESYS (GENerate Earth SYstems Science input) hydrometeorological model to simulate historical and future water supplies; (ii) link GENESYS and AquaCrop models to assess climate driven changes in water requirement and associated crop productivity; and (iii) link GENESYS and HOLOS (whole-farm model and software program that estimates GHG emissions) to estimate farm and regional level GHG emissions and seasonal nutrient balance for the crops in the watershed.

  18. Demand forecast model based on CRM

    Science.gov (United States)

    Cai, Yuancui; Chen, Lichao

    2006-11-01

    With interiorizing day by day management thought that regarding customer as the centre, forecasting customer demand becomes more and more important. In the demand forecast of customer relationship management, the traditional forecast methods have very great limitation because much uncertainty of the demand, these all require new modeling to meet the demands of development. In this paper, the notion is that forecasting the demand according to characteristics of the potential customer, then modeling by it. The model first depicts customer adopting uniform multiple indexes. Secondly, the model acquires characteristic customers on the basis of data warehouse and the technology of data mining. The last, there get the most similar characteristic customer by their comparing and forecast the demands of new customer by the most similar characteristic customer.

  19. Teaching Aggregate Demand and Supply Models

    Science.gov (United States)

    Wells, Graeme

    2010-01-01

    The author analyzes the inflation-targeting model that underlies recent textbook expositions of the aggregate demand-aggregate supply approach used in introductory courses in macroeconomics. He shows how numerical simulations of a model with inflation inertia can be used as a tool to help students understand adjustments in response to demand and…

  20. Teaching Aggregate Demand and Supply Models

    Science.gov (United States)

    Wells, Graeme

    2010-01-01

    The author analyzes the inflation-targeting model that underlies recent textbook expositions of the aggregate demand-aggregate supply approach used in introductory courses in macroeconomics. He shows how numerical simulations of a model with inflation inertia can be used as a tool to help students understand adjustments in response to demand and…

  1. Considering environmental water demands in global-scale water stress assessments: a pilot study

    Science.gov (United States)

    Doell, P.; Shmaktin, V.; Revenga, C.

    2003-04-01

    Freshwater ecosystems need certain water flow regimes to sustain their animal and plant communities. Thus, there is not only a human demand for water (i.e. for domestic, industrial and agricultural purposes) but also a demand by freshwater ecosystems, here called environmental water demand. In order to achieve a sustainable development of river basins, both human and environmental water demands need to be taken into account in water management. For a comparative global-scale analysis of freshwater scarcity, it is therefore useful to compute river- basin specific budgets which contain the following terrestrial water flows (or rather flow components): 1) total renewable water resources (runoff), 2) human water withdrawals (and consumptive water uses) and 3) environmental water demands. In a pilot study, the global water availability and use model WaterGAP 2 (spatial resolution 0.5 degree) was used to derive such budgets for all river basins of the worlds. Its sectoral water use modules estimate human water withdrawals and consumptive water uses, while its hydrological module WGHM computes monthly values of surface runoff, groundwater recharge and river discharge. WGHM calculates both natural and actual discharge by simulating the reduction of river discharge by human water consumption. It is tuned against observed discharge at 724 gauging stations (representing about 50% of the global land area) to achieve a good simulation of the long-term average river discharge. Validation efforts have shown than WGHM can satisfactorily simulate the 90% reliable monthly discharge Q90 of river basins larger than 20,000 km2. Based on these capabilities of WaterGAP 2, a first estimate of basin-specific annual environmental water demands was derived as the sum of a low flow and a high flow requirement. Drawing on experience from South Africa, Q90 was assumed to represent the low flow that the ecosystems can tolerate, as it is the flow value that is not reached in 1 out of 10 months

  2. Balancing food security and water demand for freshwater ecosystems

    Science.gov (United States)

    Pastor, Amandine; Palazzo, Amanda; Havlik, Petr; Obersteiner, Michael; Biemans, Hester; Wada, Yoshihide; Kabat, Pavel; Ludwig, Fulco

    2017-04-01

    Water is not an infinite resource and demand from irrigation, household and industry is constantly increasing. This study focused on including global water availability including environmental flow requirements with water withdrawal from irrigation and other sectors at a monthly time-step in the GLOBIOM model. This model allows re-adjustment of land-use allocation, crop management, consumption and international trade. The GLOBIOM model induces an endogenous change in water price depending on water supply and demand. In this study, the focus was on how the inclusion of water resources affects land-use and, in particular, how global change will influence repartition of irrigated and rainfed lands at global scale. We used the climate change scenario including a radiative forcing of 8.5 W/m2 (RCP8.5), the socio-economic scenario (SSP2: middle-of-road), and the environmental flow method based on monthly flow allocation (the Variable Monthly Flow method) with high and low restrictions. Irrigation withdrawals were adjusted to a monthly time-step to account for biophysical water limitations at finer time resolution. Our results show that irrigated land might decrease up to 40% on average depending on the choice of EFR restrictions. Several areas were identified as future hot-spots of water stress such as the Mediterranean and Middle-East regions. Other countries were identified to be in safe position in terms of water stress such as North-European countries. Re-allocation of rainfed and irrigated land might be useful information for land-use planners and water managers at an international level to decide on appropriate legislations on climate change mitigation/adaptation when exposure and sensitivity to climate change is high and/or on adaptation measures to face increasing water demand. For example, some countries are likely to adopt measures to increase their water use efficiencies (irrigation system, soil and water conservation practices) to face water shortages, while

  3. Modelling Demand for Broad Money in Australia

    OpenAIRE

    Abbas Valadkhani

    2002-01-01

    The existence of a stable demand for money is very important for the conduct of monetary policy. It is argued that previous work on the demand for money in Australia has not been very satisfactory in a number of ways. This paper examines the long- and short-run determinants of the demand for broad money employing the Johansen cointegration technique and a short-run dynamic model. Using quarterly data for the period 1976:3-2002:2, this paper finds, inter alia, that the demand for broad money i...

  4. Agricultural practices and irrigation water demand in Uttar Pradesh

    Science.gov (United States)

    O'Keeffe, J.; Buytaert, W.; Brozovic, N.; Mijic, A.

    2013-12-01

    Changes in farming practices within Uttar Pradesh, particularly advances in irrigation technology, have led to a significant drop in water tables across the region. While the acquisition of monitoring data in India is a challenge, current water use practices point towards water overdraught. This is exacerbated by government and state policies and practices, including the subsidising of electricity, seeds and fertilizer, and an agreement to buy all crops grown, promoting the over use of water resources. Taking India's predicted population growth, increases in industrialisation and climate change into account, both farmland and the water resources it depends upon will be subject to increased pressures in the future. This research is centred around irrigation demands on water resources within Uttar Pradesh, and in particular, quantifying those demands both spatially and temporally. Two aspects of this will be presented; the quantification of irrigation water applied and the characterisation of the spatial heterogeneity of water use practices. Calculating the volumes of applied irrigation water in the absence of observed data presents a major challenge and is achieved here through the use of crop models. Regional crop yields provided by statistical yearbooks are replicated by the crop models AquaCrop and InfoCrop, and by doing so the amount of irrigation water needed to produce the published yields is quantified. In addition, proxy information, for example electrical consumption for agricultural use, is used to verify the likely volumes of water abstracted from tubewells. Statistical analyses of borehole distribution and the characterisation of the spatial heterogeneity of water use practices, particularly farmer decision making, collected during a field trip are also presented. The evolution of agricultural practices, technological advancement and water use for irrigation is reconstructed through the use of multiple regression and principle component analysis

  5. Demand modelling for central heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    Most researchers in the field of heat demand estimation have focussed on explaning the load for a given plant based on rather few measurements. This approach is simply the only one adaptable with the very limited data material and limited computer power. This way of dealing with the subject is here called the top-down approach, due to the fact that one tries to explain the load from the overall data. The results of such efforts are discussed in the report, leading to inspiration for own work. Also the significance of the findings to the causes for given heat loads are discussed and summarised. Contrary to the top-down approach applied in literature, a here-called bottom-up approach is applied in this work, describing the causes of a given partial load in detail and combining them to explain the total load for the system. Three partial load 'components' are discussed: 1) Space heating. 2) Hot-Water Consumption. 3) Heat losses in pipe networks. The report is aimed at giving an introduction to these subjects, but at the same time at collecting the previous work done by the author. Space heating is shortly discussed and loads are generated by an advanced simulation model. A hot water consumption model is presented and heat loads, generated by this model, utilised in the overall work. Heat loads due to heat losses in district heating a given a high priority in the current work. Hence a detailed presentation and overview of the subject is given to solar heating experts normally not dealing with district heating. Based on the 'partial' loads generated by the above-mentioned method, an overall load model is built in the computer simulation environment TRNSYS. The final tool is then employed for the generation of time series for heat demand, representing a district heating area. The results are compared to alternative methods for the generation of heat demand profiles. Results form this comparison will be presented. Computerised modelling of systems

  6. Economic Analysis of Water Demand in Greenhouses of Khash Township

    Directory of Open Access Journals (Sweden)

    Javad Shahraki

    2014-06-01

    Full Text Available The main goal of this study was to investigate the way of affecting of water in production of cucumber. From aspect of econometrics, mutual relationships of production function and expenses have been analysed in which Translog cost function has been used. This function has been estimated using the conditional input demand functions, the shefard theorem, chemical fertilizer, animal fertilizer, labour force, seed, and pesticide in the framework of a system of equations by taking advantage of the irrelevant regression method. Applied inputs is for 151 cucumber Beneficiaries in Khash in farming year of 2011-12 that insider and crossing tendency of input demand for this product has been investigated through collecting questionnaires and using obtained coefficients. The results show that the translog cost model is a good fit compared to the data of research. According to the reviews, demand for water has a minor Insidersuccession tendency more than one which shows possible stretch of demand function rather than the price of the inputs. Hence, appropriate pricing policies can be used to take a positive step in preventing the extreme usage of this input and directing beneficiaries for optimum use of these inputs.

  7. Back-casting global water stress: Reconstruction of past water demand and climate variability

    Science.gov (United States)

    Wada, Y.; van Beek, L. P.; Bierkens, M. F.

    2010-12-01

    Water scarcity, caused by an existing regional imbalance of water availability and water demand, poses a serious environmental issue to the global society. Since the late 1990s, several studies have quantified blue water stress at the global scale by using the global hydrological models to simulate blue water availability (i.e., surface freshwater in rivers, lakes and reservoirs) which is confronted against water demand to compute water stress. While these assessments have identified regions suffering from current water stress and vulnerable to future water scarcity due to the effects of the climate change and prone to frequent droughts (e.g., Australia, Central and West USA, India, North-East China, Pakistan), the development of past water stress with the influences of population and economic growth and expanding irrigated area has not yet been quantified, which might give an important implication for the future assessment of water stress. Here, we developed a method to reconstruct past water demand from agricultural (i.e., irrigation and livestock), industrial and domestic (i.e., households and municipalities) sector over the period 1960 to 2001, which was used to contrast transient effects in its development against climate variability in the severity of water stress. Agricultural water demand was estimated based on past extents of irrigated area and livestock densities. We developed a simple algorithm to approximate the past economic development based on GDP, energy and household consumption and electricity production, which was subsequently used together with population numbers to estimate industrial and domestic water demand. Desalinated water use and groundwater abstraction were additionally calculated over the same period, the latter being proportional to water demand. Various annual country statistics were used but resulted estimates were gridded at a spatial resolution of 0.5° and disaggregated into a monthly temporal scale as it can be expected that

  8. System Dynamics Approach to Urban Water Demand Forecasting A Case Study of Tianjin

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hongwei; ZHANG Xuehua; ZHANG Baoan

    2009-01-01

    A system dynamics approach to urban water demand forecasting was developed based on the analysis of urban water resources system.which was characterized by multi.feedback and nonlinear interactions among system elements.As an example,Tianjin water resources system dynamic model was set up to forecast water resources demand of the planning years.The practical verification showed that the relative error was lower than 1O%.Furthermore,through the comparison and analysis of the simulation results under different development modes presented in this paper.the forecasting results ofthe water resources demand ofTianiin was achieved based on sustainable utilization strategy of water resources.

  9. Price elasticity reconsidered: Panel estimation of an agricultural water demand function

    Science.gov (United States)

    Schoengold, Karina; Sunding, David L.; Moreno, Georgina

    2006-09-01

    Using panel data from a period of water rate reform, this paper estimates the price elasticity of irrigation water demand. Price elasticity is decomposed into the direct effect of water management and the indirect effect of water price on choice of output and irrigation technology. The model is estimated using an instrumental variables strategy to account for the endogeneity of technology and output choices in the water demand equation. Estimation results indicate that the price elasticity of agricultural water demand is -0.79, which is greater than that found in previous studies.

  10. Optimal demand reponse to water pricing policies under limited water supply in irrigation: a case study

    Science.gov (United States)

    Grießbach, Ulkrike; Stange, Peter; Schuetze, Niels

    2015-04-01

    Due to climate change, extreme weather conditions such as droughts may have an increasing impact on irrigated agriculture. To cope with the higher demand of water, a new decision support framework is developed which focuses on an integrated management of both irrigation water supply and demand. For modeling the regional water demand, local stochastic water demand functions are used which are derived from optimized agronomic response on farms scale. These functions take into account different soil types, crops, stochastically generated climate scenarios considering different economic conditions, e.g., variable and fixed costs. This generic approach enables the consideration of both multiple crops at farm scale as well as of the aggregated response to water pricing at a regional scale for full and deficit irrigation systems. Within the SAPHIR (SAxonian Platform for High Performance IRrigation) project a prototype of a decision support system is developed and applied for a case study in Saxony which helps to evaluate combined water supply and demand management policies on a regional level.

  11. A Theoretic Model of Transport Logistics Demand

    Directory of Open Access Journals (Sweden)

    Natalija Jolić

    2006-01-01

    Full Text Available Concerning transport logistics as relation between transportand integrated approaches to logistics, some transport and logisticsspecialists consider the tenn tautological. However,transport is one of the components of logistics, along with inventories,resources, warehousing, infonnation and goods handling.Transport logistics considers wider commercial and operationalframeworks within which the flow of goods is plannedand managed. The demand for transport logistics services canbe valorised as highly qualitative, differentiated and derived.While researching transport phenomenon the implementationof models is inevitable and demand models highly desirable. Asa contribution to transport modelling this paper improves decisionmaking and planning in the transport logistics field.

  12. Water-saving Benefit Analysis Based on the Supply and Demand Balance and Water-using Efficiency Model%基于供需平衡和用水效率模型的节水效益分析

    Institute of Scientific and Technical Information of China (English)

    李永战

    2014-01-01

    Water conservation is an action that comprehensive measures of engineering, technique, economy and management are taken to ensure the rational use of water, improve the use efficiency of water and reduce invalid loss. Under the current conditions of water shortage and increasing serious water pollution, water conservation is a strategic infrastructure project for the exploitation and use of water resources. Evaluation system model is established by water supply and demand ratio (R1) and water-saving benefit ratio (R2). The two aspects of evaluation factors could get the level value of water-saving benefit, and they are both independent parameters, so this model has high reference value.%节约用水是在确保合理用水,以提高水资源利用效率、降低无效损耗为目的,所采取的工程、技术、经济和管理等各项综合措施的行为。在目前水资源短缺和水污染日趋严重的条件下,节约用水作为水资源开发利用的一项战略性基础工程,通过水资源供需比(R1)和节水效益比(R2)两方面评价因素来建立评价系统模型,可得到节水效益的水平值,而两者均为独立参数,减少关联因素的影响程度,此模型评价具有较高的参考价值。

  13. determinants of residential per capita water demand of makurdi ...

    African Journals Online (AJOL)

    user

    explains 43% of the variation in residential per capital water demand of Makurdi. The F test (F= 14.236 ... safe drinking water. Today, a large .... and so resort to the use of sachet water for drinking ..... Water Supply Facilities Maintenance held at.

  14. Wind increases "evaporative demand" but reduces plant water requirements

    Science.gov (United States)

    Schymanski, S. J.; Or, D.

    2015-12-01

    Transpiration is commonly conceptualised as a fraction of some potential rate, determined by stomatal or canopy resistance. Therefore, so-called "atmospheric evaporative demand" or "potential evaporation" is generally used alongside with precipitation and soil moisture to characterise the environmental conditions that affect plant water use. An increase in potential evaporation (e.g. due to climate change) is generally believed to cause increased transpiration and/or vegetation water stress, aggravating drought effects. In the present study, we investigated the question whether potential evaporation constitutes a meaningful reference for transpiration and compared sensitivity of potential evaporation and leaf transpiration to atmospheric forcing. Based on modelling results and supporting experimental evidence, we conclude that stomatal resistance cannot be parameterised as a factor relating transpiration to potential evaporation, as the ratio between transpiration and potential evaporation not only varies with stomatal resistance, but also with wind speed, air temperature, irradiance and relative humidity. Furthermore, the effect of wind speed in particular implies increase in potential evaporation, which is commonly interpreted as increased "water stress", but at the same time can reduce leaf transpiration, implying a decrease in water demand at the leaf scale. In fact, in a range of field measurements, we found that water use efficiency (WUE, carbon uptake per water transpired) commonly increases with increasing wind speed, enabling plants to conserve water during photosynthesis. We estimate that the observed global decrease in terrestrial near-surface wind speeds could have reduced WUE at a magnitude similar to the increase in WUE attributed to global rise in atmospheric carbon dioxide concentrations. We conclude that trends in wind speed and atmospheric carbon dioxide concentrations have to be considered explicitly for the estimation of drought effects on

  15. Irrigation water demand: A meta-analysis of price elasticities

    Science.gov (United States)

    Scheierling, Susanne M.; Loomis, John B.; Young, Robert A.

    2006-01-01

    Metaregression models are estimated to investigate sources of variation in empirical estimates of the price elasticity of irrigation water demand. Elasticity estimates are drawn from 24 studies reported in the United States since 1963, including mathematical programming, field experiments, and econometric studies. The mean price elasticity is 0.48. Long-run elasticities, those that are most useful for policy purposes, are likely larger than the mean estimate. Empirical results suggest that estimates may be more elastic if they are derived from mathematical programming or econometric studies and calculated at a higher irrigation water price. Less elastic estimates are found to be derived from models based on field experiments and in the presence of high-valued crops.

  16. Baseline Water Demand at Forward Operating Bases

    Science.gov (United States)

    2013-09-15

    Cluster, 2010- 11. Interview by Garth Anderson, Camp Phoenix, Afghanistan. Buchart Horn GmbH. 2004. Base camp solid waste characterization study. US...water use and water con- servation/ waste . Nonetheless, the observed rate of use at the area desig- nated as Cairo West was 13 gpcd at Bright Star 83...incorporated into all con- tingency base camps where feasible. Figures 6 and 7 show Camp Leather - neck graywater storage and new water storage tanks

  17. Natural ecological water demand in the lower Heihe River

    Institute of Scientific and Technical Information of China (English)

    Xinfeng FU; Hongmou HE; Xiaohui JIANG; Shengtian YANG; Guoqing WANG

    2008-01-01

    The ecological environment in the lower Heihe River has been deteriorating due to large water consump-tion in the upper and middle reaches, and less available water downstream. To restore the ecological environment in the lower Heihe River, the ecological water demand should be guaranteed. The natural vegetation area in the lower Heihe River was first obtained through the inter-pretation of remote sensing images taken in 1998. Based on the analysis for the Quota of the natural ecological water demand in the lower Heihe River and the deter-mination of the natural ecological water demand calcula-tion method, the ecological water demand in the lower Heihe River was calculated. Finally, the natural ecological water demand in the lower Heihe River under the current situation was calculated with the groundwater storage volume change method, Aweliyongrufe method and the measured water volume method. In comparison, the nat-ural ecological water demand in the lower Heihe River is 3.91-4.05×108 m3.

  18. An integrated stochastic approach to the assessment of agricultural water demand and adaptation to water scarcity

    Science.gov (United States)

    Foster, T.; Butler, A. P.; McIntyre, N.

    2012-12-01

    Increasing water demands from growing populations coupled with changing water availability, for example due to climate change, are likely to increase water scarcity. Agriculture will be exposed to risk due to the importance of reliable water supplies as an input to crop production. To assess the efficiency of agricultural adaptation options requires a sound understanding of the relationship between crop growth and water application. However, most water resource planning models quantify agricultural water demand using highly simplified, temporally lumped estimated crop-water production functions (CWPFs). Such CWPFs fail to capture the biophysical complexities in crop-water relations and mischaracterise farmers ability to respond to water scarcity. Application of these models in policy analyses will be ineffective and may lead to unsustainable water policies. Crop simulation models provide an alternative means of defining the complex nature of the CWPF. Here we develop a daily water-limited crop model for this purpose. The model is based on the approach used in the FAO's AquaCrop model, balancing biophysical and computational complexities. We further develop the model by incorporating improved simulation routines to calculate the distribution of water through the soil profile. Consequently we obtain a more realistic representation of the soil water balance with concurrent improvements in the prediction of water-limited yield. We introduce a methodology to utilise this model for the generation of stochastic crop-water production functions (SCWPFs). This is achieved by running the model iteratively with both time series of climatic data and variable quantities of irrigation water, employing a realistic rule-based approach to farm irrigation scheduling. This methodology improves the representation of potential crop yields, capturing both the variable effects of water deficits on crop yield and the stochastic nature of the CWPF due to climatic variability. Application to

  19. Seasonal Demand Dynamics of Residential Water End-Uses

    Directory of Open Access Journals (Sweden)

    Kumudu Rathnayaka

    2015-01-01

    Full Text Available Water demand prediction by end-use at an appropriate spatial and temporal resolution is essential for planning water supply systems that will supply water from a diversified set of sources on a fit-for-purpose basis. Understanding seasonal, daily and sub-daily water demand including peak demand by end-uses is an essential planning requirement to implement a fit-for-purpose water supply strategy. Studies in the literature assume that all indoor water uses except evaporative cooler water use are weather independent and do not exhibit seasonal variability. This paper presents an analysis undertaken to examine seasonal variability of residential water end-uses. The analysis was repeated using two sets of data to ensure the validity of findings. The study shows that shower water use is significantly different between winter and summer, in addition to irrigation, evaporative cooler and pool water end-uses, while other water end-uses are not. Weather is shown to be a significant determinant of shower water use; in particular it affects shower duration which increases with lower temperature. Further analysis on shower water use suggests that it is driven by behavioural factors in addition to weather, thus providing useful insights to improve detailed end-use water demand predictions.

  20. Water stress as a trigger of demand change: exploring the implications for drought planning

    Science.gov (United States)

    Garcia, M. E.; Islam, S.; Portney, K. E.

    2015-12-01

    Drought in the Anthropocene is a function of both supply and demand. Despite its importance, demand is typically incorporated into planning models exogenously using a single scenario of demand change over time. Alternatively, demand is incorporated endogenously in hydro-economic models based on the assumption of rationality. However, actors are constrained by limited information and information processing capabilities, casting doubt on the rationality assumption. Though the risk of water shortage changes incrementally with demand growth and hydrologic change, significant shifts in management are punctuated and often linked to periods of stress. The observation of lasting decreases in per capita demands in a number of cities during periods of water stress prompts an alternate hypothesis: the occurrence of water stress increases the tendency of cities to promote and enforce efficient technologies and behaviors and the tendency of users to adopt them. We show the relevance of this hypothesis by building a model of a hypothetical surface water system to answer the following question: what is the impact of reservoir operation policy on the reliability of water supply for a growing city? The model links the rate of demand decreases to the past reliability to compare standard operating policy (SOP) with hedging policy (HP). Under SOP, demand is fulfilled unless available supply drops below demand; under HP, water releases are reduced in anticipation of a deficit to decrease the risk of a large shortfall. The model shows that reservoir storage acts both as a buffer for variability and as a delay triggering oscillations around a sustainable level of demand. HP reduces the threshold for action thereby decreasing the delay and the oscillation effect. As a result per capita demand decrease during periods of water stress are more frequent but less drastic and the additive effect of small adjustments decreases the tendency of the system to overshoot available supplies.

  1. Workshops capacity building for agricultural water demand management; final report

    NARCIS (Netherlands)

    Vehmeijer, P.W.; Wolters, W.

    2004-01-01

    Agricultural Water Demand Management (AWDM) is at the core of the Water for Food Programme launched as a result of a pledge by the Netherlands' Minister for Agriculture at the 2nd World Water Forum in March 2000, The Hague. One of the projects that was started after the March 2000 pledge was

  2. Workshops capacity building for agricultural water demand management; final report

    NARCIS (Netherlands)

    Vehmeijer, P.W.; Wolters, W.

    2004-01-01

    Agricultural Water Demand Management (AWDM) is at the core of the Water for Food Programme launched as a result of a pledge by the Netherlands' Minister for Agriculture at the 2nd World Water Forum in March 2000, The Hague. One of the projects that was started after the March 2000 pledge was Worksho

  3. Historical patterns and drivers of global crop water demand.

    Science.gov (United States)

    Urban, D.; Lobell, D. B.; Sheffield, J.

    2015-12-01

    With climate change expected to subject staple crops in major growing regions to increased heat exposure, a critical question for agriculture and global food security is the degree to which crop water demand is also likely to change. Recent work has explored the relationship between extreme temperatures and crop water demand, finding that vapor pressure deficit (VPD), through its dependence on both temperature and humidity, provides a very good meteorological predictor of water stress. However, assessing crop water demand solely through atmospheric conditions ignores the roles of radiation and transpiration efficiency, which are increased through elevated CO2. We provide a 60-year global assessment of crop water demand in the world's major growing areas, comparing trends and drivers across key growing regions. We find that an atmospheric-based demand measure can differ significantly from that of a crop-specific sink-based approach that incorporates radiation and CO2 effects, sometimes enough to reverse the sign of historical trends. We also find that these changes differ significantly by region, and that multi-decadal trends can mask large decadal swings. To our knowledge, our work is the first to use global meteorological datasets in a global analysis of crop water demand, and should serve as a valuable reference for future work examining the interaction of hydrological, temperature, and CO2 changes on crop yields.

  4. Indonesia’s Electricity Demand Dynamic Modelling

    Science.gov (United States)

    Sulistio, J.; Wirabhuana, A.; Wiratama, M. G.

    2017-06-01

    Electricity Systems modelling is one of the emerging area in the Global Energy policy studies recently. System Dynamics approach and Computer Simulation has become one the common methods used in energy systems planning and evaluation in many conditions. On the other hand, Indonesia experiencing several major issues in Electricity system such as fossil fuel domination, demand - supply imbalances, distribution inefficiency, and bio-devastation. This paper aims to explain the development of System Dynamics modelling approaches and computer simulation techniques in representing and predicting electricity demand in Indonesia. In addition, this paper also described the typical characteristics and relationship of commercial business sector, industrial sector, and family / domestic sector as electricity subsystems in Indonesia. Moreover, it will be also present direct structure, behavioural, and statistical test as model validation approach and ended by conclusions.

  5. The development of a municipal water conservation and demand ...

    African Journals Online (AJOL)

    The implementation of water conservation and water demand management ... and the municipalities do not have the necessary financial, technical and institutional capacity to support such a ... Study' for the Vaal River system (DWAF, 2006; DWAF, 2009) ... review of existing methodologies (iii) perform status quo and.

  6. Modelling and forecasting Turkish residential electricity demand

    Energy Technology Data Exchange (ETDEWEB)

    Dilaver, Zafer, E-mail: Z.dilaver@surrey.ac.uk [Surrey Energy Economics Centre (SEEC), Department of Economics, University of Surrey, Guildford, GU2 7XH United Kingdom (United Kingdom); The Republic of Turkey Prime Ministry, PK 06573, Ankara (Turkey); Hunt, Lester C [Surrey Energy Economics Centre (SEEC), Department of Economics, University of Surrey, Guildford, GU2 7XH United Kingdom (United Kingdom)

    2011-06-15

    This research investigates the relationship between Turkish residential electricity consumption, household total final consumption expenditure and residential electricity prices by applying the structural time series model to annual data over the period from 1960 to 2008. Household total final consumption expenditure, real energy prices and an underlying energy demand trend are found to be important drivers of Turkish residential electricity demand with the estimated short run and the long run total final consumption expenditure elasticities being 0.38 and 1.57, respectively, and the estimated short run and long run price elasticities being -0.09 and -0.38, respectively. Moreover, the estimated underlying energy demand trend, (which, as far as is known, has not been investigated before for the Turkish residential sector) should be of some benefit to Turkish decision makers in terms of energy planning. It provides information about the impact of past policies, the influence of technical progress, the impacts of changes in consumer behaviour and the effects of changes in economic structure. Furthermore, based on the estimated equation, and different forecast assumptions, it is predicted that Turkish residential electricity demand will be somewhere between 48 and 80 TWh by 2020 compared to 40 TWh in 2008. - Research Highlights: > Estimated short run and long run expenditure elasticities of 0.38 and 1.57, respectively. > Estimated short run and long run price elasticities of -0.09 and -0.38, respectively. > Estimated UEDT has increasing (i.e. energy using) and decreasing (i.e. energy saving) periods. > Predicted Turkish residential electricity demand between 48 and 80 TWh in 2020.

  7. Stochastic model of forecasting spare parts demand

    Directory of Open Access Journals (Sweden)

    Ivan S. Milojević

    2012-01-01

    hypothesis of the existence of phenomenon change trends, the next step in the methodology of forecasting is the determination of a specific growth curve that describes the regularity of the development in time. These curves of growth are obtained by the analytical representation (expression of dynamic lines. There are two basic stages in the process of expression and they are: - The choice of the type of curve the shape of which corresponds to the character of the dynamic order variation - the determination of the number of values (evaluation of the curve parameters. The most widespread method of forecasting is the trend extrapolation. The basis of the trend extrapolation is the continuing of past trends in the future. The simplicity of the trend extrapolation process, on the one hand, and the absence of other information on the other hand, are the main reasons why the trend extrapolation is used for forecasting. The trend extrapolation is founded on the following assumptions: - The phenomenon development can be presented as an evolutionary trajectory or trend, - General conditions that influenced the trend development in the past will not undergo substantial changes in the future. Spare parts demand forecasting is constantly being done in all warehouses, workshops, and at all levels. Without demand forecasting, neither planning nor decision making can be done. Demand forecasting is the input for determining the level of reserve, size of the order, ordering cycles, etc. The question that arises is the one of the reliability and accuracy of a forecast and its effects. Forecasting 'by feeling' is not to be dismissed if there is nothing better, but in this case, one must be prepared for forecasting failures that cause unnecessary accumulation of certain spare parts, and also a chronic shortage of other spare parts. All this significantly increases costs and does not provide a satisfactory supply of spare parts. The main problem of the application of this model is that each

  8. Demand Analysis of Water Resources Based on Pulse Process of Complex System

    Directory of Open Access Journals (Sweden)

    Yuan Sun

    2013-04-01

    Full Text Available In this paper, we examine the demand for fresh water of China in 2025 from the complex system modeling perspective and we develop an efficient, economical and practical water strategy to meet the demand for fresh water in 2025.Different from previous research, this study focus on studying several factors that can influence the demand for fresh water, and their interplay within the complex large-scale system. We construct the Directed Graph Model and the Impulse Process Model to study the complex system in a qualitatively way. After that, on the basis of qualitative study, we study the whole system quantitatively by using the Leontief Inverse Matrix. And draw an effective, feasible, and cost-efficient water strategy, namely, adjusting the relation between seawater desalination and the water protection.

  9. An Assessment of Global Electric-Sector Water Demands to 2100 under the Latest Scenarios

    Science.gov (United States)

    Ando, N.; Yoshikawa, S.; Kanae, S.

    2016-12-01

    Electricity demands are likely to continue growing in the coming decades, due to population and economy growth. The electric growth could lead water demands to increase because some kinds of power generation methods such as thermal power generation require large amount of water. Many countries still rely on thermal power generation. Thus, we are concerned that electricity generation could be a big factor to accelerate water scarcity. In this study, to assess the electric-sector impacts on water demands, we estimated future electric-sector water withdrawal and consumption in 17 regions from 2010 to 2100. The water withdrawal and consumption are calculated by using electricity generation and water demand intensities. The data set of future electricity generation is derived by the Asia-Pacific Integrated Model. This model applied the latest scenarios for global climate change studies, the socio-economic scenario (SSPs) and the radiative forcing scenario (RCPs). We used the water demands intensity data set of Macknick et al. (2012). Water demand intensities for power plants considerably varies by power plant cooling systems. Therefore, we constructed cooling system share scenarios. Our results indicated that by 2100, the water withdrawal and consumption in current developing countries increased and caught up with that in current developed countries. We found that socio-economic scenarios (SSPs) has large impacts on the water withdrawal and consumption. Sustainable society (SSP1) and conventional development society (SSP5) have higher economic growth than fragmentation society (SSP3). The sustainable society needs smaller amount of the water withdrawal and consumption compared with fragmentation society. In contrast, the conventional development society needs larger amount of the water withdrawal and consumption compared with fragmentation society. Therefore, higher economic growth did not always lead less electric-sector water withdrawal and consumption. A shift of

  10. DERIVED DEMAND ELASTICITIES: MARKETING MARGIN METHODS VERSUS AN INVERSE DEMAND MODEL FOR CHOICE BEEF

    OpenAIRE

    Marsh, John M.

    1991-01-01

    Three methods of calculating the derived elasticity of demand for Choice slaughter beef are used: (a) a traditional marketing margin approach, (b) a modified marketing margin approach, and (c) an econometric, inverse demand model approach. The first method is more restrictive than the second but both tend to overestimate beef price flexibility and revenue changes. The econometric model, though an incomplete demand system, yields demand elasticities that are more consistent with marketing flex...

  11. Taxonomy for Modeling Demand Response Resources

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Daniel; Kiliccote, Sila; Sohn, Michael; Dunn, Laura; Piette, Mary, A

    2014-08-01

    Demand response resources are an important component of modern grid management strategies. Accurate characterizations of DR resources are needed to develop systems of optimally managed grid operations and to plan future investments in generation, transmission, and distribution. The DOE Demand Response and Energy Storage Integration Study (DRESIS) project researched the degree to which demand response (DR) and energy storage can provide grid flexibility and stability in the Western Interconnection. In this work, DR resources were integrated with traditional generators in grid forecasting tools, specifically a production cost model of the Western Interconnection. As part of this study, LBNL developed a modeling framework for characterizing resource availability and response attributes of DR resources consistent with the governing architecture of the simulation modeling platform. In this report, we identify and describe the following response attributes required to accurately characterize DR resources: allowable response frequency, maximum response duration, minimum time needed to achieve load changes, necessary pre- or re-charging of integrated energy storage, costs of enablement, magnitude of controlled resources, and alignment of availability. We describe a framework for modeling these response attributes, and apply this framework to characterize 13 DR resources including residential, commercial, and industrial end-uses. We group these end-uses into three broad categories based on their response capabilities, and define a taxonomy for classifying DR resources within these categories. The three categories of resources exhibit different capabilities and differ in value to the grid. Results from the production cost model of the Western Interconnection illustrate that minor differences in resource attributes can have significant impact on grid utilization of DR resources. The implications of these findings will be explored in future DR valuation studies.

  12. Dynamic energy-demand models. A comparison

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Feng [Department of Economics, Goeteborg University, Gothenburg (Sweden)

    2000-04-01

    This paper compares two second-generation dynamic energy demand models, a translog (TL) and a general Leontief (GL), in the study of price elasticities and factor substitutions of nine Swedish manufacturing industries: food, textiles, wood, paper, printing, chemicals, non-metallic minerals, base metals and machinery. Several model specifications are tested with likelihood ratio test. There is a disagreement on short-run adjustments; the TL model accepts putty-putty production technology of immediate adjustments, implying equal short- and long-run price elasticities of factors, while the GL model rejects immediate adjustments, giving out short-run elasticities quite different from the long-run. The two models also disagree in substitutability in many cases. 21 refs.

  13. Eco-environmental water demands for the Baiyangdian Wetland

    Institute of Scientific and Technical Information of China (English)

    Ping ZHONG; Zhifeng YANG; Baoshan CUI; Jingling LIU

    2008-01-01

    In recent years, the hydrological characters of Baiyangdian Wetland have changed greatly, which, in turn, influence the biotic component, the structure and function of the wetland ecosystem. In order to determine the demands for water resources of ecological wetland system, a method of ecological water level coefficient was suggested to calculate the water resources demands for wetland environment use. This research showed that the minimum coefficient is 0.94 and the optimal coefficient is more than 1.10. According to these two coefficients, the ecological water level and water quantity can be estimated. The results indicate that the amount of the minimal and optimal eco-environmental water require-ments are 0.87×108 and 2.78×108 m3 in average monthly, respectively, with the maximum eco-environmental water requirement in summer and the minimum in winter. The annual change ofeco-environment water demand is in accord-ing with the climate change and hydrological characters. The method of ecological water level emphasizes that wetland ecosystem adapts to the hydrological conditions, so it can be used in practice well.

  14. Grid Integration of Aggregated Demand Response, Part 2: Modeling Demand Response in a Production Cost Model

    Energy Technology Data Exchange (ETDEWEB)

    Hummon, Marissa [National Renewable Energy Lab. (NREL), Golden, CO (United States); Palchak, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Denholm, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jorgenson, Jennie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Olsen, Daniel J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kiliccote, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Matson, Nance [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sohn, Michael [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rose, Cody [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dudley, Junqiao [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Goli, Sasank [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ma, Ookie [U.S. Dept. of Energy, Washington, DC (United States)

    2013-12-01

    This report is one of a series stemming from the U.S. Department of Energy (DOE) Demand Response and Energy Storage Integration Study. This study is a multi-national-laboratory effort to assess the potential value of demand response (DR) and energy storage to electricity systems with different penetration levels of variable renewable resources and to improve our understanding of associatedmarkets and institutions. This report implements DR resources in the commercial production cost model PLEXOS.

  15. Socio-Technological Influences on Future Water Demands

    Directory of Open Access Journals (Sweden)

    Sarah M. Zadeh

    2014-07-01

    Full Text Available The traditional water supply management approach focuses on (perceived community requirements that must be met, but not on community demands, which are variable. Therefore a paradigm-shift is required to the way water is considered. In this paper two fundamental management measures to influence daily water demand and therefore conservation are considered: (1 Technological efficiency measures (i.e., via adopting water-saving devices; and (2 User behaviour (i.e., how users interact with and use the technologies. Through a newly developed futures framework, the individual and combined impact of these approaches within residential and office buildings are examined. Results show each in isolation has similar impacts (i.e., 55% reduction on domestic water consumption per capita, although the ranges over which user behaviour can operate appears to be far more diverse. Most strikingly, when these measures are considered in combination, greater impact (i.e., 80% reduction could be achieved. Conclusions are drawn as to how far water demand management, through a dual track approach, can go in terms of reducing indoor water consumption of both residential and office users within the UK. The paper provides philosophical arguments for what else is needed in order to secure sufficient, sustainable water supplies within a “liveable” future.

  16. Optimal management of water resources demand and supply in irrigated agriculture from plot to regional scale

    Science.gov (United States)

    Schütze, Niels; Wagner, Michael

    2016-04-01

    Growing water scarcity in agriculture is an increasing problem in future in many regions of the world. For assessing irrigation as a measure to increase agricultural water security a generalized stochastic optimization framework for a spatial distributed estimation of future irrigation water demand is proposed, which ensures safe yields and a high water productivity at the same time. Different open loop and closed loop control strategies are evaluated within this stochastic optimization framework in order to generate reliable stochastic crop water production functions (SCWPF). The resulting database of SCWPF can serve as a central decision support tool for both, (i) a cost benefit analysis of farm irrigation modernization on a local scale and (ii) a regional water demand management using a multi-scale approach for modeling and implementation. The new approach is applied using the example of a case study in Saxony, which is dealing with the sustainable management of future irrigation water demands and its implementation.

  17. Assessing long-term water demand of constantine province in Kébir-Rhumel Mediterranean catchment

    Science.gov (United States)

    Kiniouar, H.; Hani, A.; Younsi, A.

    2017-02-01

    By mid-century, in the southern Mediterranean countries, levies probably reach the limit level of renewable water resources. Algeria is one of the poorest countries in renewable water resources, with an annual storage capacity of 14.6 million m3 in the Mediterranean coastal watersheds, representing 7% of the land area and accounts for 90 % of total surface runoff of the country. In this paper, we assess water demand to meet the needs of water users in Constantine province. The latter is located in the Kébir-Rhumel Mediterranean basin under semi-arid climate with relatively high growth rate of population, agricultural and industrial activities. Using Water Evaluation And Planning system (WEAP), we built a model for managing water demand of Constantine province. A business as usual and five scenarii of «water demand " were calculated by WEAP model to simulate the uncertainties over the period of 20 years (2008-2027) : (1) Population growth, (2) increase in irrigated crop lands, (3) decrease in basic drinking water consumption, (4) decrease in basic irrigation water consumption and (5) increase in basic industrial water consumption. The results showed that scenario 3 is the best alternative scenario and the most efficient by reducing drinking water demand for about 12 Mm3 in 20 years, and thus preserve reaching the limits of water resources potentialities.

  18. China’s rising hydropower demand challenges water sector

    Science.gov (United States)

    Liu, Junguo; Zhao, Dandan; Gerbens-Leenes, P. W.; Guan, Dabo

    2015-01-01

    Demand for hydropower is increasing, yet the water footprints (WFs) of reservoirs and hydropower, and their contributions to water scarcity, are poorly understood. Here, we calculate reservoir WFs (freshwater that evaporates from reservoirs) and hydropower WFs (the WF of hydroelectricity) in China based on data from 875 representative reservoirs (209 with power plants). In 2010, the reservoir WF totaled 27.9 × 109 m3 (Gm3), or 22% of China’s total water consumption. Ignoring the reservoir WF seriously underestimates human water appropriation. The reservoir WF associated with industrial, domestic and agricultural WFs caused water scarcity in 6 of the 10 major Chinese river basins from 2 to 12 months annually. The hydropower WF was 6.6 Gm3 yr−1 or 3.6 m3 of water to produce a GJ (109 J) of electricity. Hydropower is a water intensive energy carrier. As a response to global climate change, the Chinese government has promoted a further increase in hydropower energy by 70% by 2020 compared to 2012. This energy policy imposes pressure on available freshwater resources and increases water scarcity. The water-energy nexus requires strategic and coordinated implementations of hydropower development among geographical regions, as well as trade-off analysis between rising energy demand and water use sustainability. PMID:26158871

  19. Chicago's water market: Dynamics of demand, prices and scarcity rents

    Science.gov (United States)

    Ipe, V.C.; Bhagwat, S.B.

    2002-01-01

    Chicago and its suburbs are experiencing an increasing demand for water from a growing population and economy and may experience water scarcity in the near future. The Chicago metropolitan area has nearly depleted its groundwater resources to a point where interstate conflicts with Wisconsin could accompany an increased reliance on those sources. Further, the withdrawals from Lake Michigan is limited by the Supreme Court decree. The growing demand and indications of possible scarcity suggest a need to reexamine the pricing policies and the dynamics of demand. The study analyses the demand for water and develops estimates of scarcity rents for water in Chicago. The price and income elasticities computed at the means are -0.002 and 0.0002 respectively. The estimated scarcity rents ranges from $0.98 to $1.17 per thousand gallons. The results indicate that the current prices do not fully account for the scarcity rents and suggest a current rate with in the range $1.53 to $1.72 per thousand gallons.

  20. Greywater reuse: A strategy for water demand management in Harare?

    Science.gov (United States)

    Madungwe, Emaculate; Sakuringwa, Saniso

    Greywater is wastewater from baths, sinks and washing machines, accounting for about 60% of the outflow from homes. It contains little pathogens and 90% less nitrogen than toilet water, so does not require the same treatment process. With the increasing demand for freshwater, its use may reduce irrigation water needs, increasing its availability of freshwater for other primary uses. Agriculture is the main water consumer in Africa, which cannot be compromised due to its role in domestic food security and export supplies. The purpose of this paper is to demonstrate findings of the research done on benefits of greywater reuse in some countries, applicable to African countries. In Australia, greywater reuse has reduced freshwater demand, strain on wastewater treatment plants and energy consumption. Aquifer recharge has improved due to increased infiltration flows from greywater uses. In Lebanon, greywater is a valuable resource for encouraging plant growth from nutrients that may otherwise have been wasted. Palestine shares similar climate and water scarcity conditions with most arid sub-Saharan African countries, yet utilizes grey water in production of crops and citrus fruits. Thus use of grey water should be possible in African cities such as Harare, where nearly two thirds of the population rely on agriculture for livelihoods. The problem of blue green algae in sewerage ponds and water reservoirs is significantly reduced by household reuse of grey water in Mexico. Water savings are increased and expenses reduced, as illustrated by the reduction in consumption of municipality freshwater supplies in South African urban areas. Rural communities and schools in Namibia and Egypt have raised funds from grey water reuse in banana plantations. A possible constraint to this strategy could be the unavailability of appropriate technology for primary treatment of grey water before reuse. This strategy may pose health risks where water quality tests are unknown or unavailable

  1. Modelling energy demand in the buildings sector within the EU

    Energy Technology Data Exchange (ETDEWEB)

    O Broin, Eoin

    2012-11-01

    In the on-going effort within the EU to tackle greenhouse gas emissions and secure future energy supplies, the buildings sector is often referred to as offering a large potential for energy savings. The aim of this thesis is to produce scenarios that highlight the parameters that affect the energy demands and thus potentials for savings of the building sector. Top-down and bottom-up approaches to modelling energy demand in EU buildings are applied in this thesis. The top-down approach uses econometrics to establish the historical contribution of various parameters to energy demands for space and water heating in the residential sectors of four EU countries. The bottom-up approach models the explicit impact of trends in energy efficiency improvement on total energy demand in the EU buildings stock. The two approaches are implemented independently, i.e., the results from the top-down studies do not feed into those from the bottom-up studies or vice versa. The explanatory variables used in the top-down approach are: energy prices; heating degree days, as a proxy for outdoor climate; a linear time trend, as a proxy for technology development; and the lag of energy demand, as a proxy for inertia in the system. In this case, inertia refers to the time it takes to replace space and water heating systems in reaction to price changes. The analysis gives long-term price elasticities of demand as follows: for France, -0.17; for Italy, -0.35; for Sweden, -0.27; and for the UK, -0.35. These results reveal that the price elasticity of demand for space and water heating is inelastic in each of these cases. Nonetheless, scenarios created for the period up to 2050 using these elasticities and an annual price increase of 3 % show that demand can be reduced by more than 1 % per year in France and Sweden and by less than 1 % per year in Italy and the UK. In the bottom-up modelling, varying rates for conversion efficiencies, heating standards for new buildings, end-use efficiency, and

  2. Crop-specific seasonal estimates of irrigation water demand in South Asia

    Directory of Open Access Journals (Sweden)

    H. Biemans

    2015-08-01

    Full Text Available Especially in the Himalayan headwaters of the main rivers in South Asia, shifts in runoff are expected as a result of a rapidly changing climate. In recent years, our insight in these shifts and their impact on water availability has increased. However, a similar detailed understanding of the seasonal pattern in water demand is surprisingly absent. This hampers a proper assessment of water stress and ways to cope and adapt. In this study, the seasonal pattern of irrigation water demand resulting from the typical practice of multiple-cropping in South Asia was accounted for by introducing double-cropping with monsoon-dependent planting dates in a hydrology and vegetation model. Crop yields were calibrated to the latest subnational statistics of India, Pakistan, Bangladesh and Nepal. The representation of seasonal land use and more accurate cropping periods lead to lower estimates of irrigation water demand compared to previous model-based studies, despite the net irrigated area being higher. Crop irrigation water demand differs sharply between seasons and regions; in Pakistan, winter (Rabi and summer (Kharif irrigation demands are almost equal, whereas in Bangladesh the Rabi demand is ~ 100 times higher. Moreover, the relative importance of irrigation supply vs. rain decreases sharply from west to east. Given the size and importance of South Asia, improved regional estimates of food production and its irrigation water demand will also affect global estimates. In models used for global water resources and food-security assessments, processes like multiple-cropping and monsoon-dependent planting dates should not be ignored.

  3. Crop-specific seasonal estimates of irrigation-water demand in South Asia

    Science.gov (United States)

    Biemans, Hester; Siderius, Christian; Mishra, Ashok; Ahmad, Bashir

    2016-05-01

    Especially in the Himalayan headwaters of the main rivers in South Asia, shifts in runoff are expected as a result of a rapidly changing climate. In recent years, our insight into these shifts and their impact on water availability has increased. However, a similar detailed understanding of the seasonal pattern in water demand is surprisingly absent. This hampers a proper assessment of water stress and ways to cope and adapt. In this study, the seasonal pattern of irrigation-water demand resulting from the typical practice of multiple cropping in South Asia was accounted for by introducing double cropping with monsoon-dependent planting dates in a hydrology and vegetation model. Crop yields were calibrated to the latest state-level statistics of India, Pakistan, Bangladesh and Nepal. The improvements in seasonal land use and cropping periods lead to lower estimates of irrigation-water demand compared to previous model-based studies, despite the net irrigated area being higher. Crop irrigation-water demand differs sharply between seasons and regions; in Pakistan, winter (rabi) and monsoon summer (kharif) irrigation demands are almost equal, whereas in Bangladesh the rabi demand is ~ 100 times higher. Moreover, the relative importance of irrigation supply versus rain decreases sharply from west to east. Given the size and importance of South Asia improved regional estimates of food production and its irrigation-water demand will also affect global estimates. In models used for global water resources and food-security assessments, processes like multiple cropping and monsoon-dependent planting dates should not be ignored.

  4. Crop-specific seasonal estimates of irrigation water demand in South Asia

    Science.gov (United States)

    Biemans, H.; Siderius, C.; Mishra, A.; Ahmad, B.

    2015-08-01

    Especially in the Himalayan headwaters of the main rivers in South Asia, shifts in runoff are expected as a result of a rapidly changing climate. In recent years, our insight in these shifts and their impact on water availability has increased. However, a similar detailed understanding of the seasonal pattern in water demand is surprisingly absent. This hampers a proper assessment of water stress and ways to cope and adapt. In this study, the seasonal pattern of irrigation water demand resulting from the typical practice of multiple-cropping in South Asia was accounted for by introducing double-cropping with monsoon-dependent planting dates in a hydrology and vegetation model. Crop yields were calibrated to the latest subnational statistics of India, Pakistan, Bangladesh and Nepal. The representation of seasonal land use and more accurate cropping periods lead to lower estimates of irrigation water demand compared to previous model-based studies, despite the net irrigated area being higher. Crop irrigation water demand differs sharply between seasons and regions; in Pakistan, winter (Rabi) and summer (Kharif) irrigation demands are almost equal, whereas in Bangladesh the Rabi demand is ~ 100 times higher. Moreover, the relative importance of irrigation supply vs. rain decreases sharply from west to east. Given the size and importance of South Asia, improved regional estimates of food production and its irrigation water demand will also affect global estimates. In models used for global water resources and food-security assessments, processes like multiple-cropping and monsoon-dependent planting dates should not be ignored.

  5. Estimated Use of Water in the Upper Duck River Watershed, Central Tennessee, and Water-Demand Projections through 2030

    Science.gov (United States)

    Hutson, Susan S.

    2008-01-01

    Future municipal water demand was estimated for the Bedford, Coffee, Marshall, and Maury-southern Williamson water-service areas in the upper Duck River watershed in central Tennessee through 2030. The Duck River, a primary source of municipal water, provided a total of 24.3 million gallons per day (Mgal/d) or 92 percent of the total water use in the study area during 2000. Municipal water use increased 46 percent from 1981 to 2000 (from 18.0 to 26.3 Mgal/d). Water demand for municipal use is expected to continue to increase through 2030 because of the recent intensive and anticipated growth in the residential and commercial sectors. Constant-rate models were used to estimate future municipal water demand. Data on residential and nonresidential billing accounts and estimates of public use and losses were used to calibrate the models. Two watershed scenarios for each water-supply system that depends on the Duck River for supply were simulated. Scenario 1 considered monthly water demand during typical weather conditions as represented by monthly per account use during 2003 and a rate of growth in customer accounts from 1999 to 2003. Results showed that total municipal water use could increase about 104 percent to 51 Mgal/d by 2030, residential water use could increase about 140 percent to 24 Mgal/d, nonresidential water use could increase about 110 percent to 17 Mgal/d, and public use and losses could increase about 83 percent to 11 Mgal/d. Scenario 2 considered monthly water demand during drought conditions as represented by monthly per account use during 2000 and recent growth in customer accounts from 1999 to 2003 or, for selected water-supply systems, an increasing rate of growth. Results showed that total municipal water use could increase about 120 percent to 55 Mgal/d, residential water use could increase about 160 percent to 26 Mgal/d, nonresidential water use could increase about 122 percent to 18 Mgal/d, and public use and losses could double and increase

  6. Demand driven decision support for efficient water resources allocation in irrigated agriculture

    Science.gov (United States)

    Schuetze, Niels; Grießbach, Ulrike Ulrike; Röhm, Patric; Stange, Peter; Wagner, Michael; Seidel, Sabine; Werisch, Stefan; Barfus, Klemens

    2014-05-01

    Due to climate change, extreme weather conditions, such as longer dry spells in the summer months, may have an increasing impact on the agriculture in Saxony (Eastern Germany). For this reason, and, additionally, declining amounts of rainfall during the growing season the use of irrigation will be more important in future in Eastern Germany. To cope with this higher demand of water, a new decision support framework is developed which focuses on an integrated management of both irrigation water supply and demand. For modeling the regional water demand, local (and site-specific) water demand functions are used which are derived from the optimized agronomic response at farms scale. To account for climate variability the agronomic response is represented by stochastic crop water production functions (SCWPF) which provide the estimated yield subject to the minimum amount of irrigation water. These functions take into account the different soil types, crops and stochastically generated climate scenarios. By applying mathematical interpolation and optimization techniques, the SCWPF's are used to compute the water demand considering different constraints, for instance variable and fix costs or the producer price. This generic approach enables the computation for both multiple crops at farm scale as well as of the aggregated response to water pricing at a regional scale for full and deficit irrigation systems. Within the SAPHIR (SAxonian Platform for High Performance Irrigation) project a prototype of a decision support system is developed which helps to evaluate combined water supply and demand management policies for an effective and efficient utilization of water in order to meet future demands. The prototype is implemented as a web-based decision support system and it is based on a service-oriented geo-database architecture.

  7. The increasing importance of atmospheric demand for ecosystem water and carbon fluxes

    Science.gov (United States)

    Novick, Kimberly A.; Ficklin, Darren L.; Stoy, Paul C.; Williams, Christopher A.; Bohrer, Gil; Oishi, A. Christopher; Papuga, Shirley A.; Blanken, Peter D.; Noormets, Asko; Sulman, Benjamin N.; Scott, Russell L.; Wang, Lixin; Phillips, Richard P.

    2016-11-01

    Soil moisture supply and atmospheric demand for water independently limit--and profoundly affect--vegetation productivity and water use during periods of hydrologic stress. Disentangling the impact of these two drivers on ecosystem carbon and water cycling is difficult because they are often correlated, and experimental tools for manipulating atmospheric demand in the field are lacking. Consequently, the role of atmospheric demand is often not adequately factored into experiments or represented in models. Here we show that atmospheric demand limits surface conductance and evapotranspiration to a greater extent than soil moisture in many biomes, including mesic forests that are of particular importance to the terrestrial carbon sink. Further, using projections from ten general circulation models, we show that climate change will increase the importance of atmospheric constraints to carbon and water fluxes in all ecosystems. Consequently, atmospheric demand will become increasingly important for vegetation function, accounting for >70% of growing season limitation to surface conductance in mesic temperate forests. Our results suggest that failure to consider the limiting role of atmospheric demand in experimental designs, simulation models and land management strategies will lead to incorrect projections of ecosystem responses to future climate conditions.

  8. Demand-driven water withdrawals by Chinese industry: a multi-regional input-output analysis

    Science.gov (United States)

    Zhang, Bo; Chen, Z. M.; Zeng, L.; Qiao, H.; Chen, B.

    2016-03-01

    With ever increasing water demands and the continuous intensification of water scarcity arising from China's industrialization, the country is struggling to harmonize its industrial development and water supply. This paper presents a systems analysis of water withdrawals by Chinese industry and investigates demand-driven industrial water uses embodied in final demand and interregional trade based on a multi-regional input-output model. In 2007, the Electric Power, Steam, and Hot Water Production and Supply sector ranks first in direct industrial water withdrawal (DWW), and Construction has the largest embodied industrial water use (EWU). Investment, consumption, and exports contribute to 34.6%, 33.3%, and 30.6% of the national total EWU, respectively. Specifically, 58.0%, 51.1%, 48.6%, 43.3%, and 37.5% of the regional EWUs respectively in Guangdong, Shanghai, Zhejiang, Jiangsu, and Fujian are attributed to international exports. The total interregional import/export of embodied water is equivalent to about 40% of the national total DWW, of which 55.5% is associated with the DWWs of Electric Power, Steam, and Hot Water Production and Supply. Jiangsu is the biggest interregional exporter and deficit receiver of embodied water, in contrast to Guangdong as the biggest interregional importer and surplus receiver. Without implementing effective water-saving measures and adjusting industrial structures, the regional imbalance between water availability and water demand tends to intensify considering the water impact of domestic trade of industrial products. Steps taken to improve water use efficiency in production, and to enhance embodied water saving in consumption are both of great significance for supporting China's water policies.

  9. Modelling energy demand of Croatian industry sector

    DEFF Research Database (Denmark)

    Medić, Zlatko Bačelić; Pukšec, Tomislav; Mathiesen, Brian Vad

    2014-01-01

    Industry represents one of the most interesting sectors when analysing Croatian final energy demand. Croatian industry represents 20% of nation's GDP and employs 25% of total labour force making it a significant subject for the economy. Today, with around 60 PJ of final energy demand...

  10. Climate Change Impacts on Water Supply and Demand in Rheraya Watershed (Morocco, with Potential Adaptation Strategies

    Directory of Open Access Journals (Sweden)

    Mohammed Yacoubi Khebiza

    2012-01-01

    Full Text Available Rheraya watershed already suffers from the impacts of climate variability and will be further affected by climate change. Severe water shortages and extremely fragile ecological conditions necessitate careful attention to water resources management. The aim of this study is to analyze Rheraya’s future water situation under different scenarios of socio-economic development and climate change until 2100. The Water Evaluation and Planning System model (WEAP has been applied to estimate the current water demands and the increased water demands resulting from climate change. WEAP was calibrated using meteorological and demand observations, then, updated with present-day and future climatic conditions using the Statistical Down-scaling Model with two projections (A2, B2 of the Intergovernmental Panel on Climate Change. Those projections show an increase in temperature of about 2–3 °C and a reduction in precipitation of 40–60% with respect to baseline. The results show that the pressure on Rheraya’s water resources will increase, leading to greater competition for surface water, and that domestic, tourist, livestock and agricultural demands will not be met by the year 2100. The Results also demonstrate that the assessments of adaptation strategies proposed by decision makers are effective but not sustainable for the watershed.

  11. Evaluating the impact of demand-side management on water resources under changing climatic conditions and increasing population.

    Science.gov (United States)

    Dawadi, Srijana; Ahmad, Sajjad

    2013-01-15

    This study investigated the effect of increasing population and changing climatic conditions on the water resources of a semi-arid region, the Las Vegas Valley (LVV) in southern Nevada. A system dynamics model was developed for the LVV from 1989 to 2035. The impact of climate change on water demand and the water supply from the Colorado River was modeled, using projections from 16 global climate models for 3 emission scenarios. Variability in water demand and supply under different scenarios of population growth and demand management, including water conservation and water pricing, was evaluated. With the population growth that was projected, if no further demand management policies were implemented, the LVV would not be able to meet the water demand in the near future. However, by combining water conservation and pricing policies, the available supply could last well into the future. The reduction in water demand in 2035 was predicted to be 327 million cubic meters (MCM) for 'status quo' population growth, or 30.6%; 408 MCM for 50% of the projected growth, or 38%; and 511 MCM for no population growth, or 47.8%. Water supply reliability decreased significantly with changing climatic conditions. Therefore, major challenges to water sustainability in the LVV would be due to rapid population growth as well as to climate variability. However, with the combination of reduced population growth rate and water conservation policies, the Colorado River supply could meet the future demand of the LVV most of the time.

  12. Estimating Water Demand in Urban Indonesia: A Maximum Likelihood Approach to block Rate Pricing Data

    NARCIS (Netherlands)

    Rietveld, Piet; Rouwendal, Jan; Zwart, Bert

    1997-01-01

    In this paper the Burtless and Hausman model is used to estimate water demand in Salatiga, Indonesia. Other statistical models, as OLS and IV, are found to be inappropiate. A topic, which does not seem to appear in previous studies, is the fact that the density function of the loglikelihood can be m

  13. Estimating Water Demand in Urban Indonesia: A Maximum Likelihood Approach to block Rate Pricing Data

    NARCIS (Netherlands)

    Rietveld, Piet; Rouwendal, Jan; Zwart, Bert

    1997-01-01

    In this paper the Burtless and Hausman model is used to estimate water demand in Salatiga, Indonesia. Other statistical models, as OLS and IV, are found to be inappropiate. A topic, which does not seem to appear in previous studies, is the fact that the density function of the loglikelihood can be

  14. Measuring demand for flat water recreation using a two-stage/disequilibrium travel cost model with adjustment for overdispersion and self-selection

    Science.gov (United States)

    McKean, John R.; Johnson, Donn; Taylor, R. Garth

    2003-04-01

    An alternate travel cost model is applied to an on-site sample to estimate the value of flat water recreation on the impounded lower Snake River. Four contiguous reservoirs would be eliminated if the dams are breached to protect endangered Pacific salmon and steelhead trout. The empirical method applies truncated negative binomial regression with adjustment for endogenous stratification. The two-stage decision model assumes that recreationists allocate their time among work and leisure prior to deciding among consumer goods. The allocation of time and money among goods in the second stage is conditional on the predetermined work time and income. The second stage is a disequilibrium labor market which also applies if employers set work hours or if recreationists are not in the labor force. When work time is either predetermined, fixed by contract, or nonexistent, recreationists must consider separate prices and budgets for time and money.

  15. The Demand-Control Model: Specific demands, specific Control, and well-defined groups

    NARCIS (Netherlands)

    Jonge, J. de; Dollard, M.F.; Dormann, C.; Blanc, P.M.; Houtman, I.L.D.

    2000-01-01

    The purpose of this study was to test the Demand-Control Model (DCM), accompanied by three goals. Firstly, we used alternative, more focused, and multifaceted measures of both job demands and job control that are relevant and applicable to today's working contexts. Secondly, this study intended to

  16. Looking at the spatial and temporal distribution of global water availability and demand

    Science.gov (United States)

    Burek, Peter; Satoh, Yusuke; Wada, Yoshihide; Floerke, Martina; Eisner, Stefanie; Hanasaki, Naota; Wiberg, David

    2016-04-01

    The human water demand for agriculture, industry, energy and domestic is less than ten per cent of the global freshwater production of around 54,000 km3 per year. Water is distributed unequally in time and space. Not a new insight, but when we zoom in and look at country and regional level and monthly time scale the global picture is dispatching into areas and periods of water abundance and water scarcity, which we can quantify. This study uses the multi-model approach of the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) to build up a consistent set of global water scenarios based on Shared Socioeconomic Pathways (SSPs) and Representative Concentration Pathways (RCPs) for the IIASA Water Futures and Solutions Initiative (WFaS). The WFaS "fast-track" assessment applies three water scenarios based on feasible combinations of two different RCPs and three SSPs, then five different hydrological models are used to estimate water availability and three water use models to estimate water demand from different sectors. Results are shown as indicators for e.g. water stress and water dependency between countries for present time and for future projections up to 2050. The alterations to previous studies are the multi-model approach and the finer temporal monthly scale, showing the temporal and spatial diversity of water demand and availability. One example scenario is based on the combination of SSP2 and RCP6.0. While in 2010 17 countries out of 249 facing severe water stress on an annual basis, the number is likely to increase up to 26 countries by 2050. Looking at the monthly time dimension 51 countries with altogether 3.8 billion people are under severe water stress in at least one month in 2010. This will rise up to 57 countries and 4.9 billion people by 2050. Main driver of this development will be the rising water demand of a growing population and to a lesser extend the changing distribution of water availability. Model biases are inevitable in

  17. The Water Demand Management by Monitoring the Technology Performance and the Water Use Efficiency

    Directory of Open Access Journals (Sweden)

    Fraj Chemak

    2012-01-01

    Full Text Available Problem statement: Given the climate constraints and the limited resources, Tunisia has developed the irrigated sector in order to diversify the agricultural production and to meet the food needs of the population. Today the policy of water supply reaches its limits and the efforts should be turned to the management of the water demand. Within this context, this research aims to analyze the farming system, the technology performance and the water use efficiency of the irrigated farms in the Sidi Bouzid region. Approach: By monitoring the sample of 47 farms during the harvesting years 2007, 2008 and 2009 we have gathered database which involved technical and economical details. By analyzing the farming system we have identified the technology process in order to estimate the production frontier using the Data Envelopment Analysis (DEA approach. The sub-vector approach of the DEA model was used to compute the water use efficiency. Results: The empirical findings showed that farmers grow olive trees, cereal crops, forage crops and horticulture crops. During the surveyed period the share of the different crops did not change significantly. The water consumption reaches only an average of 2700 m3/ha. However, the charge of irrigation represents more than 40% out of the total expenditures. The results of the DEA model showed that 50% of farms are inefficient and the technical efficiency reaches an average of 81%. The average of the scale efficiency reached 88%. However, the water use efficiency did not exceed an average of 68%. Hence, 32% of the water currently used should be saved. Conclusion: There is a wide gap to improve skills and the ability of the farmers to achieve the best of the water use efficiency. Thus, we suggest that the state intervention is necessary not only to reduce the wasting of water but also to set up an accompanying device that reconciles water conservation and the production targets.

  18. Demand Response Performance of GE Hybrid Heat Pump Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Parker, Graham B.; Petersen, Joseph M.; Baechler, Michael C.

    2013-07-01

    This report describes a project to evaluate and document the DR performance of HPWH as compared to ERWH for two primary types of DR events: peak curtailments and balancing reserves. The experiments were conducted with GE second-generation “Brillion”-enabled GeoSpring hybrid water heaters in the PNNL Lab Homes, with one GE GeoSpring water heater operating in “Standard” electric resistance mode to represent the baseline and one GE GeoSpring water heater operating in “Heat Pump” mode to provide the comparison to heat pump-only demand response. It is expected that “Hybrid” DR performance, which would engage both the heat pump and electric elements, could be interpolated from these two experimental extremes. Signals were sent simultaneously to the two water heaters in the side-by-side PNNL Lab Homes under highly controlled, simulated occupancy conditions. This report presents the results of the evaluation, which documents the demand-response capability of the GE GeoSpring HPWH for peak load reduction and regulation services. The sections describe the experimental protocol and test apparatus used to collect data, present the baselining procedure, discuss the results of the simulated DR events for the HPWH and ERWH, and synthesize key conclusions based on the collected data.

  19. Co-Adapting Water Demand and Supply to Changing Climate in Agricultural Water Systems, A Case Study in Northern Italy

    Science.gov (United States)

    Giuliani, M.; Li, Y.; Mainardi, M.; Arias Munoz, C.; Castelletti, A.; Gandolfi, C.

    2013-12-01

    Exponentially growing water demands and increasing uncertainties in the hydrologic cycle due to changes in climate and land use will challenge water resources planning and management in the next decade. Improving agricultural productivity is particularly critical, being this sector the one characterized by the highest water demand. Moreover, to meet projected growth in human population and per-capita food demand, agricultural production will have to significantly increase in the next decades, even though water availability is expected to decrease due to climate change impacts. Agricultural systems are called to adapt their strategies (e.g., changing crop patterns and the corresponding water demand, or maximizing the efficiency in the water supply modifying irrigation scheduling and adopting high efficiency irrigation techniques) in order to re-optimize the use of limited water resources. Although many studies have assessed climate change impacts on agricultural practices and water management, most of them assume few scenarios of water demand or water supply separately, while an analysis of their reciprocal feedbacks is still missing. Moreover, current practices are generally established according to historical agreements and normative constraints and, in the absence of dramatic failures, the shift toward more efficient water management is not easily achievable. In this work, we propose to activate an information loop between farmers and water managers to improve the effectiveness of agricultural water management practices by matching the needs of the farmers with the design of water supply strategies. The proposed approach is tested on a real-world case study, namely the Lake Como serving the Muzza-Bassa Lodigiana irrigation district (Italy). A distributed-parameter, dynamic model of the system allows to simulate crop growth and the final yield over a range of hydro-climatic conditions, irrigation strategies and water-related stresses. The spatial component of the

  20. Getting into hot water Problematizing hot water service demand: The case of Old Cairo

    Science.gov (United States)

    Culhane, Thomas Henry

    -help strategies, the greater flexibility they provide may lead to superior long-term outcomes in a time of uncertain and rising energy and commodities prices and an increasing availability of new, less expensive, increasingly modular, and more efficient technologies that are easier for individual households to install and use, especially if the State or non-governmental institutions can provide implementation support. The descriptive statistics and the multivariate models obtained through the analysis of the data gathered in the surveys show that while purchase price and running costs for dedicated water heating systems are considerations for families desiring hot water, the infrastructural demands of modern appliances vis a vis a consumer's given built environment and the historical/cultural legacy of the consumer's past hot water choices and practices are often more important determinants of the kind of water heating used and desired today. Our study shows, for example, that while higher income is associated with owning a water heater in a simple model with few explanatory variables (Model 3) it's significance disappears when controlling for Ethnicity and infrastructural elements (Model 1). This might suggest that while within communities there is a point at which making more money implies a shift to consumer "modernity", overall the availability of more money in these neighborhoods as a whole doesn't guarantee that the utility promised by modern appliances will be realized. A similar point can be made about formal education levels, which appear insignificant in our models. Policy that aimed merely at sending more kids to school would not address the great deficiencies that many Egyptian schools are noted for. There is no guarantee that merely expanding Egypt's "universal education" policy to include children who have fallen through the cracks would help increase consumer awareness or consumer choice. On the other hand both water availability and presence of hot water pipes, as

  1. NEW CAR DEMAND MODELING AND FORECASTING USING BASS DIFFUSION MODEL

    Directory of Open Access Journals (Sweden)

    Zuhaimy Ismail

    2013-01-01

    Full Text Available Forecasting model of new product demand has been developed and applied to forecast new vehicle demand in Malaysia. Since the publication of the Bass model in 1969, innovation of new diffusion theory has sparked considerable research among marketing science scholars, operational researchers and mathematicians. The building of Bass diffusion model for forecasting new product within the Malaysian society is presented in this study. The proposed model represents the spread level of new Proton car among a given set of the society in terms of a simple mathematical function that elapsed since the introduction of the new car. With the limited amount of data available for the new car, a robust Bass model was developed to forecast the sales volume. A procedure of the proposed diffusion model was designed and the parameters were estimated. Results obtained by applying the proposed model and numerical calculation shows that the proposed diffusion model is robust and effective for forecasting demand of new Proton car. The proposed diffusion model is shown to forecast more effectively and accurately even with insufficient previous data on the new product.

  2. Economic concepts to address future water supply-demand imbalances in Iran, Morocco and Saudi Arabia

    NARCIS (Netherlands)

    Hellegers, P.; Immerzeel, W.W.; Droogers, P.

    2013-01-01

    In Middle East and North Africa (MENA) countries, renewable groundwater and surface water supply are limited while demand for water is growing rapidly. Climate change is expected to increase water demand even further. The main aim of this paper is to evaluate the water supply–demand imbalances in Ir

  3. Demand-driven water withdrawals by Chinese industry: a multi-regional input-output analysis

    Institute of Scientific and Technical Information of China (English)

    Bo ZHANG; Z.M.CHEN; L.ZENG; H.QIAO; B.CHEN

    2016-01-01

    With ever increasing water demands and the continuous intensification of water scarcity arising from China's industrialization,the country is struggling to harmonize its industrial development and water supply.This paper presents a systems analysis of water withdrawals by Chinese industry and investigates demanddriven industrial water uses embodied in final demand and interregional trade based on a multi-regional input-output model.In 2007,the Electric Power,Steam,and Hot Water Production and Supply sector ranks first in direct industrial water withdrawal (DWW),and Construction has the largest embodied industrial water use (EWU).Investment,consumption,and exports contribute to 34.6%,33.3%,and 30.6% of the national total EWU,respectively.Specifically,58.0%,51.1%,48.6%,43.3%,and 37.5% of the regional EWUs respectively in Guangdong,Shanghai,Zhejiang,Jiangsu,and Fujian are attributed to international exports.The total interregional import/export of embodied water is equivalent to about 40% of the national total DWW,of which 55.5% is associated with the DWWs of Electric Power,Steam,and Hot Water Production and Supply.Jiangsu is the biggest interregional exporter and deficit receiver of embodied water,in contrast to Guangdong as the biggest interregional importer and surplus receiver.Without implementing effective watersaving measures and adjusting industrial structures,the regional imbalance between water availability and water demand tends to intensify considering the water impact of domestic trade of industrial products.Steps taken to improve water use efficiency in production,and to enhance embodied water saving in consumption are both of great significance for supporting China's water policies.

  4. Blue water scarcity and the economic impacts of future agricultural trade and demand

    Science.gov (United States)

    Schmitz, Christoph; Lotze-Campen, Hermann; Gerten, Dieter; Dietrich, Jan Philipp; Bodirsky, Benjamin; Biewald, Anne; Popp, Alexander

    2013-06-01

    An increasing demand for agricultural goods affects the pressure on global water resources over the coming decades. In order to quantify these effects, we have developed a new agroeconomic water scarcity indicator, considering explicitly economic processes in the agricultural system. The indicator is based on the water shadow price generated by an economic land use model linked to a global vegetation-hydrology model. Irrigation efficiency is implemented as a dynamic input depending on the level of economic development. We are able to simulate the heterogeneous distribution of water supply and agricultural water demand for irrigation through the spatially explicit representation of agricultural production. This allows in identifying regional hot spots of blue water scarcity and explicit shadow prices for water. We generate scenarios based on moderate policies regarding future trade liberalization and the control of livestock-based consumption, dependent on different population and gross domestic product (GDP) projections. Results indicate increased water scarcity in the future, especially in South Asia, the Middle East, and north Africa. In general, water shadow prices decrease with increasing liberalization, foremost in South Asia, Southeast Asia, and the Middle East. Policies to reduce livestock consumption in developed countries not only lower the domestic pressure on water but also alleviate water scarcity to a large extent in developing countries. It is shown that one of the two policy options would be insufficient for most regions to retain water scarcity in 2045 on levels comparable to 2005.

  5. Modelling global container freight transport demand

    NARCIS (Netherlands)

    Tavasszy, L.A.; Ivanova, O.; Halim, R.A.

    2015-01-01

    The objective of this chapter is to discuss methods and techniques for a quantitative and descriptive analysis of future container transport demand at a global level. Information on future container transport flows is useful for various purposes. It is instrumental for the assessment of returns of i

  6. Artificial Neural Networks and Support Vector Machines for Water Demand Time Series Forecasting

    CERN Document Server

    Msiza, Ishmael S; Nelwamondo, Fulufhelo Vincent

    2007-01-01

    Water plays a pivotal role in many physical processes, and most importantly in sustaining human life, animal life and plant life. Water supply entities therefore have the responsibility to supply clean and safe water at the rate required by the consumer. It is therefore necessary to implement mechanisms and systems that can be employed to predict both short-term and long-term water demands. The increasingly growing field of computational intelligence techniques has been proposed as an efficient tool in the modelling of dynamic phenomena. The primary objective of this paper is to compare the efficiency of two computational intelligence techniques in water demand forecasting. The techniques under comparison are the Artificial Neural Networks (ANNs) and the Support Vector Machines (SVMs). In this study it was observed that the ANNs perform better than the SVMs. This performance is measured against the generalisation ability of the two.

  7. Integrated management of water resources demand and supply in irrigated agriculture from plot to regional scale

    Science.gov (United States)

    Schütze, Niels; Wagner, Michael

    2016-05-01

    Growing water scarcity in agriculture is an increasing problem in future in many regions of the world. Recent trends of weather extremes in Saxony, Germany also enhance drought risks for agricultural production. In addition, signals of longer and more intense drought conditions during the vegetation period can be found in future regional climate scenarios for Saxony. However, those climate predictions are associated with high uncertainty and therefore, e.g. stochastic methods are required to analyze the impact of changing climate patterns on future crop water requirements and water availability. For assessing irrigation as a measure to increase agricultural water security a generalized stochastic approach for a spatial distributed estimation of future irrigation water demand is proposed, which ensures safe yields and a high water productivity at the same time. The developed concept of stochastic crop water production functions (SCWPF) can serve as a central decision support tool for both, (i) a cost benefit analysis of farm irrigation modernization on a local scale and (ii) a regional water demand management using a multi-scale approach for modeling and implementation. The new approach is applied using the example of a case study in Saxony, which is dealing with the sustainable management of future irrigation water demands and its implementation.

  8. A Theoretic Model of Transport Logistics Demand

    OpenAIRE

    Natalija Jolić; Nikolina Brnjac; Ivica Oreb

    2006-01-01

    Concerning transport logistics as relation between transportand integrated approaches to logistics, some transport and logisticsspecialists consider the tenn tautological. However,transport is one of the components of logistics, along with inventories,resources, warehousing, infonnation and goods handling.Transport logistics considers wider commercial and operationalframeworks within which the flow of goods is plannedand managed. The demand for transport logistics services canbe valorised as ...

  9. The interpersonal process model of demand/withdraw behavior.

    Science.gov (United States)

    Baucom, Brian R; Dickenson, Janna A; Atkins, David C; Baucom, Donald H; Fischer, Melanie S; Weusthoff, Sarah; Hahlweg, Kurt; Zimmermann, Tanja

    2015-02-01

    The demand/withdraw interaction pattern is a destructive cycle of relationship communication behavior that is associated with negative individual and relationship outcomes. Demand/withdraw behavior is thought to be strongly linked to partners' emotional reactions, but current theories are inconsistent with empirical findings. The current study proposes the interpersonal process model of demand/withdraw behavior, which includes linkages between each partners' emotional reactions and the interpersonal behavior of demanding and withdrawing. Data come from problem solving discussions of 55 German couples with observationally coded demand/withdraw behavior and fundamental frequency (f₀) to measure vocally encoded emotional arousal. Actor-partner interdependence models (Kenny, Kashy, & Cook, 2006) were used to examine associations among demand/withdraw behavior and f₀ in the overall discussion and 5-min segments. Significant cross-partner associations emerged for demanding and withdrawing behavior across the whole conversation as well as within 5-min segments, and these associations are partially accounted for by each individual's f₀. When behaviorally coded demanders expressed more vocal arousal, they demanded more and withdrew less while their partners withdrew more. In contrast, when behaviorally coded withdrawers expressed more vocal arousal, their partners demanded less and withdrew more. Findings demonstrate that demand/withdraw behavior varies between couples (i.e., some couples engage in a stronger demand/withdraw cycle than others) and between segments (i.e., when 1 partner increases demanding, the other increases withdrawing). Findings support key elements of the interpersonal process model, showing intra- and interpersonal pathways linking demand/withdraw behavior and emotion and demonstrate the importance of partners' behavioral roles in these linkages.

  10. ICT Solutions for Highly-Customized Water Demand Management Strategies

    Science.gov (United States)

    Giuliani, M.; Cominola, A.; Castelletti, A.; Fraternali, P.; Guardiola, J.; Barba, J.; Pulido-Velazquez, M.; Rizzoli, A. E.

    2016-12-01

    The recent deployment of smart metering networks is opening new opportunities for advancing the design of residential water demand management strategies (WDMS) relying on improved understanding of water consumers' behaviors. Recent applications showed that retrieving information on users' consumption behaviors, along with their explanatory and/or causal factors, is key to spot potential areas where targeting water saving efforts, and to design user-tailored WDMS. In this study, we explore the potential of ICT-based solutions in supporting the design and implementation of highly customized WDMS. On one side, the collection of consumption data at high spatial and temporal resolutions requires big data analytics and machine learning techniques to extract typical consumption features from the metered population of water users. On the other side, ICT solutions and gamifications can be used as effective means for facilitating both users' engagement and the collection of socio-psychographic users' information. This latter allows interpreting and improving the extracted profiles, ultimately supporting the customization of WDMS, such as awareness campaigns or personalized recommendations. Our approach is implemented in the SmartH2O platform and demonstrated in a pilot application in Valencia, Spain. Results show how the analysis of the smart metered consumption data, combined with the information retrieved from an ICT gamified web user portal, successfully identify the typical consumption profiles of the metered users and supports the design of alternative WDMS targeting the different users' profiles.

  11. An experimental test of voluntary strategies to promote urban water demand management.

    Science.gov (United States)

    Fielding, Kelly S; Spinks, Anneliese; Russell, Sally; McCrea, Rod; Stewart, Rodney; Gardner, John

    2013-01-15

    In light of the current and future threats to global water security the current research focuses on trialing interventions to promote urban water conservation. We report an experimental study designed to test the long-term impact of three different interventions on household water consumption in South East Queensland. Participants from 221 households were recruited and completed an initial survey, and their houses were fitted with smart water meters which measured total water usage at 5 s intervals. Households were allocated into one of four conditions: a control group and three interventions groups (water saving information alone, information plus a descriptive norm manipulation, and information plus tailored end-user feedback). The study is the first to use smart water metering technology as a tool for behaviour change as well as a way to test the effectiveness of demand management interventions. Growth curve modelling revealed that compared to the control, the three intervention groups all showed reduced levels of household consumption (an average reduction of 11.3 L per person per day) over the course of the interventions, and for some months afterwards. All interventions led to significant water savings, but long-term household usage data showed that in all cases, the reduction in water use resulting from the interventions eventually dissipated, with water consumption returning to pre-intervention levels after approximately 12 months. Implications for water demand management programs are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. The Potential for Snow to Supply Human Water Demand in the Present and Future

    Science.gov (United States)

    Mankin, Justin S.; Viviroli, Daniel; Singh, Deepti; Hoekstra, Arjen Y.; Diffenbaugh, Noah S.

    2015-01-01

    Runoff from snowmelt is regarded as a vital water source for people and ecosystems throughout the Northern Hemisphere (NH). Numerous studies point to the threat global warming poses to the timing and magnitude of snow accumulation and melt. But analyses focused on snow supply do not show where changes to snowmelt runoff are likely to present the most pressing adaptation challenges, given sub-annual patterns of human water consumption and water availability from rainfall. We identify the NH basins where present spring and summer snowmelt has the greatest potential to supply the human water demand that would otherwise be unmet by instantaneous rainfall runoff. Using a multi-model ensemble of climate change projections, we find that these basins - which together have a present population of approx. 2 billion people - are exposed to a 67% risk of decreased snow supply this coming century. Further, in the multi-model mean, 68 basins (with a present population of more than 300 million people) transition from having sufficient rainfall runoff to meet all present human water demand to having insufficient rainfall runoff. However, internal climate variability creates irreducible uncertainty in the projected future trends in snow resource potential, with about 90% of snow-sensitive basins showing potential for either increases or decreases over the near-term decades. Our results emphasize the importance of snow for fulfilling human water demand in many NH basins, and highlight the need to account for the full range of internal climate variability in developing robust climate risk management decisions.

  13. The potential for snow to supply human water demand in the present and future

    Science.gov (United States)

    Mankin, Justin S.; Viviroli, Daniel; Singh, Deepti; Hoekstra, Arjen Y.; Diffenbaugh, Noah S.

    2015-11-01

    Runoff from snowmelt is regarded as a vital water source for people and ecosystems throughout the Northern Hemisphere (NH). Numerous studies point to the threat global warming poses to the timing and magnitude of snow accumulation and melt. But analyses focused on snow supply do not show where changes to snowmelt runoff are likely to present the most pressing adaptation challenges, given sub-annual patterns of human water consumption and water availability from rainfall. We identify the NH basins where present spring and summer snowmelt has the greatest potential to supply the human water demand that would otherwise be unmet by instantaneous rainfall runoff. Using a multi-model ensemble of climate change projections, we find that these basins—which together have a present population of ∼2 billion people—are exposed to a 67% risk of decreased snow supply this coming century. Further, in the multi-model mean, 68 basins (with a present population of >300 million people) transition from having sufficient rainfall runoff to meet all present human water demand to having insufficient rainfall runoff. However, internal climate variability creates irreducible uncertainty in the projected future trends in snow resource potential, with about 90% of snow-sensitive basins showing potential for either increases or decreases over the near-term decades. Our results emphasize the importance of snow for fulfilling human water demand in many NH basins, and highlight the need to account for the full range of internal climate variability in developing robust climate risk management decisions.

  14. A Passenger Travel Demand Model for Copenhagen

    DEFF Research Database (Denmark)

    Overgård, Christian Hansen; Jovicic, Goran

    2003-01-01

    The passenger travel model for Copenhagen is a state-of-practice nested logit model in which the sub-models - i.e. generation, distribution and mode choice models - are connected via measure of accessibility. The model includes in its structure a large set of explanatory variables at all three...

  15. Hydrogen-on-demand using metallic alloy nanoparticles in water.

    Science.gov (United States)

    Shimamura, Kohei; Shimojo, Fuyuki; Kalia, Rajiv K; Nakano, Aiichiro; Nomura, Ken-Ichi; Vashishta, Priya

    2014-07-09

    Hydrogen production from water using Al particles could provide a renewable energy cycle. However, its practical application is hampered by the low reaction rate and poor yield. Here, large quantum molecular dynamics simulations involving up to 16,611 atoms show that orders-of-magnitude faster reactions with higher yields can be achieved by alloying Al particles with Li. A key nanostructural design is identified as the abundance of neighboring Lewis acid-base pairs, where water-dissociation and hydrogen-production require very small activation energies. These reactions are facilitated by charge pathways across Al atoms that collectively act as a "superanion" and a surprising autocatalytic behavior of bridging Li-O-Al products. Furthermore, dissolution of Li atoms into water produces a corrosive basic solution that inhibits the formation of a reaction-stopping oxide layer on the particle surface, thereby increasing the yield. These atomistic mechanisms not only explain recent experimental findings but also predict the scalability of this hydrogen-on-demand technology at industrial scales.

  16. Chitosan on Reducing Chemical Oxygen Demands in Laundry Waste Water

    Directory of Open Access Journals (Sweden)

    Tri Joko

    2016-09-01

    Full Text Available Laundry liquid waste contains several chemical substances in detergent raw materials such as phosphate, surfactants, ammonia, and total suspended solids. The existence of detergent in high concentrations and exceeds the quality standards that have been estabilished in a body of water can lead to cases of enviromental pollution in the form of increased turbidity an Chemical Oxygen Demands (COD levels. Therefore in order to maintain and to ensure the availabillity of water in terms of quality, it requires coagulation-flocculation process to laundry liquid waste before discharging into water bodies. This study aims to determine the decrease of COD levels and turbidity level in laundry liquid waste using chitosan coagulant in “X” laundry, Tembalang District, Semarang. The research is a quasi experimental study with pretest-posttest with control group research design with 6 times replication. The total samples are 60 in wich 24 tested for the levels of turbidity and 6 controls. The test results of Kruskal-Wallis with significance p-value < 0,05 indicates that dosage variation (p=0,000 gives different levels of COD and dosage variation (p=0,000 provide 755,97 mg/l and the advantage levels of turbidity before treatment was 516,20 NTU. The optimum dosage of chitosan coagulant is on the dose of 200 mg/l with the effectiveness decrease of COD levels and turbidity levels on 72,67% an 98,67% respectively.

  17. Optimizing Sustainable Integrated Use of Groundwater, Surface Water and Reclaimed Water for the Competing Demands of Agricultural Net Return and Urban Population

    OpenAIRE

    Landa, Silvia Anastasia

    2016-01-01

    Rapid population growth increases the competing water demand for agriculture and municipalities. This situation urges the necessity of using integrated water management to increase water supply and find possible symbiotic urban-agriculture relationships. Many studies have been done to simulate the integrated use of surface water, groundwater and reclaimed water for different water users. However, few studies use simulation/optimization (S-O) models for water resources to explicitly represent ...

  18. Model documentation report: Commercial Sector Demand Module of the National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This report documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Commercial Sector Demand Module. The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated through the synthesis and scenario development based on these components. The NEMS Commercial Sector Demand Module is a simulation tool based upon economic and engineering relationships that models commercial sector energy demands at the nine Census Division level of detail for eleven distinct categories of commercial buildings. Commercial equipment selections are performed for the major fuels of electricity, natural gas, and distillate fuel, for the major services of space heating, space cooling, water heating, ventilation, cooking, refrigeration, and lighting. The algorithm also models demand for the minor fuels of residual oil, liquefied petroleum gas, steam coal, motor gasoline, and kerosene, the renewable fuel sources of wood and municipal solid waste, and the minor services of office equipment. Section 2 of this report discusses the purpose of the model, detailing its objectives, primary input and output quantities, and the relationship of the Commercial Module to the other modules of the NEMS system. Section 3 of the report describes the rationale behind the model design, providing insights into further assumptions utilized in the model development process to this point. Section 3 also reviews alternative commercial sector modeling methodologies drawn from existing literature, providing a comparison to the chosen approach. Section 4 details the model structure, using graphics and text to illustrate model flows and key computations.

  19. Uncertainty in future irrigation water demand and risk of crop failure for maize in Europe

    Science.gov (United States)

    Webber, Heidi; Gaiser, Thomas; Oomen, Roelof; Teixeira, Edmar; Zhao, Gang; Wallach, Daniel; Zimmermann, Andrea; Ewert, Frank

    2016-07-01

    While crop models are widely used to assess the change in crop productivity with climate change, their skill in assessing irrigation water demand or the risk of crop failure in large area impact assessments is relatively unknown. The objective of this study is to investigate which aspects of modeling crop water use (reference crop evapotranspiration (ET0), soil water extraction, soil evaporation, soil water balance and root growth) contributes most to the variability in estimates of maize crop water use and the risk of crop failure, and demonstrate the resulting uncertainty in a climate change impact study for Europe. The SIMPLACE crop modeling framework was used to couple the LINTUL5 crop model in factorial combinations of 2-3 different approaches for simulating the 5 aspects of crop water use, resulting in 51 modeling approaches. Using experiments in France and New Zeland, analysis of total sensitivity revealed that ET0 explained the most variability in both irrigated maize water use and rainfed grain yield levels, with soil evaporation also imporatant in the French experiment. In the European impact study, net irrigation requirement differed by 36% between the Penman and Hargreaves ET0 methods in the baseline period. Average EU grain yields were similar between models, but differences approached 1-2 tonnes in parts of France and Southern Europe. EU wide esimates of crop failure in the historical period ranged between 5.4 years for Priestley-Taylor to every 7.9 years for the Penman ET0 methods. While the uncertainty in absolute values between models was significant, estimates of relative changes were similar between models, confirming the utility of crop models in assessing climate change impacts. If ET0 estimates in crop models can be improved, through the use of appropriate methods, uncertainty in irrigation water demand as well as in yield estimates under drought can be reduced.

  20. Stochastic optimization model for order acceptance with multiple demand classes and uncertain demand/supply

    Science.gov (United States)

    Yang, Wen; Fung, Richard Y. K.

    2014-06-01

    This article considers an order acceptance problem in a make-to-stock manufacturing system with multiple demand classes in a finite time horizon. Demands in different periods are random variables and are independent of one another, and replenishments of inventory deviate from the scheduled quantities. The objective of this work is to maximize the expected net profit over the planning horizon by deciding the fraction of the demand that is going to be fulfilled. This article presents a stochastic order acceptance optimization model and analyses the existence of the optimal promising policies. An example of a discrete problem is used to illustrate the policies by applying the dynamic programming method. In order to solve the continuous problems, a heuristic algorithm based on stochastic approximation (HASA) is developed. Finally, the computational results of a case example illustrate the effectiveness and efficiency of the HASA approach, and make the application of the proposed model readily acceptable.

  1. Analysis and intervention plan of water resource supply and demand in North China

    Science.gov (United States)

    Zang, Yuhang

    2017-04-01

    Firstly, this paper use Regression Analysis Prediction Method to analysis surface water, underground water and sewage treatment, so that we can predict the water supply capacity of North China in the next 15 years. After that, we test the trusting degree of this model to ensure the facticity by identifying the statistical significance of each data. Secondly, we adopt analytic hierarchy process (AHP method) to gain the factors mostly affecting sewage treatment capacity is the Chemical Oxygen Demand and ammoniac nitrogen content in sewage. So we can take measures to increase the amount of water supply in the region. Finally, we adjust the charging standard of living water and together with logistic regression, which can improve the water-saving awareness of local residents so as to effectively reduce the water consumption in the future.

  2. Modelling Dissolved Oxygen/Sediment Oxygen Demand under Ice in a Shallow Eutrophic Prairie Reservoir

    Directory of Open Access Journals (Sweden)

    Julie A. Terry

    2017-02-01

    Full Text Available Dissolved oxygen is an influential factor of aquatic ecosystem health. Future predictions of oxygen deficits are paramount for maintaining water quality. Oxygen demands depend greatly on a waterbody’s attributes. A large sediment–water interface relative to volume means sediment oxygen demand has greater influence in shallow systems. In shallow, ice-covered waterbodies the potential for winter anoxia is high. Water quality models offer two options for modelling sediment oxygen demand: a zero-order constant rate, or a sediment diagenesis model. The constant rate is unrepresentative of a real system, yet a diagenesis model is difficult to parameterise and calibrate without data. We use the water quality model CE-QUAL-W2 to increase the complexity of a zero-order sediment compartment with limited data. We model summer and winter conditions individually to capture decay rates under-ice. Using a semi-automated calibration method, we find an annual pattern in sediment oxygen demand that follows the trend of chlorophyll-a concentrations in a shallow, eutrophic Prairie reservoir. We use chlorophyll-a as a proxy for estimation of summer oxygen demand and winter decay. We show that winter sediment oxygen demand is dependent on the previous summer’s maximum chlorophyll-a concentrations.

  3. An Interactive Computer Tool for Teaching About Desalination and Managing Water Demand in the US

    Science.gov (United States)

    Ziolkowska, J. R.; Reyes, R.

    2016-12-01

    This paper presents an interactive tool to geospatially and temporally analyze desalination developments and trends in the US in the time span 1950-2013, its current contribution to satisfying water demands and its future potentials. The computer tool is open access and can be used by any user with Internet connection, thus facilitating interactive learning about water resources. The tool can also be used by stakeholders and policy makers for decision-making support and with designing sustainable water management strategies. Desalination technology has been acknowledged as a solution to a sustainable water demand management stemming from many sectors, including municipalities, industry, agriculture, power generation, and other users. Desalination has been applied successfully in the US and many countries around the world since 1950s. As of 2013, around 1,336 desalination plants were operating in the US alone, with a daily production capacity of 2 BGD (billion gallons per day) (GWI, 2013). Despite a steady increase in the number of new desalination plants and growing production capacity, in many regions, the costs of desalination are still prohibitive. At the same time, the technology offers a tremendous potential for `enormous supply expansion that exceeds all likely demands' (Chowdhury et al., 2013). The model and tool are based on data from Global Water Intelligence (GWI, 2013). The analysis shows that more than 90% of all the plants in the US are small-scale plants with the capacity below 4.31 MGD. Most of the plants (and especially larger plants) are located on the US East Coast, as well as in California, Texas, Oklahoma, and Florida. The models and the tool provide information about economic feasibility of potential new desalination plants based on the access to feed water, energy sources, water demand, and experiences of other plants in that region.

  4. A Dynamic Lot-Sizing Model with Demand Time Windows

    NARCIS (Netherlands)

    C.Y. Lee (Chung-Yee); S. Çetinkaya; A.P.M. Wagelmans (Albert)

    1999-01-01

    textabstractOne of the basic assumptions of the classical dynamic lot-sizing model is that the aggregate demand of a given period must be satisfied in that period. Under this assumption, if backlogging is not allowed then the demand of a given period cannot be delivered earlier or later than the

  5. A dynamic lot-sizing model with demand time windows

    NARCIS (Netherlands)

    C.Y. Lee (Chung-Yee); S. Cetinkaya; A.P.M. Wagelmans (Albert)

    1999-01-01

    textabstractOne of the basic assumptions of the classical dynamic lot-sizing model is that the aggregate demand of a given period must be satisfied in that period. Under this assumption, if backlogging is not allowed then the demand of a given period cannot be delivered earlier or later than the

  6. The job demands-resources model of burnout

    NARCIS (Netherlands)

    Demerouti, E.; Bakker, A.B.; Nachreiner, F.; Schaufeli, W.B.

    2001-01-01

    The job demands-resources (JD-R) model proposes that working conditions can be categorized into 2 broad categories, job demands and job resources. that are differentially related to specific outcomes. A series of LISREL analyses using self-reports as well as observer ratings of the working

  7. A dynamic lot-sizing model with demand time windows

    NARCIS (Netherlands)

    C.Y. Lee (Chung-Yee); S. Cetinkaya; A.P.M. Wagelmans (Albert)

    1999-01-01

    textabstractOne of the basic assumptions of the classical dynamic lot-sizing model is that the aggregate demand of a given period must be satisfied in that period. Under this assumption, if backlogging is not allowed then the demand of a given period cannot be delivered earlier or later than the pe

  8. A Dynamic Lot-Sizing Model with Demand Time Windows

    NARCIS (Netherlands)

    C.Y. Lee (Chung-Yee); S. Çetinkaya; A.P.M. Wagelmans (Albert)

    1999-01-01

    textabstractOne of the basic assumptions of the classical dynamic lot-sizing model is that the aggregate demand of a given period must be satisfied in that period. Under this assumption, if backlogging is not allowed then the demand of a given period cannot be delivered earlier or later than the per

  9. Water flows, energy demand, and market analysis of the informal water sector in Kisumu, Kenya.

    Science.gov (United States)

    Sima, Laura C; Kelner-Levine, Evan; Eckelman, Matthew J; McCarty, Kathleen M; Elimelech, Menachem

    2013-03-01

    In rapidly growing urban areas of developing countries, infrastructure has not been able to cope with population growth. Informal water businesses fulfill unmet water supply needs, yet little is understood about this sector. This paper presents data gathered from quantitative interviews with informal water business operators (n=260) in Kisumu, Kenya, collected during the dry season. Sales volume, location, resource use, and cost were analyzed by using material flow accounting and spatial analysis tools. Estimates show that over 76% of the city's water is consumed by less than 10% of the population who have water piped into their dwellings. The remainder of the population relies on a combination of water sources, including water purchased directly from kiosks (1.5 million m(3) per day) and delivered by hand-drawn water-carts (0.75 million m(3) per day). Energy audits were performed to compare energy use among various water sources in the city. Water delivery by truck is the highest per cubic meter energy demand (35 MJ/m(3)), while the city's tap water has the highest energy use overall (21,000 MJ/day). We group kiosks by neighborhood and compare sales volume and cost with neighborhood-level population data. Contrary to popular belief, we do not find evidence of price gouging; the lowest prices are charged in the highest-demand low-income area. We also see that the informal sector is sensitive to demand, as the number of private boreholes that serve as community water collection points are much larger where demand is greatest.

  10. Estimating the own-price elasticity of demand for irrigation water in the Musi catchment of India

    Science.gov (United States)

    Davidson, Brian; Hellegers, Petra

    2011-10-01

    SummaryAs irrigation water is an input into a production process, its demand must be 'derived'. According to theory, a derived demand schedule should be downward sloping and dependent on the outputs produced from it, the prices of other inputs and the price of the water itself. Problems arise when an attempt is made to estimate the demand for irrigation water and the resulting own-price elasticity of demand, as the uses to which water is put are spatially, temporarily and geographically diverse. Because water is not generally freely traded, what normally passes for an estimate of the own-price elasticity of demand for irrigation water is usually a well argued assumption or an estimate that is derived from a simulation model of a hypothesized producer. Such approaches tend to provide an inadequate explanation of what is an extremely complex and important relationship. An adequate explanation of the relationship between the price and the quantity demanded of water should be one that not only accords with the theoretical expectations, but also accounts for the diversity of products produced from water (which includes the management practices of farmers), the seasons in which it is used and over the region within which it is used. The objective in this article is to present a method of estimating the demand curve for irrigation water. The method uses actual field data which is collated using the Residual Method to determine the value of the marginal product of water deployed over a wide range of crops, seasons and regions. These values of the marginal products, all which must lie of the input demand schedule for water, are then ordered from the highest value to the lowest. Then, the amount of irrigation water used for each product, in each season and in each region is cumulatively summed over the range of uses according to the order of the values of the marginal products. This data, once ordered, is then used to econometrically estimate the demand schedule from which

  11. MODELING THE DEMAND FOR E85 IN THE UNITED STATES

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Changzheng [ORNL; Greene, David L [ORNL

    2013-10-01

    How demand for E85 might evolve in the future in response to changing economics and policies is an important subject to include in the National Energy Modeling System (NEMS). This report summarizes a study to develop an E85 choice model for NEMS. Using the most recent data from the states of Minnesota, North Dakota, and Iowa, this study estimates a logit model that represents E85 choice as a function of prices of E10 and E85, as well as fuel availability of E85 relative to gasoline. Using more recent data than previous studies allows a better estimation of non-fleet demand and indicates that the price elasticity of E85 choice appears to be higher than previously estimated. Based on the results of the econometric analysis, a model for projecting E85 demand at the regional level is specified. In testing, the model produced plausible predictions of US E85 demand to 2040.

  12. An EPQ Model with Increasing Demand and Demand Dependent Production Rate under Trade Credit Financing

    Directory of Open Access Journals (Sweden)

    Juanjuan QIN

    2015-05-01

    Full Text Available This paper investigates an EPQ model with the increasing demand and demand dependent production rate involving the trade credit financing policy, which is seldom reported in the literatures. The model considers the manufacturer was offered by the supplier a delayed payment time. It is assumed that the demand is a linear increasing function of the time and the production rate is proportional to the demand. That is, the production rate is also a linear function of time. This study attempts to offer a best policy for the replenishment cycle and the order quantity for the manufacturer to maximum its profit per cycle. First, the inventory model is developed under the above situation. Second, some useful theoretical results have been derived to characterize the optimal solutions for the inventory system. The Algorithm is proposed to obtain the optimal solutions of the manufacturer. Finally, the numerical examples are carried out to illustrate the theorems, and the sensitivity analysis of the optimal solutions with respect to the parameters of the inventory system is performed. Some important management insights are obtained based on the analysis.

  13. Demand for water-resources information: a conceptual framework and empirical investigation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Shabman, L.A.; Osborn, C.T.

    1986-06-01

    The continued effectiveness of the Federal water-data-collection effort is an area of special concern to many, because more than 30 Federal agencies collect some form of data. With less funding available, agencies are exploring methods to increase the efficiency of their data-collection programs and the value of the information produced. A framework based on a literature review of organizational decision processes has been developed to consider the nature of the demand and the value for decision makers in public water-management organizations. The paper reports the results of an empirical model that relates decision maker's use of the Water Resource Council's Second National Water Assessment and hypothetical expenditures on national assessment information to agency characteristics in two water basin management situations: instream versus offstream water-use competition in the Missouri River basin, and low freshwater inflows to Chesapeake Bay.

  14. A single product perishing inventory model with demand interaction ...

    African Journals Online (AJOL)

    A single product perishing inventory model with demand interaction. ... satisfied may be satisfied by an item in Phase II, based on a probability measure. ... the probability distribution of the inventory level at any arbitrary point in time is obtained.

  15. Planning for community resilience to future United States domestic water demand

    Science.gov (United States)

    Costs of repairing and expanding aging infrastructure and competing demands for water from other sectors such as industry and agriculture are stretching water managers’ abilities to meet essential domestic drinking water needs for future generations. Using Bayesian statisti...

  16. Planning for community resilience to future United States domestic water demand

    Science.gov (United States)

    Costs of repairing and expanding aging infrastructure and competing demands for water from other sectors such as industry and agriculture are stretching water managers’ abilities to meet essential domestic drinking water needs for future generations. Using Bayesian statisti...

  17. Detailed Modeling and Response of Demand Response Enabled Appliances

    Energy Technology Data Exchange (ETDEWEB)

    Vyakaranam, Bharat; Fuller, Jason C.

    2014-04-14

    Proper modeling of end use loads is very important in order to predict their behavior, and how they interact with the power system, including voltage and temperature dependencies, power system and load control functions, and the complex interactions that occur between devices in such an interconnected system. This paper develops multi-state time variant residential appliance models with demand response enabled capabilities in the GridLAB-DTM simulation environment. These models represent not only the baseline instantaneous power demand and energy consumption, but the control systems developed by GE Appliances to enable response to demand response signals and the change in behavior of the appliance in response to the signal. These DR enabled appliances are simulated to estimate their capability to reduce peak demand and energy consumption.

  18. Evaluation of the Demand Response Performance of Electric Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Widder, Sarah H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Parker, Steven A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pratt, Richard M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chassin, Forrest S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-17

    The purpose of this project is to verify or refute many of the concerns raised by utilities regarding the ability of large tank HPWHs to perform DR by measuring the performance of HPWHs compared to ERWHs in providing DR services. perform DR by measuring the performance of HPWHs compared to ERWHs in providing DR services. This project was divided into three phases. Phase 1 consisted of week-long laboratory experiments designed to demonstrate technical feasibility of individual large-tank HPWHs in providing DR services compared to large-tank ERWHs. In Phase 2, the individual behaviors of the water heaters were then extrapolated to a population by first calibrating readily available water heater models developed in GridLAB-D simulation software to experimental results obtained in Phase 1. These models were used to simulate a population of water heaters and generate annual load profiles to assess the impacts on system-level power and residential load curves. Such population modeling allows for the inherent and permanent load reduction accomplished by the more efficient HPWHs to be considered, in addition to the temporal DR services the water heater can provide by switching ON or OFF as needed by utilities. The economic and emissions impacts of using large-tank water heaters in DR programs are then analyzed from the utility and consumer perspective, based on National Impacts Analysis in Phase 3. Phase 1 is discussed in this report. Details on Phases 2 and 3 can be found in the companion report (Cooke et al. 2014).

  19. Water demand management in times of drought: What matters for water conservation

    Science.gov (United States)

    Maggioni, Elena

    2015-01-01

    Southern California is subject to long droughts and short wet spells. Its water agencies have put in place voluntary, mandatory, and market-based conservation strategies since the 1980s. By analyzing water agencies' data between 2006 and 2010, this research studies whether rebates for water efficient fixtures, water rates, or water ordinances have been effective, and tests whether structural characteristics of water agencies have affected the policy outcome. It finds that mandates to curb outdoor water uses are correlated with reductions in residential per capita water usage, while water rates and subsidies for water saving devices are not. It also confirms that size is a significant policy implementation factor. In a policy perspective, the transition from a water supply to a water demand management-oriented strategy appears guided by mandates and by contextual factors such as the economic cycle and the weather that occur outside the water governance system. Three factors could improve the conservation effort: using prices as a conservation tool, not only as a cost recovering instrument; investing in water efficient tools only when they provide significant water savings; supporting smaller agencies in order to give them opportunities to implement conservation strategies more effectively or to help them consolidate.

  20. China's water sustainability in the 21st century: a climate informed water risk assessment covering multi-sector water demands

    Directory of Open Access Journals (Sweden)

    X. Chen

    2013-08-01

    Full Text Available China is facing a water resources crisis with growing concerns as to the reliable supply of water for agricultural, industrial and domestic needs. High inter-annual rainfall variability and increasing consumptive use across the country exacerbates the situation further and is a constraint on future development. For water sustainability, it is necessary to examine the differences in water demand and supply and their spatio-temporal distribution in order to quantify the dimensions of the water risk. Here, a detailed quantitative assessment of water risk as measured by the distribution of cumulated deficits for China is presented. Considering daily precipitation and temperature variability over fifty years and the current water demands, risk measures are developed to inform county level water deficits that account for both within year and across year variations in climate. We choose political rather than watershed boundaries since economic activity and water use are organized by county and the political process is best informed through that unit. The risk measures highlight North China Plain counties as highly water stressed. Regions with high water stress are typically the regions with high inter-annual variability in rainfall and now have depleted groundwater aquifers. The stress components due to agricultural, industrial and domestic water demands are illustrated separately to assess the vulnerability of particular sectors within the country to provide a basis for targeted policy analysis for reducing water stress.

  1. Demand and routing models for urban goods movement simulation

    OpenAIRE

    Polimeni, Antonio; Russo, Francesco; Vitetta, Antonino

    2010-01-01

    This paper presents a macro-architecture for simulating goods movements in an urban area. Urban goods supply is analysed when the retailer is the decision-maker and chooses to supply his/her shop. Two components are considered: demand in terms of goods supply and vehicle routing with constraints to simulate goods movements. To analyse demand we consider a multi-step model, while to analyse goods movements a Vehicle Routing Problem with Time Windows (VRPTW) is formalized. We exa...

  2. Modelling demand for crude oil products in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Pedregal, D.J. [Escuela Tecnica Superior de Ingenieros Industriales and Instituto de Matematica Aplicada a la Ciencia y la Ingenieria (IMACI), Universidad de Castilla-La Mancha (UCLM), Avenida Camilo Jose Cela s/n, 13071 Ciudad Real (Spain); Dejuan, O.; Gomez, N.; Tobarra, M.A. [Facultad de Ciencias Economicas y Empresariales, Universidad de Castilla-La Mancha (UCLM) (Spain)

    2009-11-15

    This paper develops an econometric model for the five most important crude oil products demand in Spain. The aim is the estimation of a range of elasticities of such demands that would serve as the basis for an applied general equilibrium model used for forecasting energy demand in a broader framework. The main distinctive features of the system with respect to previous literature are (1) it takes advantage of monthly information coming from very different information sources and (2) multivariate unobserved components (UC) models are implemented allowing for a separate analysis of long- and short-run relations. UC models decompose time series into a number of unobserved though economic meaningful components mainly trend, seasonal and irregular. A module is added to such structure to take into account the influence of exogenous variables necessary to compute price, cross and income elasticities. Since all models implemented are multivariate in nature, the demand components are allowed to interact among them through the system noises (similar to a seemingly unrelated equations model). The results show unambiguously that the main factor driving demand is real income with prices having little impact on energy consumption. (author)

  3. Water resources sensitivity to the isolated effects of land use, water demand and climate change under 2 degree global warming

    Science.gov (United States)

    Bisselink, Berny; Bernhard, Jeroen; de Roo, Ad

    2017-04-01

    One of the key impacts of global change are the future water resources. These water resources are influenced by changes in land use (LU), water demand (WD) and climate change. Recent developments in scenario modelling opened new opportunities for an integrated assessment. However, for identifying water resource management strategies it is helpful to focus on the isolated effects of possible changes in LU, WD and climate that may occur in the near future. In this work, we quantify the isolated contribution of LU, WD and climate to the integrated total water resources assuming a linear model behavior. An ensemble of five EURO-CORDEX RCP8.5 climate projections for the 31-year periods centered on the year of exceeding the global-mean temperature of 2 degree is used to drive the fully distributed hydrological model LISFLOOD for multiple river catchments in Europe. The JRC's Land Use Modelling Platform LUISA was used to obtain a detailed pan-European reference land use scenario until 2050. Water demand is estimated based on socio-economic (GDP, population estimates etc.), land use and climate projections as well. For each climate projection, four model runs have been performed including an integrated (LU, WD and climate) simulation and other three simulations to isolate the effect of LU, WD and climate. Changes relative to the baseline in terms of water resources indicators of the ensemble means of the 2 degree warming period and their associated uncertainties will reveal the integrated and isolated effect of LU, WD and climate change on water resources.

  4. Estimating household water demand using revealed and contingent behaviors: Evidence from Vietnam

    Science.gov (United States)

    Cheesman, Jeremy; Bennett, Jeff; Son, Tran Vo Hung

    2008-11-01

    This article estimates the water demand of households using (1) municipal water exclusively and (2) municipal water and household well water in the capital city of Dak Lak Province in Vietnam. Household water demands are estimated using a panel data set formed by pooling household records of metered municipal water consumption and their stated preferences for water consumption contingent on hypothetical water prices. Estimates show that households using municipal water exclusively have very price inelastic demand. Households using municipal and household well water have more price elastic, but still inelastic, simultaneous water demand and treat municipal water and household well water as substitutes. Household water consumption is influenced by household water storage and supply infrastructure, income, and socioeconomic attributes. The demand estimates are used to forecast municipal water consumption by households in Buon Ma Thuot following an increase to the municipal water tariff to forecast the municipal water supply company's revenue stream following a tariff increase and to estimate the consumer surplus loss resulting from municipal water supply shortages.

  5. Future water supply and demand in response to climate change and agricultural expansion in Texas

    Science.gov (United States)

    Lee, K.; Zhou, T.; Gao, H.; Huang, M.

    2016-12-01

    With ongoing global environmental change and an increasing population, it is challenging (to say the least) to understand the complex interactions of irrigation and reservoir systems. Irrigation is critical to agricultural production and food security, and is a vital component of Texas' agricultural economy. Agricultural irrigation currently accounts for about 60% of total water demand in Texas, and recent occurrences of severe droughts has brought attention to the availability and use of water in the future. In this study, we aim to assess future agricultural irrigation water demand, and to estimate how changes in the fraction of crop irrigated land will affect future water availability in Texas, which has the largest farm area and the highest value of livestock production in the United States. The Variable Infiltration Capacity (VIC) model, which has been calibrated and validated over major Texas river basins during the historical period, is employed for this study. The VIC model, coupling with an irrigation scheme and a reservoir module, is adopted to simulate the water management and regulations. The evolution on agricultural land is also considered in the model as a changing fraction of crop for each grid cell. The reservoir module is calibrated and validated based on the historical (1915-2011) storage records of major reservoirs in Texas. The model is driven by statistically downscaled climate projections from Coupled Model Intercomparison Project Phase 5 (CMIP5) model ensembles at a spatial resolution of 1/8°. The lowest (RCP 2.6) and highest (RC P8.5) greenhouse-gas concentration scenarios are adopted for future projections to provide an estimate of uncertainty bounds. We expect that our results will be helpful to assist decision making related to reservoir operations and agricultural water planning for Texas under future climate and environmental changes.

  6. Sustainable water demand management in the face of rapid urbanization and ground water depletion for social–ecological resilience building

    Directory of Open Access Journals (Sweden)

    Md. Arfanuzzaman

    2017-04-01

    Full Text Available Necessity of Sustainable water demand management (SWDM is immensely higher in the rapidly urbanized mega cities of the world where groundwater depletion and water deficit are taking place perilously. This paper focuses on the present condition of water demand, supply, system loss, pricing strategy, groundwater level, and per capita water consumption of Dhaka city, Bangladesh. The study founds population growth has a large influence on water demand to rise and demand of water is not responsive to the existing pricing rule adopted by DWASA. It emerges that, water demand is increasing at 4% rate an average in the Dhaka city since 1990 and groundwater table goes more than 70 m down in central capital due to extensive withdrawal of water. The study suggests an integrated SWDM approach, which incorporates optimum pricing, ground and surface water regulation, water conservation, sustainable water consumption and less water foot print to ease groundwater depletion. In order to attain sustainability in water demand management (WDM the study recommends certain criteria under economic, social and environmental segment to administer the increasing water demand of growing population and conserve the fresh water resources of the world’s mega cities for social–ecological resilience building.

  7. Evaluation of actions for better water supply and demand management in Fayoum, Egypt using RIBASIM

    Directory of Open Access Journals (Sweden)

    Mohie M. Omar

    2013-10-01

    Full Text Available Fayoum Governorate faces many water-related challenges being; compensating the water shortage and controlling the volumes of drainage water effluents into Quarun Lake. There are many actions, based on water resources management approach, which can help overcome these water-related challenges. These actions are classified to developing additional water resources (supply management, and properly using the existing water resources (demand management. This study investigates using the RIBASIM (RIver BAsin SIMulation model, the most suitable actions for the future. RIBASIM was used to simulate the current condition and evaluate various scenarios in 2017 based on different actions. Three scenarios were formulated being optimistic, moderate, and pessimistic which represent different implementation rates of the tested actions. RIBASIM results indicated a water shortage of 0.59, 1, and 1.85 Billion Cubic Meter (BCM/year, for the simulated scenarios, respectively. Since Fayoum is a miniature of Egypt with respect to both, the natural and water resources systems, the results of this study can be used as guidelines for optimization of the water resources system in Egypt.

  8. Using Supply, Demand, and the Cournot Model to Understand Corruption

    Science.gov (United States)

    Hayford, Marc D.

    2007-01-01

    The author combines the supply and demand model of taxes with a Cournot model of bribe takers to develop a simple and useful framework for understanding the effect of corruption on economic activity. There are many examples of corruption in both developed and developing countries. Because corruption decreases the level of economic activity and…

  9. Using Supply, Demand, and the Cournot Model to Understand Corruption

    Science.gov (United States)

    Hayford, Marc D.

    2007-01-01

    The author combines the supply and demand model of taxes with a Cournot model of bribe takers to develop a simple and useful framework for understanding the effect of corruption on economic activity. There are many examples of corruption in both developed and developing countries. Because corruption decreases the level of economic activity and…

  10. Energy demand analytics using coupled technological and economic models

    Science.gov (United States)

    Impacts of a range of policy scenarios on end-use energy demand are examined using a coupling of MARKAL, an energy system model with extensive supply and end-use technological detail, with Inforum LIFT, a large-scale model of the us. economy with inter-industry, government, and c...

  11. Descriptive documentation for New Mexico electricity econometric final demand model

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, J.D.; Ben-David, S.

    1981-01-01

    A mathematical model is developed for computing consumption and residential electric power demands for New Mexico. Factors considered in developing the model included: number of electric utility customers, past consumption data; household devices using electric power and their energy efficiencies; climatic conditions; and power costs. (LCL)

  12. New Demands, New Supplies: A National Look at the Water Balance of Carbon Dioxide Capture and Sequestration

    Science.gov (United States)

    Roach, J. D.; Kobos, P.; Klise, G. T.; Krumhansl, J. L.; McNemar, A.

    2010-12-01

    Concerns over rising concentrations of greenhouse gases in the atmosphere have resulted in serious consideration of policies aimed at reduction of anthropogenic carbon dioxide (CO2) emissions. If large scale abatement efforts are undertaken, one critical tool will be geologic sequestration of CO2 captured from large point sources, specifically coal and natural gas fired power plants. Current CO2 capture technologies exact a substantial energy penalty on the source power plant, which must be offset with make-up power. Water demands increase at the source plant due to added cooling loads. In addition, new water demand is created by water requirements associated with generation of the make-up power. At the sequestration site however, saline water may be extracted to manage CO2 plum migration and pressure build up in the geologic formation. Thus, while CO2 capture creates new water demands, CO2 sequestration has the potential to create new supplies. Some or all of the added demand may be offset by treatment and use of the saline waters extracted from geologic formations during CO2 sequestration. Sandia National Laboratories, with guidance and support from the National Energy Technology Laboratory, is creating a model to evaluate the potential for a combined approach to saline formations, as a sink for CO2 and a source for saline waters that can be treated and beneficially reused to serve power plant water demands. This presentation will focus on the magnitude of added U.S. power plant water demand under different CO2 emissions reduction scenarios, and the portion of added demand that might be offset by saline waters extracted during the CO2 sequestration process. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

  13. Water Demands with Two Adaptation Responses to Climate Change in a Mexican Irrigation District

    Science.gov (United States)

    Ojeda, W.; Iñiguez-Covarrubias, M.; Rojano, A.

    2012-12-01

    It is well documented that climate change is inevitable and that farmers need to adapt to changes in projected climate. Changes in water demands for a Mexican irrigation district were assessed using an irrigation scheduling model. The impact of two adaptations actions on water demands were estimated and compared with a baseline scenario. Wet and dry cropping plans were selected from the last 15 water years with actual climatology (1961-1990) taken as reference and three A1B climate change projection periods P1, P2 and P3 (2011-2040, 2041-2070, and 2071-2098). Projected precipitation and air temperature (medium, maximum and minimum) data were obtained through weighted averages of the best CGCM projections for Mexico, available at the IPCC data distribution center, using the Reliability Ensemble Averaging method (REA). Two adaptation farmers' responses were analyzed: use of longer season varieties and reduction of planting dates toward colder season as warming intensifies in the future. An annual accumulated ETo value of 1554 mm was estimated for the base period P0. Cumulative and Daily irrigations demands were generated for each agricultural season using the four climate projection series and considering adaptations actions. Figure 1 integrates in a unique net flow curve for the Fall-Winter season under selected adaptations actions. The simulation results indicated that for mid century (Period P2), the use of longer-season cultivars (AV) will have more pronounced effect in daily net flow based than the reduction of planting season (APS) as climate change intensifies during present century. Without adaptation (WA), the increase in temperature will shorten the growing season of all annual crops, generating a peak shift with respect to reference case (WA-P0). Combined adoptions of adaptation actions (AP+V) can generate higher, peak and cumulative, crop water requirements than actual values as Figure 1 shows. There are clear trends that without adaptations, water

  14. Improving the local relevance of large scale water demand predictions: the way forward

    Science.gov (United States)

    Bernhard, Jeroen; Reynaud, Arnaud; de Roo, Ad

    2016-04-01

    use and water prices. Subsequently, econometric estimates allow us to make a monetary valuation of water and identify the dominant drivers of domestic and industrial water demand per country. Combined with socio-economic, demographic and climate scenarios we made predictions for future Europe. Since this is a first attempt we obtained mixed results between countries when it comes to data availability and therefore model uncertainty. For some countries we have been able to develop robust predictions based on vast amounts of data while some other countries proved more challenging. We do feel however, that large scale predictions based on regional data are the way forward to provide relevant scientific policy support. In order to improve on our work it is imperative to further expand our database of consistent regional data. We are looking forward to any kind of input and would be very interested in sharing our data to collaborate towards a better understanding of the water use system.

  15. 基于偏最小二乘回归的城市生活用水量预测研究%Estimation of Urban Water Demand Using Partial Least Squares Regression Model

    Institute of Scientific and Technical Information of China (English)

    张立杰

    2012-01-01

    the urban water demand is estimated by the least squares regression models which considers six social and economic factors as model input variables. Hie results show:There is a high multicollinearity among the input variables, the partial least squares regression model can reduce the undesirable effects of multicollinearity, and get a more accurate predict (the relative error is only 2.7% ). It has also been found that the data series length and recent data have an important effect on the estimation accuracy.%以城市生活用水量为预测研究对象,选取6个社会经济发展因素作为主要变量因子,建立偏最小二乘回归模型.研究分析表明,各变量因子间存在较强的多重共线性,采用偏最小二乘回归模型能有效克服各类因子变量间的多重共线性对模型拟合精度及其预测能力的影响,取得更接近现实的预估结果(平均相对误差为2.7%).研究还发现,数据序列的长度和变量近期的变化信息也会对模型的预测精度产生重要的影响.

  16. Low-flow appliances and household water demand: an evaluation of demand-side management policy in Albuquerque, New Mexico.

    Science.gov (United States)

    Price, James I; Chermak, Janie M; Felardo, Jeff

    2014-01-15

    Residential rebate programs for low-flow water devices have become increasingly popular as a means of reducing urban water demand. Although program specifics vary, low-flow rebates are available in most U.S. metropolitan areas, as well as in many smaller municipalities. Despite their popularity, few statistical analyses have been conducted regarding the effects of low-flow rebates on household water use. In this paper, we consider the effects of rebates from the Albuquerque Bernalillo County Water Utility Authority (ABCWUA). Using panel regression techniques with a database of rebate recipients, we estimate the marginal effects of various low-flow devices on household water demand. Results indicate a negative correlation between household water use and the presence of most low-flow devices, after controlling for water price and weather conditions. Low-flow toilets have the greatest impact on water use, while low-flow washing machines, dishwashers, showerheads, and xeriscape have smaller but significant effects. In contrast, air conditioning systems, hot water recirculators, and rain barrels have no significant impact on water use. We also test for possible rebound effects (i.e. whether low-flow appliances become less-effective over time due to poor rates of retention or behavioral changes) and compare the cost effectiveness of each rebate using levelised-costs. We find no evidence of rebound effects and substantial variation in levelised-costs, with low-flow showerheads being the most cost-effective device under the current ABCWUA rebate program. The latter result suggests that water providers can improve the efficiency of rebate programs by targeting the most cost-effective devices.

  17. Understanding Household Demand for Water: The Metro Manila Case

    OpenAIRE

    David, Cristina C; Arlene B. Inocencio

    1998-01-01

    Widespread water shortages in Metro Manila have made the urban water problem a central policy issue. President Ramos recently called a "Water Summit Meeting" and directed all concerned agencies to develop a short- and medium-term strategy for addressing the impending water crisis. In Congress, the Water Crisis Act was passed which empowered the President to contract new water supply projects expeditiously, bypassing the normal bidding procedures. About $7 million is being spent to develop an ...

  18. EnviroAtlas - Agricultural Water Demand by 12-Digit HUC for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — The national agricultural water demand metric provides insight into the amount of water currently used for agricultural irrigation in the contiguous United States....

  19. EnviroAtlas - Domestic Water Demand by 12-Digit HUC for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset includes domestic water demand attributes which provide insight into the amount of water currently used for indoor and outdoor residential...

  20. EnviroAtlas - Industrial Water Demand (2010) by 12-Digit HUC for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset includes industrial water demand attributes which provide insight into the amount of water currently used for manufacturing and production...

  1. EnviroAtlas - Industrial Water Demand by 12-Digit HUC for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset includes industrial water demand attributes which provide insight into the amount of water currently used for manufacturing and production...

  2. The job demands-resources model of burnout.

    Science.gov (United States)

    Demerouti, E; Bakker, A B; Nachreiner, F; Schaufeli, W B

    2001-06-01

    The job demands-resources (JD-R) model proposes that working conditions can be categorized into 2 broad categories, job demands and job resources. that are differentially related to specific outcomes. A series of LISREL analyses using self-reports as well as observer ratings of the working conditions provided strong evidence for the JD-R model: Job demands are primarily related to the exhaustion component of burnout, whereas (lack of) job resources are primarily related to disengagement. Highly similar patterns were observed in each of 3 occupational groups: human services, industry, and transport (total N = 374). In addition, results confirmed the 2-factor structure (exhaustion and disengagement) of a new burnout instrument--the Oldenburg Burnout Inventory--and suggested that this structure is essentially invariant across occupational groups.

  3. Structural Breaks, Parameter Stability and Energy Demand Modeling in Nigeria

    Directory of Open Access Journals (Sweden)

    Olusegun A. Omisakin

    2012-08-01

    Full Text Available This paper extends previous studies in modeling and estimating energy demand functions for both gasoline and kerosene petroleum products for Nigeria from 1977 to 2008. In contrast to earlier studies on Nigeria and other developing countries, this study specifically tests for the possibility of structural breaks/regime shifts and parameter instability in the energy demand functions using more recent and robust techniques. In addition, the study considers an alternative model specification which primarily captures the price-income interaction effects on both gasoline and kerosene demand functions. While the conventional residual-based cointegration tests employed fail to identify any meaningful long run relationship in both functions, the Gregory-Hansen structural break cointegration approach confirms the cointegration relationships despite the breakpoints. Both functions are also found to be stable under the period studied.The elasticity estimates also follow the a priori expectation being inelastic both in the long- and short run for the two functions.

  4. Backcasting in freight transport demand modelling – chances and challenges

    OpenAIRE

    Lange, Peter; Huber, Stefan

    2015-01-01

    Freight transport demand models are important tools to support policy decision-making by enabling decision makers to evaluate transport policies and correlated effects. This significance puts high pressure on freight models regarding their accuracy. In order to ensure model accuracy there are different methods within the wide area of quality assurance that can be applied. Although backcasting is such a method it is, however, often neglected or implemented insufficiently. The paper presents ma...

  5. Future agricultural water demand under climate change: regional variability and uncertainties arising from CMIP5 climate projections

    Science.gov (United States)

    Schewe, J.; Wada, Y.; Wisser, D.

    2012-12-01

    The agricultural sector (irrigation and livestock) uses by far the largest amount of water among all sectors and is responsible for 70% of the global water withdrawal. At a country scale, irrigation water withdrawal often exceeds 90% of the total water used in many of emerging and developing countries such as India, Pakistan, Iran and Mexico, sustaining much of food production and the livelihood of millions of people. The livestock sector generally accounts less than 1-2% of total water withdrawal, yet exceeds 10-30% of the total water used in many of the African countries. Future agricultural water demand is, however, subject to large uncertainties due to anticipated climate change, i.e. warming temperature and changing precipitation variability, in various regions of the world. Here, we use a global hydrological and water resources model to quantify the impact of climate change on regional irrigation and livestock water demand, and the resulting uncertainties arsing from newly available CMIP5 climate projections obtained through Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP; http://www.isi-mip.org/). Irrigation water requirement per unit crop area is estimated by simulating daily soil water balance with crop-related data. Livestock water demand is calculated by combining livestock densities with their drinking water requirements that is a function of air temperature. The results of the ensemble mean show that global irrigation and livestock water demand increased by ~6% and ~12% by 2050 respectively primarily due to higher evaporative demand as a result of increased temperature. At a regional scale, agricultural water demand decreased over some parts of Europe (e.g., Italy, Germany) and Southeast Asia (e.g., the Philippines, Malaysia), but increased over South Asia, the U.S., the Middle East and Africa. However, the projections are highly uncertain over many parts of the world. The results of the ensemble projections in agricultural water demand

  6. Water and Climate Impacts on Power System Operations: The Importance of Cooling Systems and Demand Response Measures

    Energy Technology Data Exchange (ETDEWEB)

    Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhou, Ella [National Renewable Energy Lab. (NREL), Golden, CO (United States); O' Connell, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brinkman, Gregory [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miara, Ariel [City College of New York, NY (United States); Ibanez, Eduardo [GE Energy Connections, Atlanta, GA (United States); Hummon, Marissa [Tendril, Denver, CO (United States)

    2016-12-01

    The U.S. electricity sector is highly dependent upon water resources; changes in water temperatures and water availability can affect operational costs and the reliability of power systems. Despite the importance of water for power system operations, the effects of changes in water characteristics on multiple generators in a system are generally not modeled. Moreover, demand response measures, which can change the magnitude and timing of loads and can have beneficial impacts on power system operations, have not yet been evaluated in the context of water-related power vulnerabilities. This effort provides a first comprehensive vulnerability and cost analysis of water-related impacts on a modeled power system and the potential for demand response measures to address vulnerability and cost concerns. This study uniquely combines outputs and inputs of a water and power plant system model, production cost, model, and relative capacity value model to look at variations in cooling systems, policy-related thermal curtailments, and demand response measures to characterize costs and vulnerability for a test system. Twenty-five scenarios over the course of one year are considered: a baseline scenario as well as a suite of scenarios to evaluate six cooling system combinations, the inclusion or exclusion of policy-related thermal curtailments, and the inclusion or exclusion of demand response measures. A water and power plant system model is utilized to identify changes in power plant efficiencies resulting from ambient conditions, a production cost model operating at an hourly scale is used to calculate generation technology dispatch and costs, and a relative capacity value model is used to evaluate expected loss of carrying capacity for the test system.

  7. Program Demand Cost Model for Alaskan Schools. Eighth Edition.

    Science.gov (United States)

    Morgan, Michael; Mearig, Tim; Coffee, Nathan

    The State of Alaska Department of Education has created a handbook for establishing budgets for the following three types of construction projects: new schools or additions; renovations; and combined new work and renovations. The handbook supports a demand cost model computer program that includes detailed renovation cost data, itemized by…

  8. Engaging leadership in the job demands-resources model

    NARCIS (Netherlands)

    Schaufeli, Wilmar B.

    2015-01-01

    Purpose – The purpose of this paper is to integrate leadership into the job demands-resources (JD-R) model. Based on self-determination theory, it was argued that engaging leaders who inspire, strengthen, and connect their followers would reduce employee’s levels of burnout and increase their levels

  9. A stochastic inventory model with stock dependent demand items

    Directory of Open Access Journals (Sweden)

    Lakdere Benkherouf

    2001-01-01

    Full Text Available In this paper, we propose a new continuous time stochastic inventory model for stock dependent demand items. We then formulate the problem of finding the optimal replenishment schedule that minimizes the total expected discounted costs over an infinite horizon as a Quasi-Variational Inequality (QVI problem. The QVI is shown to have a unique solution under some conditions.

  10. Modified Normal Demand Distributions in (R,S)-Inventory Models

    NARCIS (Netherlands)

    Strijbosch, L.W.G.; Moors, J.J.A.

    2003-01-01

    To model demand, the normal distribution is by far the most popular; the disadvantage that it takes negative values is taken for granted.This paper proposes two modi.cations of the normal distribution, both taking non-negative values only.Safety factors and order-up-to-levels for the familiar (R,

  11. Engaging leadership in the job demands-resources model

    NARCIS (Netherlands)

    Schaufeli, Wilmar B.|info:eu-repo/dai/nl/073779563

    2015-01-01

    Purpose – The purpose of this paper is to integrate leadership into the job demands-resources (JD-R) model. Based on self-determination theory, it was argued that engaging leaders who inspire, strengthen, and connect their followers would reduce employee’s levels of burnout and increase their levels

  12. Dew as an Adaptation Measure to Meet Agricultural and Reforestation Water Demand in a Changing Climate

    Science.gov (United States)

    Tomaszkiewicz, Marlene; Abou Najm, Majdi; Alameddine, Ibrahim; El Fadel, Mutasem

    2014-05-01

    Dew harvesting, believed to be an ancient technique, has recently re-emerged as a viable and sustainable water resource. Nightly yields are relatively low, yet non-negligible, and dew events occur more frequently than rainfall promoting its effectiveness, particularly in arid and semi-arid regions. In this study, we demonstrate how dew can be harvested and subsequently used for small-scale irrigation to meet agricultural and reforestation water demand. Polyethylene dew harvesting systems were constructed and placed in the field. Dew was harvested as a result of the radiative cooling during the night, thus allowing dew formation under conditions of high humidity. Condensed dew formed upon the planar surface was collected by gravity. Water demand for selected crops and trees within a pilot study area (Lebanon) was estimated using a deficit irrigation model. Simulations of water demand requirements of various plants and surfaces were performed and compared to dew volumes to assess the ability of the system to meet all or in part the plant water demands across seasons. Data from the polyethylene low-cost dew condensers have shown that within the pilot study, average nightly dew yields were 0.1 L m-2 of condensing surface with a maximum yield of 0.4 L m-2. Dew events occurred generally more frequently than precipitation events, with an estimated 40% of nights producing dew condensate. This translates to 50 mm of equivalent rainfall on average (during dew nights), with a maximum of 200 mm in one night, if one assumes using drip irrigation over a seedling within a 20 cm2 area. Using a simple deficit irrigation model, it was demonstrated that crops such as the tomato plant, which typically has a growing season during the dry summer, can potentially be irrigated solely by dew, thus eliminating the need for traditional irrigation sources. Similarly, young tree seedlings, such as the cedar tree, can depend upon dew as a primary water resource. Moreover, based on similar

  13. Remote sensing and simulation modelling for on-demand irrigation systems management

    NARCIS (Netherlands)

    D'Urso, G.; Menenti, M.; Santini, A.

    1996-01-01

    This paper describes a procedure for monitoring and improving the performance of on-demand irrigation networks, based on the integration of remote sensing techniques and simulation modelling of water flow in each component of the system. In order to adequately reproduce the actual operation of an on

  14. Modeling base money demand and inflation for the Turkish economy

    OpenAIRE

    Levent, Korap

    2008-01-01

    In this paper, a reserve money demand model is tried to be constructed for the Turkish economy. Using contemporaneous multivariate co-integration methodology for the investigation period 1987Q1-2007Q3 of the quarterly observations, we find that the real income elasticity of money demand is highly greater than unity which means that there exists an ongoing monetization process with regard to the increases in the real income in the economy. The most important alternative cost against the real m...

  15. The relationship between irrigation water demand and drought in the Yellow River basin

    Science.gov (United States)

    Wang, Yu; Wang, Weihao; Peng, Shaoming; Jiang, Guiqin; Wu, Jian

    2016-10-01

    In order to organize water for drought resistance reasonably, we need to study the relationship between irrigation water demand and meteorological drought in quantitative way. We chose five typical irrigation districts including the Qingtongxia irrigation district, Yellow River irrigation districts of Inner Mongolia in the upper reaches of the Yellow River, the Fen river irrigation district and the Wei river irrigation district in the middle reaches of the Yellow River and the irrigation districts in the lower reaches of the Yellow River as research area. Based on the hydrology, meteorology, groundwater and crop parameters materials from 1956 to 2010 in the Yellow River basin, we selected reconnaissance drought index (RDI) to analyze occurrence and evolution regularity of drought in the five typical irrigation districts, and calculated the corresponding irrigation water demand by using crop water balance equation. The relationship of drought and irrigation water demand in each typical irrigation district was studied by using grey correlation analysis and relevant analysis method, and the quantitative relationship between irrigation water demand and RDI was established in each typical irrigation district. The results showed that the RDI can be applied to evaluate the meteorological drought in the typical irrigation districts of the Yellow River basin. There is significant correlation between the irrigation water demand and RDI, and the grey correlation degree and correlation coefficient increased with increasing crops available effective rainfall. The irrigation water demand of irrigation districts in the upstream, middle and downstream of the Yellow River basin presented different response degrees to drought. The irrigation water demand increased 105 million m3 with the drought increasing one grade (RDI decreasing 0.5) in the Qingtongxia irrigation district and Yellow River irrigation districts of Inner Mongolia. The irrigation water demand increased 219 million m3

  16. Evaluating the effects of granular and membrane filtrations on chlorine demand in drinking water

    Institute of Scientific and Technical Information of China (English)

    Veeriah Jegatheesan; Seung Hyun Kim; C. K. Joo; GAO Baoyu

    2009-01-01

    In this study, chlorine decay experiments were conducted for the raw water from Nakdong river that is treated by Chilseo Water Treatment Plant (CWTP) situated in Haman, Korea as well as the effluents from sand and granular activated carbon (GAC) filters of CWTP and fitted using a chlorine decay model. The model estimated the fast and slow reacting nitrogenous as well as organic/inorganic compounds that were present in the water. It was found that the chlorine demand due to fast and slow reacting (FRA and SRA) organic/inorganic substances was not reduced significantly by sand as well as GAC filters. However, the treated effluents from those filters contained FRA and SRA that are less reactive and had small reaction rate constants. For the effluents from microfiltration, ultrafiltration, and nanofiltration the chlorine demand due to FRA and SRA were further reduced but the reaction rate constants were larger compared to those of sand and GAC filter effluents. This has implications in the formation of disinfection by products (DBPs). If DBPs are assumed to form due to the interactions between chlorine and SRA, then it is possible that the DBP formation potential in the effluents from membrane filtrations could be higher than that in the effluents from granular media filters.

  17. Demand Management Based on Model Predictive Control Techniques

    Directory of Open Access Journals (Sweden)

    Yasser A. Davizón

    2014-01-01

    Full Text Available Demand management (DM is the process that helps companies to sell the right product to the right customer, at the right time, and for the right price. Therefore the challenge for any company is to determine how much to sell, at what price, and to which market segment while maximizing its profits. DM also helps managers efficiently allocate undifferentiated units of capacity to the available demand with the goal of maximizing revenue. This paper introduces control system approach to demand management with dynamic pricing (DP using the model predictive control (MPC technique. In addition, we present a proper dynamical system analogy based on active suspension and a stability analysis is provided via the Lyapunov direct method.

  18. Modelling energy demand in the Norwegian building stock

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, Igor

    2008-07-15

    Energy demand in the building stock in Norway represents about 40% of the final energy consumption, of which 22% goes to the residential sector and 18% to the service sector. In Norway there is a strong dependency on electricity for heating purposes, with electricity covering about 80% of the energy demand in buildings. The building sector can play an important role in the achievement of a more sustainable energy system. The work performed in the articles presented in this thesis investigates various aspects related to the energy demand in the building sector, both in singular cases and in the stock as a whole. The work performed in the first part of this thesis on development and survey of case studies provided background knowledge that was then used in the second part, on modelling the entire stock. In the first part, a literature survey of case studies showed that, in a life cycle perspective, the energy used in the operating phase of buildings is the single most important factor. Design of low-energy buildings is then beneficial and should be pursued, even though it implies a somewhat higher embodied energy. A case study was performed on a school building. First, a methodology using a Monte Carlo method in the calibration process was explored. Then, the calibrated model of the school was used to investigate measures for the achievement of high energy efficiency standard through renovation work. In the second part, a model was developed to study the energy demand in a scenario analysis. The results showed the robustness of policies that included conservation measures against the conflicting effects of the other policies. Adopting conservation measures on a large scale showed the potential to reduce both electricity and total energy demand from present day levels while the building stock keeps growing. The results also highlighted the inertia to change of the building stock, due to low activity levels compared to the stock size. It also became clear that a deeper

  19. Demand System Analysis of the South Korean Beef Market with the Free Trade Demand Model

    OpenAIRE

    Lee, Young-Jae; Kennedy, P. Lynn

    2008-01-01

    In this study a demand system analysis for beef in South Korea is constructed. A free trade demand system was used in which the economic welfare of market participants are maximized. Recognizing implicit discrimination about non-locally sourced beef products, this study deduces market demand equations with respect to consumer preference in order to identify the marginal effect of change consumer preference has on market demand.

  20. Water supply, demand, and quality indicators for assessing the spatial distribution of water resource vulnerability in the Columbia River Basin

    Science.gov (United States)

    Chang, Heejun; Jung, Il-Won; Strecker, Angela; Wise, Daniel; Lafrenz, Martin; Shandas, Vivek; ,; Yeakley, Alan; Pan, Yangdong; Johnson, Gunnar; Psaris, Mike

    2013-01-01

    We investigated water resource vulnerability in the US portion of the Columbia River basin (CRB) using multiple indicators representing water supply, water demand, and water quality. Based on the US county scale, spatial analysis was conducted using various biophysical and socio-economic indicators that control water vulnerability. Water supply vulnerability and water demand vulnerability exhibited a similar spatial clustering of hotspots in areas where agricultural lands and variability of precipitation were high but dam storage capacity was low. The hotspots of water quality vulnerability were clustered around the main stem of the Columbia River where major population and agricultural centres are located. This multiple equal weight indicator approach confirmed that different drivers were associated with different vulnerability maps in the sub-basins of the CRB. Water quality variables are more important than water supply and water demand variables in the Willamette River basin, whereas water supply and demand variables are more important than water quality variables in the Upper Snake and Upper Columbia River basins. This result suggests that current water resources management and practices drive much of the vulnerability within the study area. The analysis suggests the need for increased coordination of water management across multiple levels of water governance to reduce water resource vulnerability in the CRB and a potentially different weighting scheme that explicitly takes into account the input of various water stakeholders.

  1. Demand for water resources information: a conceptual framework and empirical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Osborn, C.T.

    1986-01-01

    This study develops and presents a conceptual framework that builds upon and extends the economics of information literature. Combining observations that emerge from a review of literature concerning organizational decision processes, this framework considers the nature of the demand and value for water resource information by individuals who participate in the decision making process found within public water management organizations. Based upon this conceptual framework, the paper reports the results of an empirical model relating decision participant use of the Water Resource Council's Second National Water Assessment and hypothetical expenditures on national assessment type information to personal and agency characteristics in two water basin management situations. Results of the investigations indicate that previous use of specific water information products and the level of expenditures made on certain types of water information are influenced by personal and organizational characteristics. Consequently, there can exist no correct information system and thus no correct data collection plan in the absence of knowledge concerning information value.

  2. Increasing demands on limited water resources: Consequences for two endangered plants in Amargosa Valley, USA.

    Science.gov (United States)

    Hasselquist, Niles J; Allen, Michael F

    2009-03-01

    Recent population expansion throughout the Southwest United States has created an unprecedented demand for already limited water resources, which may have severe consequences on the persistence of some species. Two such species are the federally protected Nitrophila mohavensis (Chenopodiaceae) and Grindelia fraxino-pratensis (Asteraceae) found in Amargosa Valley, one valley east of Death Valley, California. Because both species are federally protected, no plant material could be harvested for analysis. We therefore used a chamber system to collect transpired water for isotopic analysis. After a correction for isotopic enrichment during transpiration, δ(18)O values of plant xylem water were significantly different between N. mohavensis and G. fraxino-pratensis throughout the study. Using a multisource mixing model, we found that both N. mohavensis and G. fraxino-pratensis used soil moisture near the soil surface in early spring when surface water was present. However, during the dry summer months, G. fraxino-pratensis tracked soil moisture to deeper depths, whereas N. mohavensis continued to use soil moisture near the soil surface. These results indicate that pumping groundwater and subsequently lowering the water table may directly prevent G. fraxino-pratensis from accessing water, whereas these same conditions may indirectly affect N. mohavensis by reducing surface soil moisture and thus its ability to access water.

  3. Optimal expansion of a drinking water infrastructure system with respect to carbon footprint, cost-effectiveness and water demand.

    Science.gov (United States)

    Chang, Ni-Bin; Qi, Cheng; Yang, Y Jeffrey

    2012-11-15

    Urban water infrastructure expansion requires careful long-term planning to reduce the risk from climate change during periods of both economic boom and recession. As part of the adaptation management strategies, capacity expansion in concert with other management alternatives responding to the population dynamics, ecological conservation, and water management policies should be systematically examined to balance the water supply and demand temporally and spatially with different scales. To mitigate the climate change impact, this practical implementation often requires a multiobjective decision analysis that introduces economic efficiencies and carbon-footprint matrices simultaneously. The optimal expansion strategies for a typical water infrastructure system in South Florida demonstrate the essence of the new philosophy. Within our case study, the multiobjective modeling framework uniquely features an integrated evaluation of transboundary surface and groundwater resources and quantitatively assesses the interdependencies among drinking water supply, wastewater reuse, and irrigation water permit transfer as the management options expand throughout varying dimensions. With the aid of a multistage planning methodology over the partitioned time horizon, such a systems analysis has resulted in a full-scale screening and sequencing of multiple competing objectives across a suite of management strategies. These strategies that prioritize 20 options provide a possible expansion schedule over the next 20 years that improve water infrastructure resilience and at low life-cycle costs. The proposed method is transformative to other applications of similar water infrastructure systems elsewhere in the world.

  4. Not all job demands are equal: differentiating job hindrances and job challenges in the job demands-resources model

    OpenAIRE

    Van den Broeck, Anja; De Cuyper, Nele; De Witte, Hans; Vansteenkiste, Maarten

    2010-01-01

    This study aimed to integrate the differentiation between two types of job demands, as made in previous studies, in the Job-Demands Resources (JD-R) model. Specifically, this study aimed to examine empirically whether the differentiation between job hindrances and job challenges, next to the category of job resources, accounts for the unexpected positive relationships between particular types of job demands (e.g., workload) and employees' work engagement. Results of confirmatory factor analys...

  5. A volume flexible inventory model with trapezoidal demand under inflation

    Directory of Open Access Journals (Sweden)

    kapil mehrotra

    2014-02-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Abstract   This article experiment. Further, the effects of different parameters are analysed by performing sensitivity analyses on the optimal policy. explores an economic production quantity model (EPQ model for deteriorating items with time-dependent demand following trapezoidal pattern taking the volume flexibility into account. We have also considered the inflation and time value of money. The solution of the model aims at determining the optimal production run-time in order to maximize the profit. The model is also illustrated by means of numerical

  6. A volume flexible inventory model with trapezoidal demand under inflation

    Directory of Open Access Journals (Sweden)

    kapil mehrotra

    2014-02-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Abstract   This article experiment. Further, the effects of different parameters are analysed by performing sensitivity analyses on the optimal policy. explores an economic production quantity model (EPQ model for deteriorating items with time-dependent demand following trapezoidal pattern taking the volume flexibility into account. We have also considered the inflation and time value of money. The solution of the model aims at determining the optimal production run-time in order to maximize the profit. The model is also illustrated by means of numerical

  7. water demand prediction using artificial neural network for ...

    African Journals Online (AJOL)

    user

    2017-01-01

    Jan 1, 2017 ... estimate water quantity and to make decisions that can prevent water scarcity. Timely ... network (ANN) and support vector machine (SVM) have led to new ... out the statistical methodology of Design of Experiments. (DOE) was .... is to implement the mechanism and systems that can be employed to forecast ...

  8. Pan-European household and industrial water demand: regional relevant estimations

    Science.gov (United States)

    Bernhard, Jeroen; Reynaud, Arnaud; de Roo, Ad

    2016-04-01

    Sustainable water management is of high importance to provide adequate quality and quantity of water to European households, industries and agriculture. Especially since demographic, economic and climate changes are expected to increase competition for water between these sectors in the future. A shortage of water implies a reduction in welfare of households or damage to economic sectors. This socio-economic component should be incorporated into the decision-making process when developing water allocation schemes, requiring detailed water use information and cost/benefit functions. We now present the results of our study which is focused at providing regionally relevant pan-European water demand and cost-benefit estimations for the household and industry sector. We gathered consistent data on water consumption, water prices and other relevant variables at the highest spatial detail available from national statistical offices and other organizational bodies. This database provides the most detailed up to date picture of present water use and water prices across Europe. The use of homogeneous data allowed us to compare regions and analyze spatial patterns. We applied econometric methods to determine the main determinants of water demand and make a monetary valuation of water for both the domestic and industry sector. This monetary valuation is important to allow water allocation based on economic damage estimates. We also attempted to estimate how population growth, as well as socio-economic and climatic changes impact future water demand up to 2050 using a homogeneous method for all countries. European projections for the identified major drivers of water demand were used to simulate future conditions. Subsequently, water demand functions were applied to estimate future water use and potential economic damage caused by water shortages. We present our results while also providing some estimation of the uncertainty of our predictions.

  9. Evaporative demand and water requirements of the principal crops of the Guadalentin valley (SE Spain) in drought periods

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Toribio, M. I.; Garcia-Marin, R.; Conesa-Garcia, C.; Lopez-Bermudez, F.

    2010-07-01

    The drought periods that affect the province of Murcia, especially the Guadalentin Valley, are aggravated by an increase in evaporative demand. The aim of the present study was to characterize the increased water demand of woody and herbaceous crops during drought periods in the Guadalentin Valley, an agricultural zone with an excellent climate for specialty crops, which is of great economic importance for Murcia. After defining the drought periods of the last three decades in time and space by means of the standard index of rainfall drought (IESP), several methods were used to determine the reference evapotranspiration (ETo): the Penman-Monteith model (ASCE and FAO models for grass), the Hargreaves method (ETo-ASCE for alfalfa), and ETo using the FAO Radiation method. Finally, the crop water requirements for each to crop type and area of cultivation were estimated using monthly crop coefficients (K{sub c}) and the mean monthly evaporative demand values were obtained by the best fitting method. The increase in the evaporative demand reflected the increased water deficits that occur in the drought years, both in summer and winter (1.23 hm{sup 3} yr{sup -}1). Drought periods are also responsible for reducing the areas dedicated to horticultural crops, because of their high water demands and the additional costs involved, resulting an aggravated socioeconomic position and increased unemployment. (Author) 25 refs.

  10. Determination of Consumers’ Demand on Water Buffalo Products

    OpenAIRE

    AZABAĞAOĞLU, M. Ömer; HURMA, Harun

    2016-01-01

    Water Buffalo whose 96.4% population is present in Asia is breed for its meat, leather and labor.When compared to cow’s milk, water buffalo milk is preferred in dairy technology since it has highfeeding properties and contains less water, higher brix level, fat, protein, and lactose. Buffalo milk ismarketed to the consumers as cream, butter, yoghurt or milk by the producers and local dairies.Nowadays, these products that are available to consumers mainly in local markets can also be found ins...

  11. Management of Water Demand in Arab Countries Using GIS

    OpenAIRE

    Magdy Shayboub Ali Mahmoud; Samir Mahmoud Adam Abdalla

    2014-01-01

    The alarming increase in the scarcity of water in various parts of the world. Scarcity of water in the Arab countries is not a new phenomenon—although population growth and economic development exacerbate the scarcity. Therefore, it is useful to examine how the problem has been dealt with during millennia of experience in the Arab world. Water is a main issue in many countries especially in those Arab countries; it has focused a global attention on the need for a stronger and more appropriate...

  12. Modeling solute transport in distribution networks with variable demand and time step sizes.

    Energy Technology Data Exchange (ETDEWEB)

    Peyton, Chad E.; Bilisoly, Roger Lee; Buchberger, Steven G. (University of Cincinnati, Cincinnati, OH); McKenna, Sean Andrew; Yarrington, Lane

    2004-06-01

    The effect of variable demands at short time scales on the transport of a solute through a water distribution network has not previously been studied. We simulate flow and transport in a small water distribution network using EPANET to explore the effect of variable demand on solute transport across a range of hydraulic time step scales from 1 minute to 2 hours. We show that variable demands at short time scales can have the following effects: smoothing of a pulse of tracer injected into a distribution network and increasing the variability of both the transport pathway and transport timing through the network. Variable demands are simulated for these different time step sizes using a previously developed Poisson rectangular pulse (PRP) demand generator that considers demand at a node to be a combination of exponentially distributed arrival times with log-normally distributed intensities and durations. Solute is introduced at a tank and at three different network nodes and concentrations are modeled through the system using the Lagrangian transport scheme within EPANET. The transport equations within EPANET assume perfect mixing of the solute within a parcel of water and therefore physical dispersion cannot occur. However, variation in demands along the solute transport path contribute to both removal and distortion of the injected pulse. The model performance measures examined are the distribution of the Reynolds number, the variation in the center of mass of the solute across time, and the transport path and timing of the solute through the network. Variation in all three performance measures is greatest at the shortest time step sizes. As the scale of the time step increases, the variability in these performance measures decreases. The largest time steps produce results that are inconsistent with the results produced by the smaller time steps.

  13. Testing simulation and structural models with applications to energy demand

    Science.gov (United States)

    Wolff, Hendrik

    2007-12-01

    This dissertation deals with energy demand and consists of two parts. Part one proposes a unified econometric framework for modeling energy demand and examples illustrate the benefits of the technique by estimating the elasticity of substitution between energy and capital. Part two assesses the energy conservation policy of Daylight Saving Time and empirically tests the performance of electricity simulation. In particular, the chapter "Imposing Monotonicity and Curvature on Flexible Functional Forms" proposes an estimator for inference using structural models derived from economic theory. This is motivated by the fact that in many areas of economic analysis theory restricts the shape as well as other characteristics of functions used to represent economic constructs. Specific contributions are (a) to increase the computational speed and tractability of imposing regularity conditions, (b) to provide regularity preserving point estimates, (c) to avoid biases existent in previous applications, and (d) to illustrate the benefits of our approach via numerical simulation results. The chapter "Can We Close the Gap between the Empirical Model and Economic Theory" discusses the more fundamental question of whether the imposition of a particular theory to a dataset is justified. I propose a hypothesis test to examine whether the estimated empirical model is consistent with the assumed economic theory. Although the proposed methodology could be applied to a wide set of economic models, this is particularly relevant for estimating policy parameters that affect energy markets. This is demonstrated by estimating the Slutsky matrix and the elasticity of substitution between energy and capital, which are crucial parameters used in computable general equilibrium models analyzing energy demand and the impacts of environmental regulations. Using the Berndt and Wood dataset, I find that capital and energy are complements and that the data are significantly consistent with duality

  14. Effect of land area on average annual suburban water demand

    African Journals Online (AJOL)

    2013-10-02

    Oct 2, 2013 ... Department of Civil Engineering, Stellenbosch University, Private Bag X1, Matieland 7602, ... would ultimately include the roads, parks and public open ...... (1995) A strategy and master plan for water supply, storage and dis-.

  15. A community demand-driven approach toward sustainable water and sanitation infrastructure development.

    Science.gov (United States)

    Hubbard, Brian; Sarisky, John; Gelting, Richard; Baffigo, Virginia; Seminario, Raul; Centurion, Carlos

    2011-07-01

    In September 2001, Cooperative Assistance and Relief Everywhere, Peru Country Office (CARE Peru), obtained funding from the United States Agency for International Development (USAID) to implement community-supported, condominial water and sanitation interventions in Manuel Cardozo Dávila, a settlement in Iquitos, Peru. With technical support from the Centers for Disease Control and Prevention (CDC), CARE Peru's Urban Environmental Health Models (Modelos Urbanos de Salud Ambiental [MUSA]) project built on previous work from implementing the Protocol for Assessing Community Excellence in Environmental Health in this same community. The project led to the municipal water supply distribution system being extended 1.3 kilometers into the Southern zone of Iquitos, where it connected to the condominial water system. Altogether, 1030 households were connected to the water supply system after the installation of a condominial water and sewerage system in Cardozo. Diarrheal disease decreased by 37% for children less than 5 years of age from 2003 to 2004. This paper illustrates the strategy used by CARE Peru in conjunction with the Cardozo community to assure that the local demand for improved water and sanitation was met. Published by Elsevier GmbH.

  16. From hydrological regimes to water use regimes: influence of the type of habitat on drinking water demand dynamics in alpine tourist resorts.

    Science.gov (United States)

    Calianno, Martin

    2017-04-01

    In the last decades, integrated water resources management studies produced integrated models that focus mainly on the assessment of water resources and water stress in the future. In some cases, socioeconomic development results to cause more impacts on the evolution of water systems than climate (Reynard et al., 2014). There is thus a need to develop demand-side approaches in the observation and modeling of human-influenced hydrological systems (Grouillet et al., 2015). We define the notion of water use cycle to differentiate water volumes that are withdrawn from the hydrological system and that circulate through anthropic hydro-systems along various steps: withdrawals, distribution, demands, consumption, restitution (Calianno et al., submitted). To address the spatial distribution and the temporal dynamics of the water use cycle, we define the concepts of water use basins and water use regimes (Calianno et al., submitted). The assessment of the temporal variability of water demands is important at thin time steps in touristic areas, where water resource regimes and water demands are highly variable. This is the case for are alpine ski resorts, where the high touristic season (winter) takes place during the low flow period in nival and glacio-nival basins. In this work, a monitoring of drinking water demands was undergone, at high temporal resolution, on different types of buildings in the ski resort of Megève (France). A dataset was created, from which a typology of water demand regimes was extracted. The analysis of these temporal signatures highlighted the factors influencing the volumes and the dynamics of drinking water demand. The main factors are the type of habitat (single family, collective, house, apartment blocks), the presence of a garden or an infrastructure linked to high standing chalets (pool, spa), the proportion of permanent and temporary habitat, the presence of snow in the ski resort. Also, temporalities linked to weekends and weekly tourism

  17. The Job Demands-Resources Model: An Analysis of Additive and Joint Effects of Demands and Resources

    Science.gov (United States)

    Hu, Qiao; Schaufeli, Wilmar B.; Taris, Toon W.

    2011-01-01

    The present study investigated the additive, synergistic, and moderating effects of job demands and job resources on well-being (burnout and work engagement) and organizational outcomes, as specified by the Job Demands-Resources (JD-R) model. A survey was conducted among two Chinese samples: 625 blue collar workers and 761 health professionals. A…

  18. Fuzzy economic production quantity model with time dependent demand rate

    Directory of Open Access Journals (Sweden)

    Susanta Kumar Indrajitsingha

    2016-09-01

    Full Text Available Background: In this paper, an economic production quantity model is considered under a fuzzy environment. Both the demand cost and holding cost are considered using fuzzy pentagonal numbers. The Signed Distance Method is used to defuzzify the total cost function. Methods: The results obtained by these methods are compared with the help of a numerical example. Sensitivity analysis is also carried out to explore the effect of changes in the values of some of the system parameters. Results and conclusions: The fuzzy EPQ model with time dependent demand rate was presented together with the possible implementation. The behavior of changes in parameters was analyzed. The possible extension of the implementation of this method was presented.

  19. MODELLING CHALLENGES TO FORECAST URBAN GOODS DEMAND FOR RAIL

    Directory of Open Access Journals (Sweden)

    Antonio COMI

    2015-12-01

    Full Text Available This paper explores the new research challenges for forecasting urban goods demand by rail. In fact, the growing interest to find urban logistics solutions for improving city sustainability and liveability, mainly due to the reduction of urban road accessibility and environmental constraints, has pushed to explore solutions alternative to the road. Multimodal urban logistics, based on the use of railway, seem an interesting alternative solution, but it remained mainly at conceptual level. Few studies have explored the factors, that push actors to find competitive such a system with respect to the road, and modelling framework for forecasting the relative demand. Therefore, paper reviews the current literature, investigates the factors involved in choosing such a mode, and finally, recalls a recent modelling framework and hence proposes some advancements that allow to point out the rail transport alternative.

  20. Equilibrium Assignment Model with Uncertainties in Traffic Demands

    Directory of Open Access Journals (Sweden)

    Aiwu Kuang

    2013-01-01

    Full Text Available In this study, we present an equilibrium traffic assignment model considering uncertainties in traffic demands. The link and route travel time distributions are derived based on the assumption that OD traffic demand follows a log-normal distribution. We postulate that travelers can acquire the variability of route travel times from past experiences and factor such variability into their route choice considerations in the form of mean route travel time. Furthermore, all travelers want to minimize their mean route travel times. We formulate the assignment problem as a variational inequality, which can be solved by a route-based heuristic solution algorithm. Some numerical studies on a small test road network are carried out to validate the proposed model and algorithm, at the same time, some reasonable results are obtained.

  1. Model for Estimation Urban Transportation Supply-Demand Ratio

    Directory of Open Access Journals (Sweden)

    Chaoqun Wu

    2015-01-01

    Full Text Available The paper establishes an estimation model of urban transportation supply-demand ratio (TSDR to quantitatively describe the conditions of an urban transport system and to support a theoretical basis for transport policy-making. This TSDR estimation model is supported by the system dynamic principle and the VENSIM (an application that simulates the real system. It was accomplished by long-term observation of eight cities’ transport conditions and by analyzing the estimated results of TSDR from fifteen sets of refined data. The estimated results indicate that an urban TSDR can be classified into four grades representing four transport conditions: “scarce supply,” “short supply,” “supply-demand balance,” and “excess supply.” These results imply that transport policies or measures can be quantified to facilitate the process of ordering and screening them.

  2. Prediction model of change tendency of urban water resources demand and its application%城市水资源需求量变化趋势预测模型及应用

    Institute of Scientific and Technical Information of China (English)

    王春娟; 冯利华

    2012-01-01

    利用灰色关联分析,可挑选出与需水量关系较为紧密的影响因子,而利用前期的影响因子进行计算,可以使物元分析具有预测功能.讨论了物元分析的方法步骤及应用.结果表明:根据物元分析来预测未来义乌市需水量的变化趋势是较为理想的.%By the utilization of grey correlation analysis, the paper pick out impact factors in close relationship with water resources demand and use of previous impact factors to calculate, witch make matter element analysis possess forecast function. The paper discussed steps and applications of matter element analysis. The result showed that the forcast of future change tendency of water resources demand in Yiwu accordance with matter element analysis is relatively ideal .

  3. Global monthly water stress: II. Water demand and severity of water

    NARCIS (Netherlands)

    Wada, Y.; Beek, L.P.H. van; Viviroli, D.; Dürr, H.H.; Weingartner, R.; Bierkens, M.F.P.

    2011-01-01

    This paper assesses global water stress at a finer temporal scale compared to conventional assessments. To calculate time series of global water stress at a monthly time scale, global water availability, as obtained from simulations of monthly river discharge from the companion paper, is confronted

  4. Global monthly water stress: II. Water demand and severity of water

    NARCIS (Netherlands)

    Wada, Y.; Beek, L.P.H. van; Viviroli, D.; Dürr, H.H.; Weingartner, R.; Bierkens, M.F.P.

    2011-01-01

    This paper assesses global water stress at a finer temporal scale compared to conventional assessments. To calculate time series of global water stress at a monthly time scale, global water availability, as obtained from simulations of monthly river discharge from the companion paper, is confronted

  5. Deterministic and heuristic models of forecasting spare parts demand

    Directory of Open Access Journals (Sweden)

    Ivan S. Milojević

    2012-04-01

    Full Text Available Knowing the demand of spare parts is the basis for successful spare parts inventory management. Inventory management has two aspects. The first one is operational management: acting according to certain models and making decisions in specific situations which could not have been foreseen or have not been encompassed by models. The second aspect is optimization of the model parameters by means of inventory management. Supply items demand (asset demand is the expression of customers' needs in units in the desired time and it is one of the most important parameters in the inventory management. The basic task of the supply system is demand fulfillment. In practice, demand is expressed through requisition or request. Given the conditions in which inventory management is considered, demand can be: - deterministic or stochastic, - stationary or nonstationary, - continuous or discrete, - satisfied or unsatisfied. The application of the maintenance concept is determined by the technological level of development of the assets being maintained. For example, it is hard to imagine that the concept of self-maintenance can be applied to assets developed and put into use 50 or 60 years ago. Even less complex concepts cannot be applied to those vehicles that only have indicators of engine temperature - those that react only when the engine is overheated. This means that the maintenance concepts that can be applied are the traditional preventive maintenance and the corrective maintenance. In order to be applied in a real system, modeling and simulation methods require a completely regulated system and that is not the case with this spare parts supply system. Therefore, this method, which also enables the model development, cannot be applied. Deterministic models of forecasting are almost exclusively related to the concept of preventive maintenance. Maintenance procedures are planned in advance, in accordance with exploitation and time resources. Since the timing

  6. The water-food nexus and the role of demand management

    OpenAIRE

    Brears, Robert C.

    2016-01-01

    With the global population projected to reach 9 billion in 2050, demand for food is expected to increase by over 50% in 2030 and 70% in 2050 (UN-Water, 2013). Already agriculture is the largest user of water with irrigation accounting for nearly 70% of all freshwater withdrawals (UN-Water, 2016).

  7. Analytical optimization of demand management strategies across all urban water use sectors

    Science.gov (United States)

    Friedman, Kenneth; Heaney, James P.; Morales, Miguel; Palenchar, John

    2014-07-01

    An effective urban water demand management program can greatly influence both peak and average demand and therefore long-term water supply and infrastructure planning. Although a theoretical framework for evaluating residential indoor demand management has been well established, little has been done to evaluate other water use sectors such as residential irrigation in a compatible manner for integrating these results into an overall solution. This paper presents a systematic procedure to evaluate the optimal blend of single family residential irrigation demand management strategies to achieve a specified goal based on performance functions derived from parcel level tax assessor's data linked to customer level monthly water billing data. This framework is then generalized to apply to any urban water sector, as exponential functions can be fit to all resulting cumulative water savings functions. Two alternative formulations are presented: maximize net benefits, or minimize total costs subject to satisfying a target water savings. Explicit analytical solutions are presented for both formulations based on appropriate exponential best fits of performance functions. A direct result of this solution is the dual variable which represents the marginal cost of water saved at a specified target water savings goal. A case study of 16,303 single family irrigators in Gainesville Regional Utilities utilizing high quality tax assessor and monthly billing data along with parcel level GIS data provide an illustrative example of these techniques. Spatial clustering of targeted homes can be easily performed in GIS to identify priority demand management areas.

  8. Methodology to determine regional water demand for instream flow and its application in the Yellow River Basin

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yuan; YANG Zhi-feng; Wang Xi-qin

    2006-01-01

    In order to realistically reflect the difference between regional water demand for instream flow and river ecological water demand as well as to resolve the problem that water demand may be counted repeatedly, a concept of regional water demand for minimum instream flow have been developed. The concept was used in the process of determining river functions and calculating ecological water demand for a river. The Yellow River watershed was used to validate the calculation methodology for regional water demand. Calculation results indicate that there are significant differences in water demands among the different regions. The regionalwater demand at the downstream of the Yellow River is the largest about 14.893 × 109 m3/a. The regional water demand of upstream,Lanzhou-Hekou section is the smallest about -5.012×109 m3/a. The total ecological water demand of the Yellow River Basin is 23.06 × 109 m3/a, about the 39% of surface water resources of the Yellow River Basin. That means the maximum available surface water resources should not exceed 61% in the Yellow River Basin. The regional river ecological water demands at the Lower Section of the Yellow River and Longyangxia-Lanzhou Section exceed the surface water resources produced in its region and need to be supplemented from other regions through the water rational planning of watershed water resources. These results provides technical basis for rational plan of water resources of the Yellow River Basin.

  9. Distributed Generation Market Demand Model (dGen): Documentation

    Energy Technology Data Exchange (ETDEWEB)

    Sigrin, Benjamin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gleason, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Preus, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States); Baring-Gould, Ian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Margolis, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-02-01

    The Distributed Generation Market Demand model (dGen) is a geospatially rich, bottom-up, market-penetration model that simulates the potential adoption of distributed energy resources (DERs) for residential, commercial, and industrial entities in the continental United States through 2050. The National Renewable Energy Laboratory (NREL) developed dGen to analyze the key factors that will affect future market demand for distributed solar, wind, storage, and other DER technologies in the United States. The new model builds off, extends, and replaces NREL's SolarDS model (Denholm et al. 2009a), which simulates the market penetration of distributed PV only. Unlike the SolarDS model, dGen can model various DER technologies under one platform--it currently can simulate the adoption of distributed solar (the dSolar module) and distributed wind (the dWind module) and link with the ReEDS capacity expansion model (Appendix C). The underlying algorithms and datasets in dGen, which improve the representation of customer decision making as well as the spatial resolution of analyses (Figure ES-1), also are improvements over SolarDS.

  10. Demand Activated Manufacturing Architecture (DAMA) model for supply chain collaboration

    Energy Technology Data Exchange (ETDEWEB)

    CHAPMAN,LEON D.; PETERSEN,MARJORIE B.

    2000-03-13

    The Demand Activated Manufacturing Architecture (DAMA) project during the last five years of work with the U.S. Integrated Textile Complex (retail, apparel, textile, and fiber sectors) has developed an inter-enterprise architecture and collaborative model for supply chains. This model will enable improved collaborative business across any supply chain. The DAMA Model for Supply Chain Collaboration is a high-level model for collaboration to achieve Demand Activated Manufacturing. The five major elements of the architecture to support collaboration are (1) activity or process, (2) information, (3) application, (4) data, and (5) infrastructure. These five elements are tied to the application of the DAMA architecture to three phases of collaboration - prepare, pilot, and scale. There are six collaborative activities that may be employed in this model: (1) Develop Business Planning Agreements, (2) Define Products, (3) Forecast and Plan Capacity Commitments, (4) Schedule Product and Product Delivery, (5) Expedite Production and Delivery Exceptions, and (6) Populate Supply Chain Utility. The Supply Chain Utility is a set of applications implemented to support collaborative product definition, forecast visibility, planning, scheduling, and execution. The DAMA architecture and model will be presented along with the process for implementing this DAMA model.

  11. Optimization of Evaporative Demand Models for Seasonal Drought Forecasting

    Science.gov (United States)

    McEvoy, D.; Huntington, J. L.; Hobbins, M.

    2015-12-01

    Providing reliable seasonal drought forecasts continues to pose a major challenge for scientists, end-users, and the water resources and agricultural communities. Precipitation (Prcp) forecasts beyond weather time scales are largely unreliable, so exploring new avenues to improve seasonal drought prediction is necessary to move towards applications and decision-making based on seasonal forecasts. A recent study has shown that evaporative demand (E0) anomaly forecasts from the Climate Forecast System Version 2 (CFSv2) are consistently more skillful than Prcp anomaly forecasts during drought events over CONUS, and E0 drought forecasts may be particularly useful during the growing season in the farming belts of the central and Midwestern CONUS. For this recent study, we used CFSv2 reforecasts to assess the skill of E0 and of its individual drivers (temperature, humidity, wind speed, and solar radiation), using the American Society for Civil Engineers Standardized Reference Evapotranspiration (ET0) Equation. Moderate skill was found in ET0, temperature, and humidity, with lesser skill in solar radiation, and no skill in wind. Therefore, forecasts of E0 based on models with no wind or solar radiation inputs may prove to be more skillful than the ASCE ET0. For this presentation we evaluate CFSv2 E0 reforecasts (1982-2009) from three different E0 models: (1) ASCE ET0; (2) Hargreaves and Samani (ET-HS), which is estimated from maximum and minimum temperature alone; and (3) Valiantzas (ET-V), which is a modified version of the Penman method for use when wind speed data are not available (or of poor quality) and is driven only by temperature, humidity, and solar radiation. The University of Idaho's gridded meteorological data (METDATA) were used as observations to evaluate CFSv2 and also to determine if ET0, ET-HS, and ET-V identify similar historical drought periods. We focus specifically on CFSv2 lead times of one, two, and three months, and season one forecasts; which are

  12. Assessment of Sustainability of Urban Water Supply and Demand Management Options: A Comprehensive Approach

    OpenAIRE

    Kumudu Rathnayaka; Hector Malano; Meenakshi Arora

    2016-01-01

    A comprehensive evaluation framework that can assess a wide range of water supply and demand management policy options in terms of economic, social, environmental, risk-based, and functional performance is crucial to ascertain their level of sustainability. However, such a detailed, generic, and holistic policy evaluation framework is not found in the literature. This paper reviews studies to evaluate water supply and/or demand management options conducted during 2000–2016. Primarily, the pap...

  13. A Dynamic, Multivariate Sustainability Measure for Robust Analysis of Water Management under Climate and Demand Uncertainty in an Arid Environment

    Directory of Open Access Journals (Sweden)

    Christian Hunter

    2015-10-01

    Full Text Available Considering water resource scarcity and uncertainty in climate and demand futures, decision-makers require techniques for sustainability analysis in resource management. Through unclear definitions of “sustainability”, however, traditional indices for resource evaluation propose options of limited flexibility by adopting static climate and demand scenarios, limiting analysis variables to a particular water-use group and time. This work proposes a robust, multivariate, dynamic sustainability evaluation technique and corresponding performance indicator called Measure of Sustainability (MoS for resource management that is more adapted to withstand future parameter variation. The range of potential future climate and demand scenarios is simulated through a calibrated hydrological model of Copiapó, Chile, a case study example of an arid watershed under extreme natural and anthropogenic water stresses. Comparing MoS and cost rankings of proposed water management schemes, this paper determines that the traditional evaluation method not only underestimates future water deficits, but also espouses solutions without considering uncertainties in supply and demand. Given the uncertainty of the future and the dependence of resources upon climate and market trajectories, the MoS methodology proposes solutions that, while perhaps are not the most optimal, are robust to variations in future parameter values and are thus the best water management options in a stochastic natural world.

  14. Modeling Supermarket Refrigeration Systems for Demand-Side Management

    Directory of Open Access Journals (Sweden)

    Jakob Stoustrup

    2013-02-01

    Full Text Available Modeling of supermarket refrigeration systems for supervisory control in the smart grid is presented in this paper. A modular modeling approach is proposed in which each module is modeled and identified separately. The focus of the work is on estimating the power consumption of the system while estimating the cold reservoir temperatures as well. The models developed for each module as well as for the overall integrated system are validated by real data collected from a supermarket in Denmark. The results show that the model is able to estimate the actual electrical power consumption with a high fidelity. Moreover a simulation benchmark is introduced based on the produced model for demand-side management in smart grid. Finally, a potential application of the proposed benchmark in direct control of the power/energy consumption is presented by a simple simulation example.

  15. Demand and welfare effects in recreational travel models

    DEFF Research Database (Denmark)

    Hellström, Jörgen; Nordström, Leif Jonas

    for the households welfare loss. Approximating the welfare loss by the change in consumer surplus, accounting for the positive e¤ect from longer stays, imposes a lower bound on the households welfare loss. From a distributional point of view, the results reveal that the CO2 tax reform is regressive, in the sense......In this paper we present a non-linear demand system for households.joint choice of number of trips and days to spend at a destination. The approach, which facilitates welfare analysis of exogenous policy and price changes, is used empirically to study the e¤ects of an increased CO2 tax....... In the empirical study, a bivariate zero-in.ated Poisson lognormal regression model is introduced in order to accommodate the large number of zeroes in the sample. The welfare analysis reveals that the equivalent variation (EV) measure, for the count data demand system, can be seen as an upper bound...

  16. Adaptive Estimation of Heteroscedastic Money Demand Model of Pakistan

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam

    2007-07-01

    Full Text Available For the problem of estimation of Money demand model of Pakistan, money supply (M1 shows heteroscedasticity of the unknown form. For estimation of such model we compare two adaptive estimators with ordinary least squares estimator and show the attractive performance of the adaptive estimators, namely, nonparametric kernel estimator and nearest neighbour regression estimator. These comparisons are made on the basis standard errors of the estimated coefficients, standard error of regression, Akaike Information Criteria (AIC value, and the Durban-Watson statistic for autocorrelation. We further show that nearest neighbour regression estimator performs better when comparing with the other nonparametric kernel estimator.

  17. Accelerated shallow water modeling

    Science.gov (United States)

    Gandham, Rajesh; Medina, David; Warburton, Timothy

    2015-04-01

    ln this talk we will describe our ongoing developments in accelerated numerical methods for modeling tsunamis, and oceanic fluid flows using two dimensional shallow water model and/or three dimensional incompressible Navier Stokes model discretized with high order discontinuous Galerkin methods. High order discontinuous Galerkin methods can be computationally demanding, requiring extensive computational time to simulate real time events on traditional CPU architectures. However, recent advances in computing architectures and hardware aware algorithms make it possible to reduce simulation time and provide accurate predictions in a timely manner. Hence we tailor these algorithms to take advantage of single instruction multiple data (SIMD) architecture that is seen in modern many core compute devices such as GPUs. We will discuss our unified and extensive many-core programming library OCCA that alleviates the need to completely re-design the solvers to keep up with constantly evolving parallel programming models and hardware architectures. We will present performance results for the flow simulations demonstrating performance leveraging multiple different multi-threading APIs on GPU and CPU targets.

  18. Predictive Control Applied to a Solar Desalination Plant Connected to a Greenhouse with Daily Variation of Irrigation Water Demand

    Directory of Open Access Journals (Sweden)

    Lidia Roca

    2016-03-01

    Full Text Available The water deficit in the Mediterranean area is a known matter severely affecting agriculture. One way to avoid the aquifers’ exploitation is to supply water to crops by using thermal desalination processes. Moreover, in order to guarantee long-term sustainability, the required thermal energy for the desalination process can be provided by solar energy. This paper shows simulations for a case study in which a solar multi-effect distillation plant produces water for irrigation purposes. Detailed models of the involved systems are the base of a predictive controller to operate the desalination plant and fulfil the water demanded by the crops.

  19. DeMand: A tool for evaluating and comparing device-level demand and supply forecast models

    DEFF Research Database (Denmark)

    Neupane, Bijay; Siksnys, Laurynas; Pedersen, Torben Bach

    2016-01-01

    datasets, forecast models, features, and errors measures, thus semi-automating most of the steps of the forecast model selection and validation process. This paper presents the architecture and data model of the DeMand system; and provides a use-case example on how one particular forecast model...

  20. A Work Psychological Model that Works: Expanding the Job Demands-Resources Model

    NARCIS (Netherlands)

    Xanthopoulou, D.

    2007-01-01

    The main purpose of the current thesis was to test and expand the recently developed Job Demands-Resources (JD-R) model. The advantage of this model is that it recognizes the uniqueness of each work environment, which has its own specific job demands and job resources. According to the JD-R model, j

  1. A Work Psychological Model that Works: Expanding the Job Demands-Resources Model

    NARCIS (Netherlands)

    Xanthopoulou, D.

    2007-01-01

    The main purpose of the current thesis was to test and expand the recently developed Job Demands-Resources (JD-R) model. The advantage of this model is that it recognizes the uniqueness of each work environment, which has its own specific job demands and job resources. According to the JD-R model,

  2. Qunatifying the relative uncertainties of climate change and water demand projections to understand risk and increase resilience in water supply planning

    Science.gov (United States)

    Chang, S. J.; Graham, W. D.; Geurink, J. S.

    2016-12-01

    Climate change can change the magnitude and temporal characteristics of hydrologic responses which could impact the risk and resilience for public water supply facilities. Sustainable water resource planning requires reliable projections of potential future spatiotemporal changes in the regional hydrologic responses. Public water suppliers need to improve understanding of hydrologic response uncertainties associated with the choice of General Circulation Model (GCM), reference evapotranspiration (ET0) estimation method, and future water demands estimates to understand risk and increase resilience through adaptive management strategies. The objective of this study is to quantify uncertainties for hydrologic responses in west-central Florida associated with GCM selection, ET0 estimation method, and future water demand scenarios. Nine GCMs, eight ET0 estimation methods and water demand scenarios were used to develop inputs to the calibrated Integrated Northern Tampa Bay (INTB) model which was used to simulate hydrologic responses for 30 years for each of 520 simulation scenarios. INTB model simulated streamflow and groundwater levels for all simulation scenarios were used to assess future risks for the public water supply facilities of Tampa Bay Water.

  3. Modeling Gasoline Demand with Structural Breaks: New Evidence from Nigeria

    Directory of Open Access Journals (Sweden)

    Olusegun Akin Omisakin

    2012-01-01

    Full Text Available This paper extends previous studies in modeling and estimating demand for gasoline for Nigeria from 1977 to 2008. The ingenious attempt of this study, contrast to earlier studies on Nigeria and other developing countries, lies in its assumption of structural breaks in the long run relationship among the variables employed. The study tests for the possibility of structural breaks/regime shifts and parameter instability in the gasoline demand function in Nigeria using more recent and robust techniques. While the conventional residual-based cointegration tests employed fail to identify any meaningful long-run relationship in the gasoline function, the Gregory-Hansen structural break cointegration approach confirms the cointegration relationships despite the breakpoints. The elasticity estimates also follow the a priori expectations being inelastic both in the long- and short-run for both price and income. Having identified plausible breaks in the systems, the test does suggest that a structural break in the cointegration vector is important and needs to be taken care of in the specification of gasoline demand functions in Nigeria. It is envisaged, therefore, that substantial policy lessons would be drawn from the findings of this study especially in the current phase of energy industry deregulation in Nigeria.

  4. Multikanban model for disassembly line with demand fluctuation

    Science.gov (United States)

    Udomsawat, Gun; Gupta, Surendra M.; Al-Turki, Yousef A. Y.

    2004-02-01

    In recent years, the continuous growth in consumer waste and dwindling natural resources has seriously threatened the environment. Realizing this, several countries have passed regulations that force manufacturers not only to manufacture environmentally conscious products, but also to take back their used products from consumers so that the components and materials recovered from the products may be reused and/or recycled. Disassembly plays an important role in product recovery. A disassembly line is perhaps the most suitable setting for disassembly of products in large quantities. Because a disassembly line has a tendency to generate excessive inventory, employing a kanban system can reduce the inventory level and let the system run more efficiently. A disassembly line is quite different from an assembly line. For example, not only can the demand arrive at the last station, it can also arrive at any of the other stations in the system. The demand for a component on the disassembly line could fluctuate widely. In fact, there are many other complicating matters that need to be considered to implement the concept of kanbans in such an environment. In this paper, we discuss the complications that are unique to a disassembly line. We discuss the complications in utilizing the conventional production control mechanisms in a disassembly line setting. We then show how to overcome them by implementing kanbans in a disassembly line setting with demand fluctuation and introduce the concept of multi-kanban mechanism. We demonstrate its effectiveness using a simulation model. An example is presented to illustrate the concept.

  5. A case study of ethanol water demand during industrial phase in Brazil

    Science.gov (United States)

    Hernandes, T.; Scarpare, F. V.; Guarenghi, M.; Pereira, T.; Galdos, M. V.

    2012-12-01

    Thayse A. D. Hernandesb, Fábio V. Scarparea, Marjorie M. Guarenghib, Tássia P. Pereirab, Marcelo V. Galdosa a Laboratório Nacional de Ciência e Tecnologia do Bioetanol - CTBE/CNPEM, Caixa Postal 6170, 13083-970 Campinas, São Paulo, Brazil, E-mail: fabio.scarpare@bioetanol.org.br b Faculdade de Engenharia Mecânica, Unicamp, Cidade Universitária "Zeferino Vaz", CEP 13083-860, Campinas, SP, Brazil In São Paulo State, the water resources have being used by sugarcane industry responsibly, through high reuse rates that may reach 95% during industrial process. The average amount of catchment water stays around 2.0 m3 Mg 1 of industrial sugarcane stalk. However, in some modern mills which use higher technical level of closed water circuit, the standard goal for sugarcane industry, 1.0 m3 Mg 1 can be reached. In some regions where the uptake water for industrial segment is high as in São Paulo State, water use assessment is desired for sustainable ethanol production. Thus, two regions in São Paulo State with two plants each were taken as a case study aiming to assess ethanol water demand during the industrial phase. Araraquara was the first study region where the water demand was classified as in critical condition in 2010 according to the Water and Electrical Energy Department of São Paulo State (DAEE). The industrial activities were responsible for 50% of the water catchment. Araçatuba was the second study region where water demand was classified as being of concern (DAEE) due to high percentage of catchment water for industrial activities, around 90%. Data regarding the amount of millable cane processed, days of the plant operation, ratio of cane used for ethanol production in 2010/2011 season were used for direct water demand estimation considering different water catchment scenarios of 2.0, 1.0 and 0.7 (technological development prediction scenario) m3 Mg-1 of millable cane. For indirect water demand estimation, data regarding installed capacity of each

  6. Balancing supply and demand of fresh water under increasing drought and salinisation in the Netherlands

    OpenAIRE

    Jeuken, A.; Beek, E. van; Duinen, R.; Veen, van der, M.Q.; Bocalon, A.; Delsman, J.; Pauw, P.S.; Oude Essink, G.; Zee, van der, KG Kristoffer; Stofberg, S.F.; Zuurbier, K.; Stuyfzand, P.; Appelman, W.; Creusen, R.; Paalman, M.

    2012-01-01

    The latest climate impact assessments show that climate change will cause an increasing mismatch between demand and supply of fresh water in many densely populated deltas around the world. Recent studies for the Netherlands show that the current water supply strategy is not climate proof in the long-run. Therefore, a future ‘climate proof’ fresh water supply is national priority on the Dutch water policy agenda

  7. A long-distance travel demand model for Europe

    DEFF Research Database (Denmark)

    Rich, Jeppe; Mabit, Stefan Lindhard

    2012-01-01

    of different level-of-service variables. The results suggest that the perception of both travel time and cost varies with journey length in a non-linear way. For car drivers and car passengers, elasticities increase with the length of the journey, whereas the opposite is true for rail, bus, and air passengers......In Europe, approximately 50% of all passenger kilometres come from trips beyond 100 km according to matrices developed in the TRANSTOOLS project. This accounts for an even larger share of CO2 emissions due to a higher modal share of air transport. Therefore long-distance trips are increasingly...... relevant from a political and environmental point of view. The paper presents the first tour-based long-distance travel demand model for passenger trips in and between 42 European countries. The model is part of a new European transport model developed for the European Commission, the TRANSTOOLS II model...

  8. Ground water security and drought in Africa: linking availability, access, and demand.

    Science.gov (United States)

    Calow, Roger C; Macdonald, Alan M; Nicol, Alan L; Robins, Nick S

    2010-01-01

    Drought in Africa has been extensively researched, particularly from meteorological, agricultural, and food security perspectives. However, the impact of drought on water security, particularly ground water dependent rural water supplies, has received much less attention. Policy responses have concentrated on food needs, and it has often been difficult to mobilize resources for water interventions, despite evidence that access to safe water is a serious and interrelated concern. Studies carried out in Ghana, Malawi, South Africa, and Ethiopia highlight how rural livelihoods are affected by seasonal stress and longer-term drought. Declining access to food and water is a common and interrelated problem. Although ground water plays a vital role in buffering the effects of rainfall variability, water shortages and difficulties in accessing water that is available can affect domestic and productive water uses, with knock-on effects on food consumption and production. Total depletion of available ground water resources is rarely the main concern. A more common scenario is a spiral of water insecurity as shallow water sources fail, additional demands are put on remaining sources, and mechanical failures increase. These problems can be planned for within normal development programs. Water security mapping can help identify vulnerable areas, and changes to monitoring systems can ensure early detection of problems. Above all, increasing the coverage of ground water-based rural water supplies, and ensuring that the design and siting of water points is informed by an understanding of hydrogeological conditions and user demand, can significantly increase the resilience of rural communities to climate variability.

  9. Modelling Demand Side Kelas Menengah Pemuda Kota Surabaya

    OpenAIRE

    Achmadi Achmadi; Gigih Prihantono

    2014-01-01

    Middle class is an interesting topic in social studies to do a research. Based on Mckenzie, there are currently 45 million people in Indonesia can be categorized as middle class, and in 2030 will reach 135 million people. The middle class is the biggest support of drive economic growth from the demand side. This study aims to perform a simple modeling of middle-class’s cuncumption behavior, which study middle-class subculture in the city of Surabaya. This study uses an econometric tool called...

  10. Sugar demand of ripening grape berries leads to recycling of surplus phloem water via the xylem.

    Science.gov (United States)

    Keller, Markus; Zhang, Yun; Shrestha, Pradeep M; Biondi, Marco; Bondada, Bhaskar R

    2015-06-01

    We tested the common assumption that fleshy fruits become dependent on phloem water supply because xylem inflow declines at the onset of ripening. Using two distinct grape genotypes exposed to drought stress, we found that a sink-driven rise in phloem inflow at the beginning of ripening was sufficient to reverse drought-induced berry shrinkage. Rewatering accelerated berry growth and sugar accumulation concurrently with leaf photosynthetic recovery. Interrupting phloem flow through the peduncle prevented the increase in berry growth after rewatering, but interrupting xylem flow did not. Nevertheless, xylem flow in ripening berries, but not berry size, remained responsive to root or shoot pressurization. A mass balance analysis on ripening berries sampled in the field suggested that phloem water inflow may exceed growth and transpiration water demands. Collecting apoplastic sap from ripening berries showed that osmotic pressure increased at distinct rates in berry vacuoles and apoplast. Our results indicate that the decrease in xylem inflow at the onset of ripening may be a consequence of the sink-driven increase in phloem inflow. We propose a conceptual model in which surplus phloem water bypasses the fruit cells and partly evaporates from the berry surface and partly moves apoplastically to the xylem for outflow. © 2014 John Wiley & Sons Ltd.

  11. Water demand for ecosystem protection in rivers with hyper-concentrated sediment-laden flow

    Institute of Scientific and Technical Information of China (English)

    LUO Huaming; LI Tianhong; NI Jinren; WANG Yudong

    2004-01-01

    Sediment transport is one of the main concerns in a river system with hyper-concentrated flows. Therefore, the water use for sediment transport must be considered in study on the water demand for river ecosystem. The conventional methods for calculating the Minimum Water Demand for River Ecosystem (MWDRE) are not appropriate for rivers with high sediment concentration. This paper studied the MWDRE in wet season, dry season and the whole year under different water-and-sediment conditions in the Lower Yellow River, which is regarded as a typical river with sediment-laden flows. The characteristics of MWDRE in the river are analyzed. Firstly,the water demand for sediment transport (WDST) is much larger than the demands for other riverine functions, the WDST accounts for the absolute majority of the MWDRE.Secondly, in wet season when the WDST is satisfied, not only most of the annual incoming sediment can be transported downstream, but also the water demands for other river functions can be satisfied automatically, so that the MWDRE in wet season is identical to the WDST. Thirdly, in dry season, when the WDST is satisfied, the water demands for other river functions can also be satisfied, but the low sediment transport efficiency results in significant waste of water resources. According to these characteristics and aiming at decreasing sediment deposition in the riverbed and improving the utilization efficiency of water resources, hydrological engineering works can be used to regulate or control flow and sediment so that the sediment incoming in dry season can be accumulated and be transported downstream intensively and thus efficiently in wet season.

  12. Sectoral Vulnerabilities to Changing Water Resources: Current and Future Tradeoffs between Supply and Demand in the Conterminous U.S

    Science.gov (United States)

    Meldrum, J.; Averyt, K.; Caldwell, P.; Sun, G.; Huber-lee, A. T.; McNulty, S.

    2012-12-01

    Assessing the sustainability of human activities depends, in part, on the availability of water supplies to meet the demands of those activities. Thermoelectric cooling, agriculture, and municipal uses all compete for water supplies, but each sector differs in its characteristic ratio of water consumption versus withdrawals. This creates different implications for contributing to water supply stress and, conversely, vulnerabilities within each sector to changing water supplies. In this study, we use two measures of water stress, relating to water withdrawals and to water consumption, and calculate the role of each of these three sectors in contributing to the two different measures. We estimate water stress with an enhanced version of the Water Supply Stress Index (WaSSI), calculating the ratio of water demand to water supply at the 8-digit Hydrologic Unit Code (HUC) scale (Sun et al. 2008, 2011; Caldwell et al. 2011). Current water supplies are based on an integrated water balance and flow routing model of the conterminous United States, which accounts for surface water supply, groundwater supply, and major return flows. Future supplies are based on simulated regional changes in streamflow in 2050 from an ensemble of 12 climate models (Milly et al. 2005). We estimate water demands separately for agriculture, municipal uses, and thermoelectric cooling, with the first two based on Kenny et al. (2005) and the last on the approach of Averyt et al. (2011). We find substantial regional variation not only in the overall WaSSI for withdrawals and consumption but also in contribution of the three water use sectors to that total. Results suggest that the relative vulnerabilities of different sectors of human activity to water supply stress vary spatially and that policies for alleviating that stress must consider the specific, regional context of the tradeoffs between competing water demands. Ref's: Averyt, K., Fisher, J., Huber-Lee, A., Lewis, A., Macknick, J., Madden, N

  13. Current and projected water demand and water availability estimates under climate change scenarios in the Weyib River basin in Bale mountainous area of Southeastern Ethiopia

    Science.gov (United States)

    Serur, Abdulkerim Bedewi; Sarma, Arup Kumar

    2017-07-01

    This study intended to estimate the spatial and temporal variation of current and projected water demand and water availability under climate change scenarios in Weyib River basin, Bale mountainous area of Southeastern Ethiopia. Future downscaled climate variables from three Earth System Models under the three RCP emission scenarios were inputted into ArcSWAT hydrological model to simulate different components of water resources of a basin whereas current and projected human and livestock population of the basin is considered to estimate the total annual water demand for various purposes. Results revealed that the current total annual water demand of the basin is found to be about 289 Mm3, and this has to increase by 83.47% after 15 years, 200.67% after 45 years, and 328.78% after 75 years by the 2020s, 2050s, and 2080s, respectively, from base period water demand mainly due to very rapid increasing population (40.81, 130.80, and 229.12% by the 2020s, 2050s, and 2080s, respectively) and climatic variability. The future average annual total water availability in the basin is observed to be increased by ranging from 15.04 to 21.61, 20.08 to 23.34, and 16.21 to 39.53% by the 2020s, 2050s, and 2080s time slice, respectively, from base period available water resources (2333.39 Mm3). The current water availability per capita per year of the basin is about 3112.23 m3 and tends to decline ranging from 11.78 to 17.49, 46.02 to 47.45, and 57.18 to 64.34% by the 2020s, 2050s, and 2080s, respectively, from base period per capita per year water availability. This indicated that there might be possibility to fall the basin under water stress condition in the long term.

  14. An Econometric Model of Healthcare Demand With Nonlinear Pricing.

    Science.gov (United States)

    Kunz, Johannes S; Winkelmann, Rainer

    2016-04-04

    From 2004 to 2012, the German social health insurance levied a co-payment for the first doctor visit in a calendar quarter. We develop a new model for estimating the effect of such a co-payment on the individual number of visits per quarter. The model combines a one-time increase in the otherwise constant hazard rate determining the timing of doctor visits with a difference-in-differences strategy to identify the reform effect. An extended version of the model accounts for a mismatch between reporting period and calendar quarter. Using data from the German Socio-Economic Panel, we do not find an effect of the co-payment on demand for doctor visits. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Balancing supply and demand of fresh water under increasing drought and salinisation in the Netherlands

    NARCIS (Netherlands)

    Jeuken, A.; Beek, E.; Duinen, R.; Veen, van der A.; Bocalon, A.; Delsman, J.; Pauw, P.S.; Oude Essink, G.; Zee, van der S.E.A.T.M.; Stofberg, S.F.; Zuurbier, K.; Stuyfzand, P.; Appelman, W.; Creusen, R.; Paalman, M.; Katschnig, D.; Rozema, J.; Mens, M.; Kwakkel, J.; Thissen, W.; Veraart, J.A.; Tolk, L.; Vries, de A.

    2012-01-01

    The latest climate impact assessments show that climate change will cause an increasing mismatch between demand and supply of fresh water in many densely populated deltas around the world. Recent studies for the Netherlands show that the current water supply strategy is not climate proof in the long

  16. Look Who's Talking. Explaining Water-Related Information Sharing and Demand for Action Among Ugandan Villagers

    Science.gov (United States)

    Holvoet, Nathalie; Dewachter, Sara; Molenaers, Nadia

    2016-11-01

    Many national water policies propagate community-based participatory approaches to overcome weaknesses in supply-driven rural water provision, operation, and maintenance. Citizen involvement is thought to stimulate bottom-up accountability and broaden the information base, which may enrich design and implementation processes and foster improved water accessibility and sustainability. Practices on the ground, however, are embedded in socio-political realities which mediate possible beneficial effects of participatory approaches. This paper builds on full social network data collected in a Ugandan village to study the social and political reality of two distinct levels of participation, i.e. local information sharing among citizens and a more active appeal to fellow citizens to improve water services. We use Logistic Regression Quadratic Assignment Procedure to explore what type of actor and network traits influence information sharing and whether the same factors are in play in the demand for action to remedy water-related problems. Whereas social aspects (social support relations) and homophily (using the same water source, the same gender) play an important role in information sharing, it is the educational level, in particular, of the villager who is called upon that is important when villagers demand action. Our findings also demonstrate that those most in need of safe water do not mobilize their information sharing ties to demand for action. This indicates that building local water policies and practice exclusively on locally existing demand for action may fail to capture the needs of the most deprived citizens.

  17. Tourism and water use: Supply, demand, and security. An international review

    NARCIS (Netherlands)

    Gössling, S.; Peeters, P.M.; Hall, C.M.; Ceron, J.P.; Dubois, G.; Lehmann, L.V.; Scott, D.

    2012-01-01

    This article reviews direct freshwater consumption in tourism from both quantitative and qualitative viewpoints to assess the current water demand of the tourism sector and to identify current and future management challenges. The article concludes that even though tourism increases global water con

  18. Determination of Biochemical Oxygen Demand of Area Waters: A Bioassay Procedure for Environmental Monitoring

    Science.gov (United States)

    Riehl, Matthew

    2012-01-01

    A graphical method for determining the 5-day biochemical oxygen demand (BOD5) for a body of water is described. In this bioassay, students collect a sample of water from a designated site, transport it to the laboratory, and evaluate the amount of oxygen consumed by naturally occurring bacteria during a 5-day incubation period. An accuracy check,…

  19. Tourism and water use: Supply, demand, and security. An international review

    NARCIS (Netherlands)

    Gössling, S.; Peeters, P.M.; Hall, C.M.; Ceron, J.P.; Dubois, G.; Lehmann, L.V.; Scott, D.

    2012-01-01

    This article reviews direct freshwater consumption in tourism from both quantitative and qualitative viewpoints to assess the current water demand of the tourism sector and to identify current and future management challenges. The article concludes that even though tourism increases global water

  20. Determination of Biochemical Oxygen Demand of Area Waters: A Bioassay Procedure for Environmental Monitoring

    Science.gov (United States)

    Riehl, Matthew

    2012-01-01

    A graphical method for determining the 5-day biochemical oxygen demand (BOD5) for a body of water is described. In this bioassay, students collect a sample of water from a designated site, transport it to the laboratory, and evaluate the amount of oxygen consumed by naturally occurring bacteria during a 5-day incubation period. An accuracy check,…

  1. Evaluation of water demand and supply in the south of Iraq

    NARCIS (Netherlands)

    Al-Furaiji, M.H.O.; Karim, U.F.A.; Augustijn, D.C.M.; Waisi, B.I.H.; Hulscher, S.J.M.H.

    2016-01-01

    This paper presents results from the first study that focuses on water resources availability and demand for different purposes in the four oil-rich provinces of southern Iraq. The region accounts for 23% of the surface area and 18% of the country's population, but holds 88% of its oil. A water shor

  2. The study of interrelationship between raw water quality parameters, chlorine demand and the formation of disinfection by-products

    Science.gov (United States)

    Abdullah, Md. Pauzi; Yee, Lim Fang; Ata, Sadia; Abdullah, Abass; Ishak, Basar; Abidin, Khairul Nidzham Zainal

    Disinfection is the most crucial process in the treatment of drinking water supply and is the final barrier against bacteriological impurities in drinking water. Chlorine is the primary disinfectant used in the drinking water treatment process throughout Malaysia. However, the occurrence of various disinfection by-products such as trihalomethanes (THM) and haloacetic acids created a major issue on the potential health hazards which may pose adverse health effects in both human and animals. To simulate real water treatment conditions and to represent the conditions inherent in a tropical country, this study was performed at an urbanized water treatment plant with a daily production of about 549,000 m 3 of treated water. The purpose of this work is to examine the relationship between the water quality parameters in the raw water with chlorine demand and the formation of disinfection by-products. This study also investigated the possibility of the statistical model applications for the prediction of chlorine demand and the THM formation. Two models were developed to estimate the chlorine demand and the THM formation. For the statistical evaluation, correlation and simple linear regression analysis were conducted using SPSS. The results of Kolmogorov-Smirnov test for the estimation of goodness-of-fit of the dependent variables of the models to the normal distribution showed that all the dependent variables followed the normal distribution at significance level of 0.05. Good linear correlations were observed between the independent parameters and formation of THM and the chlorine demand. This study also revealed that ammonia and the specific ultraviolet absorbent (SUVA) were the function of chlorine consumption in the treatment process. Chlorine dosage and SUVA increase the yield of THM. Chlorine demand and THM formation was moderately sensitive, but significant to the pH. The level of significance ( α) for the statistical tests and the inclusion of a variable in the

  3. The effects of climate change on the demand for municipal water for residential landscaping in Southern Nevada

    Science.gov (United States)

    Tchigriaeva, E.; Lott, C.; Rollins, K.

    2013-12-01

    We analyze urban residential water demand for Southern Nevada as a part of the Nevada Infrastructure for Climate Change Science, Education, and Outreach project. The Nevada Climate Change project is a statewide interdisciplinary program which has launched joint research, education, and outreach on the effects of regional climate change on ecosystem services in Nevada with a particular focus on water resources. We estimate a random effect multiple regression model of urban residential water demand in order to better understand how residential water use is impacted by weather conditions and landscape characteristics and ultimately to inform predictions of urban water demand. The project develops a methodology of unification for several datasets from various sources including the Las Vegas Valley Water District (LVVWD), the Southern Nevada Water Authority (SNWA), Clark County Assessor, and the National Climatic Data Center (NCDC) resulting in a sample of 3,671,983 observations for 62,237 households with uninterrupted water use history for Las Vegas urban residents for the period from February 2007 to December 2011. The presented results (i) are significantly robust and in accordance with the economics theories, (ii) support basic empirical knowledge of weather and surface influence on water outdoor consumption, (iii) suggest quantitative measurements for predicting future water use due to climate/temperature changes as well as landscape redesign practices, and (iv) provide quantitative evaluation of the effectiveness of the existing water conservation programs by the Southern Nevada Water Authority (SNWA). The further study of conservation programs and analysis of interactions between surfaces and weather using the developed approach looks promising.

  4. Optimal locations of monitoring stations in water distribution systems under multiple demand patterns: a flaw of demand coverage method and modification

    Institute of Scientific and Technical Information of China (English)

    Shuming LIU; Wenjun LIU; Jinduan CHEN; Qi WANG

    2012-01-01

    A flaw of demand coverage method in solving optimal monitoring stations problem under multiple demand patterns was identified in this paper. In the demand coverage method, the demand coverage of each set of monitoring stations is calculated by accumulating their demand coverage under each demand pattern, and the impact of temporal distribution between different time periods or demand patterns is ignored. This could lead to miscalculation of the optimal locations of the monitoring stations. To overcome this flaw, this paper presents a Demand Coverage Index (DCI) based method. The optimization considers extended period unsteady hydrau- lics due to the change of nodal demands with time. The method is cast in a genetic algorithm framework for integration with Environmental Protection Agency Net (EPANET) and is demonstrated through example applica- tions. Results show that the set of optimal locations of monitoring stations obtained using the DCI method can represent the water quality of water distribution systems under multiple demand patterns better than the one obtained using previous methods.

  5. Analysing water use patterns for demand management: the case of the city of Masvingo, Zimbabwe

    Science.gov (United States)

    Dube, Emmanuel; van der Zaag, Pieter

    Water use in urban centres is dynamic, fluctuates, differs between high and low-income users, and tends to increase over time. Supply infrastructure can often hardly keep pace with increased water consumption. Given (a) the high cost of infrastructure development, (b) the recent emphasis on demand management, and (c) the social obligation to provide water services to the poor, urban water providers are faced with an important choice: whether to go the demand management route, or to continue constructing new infrastructure. This paper sheds light on some of the possibilities and constraints of both choices by providing a case study of the city of Masvingo in Zimbabwe. The paper analyses water use patterns in this city with a population of 70,000, located in a drought prone region of average rainfall of 600 mm/a. Water consumption has reached the limits of the water supply capacity. The paper first looks at the long-term water use pattern of the city as a whole and the factors that have caused the observed pattern using multiple linear regression. The paper then analyses the patterns of water use of rich and poor households, and attempts to assess the (im)possibilities of influencing these by means of an appropriate tariff structure. In projecting future demand, the paper then considers a number of interventions that could influence demand, which include leakage control, pressure management, awareness campaigns, free technical advice to water users, as well as a new tariff structure. It also discusses when new supply infrastructure should be available, depending on the various demand management measures taken.

  6. Comparison of simulations of land-use specific water demand and irrigation water supply by MF-FMP and IWFM

    Science.gov (United States)

    Schmid, Wolfgang; Dogural, Emin; Hanson, Randall T.; Kadir, Tariq; Chung, Francis

    2011-01-01

    Two hydrologic models, MODFLOW with the Farm Process (MF-FMP) and the Integrated Water Flow Model (IWFM), are compared with respect to each model’s capabilities of simulating land-use hydrologic processes, surface-water routing, and groundwater flow. Of major concern among the land-use processes was the consumption of water through evaporation and transpiration by plants. The comparison of MF-FMP and IWFM was conducted and completed using a realistic hypothetical case study. Both models simulate the water demand for water-accounting units resulting from evapotranspiration and inefficiency losses and, for irrigated units, the supply from surface-water deliveries and groundwater pumpage. The MF-FMP simulates reductions in evapotranspiration owing to anoxia and wilting, and separately considers land-use-related evaporation and transpiration; IWFM simulates reductions in evapotranspiration related to the depletion of soil moisture. The models simulate inefficiency losses from precipitation and irrigation water applications to runoff and deep percolation differently. MF-FMP calculates the crop irrigation requirement and total farm delivery requirement, and then subtracts inefficiency losses from runoff and deep percolation. In IWFM, inefficiency losses to surface runoff from irrigation and precipitation are computed and subtracted from the total irrigation and precipitation before the crop irrigation requirement is estimated. Inefficiency losses in terms of deep percolation are computed simultaneously with the crop irrigation requirement. The seepage from streamflow routing also is computed differently and can affect certain hydrologic settings and magnitudes ofstreamflow infiltration. MF-FMP assumes steady-state conditions in the root zone; therefore, changes in soil moisture within the root zone are not calculated. IWFM simulates changes in the root zone in both irrigated and non-irrigated natural vegetation. Changes in soil moisture are more significant for non

  7. Impact of climate change on evaluation of future water demand in the Euphrates and Aleppo basin, Syria

    Science.gov (United States)

    Alazzy, A. A.; Lü, H.; Zhu, Y.

    2014-09-01

    Syria is one of the Middle Eastern countries that suffer from scarcity in water resources availability, which affects the growth and development of economic activities. In this research, the Water Evaluation and Planning (WEAP) model is applied to evaluate future water demand in the Euphrates and Aleppo basin (EAB), Syria, by taking into account the climate change that may affect water demand in the domestic, industrial, and agricultural sectors until 2050. The climate change projections of temperature and precipitation were assessed using a new version of the MAGICC/SCENGEN tool with two greenhouse gas emissions scenarios (A2 and B2) of the Intergovernmental Panel on Climate Change (IPCC). Based on the results of IPCC (A2, B2) scenarios projections, the EAB basin is likely to face a decrease in precipitation amount by 21 % according to A2 and by 12 % according to B2, while temperature would increase by about 2.5 °C according to A2 and by 2 °C according to B2. Within the three scenarios adopted in this research: (1) available technology development; (2) increasing treated wastewater in agriculture and industry sectors; (3) and two combined scenarios, the results of the simulation demonstrated that the proposed scenarios are effective for reducing stressors on EAB's water resources, but are not sustainable to bridge the gap between demand-supply by the year 2050, which leads to the deterioration of the available water resources.

  8. Modelling Demand Side Kelas Menengah Pemuda Kota Surabaya

    Directory of Open Access Journals (Sweden)

    Achmadi Achmadi

    2014-05-01

    Full Text Available Middle class is an interesting topic in social studies to do a research. Based on Mckenzie, there are currently 45 million people in Indonesia can be categorized as middle class, and in 2030 will reach 135 million people. The middle class is the biggest support of drive economic growth from the demand side. This study aims to perform a simple modeling of middle-class’s cuncumption behavior, which study middle-class subculture in the city of Surabaya. This study uses an econometric tool called the logistic regression with two purchases decision, impulse buying and planned buying, as dependent variables in the model. Results of this study also show that the income effect variables, motivational variables and variable materialistic values ??consume has a significant and positive effect on impulse buying purchasing decisions. While product involvement variable have positive influence on planned purchases buying behavior.

  9. Modeling and prioritizing demand response programs in power markets

    Energy Technology Data Exchange (ETDEWEB)

    Aalami, H.A.; Moghaddam, M. Parsa; Yousefi, G.R. [Tarbiat Modares University, Tehran (Iran)

    2010-04-15

    One of the responsibilities of power market regulator is setting rules for selecting and prioritizing demand response (DR) programs. There are many different alternatives of DR programs for improving load profile characteristics and achieving customers' satisfaction. Regulator should find the optimal solution which reflects the perspectives of each DR stakeholder. Multi Attribute Decision Making (MADM) is a proper method for handling such optimization problems. In this paper, an extended responsive load economic model is developed. The model is based on price elasticity and customer benefit function. Prioritizing of DR programs can be realized by means of Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method. Considerations of ISO/utility/customer regarding the weighting of attributes are encountered by entropy method. An Analytical Hierarchy Process (AHP) is used for selecting the most effective DR program. Numerical studies are conducted on the load curve of the Iranian power grid in 2007. (author)

  10. An Inventory Model for Special Display Goods with Seasonal Demand

    Science.gov (United States)

    Kawakatsu, Hidefumi

    2010-10-01

    The present study discusses the retailer's optimal replenishment policy for seasonal products. The demand rate of seasonal merchandise such as clothes, sporting goods, children's toys and electrical home appearances tends to decrease with time after reaching its maximum value. In this study, we focus on "Special Display Goods", which are heaped up in end displays or special areas at retail stores. They are sold at a fast velocity when their quantity displayed is large, but are sold at a low velocity if the quantity becomes small. We develop the model with a finite time horizon (selling period) to determine the optimal replenishment policy, which maximizes the retailer's total profit. Numerical examples are presented to illustrate the theoretical underpinnings of the proposed model.

  11. Water losses dynamic modelling in water distribution networks

    Science.gov (United States)

    Puleo, Valeria; Milici, Barbara

    2015-12-01

    In the last decades, one of the main concerns of the water system managers have been the minimisation of water losses, that frequently reach values of 30% or even 70% of the volume supplying the water distribution network. The economic and social costs associated with water losses in modern water supply systems are rapidly rising to unacceptably high levels. Furthermore, the problem of the water losses assumes more and more importance mainly when periods of water scarcity occur or when not sufficient water supply takes part in areas with fast growth. In the present analysis, a dynamic model was used for estimating real and apparent losses of a real case study. A specific nodal demand model reflecting the user's tank installation and a specific apparent losses module were implemented. The results from the dynamic model were compared with the modelling estimation based on a steady-state approach.

  12. Using System Dynamic Model and Neural Network Model to Analyse Water Scarcity in Sudan

    Science.gov (United States)

    Li, Y.; Tang, C.; Xu, L.; Ye, S.

    2017-07-01

    Many parts of the world are facing the problem of Water Scarcity. Analysing Water Scarcity quantitatively is an important step to solve the problem. Water scarcity in a region is gauged by WSI (water scarcity index), which incorporate water supply and water demand. To get the WSI, Neural Network Model and SDM (System Dynamic Model) that depict how environmental and social factors affect water supply and demand are developed to depict how environmental and social factors affect water supply and demand. The uneven distribution of water resource and water demand across a region leads to an uneven distribution of WSI within this region. To predict WSI for the future, logistic model, Grey Prediction, and statistics are applied in predicting variables. Sudan suffers from severe water scarcity problem with WSI of 1 in 2014, water resource unevenly distributed. According to the result of modified model, after the intervention, Sudan’s water situation will become better.

  13. Piped water consumption in Ghana: A case study of temporal and spatial patterns of clean water demand relative to alternative water sources in rural small towns.

    Science.gov (United States)

    Kulinkina, Alexandra V; Kosinski, Karen C; Liss, Alexander; Adjei, Michael N; Ayamgah, Gilbert A; Webb, Patrick; Gute, David M; Plummer, Jeanine D; Naumova, Elena N

    2016-07-15

    Continuous access to adequate quantities of safe water is essential for human health and socioeconomic development. Piped water systems (PWSs) are an increasingly common type of water supply in rural African small towns. We assessed temporal and spatial patterns in water consumption from public standpipes of four PWSs in Ghana in order to assess clean water demand relative to other available water sources. Low water consumption was evident in all study towns, which manifested temporally and spatially. Temporal variability in water consumption that is negatively correlated with rainfall is an indicator of rainwater preference when it is available. Furthermore, our findings show that standpipes in close proximity to alternative water sources such as streams and hand-dug wells suffer further reductions in water consumption. Qualitative data suggest that consumer demand in the study towns appears to be driven more by water quantity, accessibility, and perceived aesthetic water quality, as compared to microbiological water quality or price. In settings with chronic under-utilization of improved water sources, increasing water demand through household connections, improving water quality with respect to taste and appropriateness for laundry, and educating residents about health benefits of using piped water should be prioritized. Continued consumer demand and sufficient revenue generation are important attributes of a water service that ensure its function over time. Our findings suggest that analyzing water consumption of existing metered PWSs in combination with qualitative approaches may enable more efficient planning of community-based water supplies and support sustainable development.

  14. Forecasting Water Demand in Residential, Commercial, and Industrial Zones in Bogotá, Colombia, Using Least-Squares Support Vector Machines

    Directory of Open Access Journals (Sweden)

    Carlos Peña-Guzmán

    2016-01-01

    Full Text Available The Colombian capital, Bogotá, has undergone massive growth in a short period of time. Naturally, this growth has increased the city’s water demand. The prediction of this demand will help understand and analyze consumption behavior, thereby allowing for effective management of the urban water cycle. This paper uses the Least-Squares Support Vector Machines (LS-SVM model for forecasting residential, industrial, and commercial water demand in the city of Bogotá. The parameters involved in this study include the following: monthly water demand, number of users, and total water consumption bills (price for the three studied uses. Results provide evidence of the model’s accuracy, producing R2 between 0.8 and 0.98, with an error percentage under 12%.

  15. Simulating long-term past changes in the balance between water demand and availability and assessing their main drivers at the river basin management scale

    Directory of Open Access Journals (Sweden)

    J. Fabre

    2014-11-01

    Full Text Available The aim of this study was to assess the balance between water demand and availability and its spatial and temporal variability from 1971 to 2009 in the Herault (2500 km2, France and the Ebro (85 000 km2, Spain catchments. Natural streamflow was evaluated using a conceptual hydrological model. The regulation of river flow was accounted for through a widely applicable demand-driven reservoir management model applied to the largest dam in the Herault basin and to 11 major dams in the Ebro basin. Urban water demand was estimated from population and monthly unit water consumption data. Water demand for irrigation was computed from irrigated area, crop and soil data, and climatic forcing. Finally, a series of indicators comparing water supply and water demand at strategic resource and demand nodes were computed at a 10 day time step. Variations in water stress in each catchment over the past 40 years were successfully modeled, taking into account climatic and anthropogenic pressures and changes in water management strategies over time. Observed changes in discharge were explained by separating human and hydro-climatic pressures on water resources: respectively 20 and 3% of the decrease in the Ebro and the Herault discharges were linked to human-induced changes. Although key areas of the Herault basin were shown to be highly sensitive to hydro-climatic variability, the balance between water uses and availability in the Ebro basin appears to be more critical, owing to high agricultural pressure on water resources. The proposed modeling framework is currently being used to assess water stress under climatic and socio-economic prospective scenarios. Further research will investigate the effectiveness of adaptation policies aimed at maintaining the balance between water use and availability.

  16. Simulating long-term past changes in the balance between water demand and availability and assessing their main drivers at the river basin management scale

    Science.gov (United States)

    Fabre, J.; Ruelland, D.; Dezetter, A.; Grouillet, B.

    2014-11-01

    The aim of this study was to assess the balance between water demand and availability and its spatial and temporal variability from 1971 to 2009 in the Herault (2500 km2, France) and the Ebro (85 000 km2, Spain) catchments. Natural streamflow was evaluated using a conceptual hydrological model. The regulation of river flow was accounted for through a widely applicable demand-driven reservoir management model applied to the largest dam in the Herault basin and to 11 major dams in the Ebro basin. Urban water demand was estimated from population and monthly unit water consumption data. Water demand for irrigation was computed from irrigated area, crop and soil data, and climatic forcing. Finally, a series of indicators comparing water supply and water demand at strategic resource and demand nodes were computed at a 10 day time step. Variations in water stress in each catchment over the past 40 years were successfully modeled, taking into account climatic and anthropogenic pressures and changes in water management strategies over time. Observed changes in discharge were explained by separating human and hydro-climatic pressures on water resources: respectively 20 and 3% of the decrease in the Ebro and the Herault discharges were linked to human-induced changes. Although key areas of the Herault basin were shown to be highly sensitive to hydro-climatic variability, the balance between water uses and availability in the Ebro basin appears to be more critical, owing to high agricultural pressure on water resources. The proposed modeling framework is currently being used to assess water stress under climatic and socio-economic prospective scenarios. Further research will investigate the effectiveness of adaptation policies aimed at maintaining the balance between water use and availability.

  17. Combined desalination, water reuse, and aquifer storage and recovery to meet water supply demands in the GCC/MENA region

    KAUST Repository

    Ghaffour, Noreddine

    2013-01-01

    Desalination is no longer considered as a nonconventional resource to supply potable water in several countries, especially in the Gulf Corporation Countries (GCC) and Middle East and North Africa (MENA) region as most of the big cities rely almost 100% on desalinated water for their supply. Due to the continuous increase in water demand, more large-scale plants are expected to be constructed in the region. However, most of the large cities in these countries have very limited water storage capacity, ranging from hours to a few days only and their groundwater capacity is very limited. The growing need for fresh water has led to significant cost reduction, because of technological improvements of desalination technologies which makes it an attractive option for water supply even in countries where desalination was unthinkable in the past. In the GCC/MENA region, operating records show that water demand is relatively constant during the year, while power demand varies considerably with a high peak in the summer season. However, desalination and power plants are economically and technically efficient only if they are fully operated at close to full capacity. In addition, desalination plants are exposed to external constraints leading to unexpected shutdowns (e.g. red tides). Hybridization of different technologies, including reverse osmosis and thermal-based plants, is used to balance the power to water mismatch in the demand by using the idle power from co-generation systems during low power demand periods. This has led to consideration of storage of additional desalinated water to allow for maximum production and stability in operation. Aquifer storage and recovery (ASR) would then be a good option to store the surplus of desalinated water which could be used when water demand is high or during unexpected shutdowns of desalination plants. In addition, increased reuse of treated wastewater could bring an integrated approach to water resources management. In this

  18. Modeling, Analysis, and Control of Demand Response Resources

    Energy Technology Data Exchange (ETDEWEB)

    Mathieu, Johanna L. [Univ. of California, Berkeley, CA (United States)

    2012-05-01

    While the traditional goal of an electric power system has been to control supply to fulfill demand, the demand-side can plan an active role in power systems via Demand Response (DR), defined by the Department of Energy (DOE) as “a tariff or program established to motivate changes in electric use by end-use customers in response to changes in the price of electricity over time, or to give incentive payments designed to induce lower electricity use at times of high market prices or when grid reliability is jeopardized” [29]. DR can provide a variety of benefits including reducing peak electric loads when the power system is stressed and fast timescale energy balancing. Therefore, DR can improve grid reliability and reduce wholesale energy prices and their volatility. This dissertation focuses on analyzing both recent and emerging DR paradigms. Recent DR programs have focused on peak load reduction in commercial buildings and industrial facilities (C&I facilities). We present methods for using 15-minute-interval electric load data, commonly available from C&I facilities, to help building managers understand building energy consumption and ‘ask the right questions’ to discover opportunities for DR. Additionally, we present a regression-based model of whole building electric load, i.e., a baseline model, which allows us to quantify DR performance. We use this baseline model to understand the performance of 38 C&I facilities participating in an automated dynamic pricing DR program in California. In this program, facilities are expected to exhibit the same response each DR event. We find that baseline model error makes it difficult to precisely quantify changes in electricity consumption and understand if C&I facilities exhibit event-to-event variability in their response to DR signals. Therefore, we present a method to compute baseline model error and a metric to determine how much observed DR variability results from baseline model error rather than real

  19. Challenging pathways to safe water access in rural Uganda: From supply to demand-driven water governance

    Directory of Open Access Journals (Sweden)

    Resty Naiga

    2015-03-01

    Full Text Available Uganda has experienced a major policy shift from a supply-driven to a demand-driven approach in rural water provision since 1990. The article sheds light on the rural population’s access to safe water within the changing institutional frameworks. We analysed individual and group interviews with key informants from national to community levels and relevant official documents with the ‘Social-Ecological Systems’ framework. Since the implementation of the demand-driven approach, rural safe water coverage has slightly improved but operation and maintenance of water sources pose a great challenge hampering, long-term access to safe water. The abrupt and top-down imposed policy shift has resulted in competing signals from old and new policies creating uncertainty and ambiguity about responsibilities, rules and incentives. The analysis shows the importance of taking into account the implications of national institutional disturbances on local collective action for long-term access to safe water.

  20. MODELLING GASOLINE DEMAND IN GHANA: A STRUCTURAL TIME SERIES ANALYSIS

    Directory of Open Access Journals (Sweden)

    Ishmael Ackah

    2014-01-01

    Full Text Available Concerns about the role of energy consumption in global warming have led to policy designs that seek to reduce fossil fuel consumption or find a less polluting alternative especiallyfor the transport sector. This study seeks to estimate the elasticities of price, income, education and technology on transport gasoline demand sector inGhana. The Structural Time Series Model reports a short-run price and income elasticities of -0.0088 and 0.713. Total factor productivity is -0.408 whilstthe elasticity for education is 2.33. In the long run, the reported price and income elasticities are -0.065 and 5.129 respectively. The long run elasticityfor productivity is -2.935. The study recommends that in order to enhanceefficiency in gasoline consumption in the transport sector, there should beinvestment in productivity.

  1. Multivariate time series modeling of short-term system scale irrigation demand

    Science.gov (United States)

    Perera, Kushan C.; Western, Andrew W.; George, Biju; Nawarathna, Bandara

    2015-12-01

    Travel time limits the ability of irrigation system operators to react to short-term irrigation demand fluctuations that result from variations in weather, including very hot periods and rainfall events, as well as the various other pressures and opportunities that farmers face. Short-term system-wide irrigation demand forecasts can assist in system operation. Here we developed a multivariate time series (ARMAX) model to forecast irrigation demands with respect to aggregated service points flows (IDCGi, ASP) and off take regulator flows (IDCGi, OTR) based across 5 command areas, which included area covered under four irrigation channels and the study area. These command area specific ARMAX models forecast 1-5 days ahead daily IDCGi, ASP and IDCGi, OTR using the real time flow data recorded at the service points and the uppermost regulators and observed meteorological data collected from automatic weather stations. The model efficiency and the predictive performance were quantified using the root mean squared error (RMSE), Nash-Sutcliffe model efficiency coefficient (NSE), anomaly correlation coefficient (ACC) and mean square skill score (MSSS). During the evaluation period, NSE for IDCGi, ASP and IDCGi, OTR across 5 command areas were ranged 0.98-0.78. These models were capable of generating skillful forecasts (MSSS ⩾ 0.5 and ACC ⩾ 0.6) of IDCGi, ASP and IDCGi, OTR for all 5 lead days and IDCGi, ASP and IDCGi, OTR forecasts were better than using the long term monthly mean irrigation demand. Overall these predictive performance from the ARMAX time series models were higher than almost all the previous studies we are aware. Further, IDCGi, ASP and IDCGi, OTR forecasts have improved the operators' ability to react for near future irrigation demand fluctuations as the developed ARMAX time series models were self-adaptive to reflect the short-term changes in the irrigation demand with respect to various pressures and opportunities that farmers' face, such as

  2. EnviroAtlas - Phoenix, AZ - Domestic Water Demand per Day by U.S. Census Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — As included in this EnviroAtlas dataset, community level domestic water demand is calculated using locally available water use data per capita in gallons of water...

  3. EnviroAtlas - Fresno, CA - Domestic Water Demand per Day by U.S. Census Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — As included in this EnviroAtlas dataset, community level domestic water demand is calculated using locally available water use data per capita in gallons of water...

  4. Water relations of the tos1 tomato mutant at contrasting evaporative demand.

    Science.gov (United States)

    Jurado, Oliva; Albacete, Alfonso; Martínez-Ballesta, M Carmen; Carvajal, Micaela; Pérez-Alfocea, Francisco; Dodd, Ian C; Romero-Aranda, M Remedios

    2009-09-01

    The tos1 (tomato osmotically sensitive) mutant, isolated from an in vitro screen of root growth during osmotic stress, was less sensitive to exogenous ABA, but accumulated more ABA under osmotic stress than WT plants. We assessed growth and water relations characteristics of hydroponically grown tos1 seedlings (in the absence of osmotic stress) at low and high evaporative demands. Growth of tos1 was severely inhibited at both high and low evaporative demands. Twenty DAS, WT and tos1 genotypes had a similar leaf water and turgor potential, but mature tos1 plants (45 day old) showed a significant diurnal loss of leaf turgor, with recovery overnight. Increased evaporative demand increased turgor loss of tos1 plants. High evaporative demand at the beginning of the day decreased stomatal conductance of tos1, without diurnal recovery, thus whole plant transpiration was decreased. De-topped tos1 seedlings showed decreased root hydraulic conductance and had a 1.4-fold increase in root ABA concentration. Impaired root function of tos1 plants failed to meet transpirational water demand and resulted in shoot turgor loss, stomatal closure and growth inhibition.

  5. Simulating past changes in the balance between water demand and availability and assessing their main drivers at the river basin scale

    Science.gov (United States)

    Fabre, J.; Ruelland, D.; Dezetter, A.; Grouillet, B.

    2015-03-01

    In this study we present an integrative modeling framework aimed at assessing the balance between water demand and availability and its spatial and temporal variability over long time periods. The model was developed and tested over the period 1971-2009 in the Hérault (2500 km2, France) and the Ebro (85 000 km2, Spain) catchments. Natural streamflow was simulated using a conceptual hydrological model. The regulation of river flow was accounted for through a widely applicable demand-driven reservoir management model applied to the largest dam in the Hérault Basin and to 11 major dams in the Ebro Basin. Urban water demand was estimated from population and monthly unit water demand data. Water demand for irrigation was computed from irrigated area, crop and soil data, and climatic forcing. Water shortage was assessed at a 10-day time step by comparing water demand and availability through indicators calculated at strategic resource and demand nodes. The outcome of this study is twofold. First, we were able to correctly simulate variations in influenced streamflow, reservoir levels and water shortage between 1971 and 2009 in both basins, taking into account climatic and anthropogenic pressures and changes in water management strategies over time. Second, we provided information not available through simple data analysis on the influence of withdrawals and consumptive use on streamflow and on the drivers of imbalance between demand and availability. Observed past variations in discharge were explained by separating anthropogenic and climatic pressures in our simulations: 3% (20%) of the decrease in the Hérault (Ebro) discharge were linked to anthropogenic changes. Although key areas of the Hérault Basin were shown to be highly sensitive to hydro-climatic variability, the balance between water demand and availability in the Ebro Basin appears to be more critical, owing to high agricultural pressure on water resources. The modeling framework developed and tested in

  6. Climate change impacts on water yields and demands in south-western Australia

    Science.gov (United States)

    McFarlane, Don; Stone, Roy; Martens, Sasha; Thomas, Jonathan; Silberstein, Richard; Ali, Riasat; Hodgson, Geoff

    2012-12-01

    SummaryA climate shift in the mid 1970s reduced rainfalls in south-western Australia by 10-15% and inflows into reservoirs that supply the city of Perth (population 1.8 m) by more than half. The region has a Mediterranean climate, similar to other areas in the world experiencing reductions in rainfall and rises in temperatures. Rainfall-runoff modelling has indicated that streamflows may reduce by a further quarter by 2030 or by half if a dry future climate is experienced. Groundwater levels on the coastal plain in south-western Australia have fallen since the mid 1970s where unconfined aquifers are covered with perennial vegetation, including under the main water supply aquifer for Perth. Modelled projections are that groundwater levels in most areas will continue to fall through to 2030 under most future climate scenarios. Projected streamflows and groundwater levels indicate reduced water availability but these need to be converted to projected water yields, i.e. the amount of water that can be diverted for consumptive use. This paper reports how projections of future streamflow and groundwater levels were used to estimate 2030 divertible water yields for a 62,500 km2 area in south-western Australia. These yields were then compared with estimates of water demands in 2030 to identify areas of water surplus and deficit under clearly defined assumptions. The methods used to define future yields are based on sets of rules that could be varied by water managers if desired. Surface water yields are estimated to decrease by about 24% (possible range of -4% to -49%) which is similar to the projected reduction in runoff (-25% with a range of -7% to -42%). Groundwater yields are projected to fall by only about 2% (range of +2% to -7%) because of reductions in evapotranspiration and drainage losses as watertables fall where groundwater levels are close to the surface. In addition, recharge remains relatively high under cleared areas used for non-irrigated agriculture. In

  7. Dynamic Attribution of Global Water Demand to Surface Water and Groundwater Resources: Effects of Abstractions and Return Flows on River Discharge

    Science.gov (United States)

    de Graaf, Inge; van Beek, Rens; Wada, Yoshi; Bierkens, Marc

    2013-04-01

    As human water demand is increasing worldwide, groundwater is abstracted at rates that exceed groundwater recharge in many areas, resulting in depletion of existing groundwater stocks. Most studies, that focus on human water consumption and water stress indicate a gap between water demand and availability. However, between studies very different assumptions are made on how water abstraction is divided between surface water, groundwater, and other resources. Moreover, simplified assumptions are used of the interactions between groundwater and surface water. Here, we simulate at the global scale, the dynamic attribution of total water demand to surface water and groundwater resources, based on actual water availability and accounting for return flows and surface water- groundwater interactions. The global hydrological model PCR-GLOBWB is used to simulate water storages, abstractions, and return flows for the model period 1960-2010, with a daily time step at 0.5° x 0.5° spatial resolution. Total water demand is defined as requirements for irrigation, industry, and domestic use. Water abstractions are variably taken from surface water and groundwater resources depending on availability of both resources. Return flows of non-consumed abstracted water contribute to a single source; those of irrigation recharging groundwater, those of industry and domestic use discharging to surface waters. Groundwater abstractions are taken from renewable groundwater, or when exceeding recharge from an alternative unlimited resource. This resource consists of non-renewable groundwater, or non-local water, the former being an estimate of groundwater depletion. Results show that worldwide the effect of water abstractions is evident, especially on the magnitude and frequency of low flows when the contribution of groundwater through baseflow is substantial. River regimes are minimally affected by abstractions in industrial regions because of the high return flows. In irrigated regions the

  8. Analysis of long-term climate change on per capita water demand in urban versus suburban areas in the Portland metropolitan area, USA

    Science.gov (United States)

    Parandvash, G. Hossein; Chang, Heejun

    2016-07-01

    We investigated the impacts of long-term climate variability and change on per capita water demand in urban and suburban service areas that have different degrees of development density in the Portland metropolitan area, USA. Together with historical daily weather and water production data, socioeconomic data such as population and unemployment rate were used to estimate daily per capita water demand in the two service areas. The structural time series regression model results show that the sensitivity of per capita water demand to both weather and unemployment rate variables is higher in suburban areas than in urban areas. This is associated with relatively higher proportional demand by the residential sector in the suburban area. The estimated coefficients of the historical demand model were used to project the mid-21st century (2035-2064) per capita water demand under three climate change scenarios that represent high (HadGEM2-ES), medium (MIROC5), and low (GFDL) climate changes. Without climate adaptation, compared to the historical period between 1983 and 2012, per capita water demand is projected to increase by 10.6% in the 2035-2064 period under the HadGEM2-ES in suburban areas, while per capita demand is projected to increase by 4.8% under the same scenario in urban areas. Our findings have implications for future urban water resource management and land use planning in the context of climate variability and change. A tight integration between water resource management and urban planning is needed for preparing for climate adaptation in municipal water planning and management.

  9. Clustering and Support Vector Regression for Water Demand Forecasting and Anomaly Detection

    Directory of Open Access Journals (Sweden)

    Antonio Candelieri

    2017-03-01

    Full Text Available This paper presents a completely data-driven and machine-learning-based approach, in two stages, to first characterize and then forecast hourly water demand in the short term with applications of two different data sources: urban water demand (SCADA data and individual customer water consumption (AMR data. In the first case, reliable forecasting can be used to optimize operations, particularly the pumping schedule, in order to reduce energy-related costs, while in the second case, the comparison between forecast and actual values may support the online detection of anomalies, such as smart meter faults, fraud or possible cyber-physical attacks. Results are presented for a real case: the water distribution network in Milan.

  10. Modeling of Energy Demand in the Greenhouse Using PSO-GA Hybrid Algorithms

    Directory of Open Access Journals (Sweden)

    Jiaoliao Chen

    2015-01-01

    Full Text Available Modeling of energy demand in agricultural greenhouse is very important to maintain optimum inside environment for plant growth and energy consumption decreasing. This paper deals with the identification parameters for physical model of energy demand in the greenhouse using hybrid particle swarm optimization and genetic algorithms technique (HPSO-GA. HPSO-GA is developed to estimate the indistinct internal parameters of greenhouse energy model, which is built based on thermal balance. Experiments were conducted to measure environment and energy parameters in a cooling greenhouse with surface water source heat pump system, which is located in mid-east China. System identification experiments identify model parameters using HPSO-GA such as inertias and heat transfer constants. The performance of HPSO-GA on the parameter estimation is better than GA and PSO. This algorithm can improve the classification accuracy while speeding up the convergence process and can avoid premature convergence. System identification results prove that HPSO-GA is reliable in solving parameter estimation problems for modeling the energy demand in the greenhouse.

  11. Demand Response Resource Quantification with Detailed Building Energy Models

    Energy Technology Data Exchange (ETDEWEB)

    Hale, Elaine; Horsey, Henry; Merket, Noel; Stoll, Brady; Nag, Ambarish

    2017-04-03

    Demand response is a broad suite of technologies that enables changes in electrical load operations in support of power system reliability and efficiency. Although demand response is not a new concept, there is new appetite for comprehensively evaluating its technical potential in the context of renewable energy integration. The complexity of demand response makes this task difficult -- we present new methods for capturing the heterogeneity of potential responses from buildings, their time-varying nature, and metrics such as thermal comfort that help quantify likely acceptability of specific demand response actions. Computed with an automated software framework, the methods are scalable.

  12. Economic analysis of the water demand in the hotels and restaurants sector: Shadow prices and elasticities

    Science.gov (United States)

    Angulo, Ana; Atwi, Majed; Barberán, Ramón; Mur, Jesús

    2014-08-01

    Despite the growing economic importance of tourism, and its impact on relative water shortage, little is known about the role that water plays in the productive process of hotels and restaurants and, therefore, the possible implications of water demand management policy for this sector. This study aims to fill this gap. It is based on the microdata of 676 firms in the sector, operating in the city of Zaragoza (Spain) for a 12 year period. Based on the Translog cost function, we estimate the shadow price of water in the short run and, from a long-run perspective, its direct price elasticity, its cross elasticities relative to labor, capital, and supplies, and its elasticity with respect to the level of output. The results obtained show that water provides sector firms returns that are on average higher than its price, although in the case of hotels the margin is really narrow. This situation provides policy makers with a margin for applying price increases without affecting the sector's viability, with some caution in the case of hotels. Water demand elasticity equals -0.38 in the case of hotels, but it is not significant in the case of restaurants and bar-cafes; hence, only in hotels is there potential for influencing water use patterns, encouraging the resource's conservation through pricing policy. Moreover, capital is a substitutive factor of water, and the elasticity of water with respect to output is 0.40, all of which should also be considered by policy makers in water resource management.

  13. Just add water: reproducible singly dispersed silver nanoparticle suspensions on-demand

    Science.gov (United States)

    MacCuspie, Robert I.; Allen, Andrew J.; Martin, Matthew N.; Hackley, Vincent A.

    2013-07-01

    Silver nanoparticles (AgNPs) are of interest due to their antimicrobial attributes, which are derived from their inherent redox instability and subsequent release of silver ions. At the same time, this instability is a substantial challenge for achieving stable long-term storage for on-demand use of AgNPs. In this study, we describe and validate a "just add water" approach for achieving suspensions of principally singly dispersed AgNPs. By lyophilizing (freeze drying) the formulated AgNPs into a solid powder, or cake, water is removed thereby eliminating solution-based chemical changes. Storing under inert gas further reduces surface reactions such as oxidation. An example of how to optimize a lyophilization formulation is presented, as well as example formulations for three AgNP core sizes. This "just add water" approach enables ease of use for the researcher desiring on-demand singly dispersed AgNP suspensions from a single master batch. Implementation of this methodology will enable studies to be performed over long periods of time and across different laboratories using particles that are identical chemically and physically and available on-demand. In addition, the approach of freeze drying and on-demand reconstitution by adding water has enabled the development of AgNP reference materials with the required shelf-life stability, one of the principal objectives of this research.

  14. Just add water: reproducible singly dispersed silver nanoparticle suspensions on-demand

    Energy Technology Data Exchange (ETDEWEB)

    MacCuspie, Robert I., E-mail: robert.maccuspie@nist.gov; Allen, Andrew J.; Martin, Matthew N.; Hackley, Vincent A. [National Institute of Standards and Technology, Materials Measurement Science Division (United States)

    2013-07-15

    Silver nanoparticles (AgNPs) are of interest due to their antimicrobial attributes, which are derived from their inherent redox instability and subsequent release of silver ions. At the same time, this instability is a substantial challenge for achieving stable long-term storage for on-demand use of AgNPs. In this study, we describe and validate a 'just add water' approach for achieving suspensions of principally singly dispersed AgNPs. By lyophilizing (freeze drying) the formulated AgNPs into a solid powder, or cake, water is removed thereby eliminating solution-based chemical changes. Storing under inert gas further reduces surface reactions such as oxidation. An example of how to optimize a lyophilization formulation is presented, as well as example formulations for three AgNP core sizes. This 'just add water' approach enables ease of use for the researcher desiring on-demand singly dispersed AgNP suspensions from a single master batch. Implementation of this methodology will enable studies to be performed over long periods of time and across different laboratories using particles that are identical chemically and physically and available on-demand. In addition, the approach of freeze drying and on-demand reconstitution by adding water has enabled the development of AgNP reference materials with the required shelf-life stability, one of the principal objectives of this research.

  15. Ultimate biochemical oxygen demand in semi-intensively managed shrimp pond waters

    Science.gov (United States)

    Three independent studies were conducted to quantified ultimate biochemical oxygen demand (UBOD) and the corresponding decomposition rate constant for production pond (average 21.5 ha each) waters and effluents on six semi-intensively managed marine shrimp (Litopenaeus vannamei) farms in Honduras. S...

  16. Ecological and environmental water demand of the lakes in the Haihe-Luanhe Basin of North China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The purpose of this paper is to present a brief concept of the ecological and environmental water demand of lake. The present situation and affecting factors of lake ecological system in the Haihe-Luanhe Basin of North China was analyzed. The calculating method of the ecological and environmental water demand of the lake basis on the water body and the calculating method of the ecological and environmental water demand of the lake basis on the aquatic ecosystem, wetland and vegetation were compared and discussed. As the examples of Baiyangdian Lake and Beidagang Lake in Haihe-Luanhe river basin, the ecological and environmental water demand of the two lakes was calculated to be 27× 108m3 . It is 6.75 times to the water demand according to the calculating method of the ecological and environmental water demand of the lake basis on the water body. The research result indicated: ( 1 ) The calculating methods of the ecological and environmental water demand of the lake basis on the aquatic ecosystem should be better than only basis on the water body of lake. (2) The data, such as area of the vegetation kind around and in the lake, the vegetation coefficient, the evaporating amount of the vegetation and the vegetation water demand itself around and in the lake are lack and urgent need. Some suggestions for controlling and regulating the water resource of the lake in North China were proposed.

  17. Modeling Water Quality in Rivers

    Directory of Open Access Journals (Sweden)

    Liren Yu

    2005-01-01

    Full Text Available This study reports a PC software, used in a Windows-based environment, which was developed based on the first order reaction of Biological Oxygen Demand (BOD and a modified Streeter and Phelps equation, in order to simulate and determine the variations of Dissolved Oxygen (DO and of the BOD along with the studied river reaches. The software considers many impacts of environmental factors, such as the different type of discharges (concentrated or punctual source, tributary contribution, distributed source, nitrogenous BOD, BOD sedimentation, photosynthetic production and benthic demand of oxygen, and so on. The software has been used to model the DO profile along one river, with the aim to improve the water quality through suitable engineering measure.

  18. Optimizing Virtual Land and Water Resources Flow Through Global Trade to Meet World Food and Biofuel Demand

    Science.gov (United States)

    Zhang, X.; Cai, X.; Zhu, T.

    2013-12-01

    Biofuels is booming in recent years due to its potential contributions to energy sustainability, environmental improvement and economic opportunities. Production of biofuels not only competes for land and water with food production, but also directly pushes up food prices when crops such as maize and sugarcane are used as biofuels feedstock. Meanwhile, international trade of agricultural commodities exports and imports water and land resources in a virtual form among different regions, balances overall water and land demands and resource endowment, and provides a promising solution to the increasingly severe food-energy competition. This study investigates how to optimize water and land resources uses for overall welfare at global scale in the framework of 'virtual resources'. In contrast to partial equilibrium models that usually simulate trades year-by-year, this optimization model explores the ideal world where malnourishment is minimized with optimal resources uses and trade flows. Comparing the optimal production and trade patterns with historical data can provide meaningful implications regarding how to utilize water and land resources more efficiently and how the trade flows would be changed for overall welfare at global scale. Valuable insights are obtained in terms of the interactions among food, water and bioenergy systems. A global hydro-economic optimization model is developed, integrating agricultural production, market demands (food, feed, fuel and other), and resource and environmental constraints. Preliminary results show that with the 'free market' mechanism and land as well as water resources use optimization, the malnourished population can be reduced by as much as 65%, compared to the 2000 historical value. Expected results include: 1) optimal trade paths to achieve global malnourishment minimization, 2) how water and land resources constrain local supply, 3) how policy affects the trade pattern as well as resource uses. Furthermore, impacts of

  19. New challenges in integrated water quality modelling

    NARCIS (Netherlands)

    Rode, M.; Arhonditsis, G.; Balin, D.; Kebede, T.; Krysanova, V.; Griensven, A.; Zee, van der S.E.A.T.M.

    2010-01-01

    There is an increasing pressure for development of integrated water quality models that effectively couple catchment and in-stream biogeochemical processes. This need stems from increasing legislative requirements and emerging demands related to contemporary climate and land use changes. Modelling w

  20. The Job Demands-Resources Model in China: Validation and Extension

    NARCIS (Netherlands)

    Hu, Q.

    2014-01-01

    The Job Demands-Resources (JD-R) Model assumes that employee health and well-being result from the interplay between job demands and job resources. Based on its openheuristic nature, the JD-R model can be applied to various occupational settings, irrespective of the particular demands and resources

  1. Self-Efficacy and Workaholism as Initiators of the Job Demands-Resources Model

    Science.gov (United States)

    Guglielmi, Dina; Simbula, Silvia; Schaufeli, Wilmar B.; Depolo, Marco

    2012-01-01

    Purpose: This study aims to investigate school principals' well-being by using the job demands-resources (JD-R) model as a theoretical framework. It aims at making a significant contribution to the development of this model by considering not only job demands and job resources, but also the role of personal resources and personal demands as…

  2. On the (S-1, S) Lost Sales Inventory Model with Priority Demand Classes

    NARCIS (Netherlands)

    R. Dekker (Rommert); R.M. Hill; M.J. Kleijn (Marcel)

    1997-01-01

    textabstractIn this paper an inventory model with several demand classes, prioritised according to importance, is analysed. We consider a lot-for-lot or (S-1,S) inventory model with lost sales. For each demand class there is a critical stock level at and below which demand from that class is not

  3. On the (S-1,S) model for renewal demand processes: Poisson's poison

    NARCIS (Netherlands)

    M.A.J. Smith; R. Dekker (Rommert)

    1997-01-01

    textabstractIn the standard (S - 1,S) stock model, demand follows a Poisson process. It has appeared to many stock analysts that this model causes an abundance of stock in reality. In case demand is caused by failure or is derived from another process, demand typically does not follow a Poisson proc

  4. Improving the Model for Energy Consumption Load Demand Forecasting

    Science.gov (United States)

    Bunnoon, Pituk; Chalermyanont, Kusumal; Limsakul, Chusak

    This paper proposes an application of a filter method in preprocessing stage for mid-term load demand forecasting to improve electricity load forecasting and to guarantee satisfactory forecasting accuracy. Case study employs the historical electricity consumption demand data in Thailand which were recorded in the 12 years of 1997 through to 2007. The load demand forecasted value is used for unit commitment and fuel reserve planning in the power system. This method consists of a trend component and a cyclical component decomposed from the original load demand using the Hodrick-Prescott (HP) filter in the preprocessing stage and the forecasting of each component using Double Neural Networks (DNNs) in the forecasting stage. Experimental results show that with preprocessing before forecasting can predict the load demand better than that without preprocessing.

  5. Nationwide water availability data for energy-water modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Tidwell, Vincent Carroll; Zemlick, Katie M.; Klise, Geoffrey Taylor

    2013-11-01

    The purpose of this effort is to explore where the availability of water could be a limiting factor in the siting of new electric power generation. To support this analysis, water availability is mapped at the county level for the conterminous United States (3109 counties). Five water sources are individually considered, including unappropriated surface water, unappropriated groundwater, appropriated water (western U.S. only), municipal wastewater and brackish groundwater. Also mapped is projected growth in non-thermoelectric consumptive water demand to 2035. Finally, the water availability metrics are accompanied by estimated costs associated with utilizing that particular supply of water. Ultimately these data sets are being developed for use in the National Renewable Energy Laboratories' (NREL) Regional Energy Deployment System (ReEDS) model, designed to investigate the likely deployment of new energy installations in the U.S., subject to a number of constraints, particularly water.

  6. Modeling the Effects of Future Growing Demand for Charcoal in the Tropics

    Directory of Open Access Journals (Sweden)

    M. J. Santos

    2017-06-01

    Full Text Available Global demand for charcoal is increasing mainly due to urban population in developing countries. More than half the global population now lives in cities, and urban-dwellers are restricted to charcoal use because of easiness of production, access, transport, and tradition. Increasing demand for charcoal, however, may lead to increasing impacts on forests, food, and water resources, and may even create additional pressures on the climate system. Here we assess how different charcoal scenarios based on the Shared Socio-economic Pathways (SSP relate to potential biomass supply. For this, we use the energy model TIMER to project the demand for fuelwood and charcoal for different socio-economic pathways for urban and rural populations, globally, and for four tropical regions (Central America, South America, Africa and Indonesia. Second, we assess whether the biomass demands for each scenario can be met with current and projected forest biomass estimated with remote sensing and modeled Net Primary Productivity (NPP using a Dynamic Global Vegetation Model (LPJ-GUESS. Currently one third of residential energy use is based on traditional bioenergy, including charcoal. Globally, biomass needs by urban households by 2100 under the most sustainable scenario, SSP1, are of 14.4 mi ton biomass for charcoal plus 17.1 mi ton biomass for fuelwood (31.5 mi ton biomass in total. Under SSP3, the least sustainable scenario, we project a need of 205 mi tons biomass for charcoal plus 243.8 mi ton biomass for fuelwood by 2100 (total of 450 mi ton biomass. Africa and South America contribute the most for this biomass demand, however, all areas are able to meet the demand. We find that the future of the charcoal sector is not dire. Charcoal represents a small fraction of the energy requirements, but its biomass demands are disproportionate and in some regions require a large fraction of forest. This could be because of large growing populations moving to urban areas

  7. Agricultural water supply/demand changes under projected future climate change in the arid region of northwestern China

    Science.gov (United States)

    Guo, Ying; Shen, Yanjun

    2016-09-01

    The water resources in the arid region of northwestern China, which are impacted by climate change, tend to be more unstable, and the environment and ecosystems will suffer from severe water shortage. In this paper, potential future climate trends were predicted based on CMIP5 simulations in this region. The water availability and agricultural water demand under future climate change scenarios were estimated. Impacted by increases in temperature, the irrigation water demand will increase by 4.27-6.15 billion m3 in this region over the next 60 years, compared to the demand of 32.75 billion m3 during 1971-2000. However, the annual runoff will only increase by 4.8-8.5 billion m3, which is equivalent to or even less than the increased irrigation water demand. In fact, the increased demand for industrial, domestic and ecological water were not considered here. Thus, the water supply/demand contradiction will result in more severe water shortages in the future. According to a comparison with simulated irrigation water demand under three adaptation strategy scenarios, we should take effective measures such as improving the efficiency of irrigation water utilization, reducing crop planting areas and adjusting crop planting structures to alleviate the impacts of future climate changes and human activities on the water supply and water use in this region.

  8. Nambe Pueblo Water Budget and Forecasting model.

    Energy Technology Data Exchange (ETDEWEB)

    Brainard, James Robert

    2009-10-01

    This report documents The Nambe Pueblo Water Budget and Water Forecasting model. The model has been constructed using Powersim Studio (PS), a software package designed to investigate complex systems where flows and accumulations are central to the system. Here PS has been used as a platform for modeling various aspects of Nambe Pueblo's current and future water use. The model contains three major components, the Water Forecast Component, Irrigation Scheduling Component, and the Reservoir Model Component. In each of the components, the user can change variables to investigate the impacts of water management scenarios on future water use. The Water Forecast Component includes forecasting for industrial, commercial, and livestock use. Domestic demand is also forecasted based on user specified current population, population growth rates, and per capita water consumption. Irrigation efficiencies are quantified in the Irrigated Agriculture component using critical information concerning diversion rates, acreages, ditch dimensions and seepage rates. Results from this section are used in the Water Demand Forecast, Irrigation Scheduling, and the Reservoir Model components. The Reservoir Component contains two sections, (1) Storage and Inflow Accumulations by Categories and (2) Release, Diversion and Shortages. Results from both sections are derived from the calibrated Nambe Reservoir model where historic, pre-dam or above dam USGS stream flow data is fed into the model and releases are calculated.

  9. Framework for Enhancing the Supply-Demand Balance of a Tri-Supply Urban Water Scheme in Australia

    OpenAIRE

    Edoardo Bertone; Rodney A. Stewart

    2011-01-01

    Fit-for-purpose potable source substitution of appropriate water end uses with rainwater or recycled water is often essential to maintain water security in growing urban regions. This paper provides the results of a detailed supply-demand forecasting review of a unique tri-supply (i.e., potable, A+ recycled and rain water sources reticulated to household) urban water scheme located in Queensland, Australia. Despite the numerous benefits of this scheme, system efficiency (e.g., reduced demand ...

  10. Modeling, Analysis, and Control of Demand Response Resources

    Energy Technology Data Exchange (ETDEWEB)

    Mathieu, Johanna L. [Univ. of California, Berkeley, CA (United States)

    2012-05-01

    While the traditional goal of an electric power system has been to control supply to fulfill demand, the demand-side can plan an active role in power systems via Demand Response (DR), defined by the Department of Energy (DOE) as “a tariff or program established to motivate changes in electric use by end-use customers in response to changes in the price of electricity over time, or to give incentive payments designed to induce lower electricity use at times of high market prices or when grid reliability is jeopardized” [29]. DR can provide a variety of benefits including reducing peak electric loads when the power system is stressed and fast timescale energy balancing. Therefore, DR can improve grid reliability and reduce wholesale energy prices and their volatility. This dissertation focuses on analyzing both recent and emerging DR paradigms. Recent DR programs have focused on peak load reduction in commercial buildings and industrial facilities (C&I facilities). We present methods for using 15-minute-interval electric load data, commonly available from C&I facilities, to help building managers understand building energy consumption and ‘ask the right questions’ to discover opportunities for DR. Additionally, we present a regression-based model of whole building electric load, i.e., a baseline model, which allows us to quantify DR performance. We use this baseline model to understand the performance of 38 C&I facilities participating in an automated dynamic pricing DR program in California. In this program, facilities are expected to exhibit the same response each DR event. We find that baseline model error makes it difficult to precisely quantify changes in electricity consumption and understand if C&I facilities exhibit event-to-event variability in their response to DR signals. Therefore, we present a method to compute baseline model error and a metric to determine how much observed DR variability results from baseline model error rather than real

  11. Risk Assessment of Regional Irrigation Water Demand and Supply in an Arid Inland River Basin of Northwestern China

    Directory of Open Access Journals (Sweden)

    Bin Guo

    2015-09-01

    Full Text Available Irrigation water demand accounts for more than 95% of the total water use in the Kaidu-kongqi River Basin. Determination of the spatial and temporal trends in irrigation water demand is important for making sustainable and wise water management strategies in this highly water deficit region. In this study, the spatial and temporal trends in irrigation water demand as well as net crop irrigation water requirements for nine major crops during 1985–2009 were analyzed by combining the Penman-Monteith equation recommended by Food and Agriculture Organization (FAO and GIS technology. The regional water stress was also evaluated based on the total irrigation water demand and river discharge at the annual and monthly scales. The results indicated that the annual irrigation water demand in this arid region showed a significant increasing trend during the past 25 years. Total irrigation water demand increased from 14.68 × 108 m3 in 1985 to 34.15 × 108 m3 in 2009. The spatial pattern of total irrigation water demand was significantly affected by the changes in cotton growing area. Due to differences in crop planting structure, the monthly average irrigation water demands in Korla City and Yuli County amounted to the peak in July, while those in other regions reached the maximum in June. Although the annual river runoff was much larger than the irrigation water demand, there was serious water deficit during the critical water use period in May and June in some dry years. The presented study provides important information for managers and planners on sustainable use of water resources in this arid region.

  12. Demand-control-person: integrating the demand-control and conservation of resources models to test an expanded stressor-strain model.

    Science.gov (United States)

    Rubino, Cristina; Perry, Sara Jansen; Milam, Alex C; Spitzmueller, Christiane; Zapf, Dieter

    2012-10-01

    We propose an expanded stressor-strain model that explicitly incorporates person characteristics, the Demand-Control-Person model. This model integrates Karasek's traditional Demand-Control model with Hobfoll's (1989) Conservation of Resources theory. With participants from two organizations, we tested the moderating role of emotional stability in conjunction with two job demands (i.e., uncertainty and time pressure) and control (i.e., decision latitude) in predicting two forms of strain (i.e., job dissatisfaction and disengagement). Our findings support the expanded Demand-Control-Person model, such that a significant three-way interaction emerged for uncertainty and time pressure. As predicted, the traditional Demand-Control model only held among individuals high in emotional stability, such that low-emotional stability individuals did either not benefit as readily from decision latitude or were more susceptible to job demands when they had decision latitude. Thus, the Demand-Control-Person model may provide a more comprehensive model and consistent prediction of the effect of stressors on strain as determined by individual characteristics.

  13. Analysis of Water Resources Supply and Demand and Security of Water Resources Development in Irrigation Regions of the Middle Reaches of the Heihe River Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    JI Xi-bin; KANG Er-si; CHEN Ren-sheng; ZHAO Wen-zhi; XIAO Sheng-chun; JIN Bo-wen

    2006-01-01

    Based on the data for meteorology, hydrology, soil, planting, vegetation, and socio-economic development of the irrigation region in the middle reaches of the Heihe River basin, Northwest China, the model of balance of water supply and demand in the region was established, and the security of water resource was assessed, from which the results that the effects of unified management of water resources in the Heihe River basin between Gansu Province and Inner Mongolia on regional hydrology are significant with a decrease in water supply diverted from Heihe River and an increase in groundwater extracted. In addition, it was found that the groundwater level has been steadily decreasing due to over pumping and decrease in recharges. In present year (2003), the volume of potential groundwater in the irrigation districts is far small because of the groundwater overdraft; even in the particular regions, there is no availability of groundwater resources for use. By 2003, water supply is not sufficient to meet the water demand in the different irrigation districts, the sustainable development and utilization of water resources are not secured, and the water supply crisis occurs in Pingchuan irrigation district. Achieving water security for the sustainable development of society, agriculture, economy, industry, and livelihoods while maintaining or improving the abilities of the management and planning of water resources, determining of the reasonable percentage between water supply and groundwater utilization and water saving in agricultural irrigation are taken into account. If this does not occur, it is feared that the present performance of water development and planning may further aggravate the problem of scarcities of water resources and further damage the fragile ecological system.

  14. Water demand management in Malawi: problems and prospects for its promotion

    Science.gov (United States)

    Mulwafu, W.; Chipeta, C.; Chavula, G.; Ferguson, A.; Nkhoma, B. G.; Chilima, G.

    This paper discusses the status of water demand management (WDM) in Malawi. Findings from the study indicate that, while WDM is highly advocated in the urban and peri-urban areas, very few aspects of WDM are practiced in the rural areas. The water pricing structure that the supplying institutions established serves as a disincentive for water wastages in the urban areas. Both private firms and individuals use various measures to conserve water as a way of minimizing water consumption. The motives for water conservation range from profit maximization to inadequate financial resources to meet the costs of water respectively. In the rural areas where water is supplied at no cost, the people tend to pay less attention to water conservation. In cases where water providers attempted to institute factors of cost sharing, the rural inhabitants tended to be reluctant to contribute. This is so because people view water as a social good that should be supplied to them free of charge. The paper demonstrates that although some aspects of WDM are being practiced in the country, the existing conditions on the ground militate against its increased expansion as a strategy for promoting an efficient and equitable use of existing water resources. A large section of the population still lack access to potable water and the Malawi government is committed to the provision of basic water services. Yet WDM will become even more critical in future because of the growing competition for water resources, particularly due to the growing population and the increasing economic activities such as farming, industrialization and urbanization. The paper argues that despite the promising benefits that WDM has, its promotion must necessarily be infused with ideas of water supply, considering that the largest population still lacks access to potable water. Coupled with this will be the need for a proper policy framework that promotes public awareness for people to start appreciating the economic value

  15. Order Level Inventory Models for Deteriorating Seasonable/Fashionable Products with Time Dependent Demand and Shortages

    Directory of Open Access Journals (Sweden)

    K. Skouri

    2009-01-01

    Full Text Available An order level inventory model for seasonable/fashionable products subject to a period of increasing demand followed by a period of level demand and then by a period of decreasing demand rate (three branches ramp type demand rate is considered. The unsatisfied demand is partially backlogged with a time dependent backlogging rate. In addition, the product deteriorates with a time dependent, namely, Weibull, deterioration rate. The model is studied under the following different replenishment policies: (a starting with no shortages and (b starting with shortages. The optimal replenishment policy for the model is derived for both the above mentioned policies.

  16. A leader-follower-interactive method for regional water resources management with considering multiple water demands and eco-environmental constraints

    Science.gov (United States)

    Chen, Yizhong; Lu, Hongwei; Li, Jing; Ren, Lixia; He, Li

    2017-05-01

    This study presents the mathematical formulation and implementations of a synergistic optimization framework based on an understanding of water availability and reliability together with the characteristics of multiple water demands. This framework simultaneously integrates a set of leader-followers-interactive objectives established by different decision makers during the synergistic optimization. The upper-level model (leader's one) determines the optimal pollutants discharge to satisfy the environmental target. The lower-level model (follower's one) accepts the dispatch requirement from the upper-level one and dominates the optimal water-allocation strategy to maximize economic benefits representing the regional authority. The complicated bi-level model significantly improves upon the conventional programming methods through the mutual influence and restriction between the upper- and lower-level decision processes, particularly when limited water resources are available for multiple completing users. To solve the problem, a bi-level interactive solution algorithm based on satisfactory degree is introduced into the decision-making process for measuring to what extent the constraints are met and the objective reaches its optima. The capabilities of the proposed model are illustrated through a real-world case study of water resources management system in the district of Fengtai located in Beijing, China. Feasible decisions in association with water resources allocation, wastewater emission and pollutants discharge would be sequentially generated for balancing the objectives subject to the given water-related constraints, which can enable Stakeholders to grasp the inherent conflicts and trade-offs between the environmental and economic interests. The performance of the developed bi-level model is enhanced by comparing with single-level models. Moreover, in consideration of the uncertainty in water demand and availability, sensitivity analysis and policy analysis are

  17. A Theoretical Model of Water and Trade

    Science.gov (United States)

    Dang, Q.; Konar, M.; Reimer, J.; Di Baldassarre, G.; Lin, X.; Zeng, R.

    2015-12-01

    Water is an essential factor of agricultural production. Agriculture, in turn, is globalized through the trade of food commodities. In this paper, we develop a theoretical model of a small open economy that explicitly incorporates water resources. The model emphasizes three tradeoffs involving water decision-making that are important yet not always considered within the existing literature. One tradeoff focuses on competition for water among different sectors when there is a shock to one of the sectors only, such as trade liberalization and consequent higher demand for the product. A second tradeoff concerns the possibility that there may or may not be substitutes for water, such as increased use of sophisticated irrigation technology as a means to increase crop output in the absence of higher water availability. A third tradeoff explores the possibility that the rest of the world can be a source of supply or demand for a country's water-using products. A number of propositions are proven. For example, while trade liberalization tends to increase water use, increased pressure on water supplies can be moderated by way of a tax that is derivable with observable economic phenomena. Another example is that increased riskiness of water availability tends to cause water users to use less water than would be the case under profit maximization. These theoretical model results generate hypotheses that can be tested empirically in future work.

  18. Integrated water resources modelling for assessing sustainable water governance

    Science.gov (United States)

    Skoulikaris, Charalampos; Ganoulis, Jacques; Tsoukalas, Ioannis; Makropoulos, Christos; Gkatzogianni, Eleni; Michas, Spyros

    2015-04-01

    Climatic variations and resulting future uncertainties, increasing anthropogenic pressures, changes in political boundaries, ineffective or dysfunctional governance of natural resources and environmental degradation are some of the most fundamental challenges with which worldwide initiatives fostering the "think globally, act locally" concept are concerned. Different initiatives target the protection of the environment through sustainable development; Integrated Water Resources Management (IWRM) and Transboundary Water Resources Management (TWRM) in the case of internationally shared waters are frameworks that have gained wide political acceptance at international level and form part of water resources management planning and implementation on a global scale. Both concepts contribute in promoting economic efficiency, social equity and environmental sustainability. Inspired by these holistic management approaches, the present work describes an effort that uses integrated water resources modelling for the development of an integrated, coherent and flexible water governance tool. This work in which a sequence of computer based models and tools are linked together, aims at the evaluation of the sustainable operation of projects generating renewable energy from water as well as the sustainability of agricultural demands and environmental security in terms of environmental flow under various climatic and operational conditions. More specifically, catchment hydrological modelling is coupled with dams' simulation models and thereafter with models dedicated to water resources management and planning,while the bridging of models is conducted through geographic information systems and custom programming tools. For the case of Mesta/Nestos river basin different priority rules in the dams' operational schedule (e.g. priority given to power production as opposed to irrigation needs and vice versa), as well as different irrigation demands, e.g. current water demands as opposed to

  19. The Community Water Model (CWATM) / Development of a community driven global water model

    Science.gov (United States)

    Burek, Peter; Satoh, Yusuke; Greve, Peter; Kahil, Taher; Wada, Yoshihide

    2017-04-01

    With a growing population and economic development, it is expected that water demands will increase significantly in the future, especially in developing regions. At the same time, climate change is expected to alter spatial patterns of hydrological cycle and will have global, regional and local impacts on water availability. Thus, it is important to assess water supply, water demand and environmental needs over time to identify the populations and locations that will be most affected by these changes linked to water scarcity, droughts and floods. The Community Water Model (CWATM) will be designed for this purpose in that it includes an accounting of how future water demands will evolve in response to socioeconomic change and how water availability will change in response to climate. CWATM represents one of the new key elements of IIASA's Water program. It has been developed to work flexibly at both global and regional level at different spatial resolutions. The model is open source and community-driven to promote our work amongst the wider water community worldwide and is flexible enough linking to further planned developments such as water quality and hydro-economic modules. CWATM will be a basis to develop a next-generation global hydro-economic modeling framework that represents the economic trade-offs among different water management options over a basin looking at water supply infrastructure and demand managements. The integrated modeling framework will consider water demand from agriculture, domestic, energy, industry and environment, investment needs to alleviate future water scarcity, and will provide a portfolio of economically optimal solutions for achieving future water management options under the Sustainable Development Goals (SDG) for example. In addition, it will be able to track the energy requirements associated with the water supply system e.g., pumping, desalination and interbasin transfer to realize the linkage with the water-energy economy. In

  20. Incorporating Logistics in Freight Transport Demand Models: State-of-the-Art and Research Opportunities

    NARCIS (Netherlands)

    Tavasszy, L.A.; Ruijgrok, K.; Davydenko, I.

    2012-01-01

    Freight transport demand is a demand derived from all the activities needed to move goods between locations of production to locations of consumption, including trade, logistics and transportation. A good representation of logistics in freight transport demand models allows us to predict the effects

  1. Meeting multiple demands: Water transaction opportunities for environmental benefits promoting adaptation to climate change

    Science.gov (United States)

    McCoy, Amy

    2015-04-01

    In arid regions, the challenge of balancing water use among a diversity of sectors expands in lock step with conditions of water stress that are exacerbated by climate variability, prolonged drought, and growing water-use demands. The elusiveness of achieving a sustainable balance under conditions of environmental change in the southwestern United States is evidenced by reductions in both overall water availability and freshwater ecosystem health, as well as by recent projections of shortages on the Colorado River within the next five years. The water sustainability challenge in this region, as well as drylands throughout the world, can therefore be viewed through the lens of water stress, a condition wherein demands on land and water -- including the needs of freshwater ecosystems -- exceed reliable supplies, and the full range of water needs cannot be met without tradeoffs across multiple uses. Water stress influences not only ecosystems, but a region's economy, land management, quality of life, and cultural heritage -- each of which requires water to thrive. With respect to promoting successful adaptation to climate change, achieving full water sustainability would allow for water to be successfully divided among water users -- including municipalities, agriculture, and freshwater ecosystems -- at a level that meets the goals of water users and the governing body. Over the last ten to fifteen years, the use of transactional approaches in the western U.S., Mexico, and Australia has proven to be a viable management tool for achieving stream flow and shallow aquifer restoration. By broad definition, environmental water transactions are an equitable and adaptable tool that brings diverse stakeholders to the table to facilitate a fair-market exchange of rights to use water in a manner that benefits both water users and the environment. This talk will present a basic framework of necessary stakeholder engagement, hydrologic conditions, enabling laws and policies

  2. How to meet the increasing demands of water, food and energy in the future?

    Science.gov (United States)

    Shi, Haiyun; Chen, Ji; Sivakumar, Bellie; Peart, Mervyn

    2017-04-01

    Regarded as a driving force in water, food and energy demands, the world's population has been increasing rapidly since the beginning of the 20th century. According to the medium-growth projection scenario of the United Nations, the world's population will reach 9.5 billion by 2050. In response to the continuously growing population during this century, water, food and energy demands have also been increasing rapidly, and social problems (e.g., water, food, and energy shortages) will be most likely to occur, especially if no proper management strategies are adopted. Then, how to meet the increasing demands of water, food and energy in the future? This study focuses on the sustainable developments of population, water, food, energy and dams, and the significances of this study can be concluded as follows: First, we reveal the close association between dams and social development through analysing the related data for the period 1960-2010, and argue that construction of additional large dams will have to be considered as one of the best available options to meet the increasing water, food and energy demands in the future. We conduct the projections of global water, food and energy consumptions and dam development for the period 2010-2050, and the results show that, compared to 2010, the total water, food and energy consumptions in 2050 will increase by 20%, 34% and 37%, respectively. Moreover, it is projected that additional 4,340 dams will be constructed by 2050 all over the world. Second, we analyse the current situation of global water scarcity based on the related data representing water resources availability (per capita available water resources), dam development (the number of dams), and the level of economic development (per capita gross domestic product). At the global scale, water scarcity exists in more than 70% of the countries around the world, including 43 countries suffering from economic water scarcity and 129 countries suffering from physical water

  3. Program Demand Cost Model for Alaskan Schools. 6th Edition. Revised.

    Science.gov (United States)

    Alaska State Dept. of Education, Juneau.

    The Program Demand Cost Model for Alaskan Schools (Cost Model) is a tool for use by school districts and their consultants in estimating school construction costs in the planning phase of a project. This document sets out the sixth edition of the demand-cost model, a rewrite of the whole system. The model can be used to establish a complete budget…

  4. The Job Demands-Resources model: Further evidence for the buffering effect of personal resources

    OpenAIRE

    Maxime A. Tremblay; Deanna Messervey

    2011-01-01

    Orientation: In work and organisational psychology, the adverse effects of job demands have often been demonstrated empirically for various indicators of job strain.Research purpose: Using the Job Demands-Resources (JD-R) model as a theoretical framework, the present study examined the role of compassion satisfaction, conceptualised as a personal resource, in buffering the relationship between job demands and job strain.Motivation for the study: Accordingly, four demanding aspects of the job ...

  5. On the Behavior of Different PCMs in a Hot Water Storage Tank against Thermal Demands

    Directory of Open Access Journals (Sweden)

    Jacobo Porteiro

    2016-03-01

    Full Text Available Advantages, such as thermal storage improvement, are found when using PCMs (Phase Change Materials in storage tanks. The inclusion of three different types of materials in a 60 l test tank is studied. Two test methodologies were developed, and four tests were performed following each methodology. A thermal analysis is performed to check the thermal properties of each PCM. The distributions of the water temperatures inside the test tanks are evaluated by installing four Pt-100 sensors at different heights. A temperature recovery is observed after exposing the test tank to an energy demand. An energetic analysis that takes into account the energy due to the water temperature, the energy due to the PCM and the thermal loss to the ambient environment is also presented. The percentage of each PCM that remains in the liquid state after the energy demand is obtained.

  6. A Survey of Water Demand Forecasting Procedures on Fixed Army Installations.

    Science.gov (United States)

    1985-02-01

    Fort Dix, New Jersey Fort Hamilton, New York Fort Eustis, Virginia Fort Pickett, Virginia Fort Gordon, Georgia Fort Rucker, Alabama Fort Benjamin ...Vol 15, No. 4 (August 1979), pp 763-767. Darr , P., S. L. Feldman, and C. Komen, The Demand for Urban Water (Leiden, the Netherlands: Martinus...Fort Knox 5090 6635 -1545 628,6 -1196 Fort Leavenworth 2055 2070 -15 2144 -90 Fort Benjamin Harrison 552 2656 -2104 1554 -1001 Fort Lee 1655 2878 -1223

  7. Model documentation report: Industrial sector demand module of the National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    This report documents the objectives, analytical approach, and development of the National Energy Modeling System (NEMS) Industrial Demand Model. The report catalogues and describes model assumptions, computational methodology, parameter estimation techniques, and model source code. This document serves three purposes. First, it is a reference document providing a detailed description of the NEMS Industrial Model for model analysts, users, and the public. Second, this report meets the legal requirement of the Energy Information Administration (EIA) to provide adequate documentation in support of its models. Third, it facilitates continuity in model development by providing documentation from which energy analysts can undertake model enhancements, data updates, and parameter refinements as future projects. The NEMS Industrial Demand Model is a dynamic accounting model, bringing together the disparate industries and uses of energy in those industries, and putting them together in an understandable and cohesive framework. The Industrial Model generates mid-term (up to the year 2015) forecasts of industrial sector energy demand as a component of the NEMS integrated forecasting system. From the NEMS system, the Industrial Model receives fuel prices, employment data, and the value of industrial output. Based on the values of these variables, the Industrial Model passes back to the NEMS system estimates of consumption by fuel types.

  8. Model documentation report: Industrial sector demand module of the National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    This report documents the objectives, analytical approach, and development of the National Energy Modeling System (NEMS) Industrial Demand Model. The report catalogues and describes model assumptions, computational methodology, parameter estimation techniques, and model source code. This document serves three purposes. First, it is a reference document providing a detailed description of the NEMS Industrial Model for model analysts, users, and the public. Second, this report meets the legal requirement of the Energy Information Administration (EIA) to provide adequate documentation in support of its models. Third, it facilitates continuity in model development by providing documentation from which energy analysts can undertake model enhancements, data updates, and parameter refinements as future projects. The NEMS Industrial Demand Model is a dynamic accounting model, bringing together the disparate industries and uses of energy in those industries, and putting them together in an understandable and cohesive framework. The Industrial Model generates mid-term (up to the year 2015) forecasts of industrial sector energy demand as a component of the NEMS integrated forecasting system. From the NEMS system, the Industrial Model receives fuel prices, employment data, and the value of industrial output. Based on the values of these variables, the Industrial Model passes back to the NEMS system estimates of consumption by fuel types.

  9. Model documentation report: Industrial sector demand module of the national energy modeling system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This report documents the objectives, analytical approach, and development of the National Energy Modeling System (NEMS) Industrial Demand Model. The report catalogues and describes model assumptions, computational methodology, parameter estimation techniques, and model source code. This document serves three purposes. First, it is a reference document providing a detailed description of the NEMS Industrial Model for model analysts, users, and the public. Second, this report meets the legal requirements of the Energy Information Administration (EIA) to provide adequate documentation in support of its model. Third, it facilitates continuity in model development by providing documentation from which energy analysts can undertake model enhancements, data updates, and parameter refinements as future projects.

  10. Demand-based water options for arsenic mitigation: an experience from rural Bangladesh.

    Science.gov (United States)

    Hoque, B A; Hoque, M M; Ahmed, T; Islam, S; Azad, A K; Ali, N; Hossain, M; Hossain, M S

    2004-01-01

    A supply of safe drinking water is a recognized global concern. The arsenic contamination of groundwater in Bangladesh and other countries has furthered this concern. Lack of appropriate water options is one of the main barriers to the supply of safe drinking water for 30-60 million people who are exposed to the risk of drinking arsenic-contaminated water in Bangladesh. This paper describes the experience from a water supply programme for arsenic mitigation based on demand and participation of 30,000 rural people in Srinagar, a subdistrict of Bangladesh. About 85% of the 912 tubewell water samples tested had an arsenic content higher than 0.05 mg/l. The project promoted 11 options including groundwater, surface-water and rainwater-harvesting household-based options as well as community managed technologies. Most people, particularly women, wanted piped water, and hand-operated deep tubewells were also requested. Four cluster-based motorized piped water systems, 20 home-based arsenic-removal options (two types) and an arsenic-removal filter plant were installed. The public contributed about 49, 25 and 20% of the installation costs of piped water, home-based options and filter options, respectively, and 100% of all operation and maintenance costs. The household options and filter plant were abandoned within a few weeks. Reportedly, those options required too much attention, discharged small volumes of water at low rates, were difficult to maintain, and discharged poor-quality water. The proportion of families (54%) that drank arsenic-contaminated water during the final survey was significantly lower than in the baseline survey (87%). For arsenic-affected areas, it is recommended that a cluster-based piped water system be given proper consideration when selecting appropriate water options rather than household-based options or the development of new low-cost options.

  11. When the 'soft-path' gets hard: demand management and financial instability for water utilities

    Science.gov (United States)

    Zeff, H. B.; Characklis, G. W.

    2014-12-01

    In the past, cost benefit analysis (CBA) has been viewed as an effective means of evaluating water utility strategies, particularly those that were dependent on the construction of new supply infrastructure. As water utilities have begun to embrace 'soft-path' approaches as a way to reduce the need for supply-centric development, CBA fails to recognize some important financial incentives affected by reduced water consumption. Demand management, both as a short-term response to drought and in longer-term actions to accommodate demand growth, can introduce revenue risks that adversely affect a utility's ability to repay debt, re-invest in aging infrastructure, or maintain reserve funds for use in a short-term emergency. A utility that does not generate sufficient revenue to support these functions may be subject to credit rating downgrades, which in turn affect the interest rate it pays on its debt. Interest rates are a critical consideration for utility managers in the capital-intensive water sector, where debt payments for infrastructure often account for a large portion of a utility's overall costs. Even a small increase in interest rates can add millions of dollars to the cost of new infrastructure. Recent studies have demonstrated that demand management techniques can lead to significant revenue variability, and credit rating agencies have begun to take notice of drought response plans when evaluating water utility credit ratings, providing utilities with a disincentive to fully embrace soft-path approaches. This analysis examines the impact of demand management schemes on key credit rating metrics for a water utility in Raleigh, North Carolina. The utility's consumer base is currently experiencing rapid population growth, and demand management has the potential to reduce the dependence on costly new supply infrastructure but could lead to financial instability that will significantly increase the costs of financing future projects. This work analyzes how 'soft

  12. Assessment of Sustainability of Urban Water Supply and Demand Management Options: A Comprehensive Approach

    Directory of Open Access Journals (Sweden)

    Kumudu Rathnayaka

    2016-12-01

    Full Text Available A comprehensive evaluation framework that can assess a wide range of water supply and demand management policy options in terms of economic, social, environmental, risk-based, and functional performance is crucial to ascertain their level of sustainability. However, such a detailed, generic, and holistic policy evaluation framework is not found in the literature. This paper reviews studies to evaluate water supply and/or demand management options conducted during 2000–2016. Primarily, the paper reviews the evaluation criteria used by different studies for decision making given their significant difference and the importance of a comprehensive set of criteria to complete a rigorous evaluation. In addition, a comprehensive set of water supply and demand management options are not considered together for a comparative assessment to prioritise best options for a certain area and time. Further, performance of these options needs to be evaluated for a range of uncertainties arising from changes of spatial and temporal variables of the system. While this paper highlights the important aspects that need to be included in a comprehensive policy evaluation framework, available studies collectively present a rich set of information to support it.

  13. Development of S-ARIMA Model for Forecasting Demand in a Beverage Supply Chain

    Science.gov (United States)

    Mircetic, Dejan; Nikolicic, Svetlana; Maslaric, Marinko; Ralevic, Nebojsa; Debelic, Borna

    2016-11-01

    Demand forecasting is one of the key activities in planning the freight flows in supply chains, and accordingly it is essential for planning and scheduling of logistic activities within observed supply chain. Accurate demand forecasting models directly influence the decrease of logistics costs, since they provide an assessment of customer demand. Customer demand is a key component for planning all logistic processes in supply chain, and therefore determining levels of customer demand is of great interest for supply chain managers. In this paper we deal with exactly this kind of problem, and we develop the seasonal Autoregressive IntegratedMoving Average (SARIMA) model for forecasting demand patterns of a major product of an observed beverage company. The model is easy to understand, flexible to use and appropriate for assisting the expert in decision making process about consumer demand in particular periods.

  14. Improving irrigation efficiency will be insufficient to meet future water demand in the Nile Basin

    Directory of Open Access Journals (Sweden)

    S. Multsch

    2017-08-01

    We found that water savings from improved irrigation technology will not be able to meet the additional needs of planned areas. Under a theoretical scenario of maximum possible efficiency, the deficit would still be 5  km3yr−1. For more likely efficiency improvement scenarios, the deficit ranges between 23 and 29 km3yr−1. Our results suggest that improving irrigation efficiency may substantially contribute to decreasing water stress on the Nile system but would not completely meet the demand.

  15. Model documentation report: Residential sector demand module of the national energy modeling system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This report documents the objectives, analytical approach, and development of the National Energy Modeling System (NEMS) Residential Sector Demand Module. The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, and FORTRAN source code. This reference document provides a detailed description for energy analysts, other users, and the public. The NEMS Residential Sector Demand Module is currently used for mid-term forecasting purposes and energy policy analysis over the forecast horizon of 1993 through 2020. The model generates forecasts of energy demand for the residential sector by service, fuel, and Census Division. Policy impacts resulting from new technologies, market incentives, and regulatory changes can be estimated using the module. 26 refs., 6 figs., 5 tabs.

  16. Overcoming constraints to the implementation of water demand management in southern Africa

    Science.gov (United States)

    Mwendera, E. J.; Hazelton, D.; Nkhuwa, D.; Robinson, P.; Tjijenda, K.; Chavula, G.

    This paper presents results of a study on water demand management status and overcoming constraints to implementation of water demand management in the southern African region, as part of Phase II of water demand management (WDM) programme implemented by the IUCN (The World Conservation Union). The study was conducted in Malawi, Namibia, South Africa, Swaziland, Zambia and Zimbabwe. The study methodology consisted of a survey of literature, and interviewing and communicating with stakeholders in order to learn from stakeholders on the critical constraints to WDM implementation and strategies to overcome them. The study has shown that, despite the potential savings that would accrue from implementation of WDM, the water sector across the southern African region continues to focus on water supply augmentation. There are inadequate financial and human resources for rehabilitation, operation and maintenance of water conveyance systems resulting in system leaks, which contribute to high levels of unaccounted-for water, a situation that masks the potential benefits of WDM. In most countries, the water sector operates on ad-hoc sub-sector water user objectives, which provided guidelines only for development and management purposes. Most of the institutional frameworks have remained diffuse, resulting into poor performance in the sector, and into crisis management in the water resources development. Though the WDM policy in most countries is already accessible through guidelines for catchment management institutions and water supply institutions; there is a lack of broad commitment to implementing them. In other countries the instruments are relatively new and have not been applied widely. Similarly, the effectiveness of instruments has not been well evaluated in most countries. In countries where policy is weak there is often a lack of clarity as to who is responsible for WDM implementation, and even less clarity on who is responsible for facilitating and monitoring

  17. Impacts of increased bioenergy demand on global food markets: an AgMIP economic model intercomparison

    Energy Technology Data Exchange (ETDEWEB)

    Lotze-Campen, Hermann; von Lampe, Martin; Kyle, G. Page; Fujimori, Shinichiro; Havlik, Petr; van Meijl, Hans; Hasegawa, Tomoko; Popp, Alexander; Schmitz, Christoph; Tabeau, Andrzej; Valin, Hugo; Willenbockel, Dirk; Wise, Marshall A.

    2014-01-01

    Integrated Assessment studies have shown that meeting ambitious greenhouse gas mitigation targets will require substantial amounts of bioenergy as part of the future energy mix. In the course of the Agricultural Model Comparison and Improvement Project (AgMIP), five global agro-economic models were used to analyze a future scenario with global demand for ligno-cellulosic bioenergy rising to about 100 ExaJoule in 2050. From this exercise a tentative conclusion can be drawn that ambitious climate change mitigation need not drive up global food prices much, if the extra land required for bioenergy production is accessible or if the feedstock, e.g. from forests, does not directly compete for agricultural land. Agricultural price effects across models by the year 2050 from high bioenergy demand in an RCP2.6-type scenario appear to be much smaller (+5% average across models) than from direct climate impacts on crop yields in an RCP8.5-type scenario (+25% average across models). However, potential future scarcities of water and nutrients, policy-induced restrictions on agricultural land expansion, as well as potential welfare losses have not been specifically looked at in this exercise.

  18. Bridging the climate-induced water gap in the twenty-first century: adaptation support based on water supply, demand, adaptation and financing.

    Science.gov (United States)

    Straatsma, Menno; Droogers, Peter; Brandsma, Jaïrus; Buytaert, Wouter; Karssenberg, Derek; Van Beek, Rens; Wada, Yoshihide; Sutanudjaja, Edwin; Vitolo, Claudia; Schmitz, Oliver; Meijer, Karen; Van Aalst, Maaike; Bierkens, Marc

    2014-05-01

    Water scarcity affects large parts of the world. Over the course of the twenty-first century, water demand is likely to increase due to population growth and associated food production, and increased economic activity, while water supply is projected to decrease in many regions due to climate change. Despite recent studies that analyze the effect of climate change on water scarcity, e.g. using climate projections under representative concentration pathways (RCP) of the fifth assessment report of the IPCC (AR5), decision support for closing the water gap between now and 2100 does not exist at a meaningful scale and with a global coverage. In this study, we aimed (i) to assess the joint impact of climatic and socio-economic change on water scarcity, (ii) to integrate impact and potential adaptation in one workflow, (iii) to prioritize adaptation options to counteract water scarcity based on their financial, regional socio-economic and environmental implications, and (iv) to deliver all this information in an integrated user-friendly web-based service. To enable the combination of global coverage with local relevance, we aggregated all results for 1604 water provinces (food producing units) delineated in this study, which is five times smaller than previous food producing units. Water supply was computed using the PCR-GLOBWB hydrological and water resources model, parameterized at 5 arcminutes for the whole globe, excluding Antarctica and Greenland. We ran PCR-GLOBWB with a daily forcing derived from five different GCM models from the CMIP5 (GFDL-ESM2M, Hadgem2-ES, IPSL-CMA5-LR, MIROC-ESM-CHEM, NorESM1-M) that were bias corrected using observation-based WATCH data between 1960-1999. For each of the models all four RCPs (RCP 2.6, 4.5, 6.0, and 8.5) were run, producing the ensemble of 20 future projections. The blue water supply was aggregated per month and per water province. Industrial, domestic and irrigation water demands were computed for a limited number of

  19. Balance of Water Supply-demand in Paddy Fields in Hilly Regions in Sichuan Province

    Institute of Scientific and Technical Information of China (English)

    Hong ZHANG; Xinlu JIANG; Hongzhu FAN; Jiaguo ZHENG

    2012-01-01

    Abstract [Objective] The aim was to study the effects of water supply and con- sumption on water saving and drought resistance. [Method] Controlling field experi- ment was conducted to explore water balance between supply and demand in paddy fields in hilly regions in Sichuan Province. [Result] Rainfall in hilly areas was 3 611.10 m3/hm2; water for irrigation was 6 299.25 m3/hm~, evapotranspiration of rice was 6 424.95 m3/hm2; deep leakage was 2 459.55 m3/hm2; overflowing amount was 1 026.00 m3/hm2. In addition, water consumption totaled 8 884.50 m3/hm2 during rice production; water use was 0.99 kg/m3 and use efficiency of irrigated water was 1.40 kg/m3, [Conclu- sion] Water supply and consumption should be further organized to save water and fight against drought in hilly areas in Sichuan Province.

  20. Water demand management in Yemen and Jordan: addressing power and interests.

    Science.gov (United States)

    Zeitoun, Mark; Allan, Tony; Al Aulaqi, Nasser; Jabarin, Amer; Laamrani, Hammou

    2012-01-01

    This paper investigates the extent to which entrenched interests of stakeholder groups both maintain water use practice, and may be confronted. The focus is on the agricultural sectors of Yemen and Jordan, where water resource policymakers face resistance in their attempts to reduce water use to environmentally sustainable levels through implementation of water demand management (WDM) activities. Some farmers in both countries that have invested in irrigated production of high-value crops (such as qat and bananas) benefit from a political economy that encourages increased rather than reduced water consumption. The resultant over-exploitation of water resources affects groups in unequal measures. Stakeholder analysis demonstrates that the more ‘powerful’ groups (chiefly the large landowners and the political elites, as well as the ministries of irrigation over which they exert influence) are generally opposed to reform in water use, while the proponents of WDM (e.g. water resource managers, environmental ministries and NGOs, and the international donor community) are found to have minimal influence over water use policy and decisionmaking. Efforts and ideas attempted by this latter group to challenge the status quo are classified here as either (a) influencing or (b) challenging the power asymmetry, and the merits and limits of both approaches are discussed. The interpretation of evidence suggests current practice is likely to endure, but may be more effectively challenged if a long-term approach is taken with an awareness of opportunities generated by windows of opportunity and the participation of ‘overlap groups’.

  1. A Simple Discussion on the Supply and Demand of Water Resources in the Western Region of China

    Institute of Scientific and Technical Information of China (English)

    Yu Hongbo

    2006-01-01

    We are accustomed to solve the problem of the water scarcity in the western region by the thought of increasing the effective supply of water to meet the needs of Go-west Campaign. After introducing the dynamic equilibrium principle on supply and demand in economy,we find that we should solve the problem of the water scarcity in the western region through reducing total demand to achieve the dynamic equilibrium of supply and demand. Finally water resources in the western region can be enlarged by an accumulated way.

  2. A critical review of the Job demands-Resources model: Implications for improving work and health

    NARCIS (Netherlands)

    Schaufeli, W.B.; Taris, T.W.

    2014-01-01

    The Job Demands-Resources model (JD-R model) became highly popular among researchers. The current version of the model proposes that high job demands lead to strain and health impairment (the health impairment process), and that high resources lead to increased motivation and higher productivity (th

  3. Capacity building in water demand management as a key component for attaining millennium development goals

    Science.gov (United States)

    Gumbo, Bekithemba; Forster, Laura; Arntzen, Jaap

    Successful water demand management (WDM) implementation as a component of integrated water resource management (IWRM) can play a significant role in the alleviation of poverty through more efficient use of available water resources. The urban population in Southern African cities is characterised by so-called ‘water poor’ communities who typically expend a high percentage of their household income on poor quality water. Usually they have no access to an affordable alternative source. Although WDM as a component of IWRM is not a panacea for poverty, it can help alleviate poverty by facilitating water services management by municipal water supply agencies (MWSAs) in the region. WDM is a key strategy for achieving the millennium development goals (MDGs) and, as such, should be given due attention in the preparation of national IWRM and water efficiency plans. Various studies in the Southern African region have indicated that capacity building is necessary for nations to develop IWRM and water-use efficiency plans to meet the targets set out in the MDGs. WDM education and training of water professionals and end-users is particularly important in developing countries, which are resource and information-access poor. In response to these findings, The World Conservation Union (IUCN) and its consulting partners, the Training and Instructional Design Academy of South Africa (TIDASA), and Centre for Applied Research (CAR) designed, developed and presented a pilot WDM Guideline Training Module for MWSAs as part of Phase II of IUCN’s Southern Africa regional WDM project. Pilot training was conducted in July 2004 in Lusaka, Zambia for a group of 36 participants involved in municipal water supply from nine Southern African countries. This paper looks at the links between building the capacity of professionals, operational staff and other role-players in the municipal water supply chain to implement WDM as part of broader IWRM strategies, and the subsequent potential for

  4. Soft Measurement Modeling Based on Chaos Theory for Biochemical Oxygen Demand (BOD

    Directory of Open Access Journals (Sweden)

    Junfei Qiao

    2016-12-01

    Full Text Available The precision of soft measurement for biochemical oxygen demand (BOD is always restricted due to various factors in the wastewater treatment plant (WWTP. To solve this problem, a new soft measurement modeling method based on chaos theory is proposed and is applied to BOD measurement in this paper. Phase space reconstruction (PSR based on Takens embedding theorem is used to extract more information from the limited datasets of the chaotic system. The WWTP is first testified as a chaotic system by the correlation dimension (D, the largest Lyapunov exponents (λ1, the Kolmogorov entropy (K of the BOD and other water quality parameters time series. Multivariate chaotic time series modeling method with principal component analysis (PCA and artificial neural network (ANN is then adopted to estimate the value of the effluent BOD. Simulation results show that the proposed approach has higher accuracy and better prediction ability than the corresponding modeling approaches not based on chaos theory.

  5. Water Demand Management Strategies and Challenges in the Upper Colorado River Basin

    Science.gov (United States)

    Kuhn, R. E.

    2016-12-01

    Under the 1922 Colorado River Compact, the Upper Basin (Colorado, New Mexico, Utah, and Wyoming) has flow obligations at Lee Ferry to downstream states and Mexico. The Colorado River Storage Project Act (CRSPA) of 1956 led to the construction of four large storage reservoirs. These provide river regulation to allow the Upper Basin to meet its obligations. Lake Powell, the largest and most important, and Lake Mead are now operated in a coordinated manner under the 2007 Interim Guidelines. Studies show that at current demand levels and if the hydrologic conditions the Basin has experienced since the mid-1980s continue or get drier, reservoir operations, alone, may not provide the necessary water to meet the Upper Basin's obligations. Therefore, the Upper Basin states are now studying demand management strategies that will reduce consumptive uses when total system reservoir storage reaches critically low levels. Demand management has its own economic, political and technical challenges and limitations and will provide new opportunities for applied research. This presentation will discuss some of those strategies, their challenges, and the kinds of information that research could provide to inform demand management.

  6. Integrated Water Resources Simulation Model for Rural Community

    Science.gov (United States)

    Li, Y.-H.; Liao, W.-T.; Tung, C.-P.

    2012-04-01

    The purpose of this study is to develop several water resources simulation models for residence houses, constructed wetlands and farms and then integrate these models for a rural community. Domestic and irrigation water uses are the major water demand in rural community. To build up a model estimating domestic water demand for residence houses, the average water use per person per day should be accounted first, including water uses of kitchen, bathroom, toilet and laundry. On the other hand, rice is the major crop in the study region, and its productive efficiency sometimes depends on the quantity of irrigation water. The water demand can be estimated by crop water use, field leakage and water distribution loss. Irrigation water comes from rainfall, water supply system and reclaimed water which treated by constructed wetland. In recent years, constructed wetlands play an important role in water resources recycle. They can purify domestic wastewater for water recycling and reuse. After treating from constructed wetlands, the reclaimed water can be reused in washing toilets, watering gardens and irrigating farms. Constructed wetland is one of highly economic benefits for treating wastewater through imitating the processing mechanism of natural wetlands. In general, the treatment efficiency of constructed wetlands is determined by evapotranspiration, inflow, and water temperature. This study uses system dynamics modeling to develop models for different water resource components in a rural community. Furthermore, these models are integrated into a whole system. The model not only is utilized to simulate how water moves through different components, including residence houses, constructed wetlands and farms, but also evaluates the efficiency of water use. By analyzing the flow of water, the water resource simulation model can optimizes water resource distribution under different scenarios, and the result can provide suggestions for designing water resource system of a

  7. Modelling seasonal farm labour demand: What can we learn from rural Kakamega district, western Kenya?

    Directory of Open Access Journals (Sweden)

    Vincent Canwat

    2012-09-01

    Full Text Available Seasonality of agricultural activities causes fluctuation in the quantity of labour consumed by these activities, and yet many rural labour studies in developing countries still treat labour demand in agriculture as if it is the same across different farm operations. To unearth the amount of information hidden by this aggregated analysis, labour demand for specific farm operations was estimated based on data collected from Kakamega District. This analysis shows that increasing household size increases labour demand for planting, weeding and harvesting. Increasing the share of elderly household members has a negligible effect on labour demand for farm activities except for land preparation, with which it is positively related. Participation of primary school-going children in farm activities is the highest in planting and harvesting. Participation in off-farm employment seems to increase labour demand only during peak seasons. The area planted appears to have an insignificant effect on labour demand for land preparation. Planting sugar cane appears to reduce labour demand for weeding and primary processing, but planting tea increases labour demand for planting. Mechanising land preparation only reduces labour demand for land preparation, but it seems to be offset by other labour-intensive farm operations. The distance from water source is positively related to labour demand for land preparation, but the distance to the market is negatively related to labour demand for weeding and harvesting. These observations point to the need for supporting and investing in technological and organisational innovations in agriculture.

  8. Inventory rationing in an (s, Q) inventory model with lost sales a two demand classes

    OpenAIRE

    Melchiors, Ph.; Dekker, Rommert; Kleijn, Marcel

    1998-01-01

    textabstractWhenever demand for a single item can be categorized into classes of different priority, an inventory rationing policy should be considered. In this paper we analyse a continuous review (s,Q) model with lost sales and two demand classes. A so-called critical level policy is applied to ration the inventory among the two demand classes. With this policy, low--priority demand is rejected in anticipation of future high--priority demand whenever the inventory level is at or below a pre...

  9. Industrial water demand management and cleaner production potential: a case of three industries in Bulawayo, Zimbabwe

    Science.gov (United States)

    Gumbo, Bekithemba; Mlilo, Sipho; Broome, Jeff; Lumbroso, Darren

    The combination of water demand management and cleaner production concepts have resulted in both economical and ecological benefits. The biggest challenge for developing countries is how to retrofit the industrial processes, which at times are based on obsolete technology, within financial, institutional and legal constraints. Processes in closed circuits can reduce water intake substantially and minimise resource input and the subsequent waste thereby reducing pollution of finite fresh water resources. Three industries were studied in Bulawayo, Zimbabwe to identify potential opportunities for reducing water intake and material usage and minimising waste. The industries comprised of a wire galvanising company, soft drink manufacturing and sugar refining industry. The results show that the wire galvanising industry could save up to 17% of water by recycling hot quench water through a cooling system. The industry can eliminate by substitution the use of toxic materials, namely lead and ammonium chloride and reduce the use of hydrochloric acid by half through using an induction heating chamber instead of lead during the annealing step. For the soft drink manufacturing industry water intake could be reduced by 5% through recycling filter-backwash water via the water treatment plant. Use of the pig system could save approximately 12 m 3/month of syrup and help reduce trade effluent fees by Z30/m 3 of “soft drink”. Use of a heat exchanger system in the sugar refining industry can reduce water intake by approximately 57 m 3/100 t “raw sugar” effluent volume by about 28 m 3/100 t “raw sugar”. The water charges would effectively be reduced by 52% and trade effluent fees by Z3384/100 t “raw sugar” (57%). Proper equipment selection, equipment modification and good house-keeping procedures could further help industries reduce water intake and minimise waste.

  10. Improving rice production sustainability by reducing water demand and greenhouse gas emissions with biodegradable films

    Science.gov (United States)

    Yao, Zhisheng; Zheng, Xunhua; Liu, Chunyan; Lin, Shan; Zuo, Qiang; Butterbach-Bahl, Klaus

    2017-01-01

    In China, rice production is facing unprecedented challenges, including the increasing demand, looming water crisis and on-going climate change. Thus, producing more rice at lower environmental cost is required for future development, i.e., the use of less water and the production of fewer greenhouse gas (GHG) per unit of rice. Ground cover rice production systems (GCRPSs) could potentially address these concerns, although no studies have systematically and simultaneously evaluated the benefits of GCRPS regarding yields and considering water use and GHG emissions. This study reports the results of a 2-year study comparing conventional paddy and various GCRPS practices. Relative to conventional paddy, GCRPSs had greater rice yields and nitrogen use efficiencies (8.5% and 70%, respectively), required less irrigation (-64%) and resulted in less total CH4 and N2O emissions (-54%). On average, annual emission factors of N2O were 1.67% and 2.00% for conventional paddy and GCRPS, respectively. A cost-benefit analysis considering yields, GHG emissions, water demand and labor and mulching costs indicated GCRPSs are an environmentally and economically profitable technology. Furthermore, substituting the polyethylene film with a biodegradable film resulted in comparable benefits of yield and climate. Overall, GCRPSs, particularly with biodegradable films, provide a promising solution for farmers to secure or even increase yields while reducing the environmental footprint.

  11. Demand-Supply Optimization with Risk Management for a Multi-Connection Water Reservoir Network

    CERN Document Server

    Chatpatanasiri, Ratthachat

    2009-01-01

    In this paper, we propose a framework to solve a demand-supply optimization problem of long-term water resource allocation on a multi-connection reservoir network which, in two aspects, is different to the problem considered in previous works. First, while all previous works consider a problem where each reservoir can transfer water to only one fixed reservoir, we consider a multi-connection network being constructed in Thailand in which each reservoir can transfer water to many reservoirs in one period of time. Second, a demand-supply plan considered here is static, in contrast to a dynamic policy considered in previous works. Moreover, in order to efficiently develop a long-term static plan, a severe loss (a risk) is taken into account, i.e. a risk occurs if the real amount of water stored in each reservoir in each time period is less than what planned by the optimizer. The multi-connection function and the risk make the problem rather complex such that traditional stochastic dynamic programming and determi...

  12. User Demand Aware Grid Scheduling Model with Hierarchical Load Balancing

    Directory of Open Access Journals (Sweden)

    P. Suresh

    2013-01-01

    Full Text Available Grid computing is a collection of computational and data resources, providing the means to support both computational intensive applications and data intensive applications. In order to improve the overall performance and efficient utilization of the resources, an efficient load balanced scheduling algorithm has to be implemented. The scheduling approach also needs to consider user demand to improve user satisfaction. This paper proposes a dynamic hierarchical load balancing approach which considers load of each resource and performs load balancing. It minimizes the response time of the jobs and improves the utilization of the resources in grid environment. By considering the user demand of the jobs, the scheduling algorithm also improves the user satisfaction. The experimental results show the improvement of the proposed load balancing method.

  13. Incorporating demand uncertainty and forecasting in supply chain planning models

    OpenAIRE

    Fildes, R A; Kingsman, B G

    2011-01-01

    This paper develops a framework for examining the effect of demand uncertainty and forecast error on unit costs and customer service levels in the supply chain, including Material Requirements Planning (MRP) type manufacturing systems. The aim is to overcome the methodological limitations and confusion that has arisen in much earlier research. To illustrate the issues, the problem of estimating the value of improving forecasting accuracy for a manufacturer was simulated. The topic is of pract...

  14. Agricultural water demand, water quality and crop suitability in Souk-Alkhamis Al-Khums, Libya

    Science.gov (United States)

    Abunnour, Mohamed Ali; Hashim, Noorazuan Bin Md.; Jaafar, Mokhtar Bin

    2016-06-01

    Water scarcity, unequal population distribution and agricultural activities increased in the coastal plains, and the probability of seawater intrusion with ground water. According to this, the quantitative and qualitative deterioration of underground water quality has become a potential for the occurrence, in addition to the decline in agricultural production in the study area. This paper aims to discover the use of ground water for irrigation in agriculture and their suitability and compatibility for agricultural. On the other hand, the quality is determines by the cultivated crops. 16 random samples of regular groundwater are collected and analyzed chemically. Questionnaires are also distributed randomly on regular basis to farmers.

  15. Demand Estimation for US Apple Juice Imports: A Restricted Source Differentiated AIDS Model

    OpenAIRE

    Mekonnen, Dawit Kelemework; Fonsah, Esendugue Greg

    2011-01-01

    Although this paper focuses on apple juice, a restricted version of source differentiated Almost Ideal Demand System (RSDAIDS) was used to examine U.S. import demand for fresh apple, apple juice and other processed apple. Apple imports were differentiated by type and source of origin and the RSDAIDS model was estimated after imposing the general demand restrictions of adding-up, homogeneity and slutsky symmetry. Seasonality and trend variables were also included on the model. The estimation r...

  16. An oil demand and supply model incorporating monetary policy

    Energy Technology Data Exchange (ETDEWEB)

    Askari, Hossein [George Washington University, 17795 Canby Road, Leesburg, VA 20175 (United States); Krichene, Noureddine [International Monetary Fund, 700 19th Street, NW, Washington DC 20431 (United States)

    2010-05-15

    Oil price inflation may have had a significant role in pushing the world economy into its worst post-war recession during 2008-2009. Reserve currency central banks pursued an overly expansionary monetary policy during 2001-2009, in the form of low or negative real interest rates and accompanied by a rapidly falling US dollar, while paying inadequate attention to the destabilizing effects on oil markets. In this paper, we show that monetary policy variables, namely key interest rates and the US dollar exchange rate, had a powerful effect on oil markets. World oil demand was significantly influenced by interest and dollar exchange rates, while oil supply was rigid. Oil demand and supply have very low price elasticity and this characteristic makes oil prices highly volatile and subject to wider fluctuations than the prices of other commodities. Aggressive monetary policy would stimulate oil demand, however, it would be met with rigid oil supply and would turn inflationary and disruptive to economic growth if there was little excess capacity in oil output. We argue that a measure of stability in oil markets cannot be achieved unless monetary policy is restrained and real interest rates become significantly positive. Monetary tightening during 1979-1982 might imply that monetary policy has to be restrained for a long period and with high interest rates in order to bring stability back to oil markets. (author)

  17. EPANET water quality model

    Energy Technology Data Exchange (ETDEWEB)

    Rossman, L.A.

    1993-01-01

    EPANET represents a third generation of water quality modeling software developed by the U.S. EPA's Drinking Water Research Division, offering significant advances in the state of the art for network water quality analysis. EPANET performs extended period simulation of hydraulic and water quality behavior within water distribution systems. In addition to substance concentration, water age and source tracing can also be simulated. EPANET includes a full featured hydraulic simulation model that can handle various types of pumps, valves, and their control rules. The water quality module is equipped to handle constituent reactions within the bulk pipe flow and at the pipe wall. It also features an efficient computational scheme that automatically determines optimal time steps and pipe segmentation for accurate tracking of material transport over time. EPANET is currently being used in the US to study such issues as loss of chlorine residual, source blending and trihalomethane (THM) formation, how altered tank operation affects water age, and total dissolved solids (TDS) control for an irrigation network.

  18. Stream Water Quality Model

    Data.gov (United States)

    U.S. Environmental Protection Agency — QUAL2K (or Q2K) is a river and stream water quality model that is intended to represent a modernized version of the QUAL2E (or Q2E) model (Brown and Barnwell 1987).

  19. Uncertainty analysis of daily potable water demand on the performance evaluation of rainwater harvesting systems in residential buildings.

    Science.gov (United States)

    Silva, Arthur Santos; Ghisi, Enedir

    2016-09-15

    The objective of this paper is to perform a sensitivity analysis of design variables and an uncertainty analysis of daily potable water demand to evaluate the performance of rainwater harvesting systems in residential buildings. Eight cities in Brazil with different rainfall patterns were analysed. A numeric experiment was performed by means of computer simulation of rainwater harvesting. A sensitivity analysis was performed using variance-based indices for identifying the most important design parameters for rainwater harvesting systems when assessing the potential for potable water savings and underground tank capacity sizing. The uncertainty analysis was performed for different scenarios of potable water demand with stochastic variations in a normal distribution with different coefficients of variation throughout the simulated period. The results have shown that different design variables, such as potable water demand, number of occupants, rainwater demand, and roof area are important for obtaining the ideal underground tank capacity and estimating the potential for potable water savings. The stochastic variations on the potable water demand caused amplitudes of up to 4.8% on the potential for potable water savings and 9.4% on the ideal underground tank capacity. Average amplitudes were quite low for all cities. However, some combinations of parameters resulted in large amplitude of uncertainty and difference from uniform distribution for tank capacities and potential for potable water savings. Stochastic potable water demand generated low uncertainties in the performance evaluation of rainwater harvesting systems; therefore, uniform distribution could be used in computer simulation.

  20. Pengembangan Model Economic Production Quantity (EPQ dengan Sinkronisasi Demand Kontinu dan Diskrit Secara Simultan

    Directory of Open Access Journals (Sweden)

    Nurike Oktavia

    2016-04-01

    Full Text Available The most popular inventory model to determine production lot size is Economic Production Quantity (EPQ. It shows enterprise how to minimize total production cost by reducing inventory cost. But, three main parameters in EPQ which are demand, machine set up cost, and holding cost, are not suitable to solve issues nowadays. When enterprise has two types of demand, continue and discrete demand, the basic EPQ would be no longer useful. Demand continue comes from customer who wants their needs to be fullfilled everytime per unit time, while fullfillment of demand descrete is at a fixed interval of time. Literature review is done by writers to observe other formulation of EPQ model. As there is no other research can be found which adopt this topic, this study try to develop EPQ model considering two types of demand simoultaneously.

  1. Infrastructure sufficiency in meeting water demand under climate-induced socio-hydrological transition in the urbanizing Capibaribe River Basin - Brazil

    Science.gov (United States)

    Ribeiro Neto, A.; Scott, C. A.; Lima, E. A.; Montenegro, S. M. G. L.; Cirilo, J. A.

    2014-03-01

    Water availability for a range of human uses will increasingly be affected by climate change especially in the arid and semi-arid tropics. This paper aims to evaluate the ability of reservoirs and related infrastructure to meet targets for water supply in the Capibaribe River Basin (CRB), in the state of Pernambuco, Brazil. The basin has experienced spatial and sectoral (agriculture-urban) reconfiguration of water demands. Human settlements that were once dispersed, relying on intermittent sources of surface water, are now increasingly experiencing water-scarcity effects. As a result, rural populations in the CRB are concentrating around infrastructural water supplies in a socio-hydrological transition process that results from (a) hydroclimatic variability, (b) investment and assistance programs that may enhance but can also supplant local adaptive capacity, and (c) demographic trends driving urbanization of the state capital, Recife, which mirror urban growth across Brazil. In the CRB, demands are currently composed of 69.1% urban potable water, 14.3% industrial, 16.6% irrigation (with ecosystem-service demands met by residual flow). Based on the application of linked hydrologic and water-resources models using precipitation and temperature projections of the IPCC SRES A1B scenario, a reduction in rainfall of 31.8% translated to streamflow reduction of 67.4% under present reservoir operations rules. The increasing demand due to population was also taken into account. This would entail severe water supply reductions for human consumption (-45.3%) and irrigation (-78.0%) by the end of the 21st century. This study demonstrates the vulnerabilities of the infrastructure system during socio-hydrological transition in response to hydroclimatic and demand variabilities in the CRB and also indicates the differential spatial impacts and vulnerability of multiple uses of water to changes over time. The paper concludes with a discussion of the broader implications of climate

  2. Evaluating Water Conservation and Reuse Policies Using a Dynamic Water Balance Model

    Science.gov (United States)

    Qaiser, Kamal; Ahmad, Sajjad; Johnson, Walter; Batista, Jacimaria R.

    2013-02-01

    A dynamic water balance model is created to examine the effects of different water conservation policies and recycled water use on water demand and supply in a region faced with water shortages and significant population growth, the Las Vegas Valley (LVV). The model, developed using system dynamics approach, includes an unusual component of the water system, return flow credits, where credits are accrued for returning treated wastewater to the water supply source. In LVV, Lake Mead serves as, both the drinking water source and the receiving body for treated wastewater. LVV has a consumptive use allocation from Lake Mead but return flow credits allow the water agency to pull out additional water equal to the amount returned as treated wastewater. This backdrop results in a scenario in which conservation may cause a decline in the available water supply. Current water use in LVV is 945 lpcd (250 gpcd), which the water agency aims to reduce to 752 lpcd (199 gpcd) by 2035, mainly through water conservation. Different conservation policies focused on indoor and outdoor water use, along with different population growth scenarios, are modeled for their effects on the water demand and supply. Major contribution of this study is in highlighting the importance of outdoor water conservation and the effectiveness of reducing population growth rate in addressing the future water shortages. The water agency target to decrease consumption, if met completely through outdoor conservation, coupled with lower population growth rate, can potentially satisfy the Valley's water demands through 2035.

  3. Demand model for production of an enterprise taking into account factor of consumer expectations

    Directory of Open Access Journals (Sweden)

    L.V. Potrashkova

    2012-12-01

    Full Text Available This article presents a dynamic mathematical model of demand for innovative and uninnovative production of enterprises. The model allows to estimate future demand as a result of consumer expectations of production quality. Consumer expectations are considered as the resource component of enterprise marketing potential.

  4. Demand and welfare effects in recreational travel models

    DEFF Research Database (Denmark)

    Hellström, Jörgen; Nordström, Leif Jonas

    2012-01-01

    In this paper we present a non-linear demand system for households’ joint choice of numberof trips and days to spend at a destination. The approach, which facilitates welfare analysis of exogenous policy and price changes, is used empirically to study the effects of an increased CO2 tax...... the importance of accounting for substitutions toward longer stays in traveldemand policy evaluations........ In particular, we focus on the effect of including substitution betweenhouseholds choice of the number of trips and days to spend at a destination in the welfareanalysis. The analysis reveals that the equivalent variation (EV) measure, for the count datademand system, can be seen as an upper bound...

  5. Demand and welfare effects in recreational travel models

    DEFF Research Database (Denmark)

    Hellström, Jörgen; Nordström, Leif Jonas

    In this paper we present a non-linear demand system for households.joint choice of number of trips and days to spend at a destination. The approach, which facilitates welfare analysis of exogenous policy and price changes, is used empirically to study the e¤ects of an increased CO2 tax...... for the households welfare loss. Approximating the welfare loss by the change in consumer surplus, accounting for the positive e¤ect from longer stays, imposes a lower bound on the households welfare loss. From a distributional point of view, the results reveal that the CO2 tax reform is regressive, in the sense...

  6. Scheduling and adaptation of London's future water supply and demand schemes under uncertainty

    Science.gov (United States)

    Huskova, Ivana; Matrosov, Evgenii S.; Harou, Julien J.; Kasprzyk, Joseph R.; Reed, Patrick M.

    2015-04-01

    The changing needs of society and the uncertainty of future conditions complicate the planning of future water infrastructure and its operating policies. These systems must meet the multi-sector demands of a range of stakeholders whose objectives often conflict. Understanding these conflicts requires exploring many alternative plans to identify possible compromise solutions and important system trade-offs. The uncertainties associated with future conditions such as climate change and population growth challenge the decision making process. Ideally planners should consider portfolios of supply and demand management schemes represented as dynamic trajectories over time able to adapt to the changing environment whilst considering many system goals and plausible futures. Decisions can be scheduled and adapted over the planning period to minimize the present cost of portfolios while maintaining the supply-demand balance and ecosystem services as the future unfolds. Yet such plans are difficult to identify due to the large number of alternative plans to choose from, the uncertainty of future conditions and the computational complexity of such problems. Our study optimizes London's future water supply system investments as well as their scheduling and adaptation over time using many-objective scenario optimization, an efficient water resource system simulator, and visual analytics for exploring key system trade-offs. The solutions are compared to Pareto approximate portfolios obtained from previous work where the composition of infrastructure portfolios that did not change over the planning period. We explore how the visual analysis of solutions can aid decision making by investigating the implied performance trade-offs and how the individual schemes and their trajectories present in the Pareto approximate portfolios affect the system's behaviour. By doing so decision makers are given the opportunity to decide the balance between many system goals a posteriori as well as

  7. Projecting and attributing future changes of evaporative demand over China in CMIP5 climate models

    Science.gov (United States)

    Liu, Wenbin; Sun, Fubao

    2017-04-01

    Atmospheric evaporative demand plays a pivotal role in global water and energy budgets and its change is very important for drought monitoring, irrigation scheduling and water resource management under a changing environment. Here, we first projected and attributed future changes of pan evaporation (E_pan), a measurable indictor for atmospheric evaporative demand, over China through a physical- based approach, namely PenPan model, forced with outputs form twelve state-of-the-art Coupled Model Intercomparison Project Phase 5 (CMIP5) climate models. An equidistant quantile mapping method was also used to correct the biases in GCMs outputs to reduce uncertainty in〖 E〗_pan projection. The results indicated that the E_panwould increase during the periods 2021-2050 and 2071-2100 relative to the baseline period 1971-2000 under the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios, which can mainly be attributed to the projected increase in air temperature and vapour pressure deficit over China. The percentage increase of E_pan is relatively larger in eastern China than that in western China, which is due to the spatially inconsistent increases in air temperature, net radiation, wind speed and vapour pressure deficit over China. The widely reported "pan evaporation paradox" was not well reproduced for the period 1961-2000 in the climate models, before or after bias correction, suggesting discrepancy between observed and modeled trends. With that caveat, we found that the pan evaporation has been projected to increase at a rate of 117 167 mm/yr per K (72 80 mm/yr per K) over China using the multiple GCMs under the RCP4.5 (RCP8.5) scenario with increased greenhouse gases and the associated warming of the climate system. References: Liu W, and Sun F, 2017. Projecting and attributing future changes of evaporative demand over China in CMIP5 climate models, Journal of Hydrometeorology, doi: 10.1175/JHM-D-16-0204.1

  8. Development of a model for activated sludge aeration systems: linking air supply, distribution, and demand.

    Science.gov (United States)

    Schraa, Oliver; Rieger, Leiv; Alex, Jens

    2017-02-01

    During the design of a water resource recovery facility, it is becoming industry practice to use simulation software to assist with process design. Aeration is one of the key components of the activated sludge process, and is one of the most important aspects of modelling wastewater treatment systems. However, aeration systems are typically not modelled in detail in most wastewater treatment process modelling studies. A comprehensive dynamic aeration system model has been developed that captures both air supply and demand. The model includes sub-models for blowers, pipes, fittings, and valves. An extended diffuser model predicts both oxygen transfer efficiency within an aeration basin and pressure drop across the diffusers. The aeration system model allows engineers to analyse aeration systems as a whole to determine biological air requirements, blower performance, air distribution, control valve impacts, controller design and tuning, and energy costs. This enables engineers to trouble-shoot the entire aeration system including process, equipment and controls. It also allows much more realistic design of these highly complex systems.

  9. Business process modelling in demand-driven agri-food supply chains : a reference framework

    NARCIS (Netherlands)

    Verdouw, C.N.

    2010-01-01

    Keywords: Business process models; Supply chain management; Information systems; Reference information models; Market orientation; Mass customisation; Configuration; Coordination; Control; SCOR; Pot plants; Fruit industry Abstract The increasing volatility and diversity of demand urge agri-food

  10. Estimating Money Demand Function by a Smooth Transition Regression Model: An Evidence for Turkey

    OpenAIRE

    Sahin, Afsin

    2013-01-01

    The money supply process is assumed to be fixed in economic literature or at least there is a central bank trying to control the liquidity in the economy. On the other hand, the demand side is more volatile and more uncertain. This situation hinders the homogenous and symmetric information assumptions of the monetary models. The amount of money demanded is a dynamic process and changes depending on the transition variable in concern. The money demand increases in the boom periods of the econo...

  11. Avoid population growth to reduce water stress and food demand. Prof. Malin Falkenmark on water, food and population.

    Science.gov (United States)

    1996-01-01

    Global food security is closely linked to the overall availability of water. In some regions of the world, water scarcity will increasingly constrain crop production, forcing a dependency upon food imports. This problem will be particularly acute in dry-climate countries with rapid population growth. Water availability is therefore a fundamental condition for socioeconomic development which requires policymaker attention. Crops depend upon soil moisture and aquifers and rivers. Poor rainfalls and depleted aquifers threaten crop yields. The larger the population, the more water is needed for social and economic needs, including irrigation. However, water for irrigation competes with the water needs of households and industry. Recent research indicates that many dry-climate countries are moving farther away from the possibility of food self-sufficiency. These countries should study their comparative advantages to determine what to export in exchange for food imports from the sub-humid and humid regions of the world. Governments should also promote family planning and the small family norm with the goal of reducing water stress and food demand.

  12. A Novel Statistical Model for Water Age Estimation in Water Distribution Networks

    Directory of Open Access Journals (Sweden)

    Wei-ping Cheng

    2015-01-01

    Full Text Available The water retention time in the water distribution network is an important indicator for water quality. The water age fluctuates with the system demand. The residual chlorine concentration varies with the water age. In general, the concentration of residual chlorine is linearly dependent on the water demand. A novel statistical model using monitoring data of residual chlorine to estimate the nodal water age in water distribution networks is put forward in the present paper. A simplified two-step procedure is proposed to solve this statistical model. It is verified by two virtual systems and a practical application to analyze the water distribution system of Hangzhou city, China. The results agree well with that from EPANET. The model provides a low-cost and reliable solution to evaluate the water retention time.

  13. Profitability Variations of a Solar System with an Evacuated Tube Collector According to Schedules and Frequency of Hot Water Demand

    Directory of Open Access Journals (Sweden)

    Carlos J. Porras-Prieto

    2016-12-01

    Full Text Available The use of solar water heating systems with evacuated tube collectors has been experiencing a rapid growth in recent years. Times when there is demand for hot water, the days of use and the volumes demanded may determine the profitability of these systems, even within the same city. Therefore, this paper characterizes the behavior of a solar system with active circulation with the objective of determining the profitability variations according to the timing and schedule of demand. Through a simplified methodology based on regression equations, calculated for each hour of the day based on data from an experimental facility, the useful energy is estimated from the time and frequency of the demand for hot water at 60 °C. The analysis of the potential profitability of the system in more than 1000 scenarios analyzed shows huge differences depending on the number of days when the water is demanded, the time when demand occurs, the irradiation and the average price of energy. In cities with high irradiation and high energy prices, the system could be profitable even in homes where it is used only on weekends. The study of profitability in a building of 10 homes shows that by applying an average European household’s profile for hot water demand, levels close to full potential would be reached; for this, it is necessary to optimize the collection surface.

  14. Mindfulness as a personal resource to reduce work stress in the job demands-resources model.

    Science.gov (United States)

    Grover, Steven L; Teo, Stephen T T; Pick, David; Roche, Maree

    2017-10-01

    Based on the job demands-resources (JD-R) model, this study examines the different ways that the personal resource of mindfulness reduces stress. Structural equation modeling based on data from 415 Australian nurses shows that mindfulness relates directly and negatively to work stress and perceptions of emotional demands as well as buffering the relation of emotional demands on psychological stress. This study contributes to the literature by employing empirical analysis to the task of unravelling how personal resources function within the JD-R model. It also introduces mindfulness as a personal resource in the JD-R model. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Study on Determination of Chemical Oxygen Demand in Water with Ion Chromatography

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhong-Hai; DING Hong-Chun; FANG Yan-Ju; XIAN Yue-Zhong; JIN Li-Tong

    2007-01-01

    A new method for determining chemical oxygen demand (COD) value in water using ion chromatography coupled with nano TiO2-K2S2O8 co-existing system was described. The photocatalytic oxidation system and nano TiO2-K2S2O8 co-existing system could degrade the organic compounds in water. All sulfur-containing species in the reactive solution were eventually transformed to sulfate which could be determined by conductivity detector in ion chromatography. The change of conductivity of sulfate was proportional to COD value. The optimal experimental conditions and the mechanism of the detection were discussed. The application range was 10.0-300.0 mg·L -1 and the lowest limit of detection was 3.5 mg·L -1. It was considered that the value obtained could be reliably correlated with the COD value obtained using the conventional methods.

  16. Peroxone mineralization of chemical oxygen demand for direct potable water reuse: Kinetics and process control.

    Science.gov (United States)

    Wu, Tingting; Englehardt, James D

    2015-04-15

    Mineralization of organics in secondary effluent by the peroxone process was studied at a direct potable water reuse research treatment system serving an occupied four-bedroom, four bath university residence hall apartment. Organic concentrations were measured as chemical oxygen demand (COD) and kinetic runs were monitored at varying O3/H2O2 dosages and ratios. COD degradation could be accurately described as the parallel pseudo-1st order decay of rapidly and slowly-oxidizable fractions, and effluent COD was reduced to below the detection limit (water, and a relationship is proposed and demonstrated to estimate the pseudo-first order rate constant for design purposes. At this O3/H2O2 mass ratio, ORP and dissolved ozone were found to be useful process control indicators for monitoring COD mineralization in secondary effluent. Moreover, an average second order rate constant for OH oxidation of secondary effluent organics (measured as MCOD) was found to be 1.24 × 10(7) ± 0.64 × 10(7) M(-1) S(-1). The electric energy demand of the peroxone process is estimated at 1.73-2.49 kW h electric energy for removal of one log COD in 1 m(3) secondary effluent, comparable to the energy required for desalination of medium strength seawater. Advantages/disadvantages of the two processes for municipal wastewater reuse are discussed.

  17. Effects of spatially distributed sectoral water management on the redistribution of water resources in an integrated water model

    Science.gov (United States)

    Voisin, Nathalie; Hejazi, Mohamad I.; Leung, L. Ruby; Liu, Lu; Huang, Maoyi; Li, Hong-Yi; Tesfa, Teklu

    2017-05-01

    Realistic representations of sectoral water withdrawals and consumptive demands and their allocation to surface and groundwater sources are important for improving modeling of the integrated water cycle. To inform future model development, we enhance the representation of water management in a regional Earth system (ES) model with a spatially distributed allocation of sectoral water demands simulated by a regional integrated assessment (IA) model to surface and groundwater systems. The integrated modeling framework (IA-ES) is evaluated by analyzing the simulated regulated flow and sectoral supply deficit in major hydrologic regions of the conterminous U.S, which differ from ES studies looking at water storage variations. Decreases in historical supply deficit are used as metrics to evaluate IA-ES model improvement in representating the complex sectoral human activities for assessing future adaptation and mitigation strategies. We also assess the spatial changes in both regulated flow and unmet demands, for irrigation and nonirrigation sectors, resulting from the individual and combined additions of groundwater and return flow modules. Results show that groundwater use has a pronounced regional and sectoral effect by reducing water supply deficit. The effects of sectoral return flow exhibit a clear east-west contrast in the hydrologic patterns, so the return flow component combined with the IA sectoral demands is a major driver for spatial redistribution of water resources and water deficits in the US. Our analysis highlights the need for spatially distributed sectoral representation of water management to capture the regional differences in interbasin redistribution of water resources and deficits.

  18. Modeling Supermarket Refrigeration Systems for Demand-Side Management

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Rasmussen, Henrik; Stoustrup, Jakob

    2013-01-01

    Modeling of supermarket refrigeration systems for supervisory control in the smart grid is presented in this paper. A modular modeling approach is proposed in which each module is modeled and identified separately. The focus of the work is on estimating the power consumption of the system while...

  19. A Demands-Resources Model of Work Pressure in IT Student Task Groups

    Science.gov (United States)

    Wilson, E. Vance; Sheetz, Steven D.

    2010-01-01

    This paper presents an initial test of the group task demands-resources (GTD-R) model of group task performance among IT students. We theorize that demands and resources in group work influence formation of perceived group work pressure (GWP) and that heightened levels of GWP inhibit group task performance. A prior study identified 11 factors…

  20. Explaining Employees' Evaluations of Organizational Change with the Job-Demands Resources Model

    Science.gov (United States)

    van Emmerik, I. J. Hetty; Bakker, Arnold B.; Euwema, Martin C.

    2009-01-01

    Purpose: Departing from the Job Demands-Resources (JD-R) model, the paper examined the relationship between job demands and resources on the one hand, and employees' evaluations of organizational change on the other hand. Design/methodology/approach: Participants were 818 faculty members within six faculties of a Dutch university. Data were…

  1. An EOQ Model with Two-Parameter Weibull Distribution Deterioration and Price-Dependent Demand

    Science.gov (United States)

    Mukhopadhyay, Sushanta; Mukherjee, R. N.; Chaudhuri, K. S.

    2005-01-01

    An inventory replenishment policy is developed for a deteriorating item and price-dependent demand. The rate of deterioration is taken to be time-proportional and the time to deterioration is assumed to follow a two-parameter Weibull distribution. A power law form of the price dependence of demand is considered. The model is solved analytically…

  2. School Burnout and Engagement in the Context of Demands-Resources Model

    Science.gov (United States)

    Salmela-Aro, Katariina; Upadyaya, Katja

    2014-01-01

    Background: A four-wave longitudinal study tested the demands-resources model in the school context. Aim: To examine the applicability of the demands-resources to the school context. Method: Data of 1,709 adolescents were gathered, once during the transition from comprehensive to post-comprehensive education, twice during post-comprehensive…

  3. Explaining Employees' Evaluations of Organizational Change with the Job-Demands Resources Model

    Science.gov (United States)

    van Emmerik, I. J. Hetty; Bakker, Arnold B.; Euwema, Martin C.

    2009-01-01

    Purpose: Departing from the Job Demands-Resources (JD-R) model, the paper examined the relationship between job demands and resources on the one hand, and employees' evaluations of organizational change on the other hand. Design/methodology/approach: Participants were 818 faculty members within six faculties of a Dutch university. Data were…

  4. Inventory rationing in an (s, Q) inventory model with lost sales a two demand classes

    NARCIS (Netherlands)

    Ph. Melchiors; R. Dekker (Rommert); M.J. Kleijn (Marcel)

    1998-01-01

    textabstractWhenever demand for a single item can be categorized into classes of different priority, an inventory rationing policy should be considered. In this paper we analyse a continuous review (s,Q) model with lost sales and two demand classes. A so-called critical level policy is applied to

  5. School Burnout and Engagement in the Context of Demands-Resources Model

    Science.gov (United States)

    Salmela-Aro, Katariina; Upadyaya, Katja

    2014-01-01

    Background: A four-wave longitudinal study tested the demands-resources model in the school context. Aim: To examine the applicability of the demands-resources to the school context. Method: Data of 1,709 adolescents were gathered, once during the transition from comprehensive to post-comprehensive education, twice during post-comprehensive…

  6. Water demand prediction using artificial neural networks and support vector regression

    CSIR Research Space (South Africa)

    Msiza, IS

    2008-11-01

    Full Text Available Computational Intelligence techniques have been proposed as an efficient tool for modeling and forecasting in recent years and in various applications. Water is a basic need and as a result, water supply entities have the responsibility to supply...

  7. Modelling of Sudan’s Energy Supply, Transformation, and Demand

    Directory of Open Access Journals (Sweden)

    Ali A. Rabah

    2016-01-01

    Full Text Available The study aimed to develop energy flow diagram (Sankey diagram of Sudan for the base year 2014. The developed Sankey diagram is the first of its kind in Sudan. The available energy balance for the base year 2012 is a simple line draw and did not count the energy supply by private and mixed sectors such as sugar and oil industries and marine and civil aviation. The private and mixed sectors account for about 7% of the national grid electric power. Four energy modules are developed: resources, transformation, demand, and export and import modules. The data are obtained from relevant Sudanese ministries and directorates and Sudan Central Bank. “e!Sankey 4 pro” software is used to develop the Sankey diagram. The main primary types of energy in Sudan are oil, hydro, biomass, and renewable energy. Sudan has a surplus of gasoline, petroleum coke, and biomass and deficit in electric power, gasoil, jet oil, and LPG. The surplus of gasoline is exported; however, the petroleum coke is kept as reserve. The deficit is covered by import. The overall useful energy is 76% and the loss is 24%. The useful energy is distributed among residential (38%, transportation (33%, industry (12%, services (16%, and agriculture (1% sectors.

  8. Job stress, fatigue, and job dissatisfaction in Dutch lorry drivers: towards an occupation specific model of job demands and control

    OpenAIRE

    de Croon, E.M.; Blonk, R. W. B.; de Zwart, B.C.H.; Frings-Dresen, M.H.W.; Broersen, J.P.J.

    2002-01-01

    Objectives: Building on Karasek's model of job demands and control (JD-C model), this study examined the effects of job control, quantitative workload, and two occupation specific job demands (physical demands and supervisor demands) on fatigue and job dissatisfaction in Dutch lorry drivers.

  9. An economic production model for time dependent demand with rework and multiple production setups

    Directory of Open Access Journals (Sweden)

    S.R. Singh

    2014-04-01

    Full Text Available In this paper, we present a model for time dependent demand with multiple productions and rework setups. Production is demand dependent and greater than the demand rate. Production facility produces items in m production setups and one rework setup (m, 1 policy. The major reason of reverse logistic and green supply chain is rework, so it reduces the cost of production and other ecological problems. Most of the researchers developed a rework model without deteriorating items. A numerical example and sensitivity analysis is shown to describe the model.

  10. Residential Water Demand in a Mexican Biosphere Reserve: Evidence of the Effects of Perceived Price

    Directory of Open Access Journals (Sweden)

    Marco Antonio Almendarez-Hernández

    2016-09-01

    Full Text Available The purpose of this paper is to provide empirical evidence for policy-makers of water management, evaluate the applicability of economic variables such as price and other factors that affect demand, and determine the impact thereof on decision-making surrounding water management in the El Vizcaino Biosphere Reserve in Mexico. We estimated a dynamic function with an average price specification, as well as price perception specification. Findings demonstrated that consumers tend to react to perceived average price but not to the marginal price. Furthermore, long-term price elasticity was found to be higher than short-term elasticity, and both elasticities were found to be inelastic. Inelastic elasticities, coupled with rising prices, generate substantial revenues with which to improve water planning and supply quality and to expand service coverage. The results suggest that users’ level of knowledge surrounding price is a key factor to take into account when restructuring rates, especially in situations where consumers do not readily possess the necessary information about their rate structure and usage within a given billing period. Furthermore, the results can help water management policy-makers to achieve goals of economic efficiency, social equity, and environmental sustainability.

  11. Competition with Online and Offline Demands considering Logistics Costs Based on the Hotelling Model

    Directory of Open Access Journals (Sweden)

    Zhi-Hua Hu

    2014-01-01

    Full Text Available Through popular information technologies (e.g., call centers, web portal, ecommerce and social media, etc., traditional shops change their functions for servicing online demands while still providing offline sales and services, which expand the market and the service capacity. In the Hotelling model that formulates the demand effect by considering just offline demand, the shops in a line city will locate at the center as a the result of competition by games. The online demands are met by the delivery logistics services provided by the shops with additional cost; the consumers’ waiting time after their orders also affects their choices for shops. The main purpose is to study the effects of the following aspects on the shops’ location competition: two logistics costs (consumers’ travelling cost for offline demands and the shops’ delivery logistics cost for online demands, the consumers’ waiting cost for online orders, and the ratios of online demands to the whole demands. Therefore, this study primarily contributes to the literature on the formulation of these aspects by extending the Hotelling model. These features and effects are demonstrated by experiments using the extended Hotelling models.

  12. Prediction of Low Cost Housing Demand in Malaysia Using ARIMA Model

    Directory of Open Access Journals (Sweden)

    Zainun N. Y.

    2016-01-01

    Full Text Available Among the key challenges in construction industry sector faces are matching supply of and demand for affordable housing. It is very crucial to predict low-cost housing demand to match the demand and supply so that the government can plan the allocation of low cost housing based on the demand. In Johor, housing provision is very crucial due to urbanization. The supply of houses seems to be swamping the demand for luxury condos and houses especially in Johor Bharu. Thus the aim of this study is to predict low-cost housing demand in Johor, Malaysia using ARIMA model. Time series data on low-cost housing demand have been converted to Ln before develop the model. The actual data and forecasted data will be compared and validate using Mean Absolute Percentage Error (MAPE. After that, the results using ARIMA method will be compared with ANN method. The results show that MAPE analysis for ARIMA is 15.39% while ANN is 18.27%. It can be conclude that ARIMA model can forecast low cost housing demand in Johor quite good.

  13. A Holistic ICT Solution to Improve Matching between Supply and Demand over the Water Supply Distribution Chain

    Directory of Open Access Journals (Sweden)

    Gabriel Anzaldi

    2014-12-01

    Full Text Available While many water management tools exist, these systems are not usually interconnected and therefore cannot communicate between one another, preventing Integrated Water Resources Management to be fully achieved. This paper presents the solution proposed by WatERP project* where a novel solution enables better matching between water supply and demand from holistic perspective. Subsystems that control the production, management and consumption of water will be interconnected through both information architecture and intelligent infrastructure. The main outcome will consist of, a web-based Open Management Platform integrating near real-time knowledge on water supplies and demand, from sources to users, across geographic and organizational scales and supported by a knowledge base where information will be structured in water management ontology to ensure interoperability and maximize usability. WatERP will thus provide a major contribution to: 1 Improve coordination among actors, 2 Foster behavioural change, 3 Reduce water and energy consumption, 4 Optimize water accountability.

  14. An automotive supply chain model for a demand-driven environment

    Directory of Open Access Journals (Sweden)

    Intaher M. Ambe

    2011-11-01

    Full Text Available The purpose of this article is to demonstrate the development of a supply chain model for the automotive industry that would respond to changing consumer demand. Now more than ever, businesses need to improve the efficiency of their supply chains in order to maintain a competitive advantage. The principles of lean manufacturing and just-intime (JIT inventory control that were renowned for helping companies like Toyota, Dell and Walmart to rise to the top of their respective industries are no longer adequate. Leading companies are applying new technologies and sophisticated analytics to make their supply chains more responsive to customer demand. This challenge is driven by fierce competition, fluctuating market demand and rising customer requirements that have led to customers becoming more demanding with increased preferences. The article is based on theoretical reviews and suggests guidelines for the implementation of an automotive supply chain model for a demand-driven environment.

  15. Model for Assembly Line Re-Balancing Considering Additional Capacity and Outsourcing to Face Demand Fluctuations

    Science.gov (United States)

    Samadhi, TMAA; Sumihartati, Atin

    2016-02-01

    The most critical stage in a garment industry is sewing process, because generally, it consists of a number of operations and a large number of sewing machines for each operation. Therefore, it requires a balancing method that can assign task to work station with balance workloads. Many studies on assembly line balancing assume a new assembly line, but in reality, due to demand fluctuation and demand increased a re-balancing is needed. To cope with those fluctuating demand changes, additional capacity can be carried out by investing in spare sewing machine and paying for sewing service through outsourcing. This study develops an assembly line balancing (ALB) model on existing line to cope with fluctuating demand change. Capacity redesign is decided if the fluctuation demand exceeds the available capacity through a combination of making investment on new machines and outsourcing while considering for minimizing the cost of idle capacity in the future. The objective of the model is to minimize the total cost of the line assembly that consists of operating costs, machine cost, adding capacity cost, losses cost due to idle capacity and outsourcing costs. The model develop is based on an integer programming model. The model is tested for a set of data of one year demand with the existing number of sewing machines of 41 units. The result shows that additional maximum capacity up to 76 units of machine required when there is an increase of 60% of the average demand, at the equal cost parameters..

  16. A high turndown, ultra low emission low swirl burner for natural gas, on-demand water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Robert K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Therkelsen, Peter L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-06-13

    Previous research has shown that on-demand water heaters are, on average, approximately 37% more efficient than storage water heaters. However, approximately 98% of water heaters in the U.S. use storage water heaters while the remaining 2% are on-demand. A major market barrier to deployment of on-demand water heaters is their high retail cost, which is due in part to their reliance on multi-stage burner banks that require complex electronic controls. This project aims to research and develop a cost-effective, efficient, ultra-low emission burner for next generation natural gas on-demand water heaters in residential and commercial buildings. To meet these requirements, researchers at the Lawrence Berkeley National Laboratory (LBNL) are adapting and testing the low-swirl burner (LSB) technology for commercially available on-demand water heaters. In this report, a low-swirl burner is researched, developed, and evaluated to meet targeted on-demand water heater performance metrics. Performance metrics for a new LSB design are identified by characterizing performance of current on-demand water heaters using published literature and technical specifications, and through experimental evaluations that measure fuel consumption and emissions output over a range of operating conditions. Next, target metrics and design criteria for the LSB are used to create six 3D printed prototypes for preliminary investigations. Prototype designs that proved the most promising were fabricated out of metal and tested further to evaluate the LSB’s full performance potential. After conducting a full performance evaluation on two designs, we found that one LSB design is capable of meeting or exceeding almost all the target performance metrics for on-demand water heaters. Specifically, this LSB demonstrated flame stability when operating from 4.07 kBTU/hr up to 204 kBTU/hr (50:1 turndown), compliance with SCAQMD Rule 1146.2 (14 ng/J or 20 ppm NOX @ 3% O2), and lower CO emissions than state

  17. Energy demand modelling and GHG emission reduction: case study Croatia

    DEFF Research Database (Denmark)

    Pukšec, Tomislav; Mathiesen, Brian Vad; Novosel, Tomislav

    2013-01-01

    In the light of new European energy-climate package and its measures for increasing security of supply, decreasing the impact on environment and stimulating sustainable development with special emphasis on job creation and regional growth, Croatia as a future EU member state, needs to reconsider...... GHG module was assembled and added to the NeD model covering all six sectors and calculating its emissions. The model is based on bottom up approach, where data was available, which combines and process large number of input data at the end use level. NeD model was used to present different future GHG...

  18. A simple model of money, credit and aggregate demand

    OpenAIRE

    Spencer Dale; Andrew Haldane

    1993-01-01

    The paper presents a theoretical model of how banks and the non-bank private sector respond to changes in monetary policy. Unlike many textbook models in which banks play no active role, the banking sector is recognised here as playing a key part in transmitting changes in monetary policy to the real economy. In a conventional IS/LM model, the impact of a change in monetary policy arises from the response of expenditure to changes in interest rates (the "monetary" channel). If, however, bank ...

  19. Model documentation report: Commercial Sector Demand Module of the National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-01

    This report documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Commercial Sector Demand Module. The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated through the synthesis and scenario development based on these components. This report serves three purposes. First, it is a reference document providing a detailed description for model analysts, users, and the public. Second, this report meets the legal requirement of the Energy Information Administration (EIA) to provide adequate documentation in support of its statistical and forecast reports (Public Law 93-275, section 57(b)(1)). Third, it facilitates continuity in model development by providing documentation from which energy analysts can undertake model enhancements, data updates, and parameter refinements as future projects.

  20. A Supply and Demand Model of the College Admissions Problem

    OpenAIRE

    2009-01-01

    We develop the first Bayesian model of decentralized college admissions, with heterogeneous students, costly portfolio applications, and noisy college evaluations. Students face a nontrivial portfolio choice, and colleges choose admissions standards that act like market-clearing prices. We derive the two college model equilibrium, deriving a “law of demand”. Surprisingly, the worse college might impose higher standards, and weaker students sometimes apply more aggressively. The lesser coll...

  1. Determinants of orthodontic treatment need and demand: a cross-sectional path model study.

    Science.gov (United States)

    Taghavi Bayat, Jari; Huggare, Jan; Mohlin, Bengt; Akrami, Nazar

    2017-02-01

    To put forward a model predicting orthodontic treatment need and demand. Furthermore, to explore how much of the variance in treatment demand could be explained by a set of self-assessed measures, and how these measures relate to professionally assessed treatment need. One hundred and fifty adolescents, aged 13 years, completed a questionnaire which included a set of self-assessed measures dealing with self-esteem, such as dental and global self-esteem, various aspects of malocclusion, such as perceived malocclusion and perceived functional limitation, and treatment demand. Treatment need was assessed by Dental Health Component of the Index of Orthodontic Treatment Need grading. Path analysis was used to examine the relations between the measures and if they could predict treatment need and demand. The measures proved to be reliable and inter-correlated. Path analysis revealed that the proposed model had good fit to the data, providing a test of the unique effect of all included measures on treatment need and demand. The model explained 33% of the variance in treatment demand and 22% of the variance in treatment need. The specific age group could affect the generalizability of the findings. Moreover, although showing good fit to data, the final model is based on a combination of theoretical reasoning and semi-explorative approach. The proposed model displays the unique effect of each included measure on treatment need and demand, explaining a large proportion of the variance in perceived treatment demand and professionally assessed treatment need. The model would hopefully lead to improved and more cost-efficient predictions of treatment need and demand. © The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. Assessing the ability of potential evapotranspiration models in capturing dynamics of evaporative demand across various biomes and climatic regimes with ChinaFLUX measurements

    Science.gov (United States)

    Zheng, Han; Yu, Guirui; Wang, Qiufeng; Zhu, Xianjin; Yan, Junhua; Wang, Huimin; Shi, Peili; Zhao, Fenghua; Li, Yingnian; Zhao, Liang; Zhang, Junhui; Wang, Yanfen

    2017-08-01

    Estimates of atmospheric evaporative demand have been widely required for a variety of hydrological analyses, with potential evapotranspiration (PET) being an important measure representing evaporative demand of actual vegetated surfaces under given metrological conditions. In this study, we assessed the ability of various PET models in capturing long-term (typically 2003-2011) dynamics of evaporative demand at eight ecosystems across various biomes and climatic regimes in China. Prior to assessing PET dynamics, we first examined the reasonability of fourteen PET models in representing the magnitudes of evaporative demand using eddy-covariance actual evapotranspiration (AET) as an indicator. Results showed that the robustness of the fourteen PET models differed somewhat across the sites, and only three PET models could produce reasonable magnitudes of evaporative demand (i.e., PET ≥ AET on average) for all eight sites, including the: (i) Penman; (ii) Priestly-Taylor and (iii) Linacre models. Then, we assessed the ability of these three PET models in capturing dynamics of evaporative demand by comparing the annual and seasonal trends in PET against the equivalent trends in AET and precipitation (P) for particular sites. Results indicated that nearly all the three PET models could faithfully reproduce the dynamics in evaporative demand for the energy-limited conditions at both annual and seasonal scales, while only the Penman and Linacre models could represent dynamics in evaporative demand for the water-limited conditions. However, the Linacre model was unable to reproduce the seasonal switches between water- and energy-limited states for some sites. Our findings demonstrated that the choice of PET models would be essential for the evaporative demand analyses and other related hydrological analyses at different temporal and spatial scales.

  3. A MULTI-OBJECTIVE ROBUST OPERATION MODEL FORELECTRONIC MARKET ENABLED SUPPLY CHAIN WITH UNCERTAIN DEMANDS

    Institute of Scientific and Technical Information of China (English)

    Jiawang XU; Xiaoyuan HUANG; Nina YAN

    2007-01-01

    A multi-objective robust operation model is proposed in this paper for an electronic market enabled supply chain consisting of multi-supplier and multi-customer with uncertain demands.Suppliers in this supply chain provide many kinds of products to different customers directly or through electronic market.Uncertain demands are described as a scenario set with certain probability; the supply chain operation model is constructed by using the robust optimization method based on scenario analyses.The operation model we proposed is a multi-objective programming problem satisfying several conflict objectives,such as meeting the demands of all customers,minimizing the system cost,the availabilities of suppliers' capacities not below a certain level,and robustness of decision to uncertain demands.The results of numerical examples proved that the solution of the model is most conservative; however,it can ensure the robustness of the operation of the supply chain effectively.

  4. Three stage supply chain model with two warehouse, imperfect production, variable demand rate and inflation

    Directory of Open Access Journals (Sweden)

    Preety Gupta

    2013-01-01

    Full Text Available This study develops an integrated production inventory model from the perspectives of vendor, supplier and buyer. The demand rate is time dependent for the vendor and supplier and buyer assumes the stock dependent demand rate. As per the demand, supplier uses two warehouses (rented and owned for the storage of excess quantities. Shortages are allowed at the buyer’s part only and the unfulfilled demand is partially backlogged. The effect of imperfect production processes on lot sizing is also considered. This complete model is studied under the effect of inflation. The objective is to minimize the total cost for the system. A solution procedure is developed to find a near optimal solution for the model. A numerical example along with sensitivity analysis is given to illustrate the model.

  5. Multi-agent agro-economic simulation of irrigation water demand with climate services for climate change adaptation

    Directory of Open Access Journals (Sweden)

    Stefano Balbi

    2013-09-01

    Full Text Available Farmers’ irrigation practices play a crucial role in the sustainability of crop production and water consumption, and in the way they deal with the current and future effects of climate change. In this study, a system dynamic multi-agent model adopting the soil water balance provided by the Food and Agriculture Organization (FAO Irrigation and Drainage Paper 56 was developed to explore how farmers’ decision making may affect future water needs and use with a focus on the role of climate services, i.e. forecasts and insurance. A climatic projection record representing the down-scaled A1B market scenario (a balance across all sources of the assessment report of the Intergovernmental Panel on Climate Change (IPCC is used to produce future daily data about relative humidity, precipitation, temperature and wind speed. Two types of meteorological services are made available: i a bi-weekly bulletin; and ii seasonal forecasts. The precision of these services was altered to represent different conditions, from perfect knowledge to poor forecasts. Using the available forecasts, farming agents take adaptation decisions concerning crop allocation and irrigation management on the basis of their own risk attitudes. Farmers’ attitudes are characterized by fuzzy classifications depending on age, relative income and crop profitability. Farming agents’ adaptation decisions directly affect the crop and irrigation parameters, which in turn affect future water needs on a territorial level. By incorporating available and future meteorological services, the model allows the farmer’s decision making-process to be explored together with the consequent future irrigation water demand for the period 2015 to 2030. The model prototype is applied to a data set of the Venice Lagoon Watershed, an area of 2038 km2 in north-east Italy, for a preliminary test of its performance and to design future development objectives.

  6. Water quality modelling of Lis River, Portugal.

    Science.gov (United States)

    Vieira, Judite; Fonseca, André; Vilar, Vítor J P; Boaventura, Rui A R; Botelho, Cidália M S

    2013-01-01

    The aim of the study was to predict the impact of flow conditions, discharges and tributaries on the water quality of Lis River using QUAL2Kw model. Calibration of the model was performed, based on data obtained in field surveys carried out in July 2004 and November 2006. Generally the model fitted quite well the experimental data. The results indicated a decrease of water quality in the downstream area of Lis River, after the confluence of Lena, Milagres and Amor tributaries, as a result of discharges of wastewaters containing degradable organics, nutrients and pathogenic organisms from cattle-raising wastewaters, domestic effluents and agricultural runoff. The water quality criteria were exceeded in these areas for dissolved oxygen, biochemical oxygen demand, total nitrogen and faecal coliforms. Water quality modelling in different scenarios showed that the impact of tributaries on the quality of Lis River water was quite negligible and mainly depends on discharges, which are responsible by an increase of almost 45, 13 and 44 % of ultimate carbonaceous biochemical oxygen demand (CBOD(u)), ammonium nitrogen and faecal coliforms, for winter simulation, and 23, 33 and 36 % for summer simulation, respectively, when compared to the real case scenario.

  7. Multi-Objective Demand Response Model Considering the Probabilistic Characteristic of Price Elastic Load

    Directory of Open Access Journals (Sweden)

    Shengchun Yang

    2016-01-01

    Full Text Available Demand response (DR programs provide an effective approach for dealing with the challenge of wind power output fluctuations. Given that uncertain DR, such as price elastic load (PEL, plays an important role, the uncertainty of demand response behavior must be studied. In this paper, a multi-objective stochastic optimization problem of PEL is proposed on the basis of the analysis of the relationship between price elasticity and probabilistic characteristic, which is about stochastic demand models for consumer loads. The analysis aims to improve the capability of accommodating wind output uncertainty. In our approach, the relationship between the amount of demand response and interaction efficiency is developed by actively participating in power grid interaction. The probabilistic representation and uncertainty range of the PEL demand response amount are formulated differently compared with those of previous research. Based on the aforementioned findings, a stochastic optimization model with the combined uncertainties from the wind power output and the demand response scenario is proposed. The proposed model analyzes the demand response behavior of PEL by maximizing the electricity consumption satisfaction and interaction benefit satisfaction of PEL. Finally, a case simulation on the provincial power grid with a 151-bus system verifies the effectiveness and feasibility of the proposed mechanism and models.

  8. SARX Model Application for Industrial Power Demand Forecasting in Brazil

    Directory of Open Access Journals (Sweden)

    Alessandra de Ávila Montini

    2012-06-01

    Full Text Available The objective of this paper is to propose the application of the SARX model to arrive at industrial power consumption forecasts in Brazil, which are critical to support decision-making in the energy sector, based on technical, economic and environmentally sustainable grounds. The proposed model has a seasonal component and considers the influence of exogenous variables on the projection of the dependent variable and utilizes an autoregressive process for residual modeling so as to improve its explanatory power. Five exogenous variables were included: industrial capacity utilization, industrial electricity tariff, industrial real revenues, exchange rate, and machinery and equipment inflation. In addition, the model assumed that power forecast was dependent on its own time lags and also on a dummy variable to reflect 2009 economic crisis. The study used 84 monthly observations, from January 2003 to December 2009. The backward method was used to select exogenous variables, assuming a 0.10 descriptive value. The results showed an adjusted coefficient of determination of 93.9% and all the estimated coefficients were statistically significant at a 0.10 descriptive level. Forecasts were also made from January to May 2010 at a 95% confidence interval, which included actual consumption values for this period. The SARX model has demonstrated an excellent performance for industrial power consumption forecasting in Brazil.

  9. Identifying of risks in pricing using a regression model of demand on price dependence

    Directory of Open Access Journals (Sweden)

    O.I. Yashkina

    2016-09-01

    Full Text Available The aim of the article. The main purpose of the article is to describe scientific and methodological approaches of determining the price elasticity of demand as a regression model based on the price and risk assessment of price variations on the received model. The results of the analysis. The study is based on the assumption that the index of price elasticity of demand on high-tech innovation is not constant as it is commonly understood in the classical sense. On the stage of commodity market release and subsequent sales growth, the index of price elasticity of demand may vary within certain limits. Index value and thereafter market response are closely related to the current price. Achieving the stated purpose of the article is possible when having factual information about prices and corresponding volumes of sales of new high-tech products for a short period of time, on the basis of which types of demand and prices interrelation are modeled. Risk assessment of pricing and profit optimization by the regression of demand depending on price consists of three stages: a obtaining of a regression model of the demand on the price; b obtaining of function of demand price elasticity and risk assessment of pricing depending on behavior of the function; c determination of the price of company to receive a maximum operating profit based on the specific model of price to demand function. To receive the regression model of dependence of demand on price it is recommended to use specific reference models. The article includes linear, hyperbolic and parabolic models. The regression dependence of price elasticity of demand on price for each of the reference models of demand is obtained on the basis of the function elasticity concept in mathematical analysis. The concept of «function of price elasticity of demand» expresses this dependence. For the received functions of price elasticity of demand, the article provides intervals with the highest and lowest

  10. Development of oil supply and demand planning model for mid- and long-term

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hyun [Korea Energy Economics Institute, Euiwang (Korea)

    1997-10-01

    Despite the liberalization of oil market, a systematic model is required for reasonable supply and demand of oil, which still has an important influence on industry and state economy. It is required a demand model deriving prospects of each sector and product and a supply model examining the optimum rate of operation, production mix of products, stock, export and import, and the size of equipment investment to meet given demand. As the first phase for the development of supply and demand model, the existing oil and energy models in domestic and overseas were reviewed and recommendations for establishing a Korean oil supply and demand model were derived in this study. Based on these, a principle for establishing a model and a rough framework were set up. In advance of mid- and long-term prospects, a short-term prospect model was established and the short-term prospects for the first quarter of 1999 and for the year 1999 were presented on trial. Due to the size and characters of a supply model, a plan for an ideal model was first explained and then a plan for creating a model step by step was presented as a realistic scheme. (author). 16 refs., 9 figs., 19 tabs.

  11. A model for estimation of the demand for on-street parking

    DEFF Research Database (Denmark)

    Madsen, Edith; Mulalic, Ismir; Pilegaard, Ninette

    2013-01-01

    ). The cost of cruising is usually unobserved. Ignoring this issue implies a downward bias of the elasticity of demand with respect to the total cost of parking since the cost of cruising depends on the number of cars parked. We also demonstrate that, even when the cost of cruising is unobserved, the demand...... elasticity can be identifed by extending the econometric model to include the spatial interaction between the parking facilities. We illustrate the model with on-street parking data from Copenhagen and Önd indications of a somewhat greater parking demand elasticity than is usually reported in the literature....

  12. [Demand-Control model and occupational stress among nursing professionals: integrative review].

    Science.gov (United States)

    Schmidt, Denise Rodrigues Costa

    2013-01-01

    The Demand Control model aims to evaluate the occupational stress. This study aimed to know, through an integrative review of the literature, the scientific production about the Demand Control Model to investigation occupational stress among nursing professionals from 2000 to 2011.Of the 16 selected studies, five were published in 2009. Of these studies, 56.25% assessed the Demand and Control dimensions and their correlations with workers' health problems; 37.5% of these studies were related with mental health. The results showed a lack of national publications. We recommend that authors conduct experimental studies to reduce the occupational stress for better conditions of workers' mental health.

  13. Capacity expansion modelling to aid water supply investment decisions

    OpenAIRE

    Padula, S

    2015-01-01

    Increasing population, economic development, and environmental changes imply that maintaining the water supply-demand balance will remain a top priority. Water resource systems may need to be expanded in order to respond to demand growth. Capacity expansion studies can be used to answer the question of what the optimal expansion size, timing and location of new infrastructure should be. This thesis develops and applies capacity expansion optimisation modelling approaches. We begin with the 'E...

  14. Forecasting and Analysis of Agricultural Product Logistics Demand in Tibet Based on Combination Forecasting Model

    Institute of Scientific and Technical Information of China (English)

    Wenfeng; YANG

    2015-01-01

    Over the years,the logistics development in Tibet has fallen behind the transport. Since the opening of Qinghai-Tibet Railway in2006,the opportunity for development of modern logistics has been brought to Tibet. The logistics demand analysis and forecasting is a prerequisite for regional logistics planning. By establishing indicator system for logistics demand of agricultural products,agricultural product logistics principal component regression model,gray forecasting model,BP neural network forecasting model are built. Because of the single model’s limitations,quadratic-linear programming model is used to build combination forecasting model to predict the logistics demand scale of agricultural products in Tibet over the next five years. The empirical analysis results show that combination forecasting model is superior to single forecasting model,and it has higher precision,so combination forecasting model will have much wider application foreground and development potential in the field of logistics.

  15. Reducing the chlorine dioxide demand in final disinfection of drinking water treatment plants using activated carbon.

    Science.gov (United States)

    Sorlini, Sabrina; Biasibetti, Michela; Collivignarelli, Maria Cristina; Crotti, Barbara Marianna

    2015-01-01

    Chlorine dioxide is one of the most widely employed chemicals in the disinfection process of a drinking water treatment plant (DWTP). The aim of this work was to evaluate the influence of the adsorption process with granular activated carbon (GAC) on the chlorine dioxide consumption in final oxidation/disinfection. A first series of tests was performed at the laboratory scale employing water samples collected at the outlet of the DWTP sand filter of Cremona (Italy). The adsorption process in batch conditions with seven different types of GAC was studied. A second series of tests was performed on water samples collected at the outlet of four GAC columns installed at the outlet of the DWTP sand filter. The results showed that the best chlorine dioxide demand (ClO2-D) reduction yields are equal to 60-80% and are achieved in the first 30 min after ClO2 addition, during the first 16 days of the column operation using a mineral, coal-based, mesoporous GAC. Therefore, this carbon removes organic compounds that are more rapidly reactive with ClO2. Moreover, a good correlation was found between the ClO2-D and UV absorbance at wavelength 254 nm using mineral carbons; therefore, the use of a mineral mesoporous GAC is an effective solution to control the high ClO2-D in the disinfection stage of a DWTP.

  16. The economic impact of uncertain tourism demand in Hawaii: risk in a computable general equilibrium model

    OpenAIRE

    2009-01-01

    This thesis estimates the economic impact of uncertain tourism demand in Hawaii. It does this by incorporating risk into a Computable General Equilibrium (CGE) model. CGE models have been used to investigate a wide range of policy issues. To date, none have investigated how uncertainty regarding future tourism demand impacts on an economy. The context in which this research is set is the US State of Hawaii. The economy of Hawaii is heavily dependent on tourism as a source of income and a...

  17. Determinants of International Tourism Demand for the Philippines: An Augmented Gravity Model Approach

    OpenAIRE

    Deluna, Roperto Jr; Jeon, Narae

    2014-01-01

    This study was conducted to investigate the determinants of international tourism demand for the Philippines.This study employed a double-log augmented form of gravity model estimated using the robust random effects model.Results revealed that tourist arrival in the Philippines are generally increasing from 2001 to 2012. Empirical estimation was conducted to determine factors affecting Philippine tourism demand. These factors include income, market size, and distance. Relative prices was also...

  18. An EOQ model with time dependent Weibull deterioration and ramp type demand ,

    Directory of Open Access Journals (Sweden)

    Chaitanya Kumar Tripathy

    2011-04-01

    Full Text Available This paper presents an order level inventory system with time dependent Weibull deterioration and ramp type demand rate where production and demand are time dependent. The proposed model of this paper considers economic order quantity under two different cases. The implementation of the proposed model is illustrated using some numerical examples. Sensitivity analysis is performed to show the effect of changes in the parameters on the optimum solution.

  19. Het Job-demands resources model: Een motivationele analyse vanuit de Zelf-Determinatie Theorie

    OpenAIRE

    2013-01-01

    This article details the doctoral dissertation of Anja Van Broeck (2010) detailing employee motivation from two different recent perspectives: the job demands-resources model (JD-R model) en the self-determination theory (SDT). This article primarily highlights how the studies of this dissertation add to the JDR by relying on SDT. First, a distinction is made between two types of job demands: job hindrances and job challenges Second, motivation is shown to represent the underlying mechanism ...

  20. Norwegian Residential Energy Demand: Coordinated use of a System Engineering and a Macroeconomic Model

    Directory of Open Access Journals (Sweden)

    Tor A Johnsen

    1996-07-01

    Full Text Available In Norway, the system engineering model MARKAL and the macroeconomic model MSG-EE are both used in studies of national CO2 controlling strategies. MARKAL is a linear programming model that calculates a composite set of technologies necessary to meet demand and environmental constraints at minimised total energy expenditure. MSG-EE is an applied general equilibrium model including the link between economic activity, energy demand and emissions to air. MSG-EE has a theory consistent description of the link between income, prices and energy demand, but the representation of technological improvements is simple. MARKAL has a sophisticated description of future energy technology options, but includes no feedback to the general economy. A project for studying the potential for a coordinated use of these two models was initiated and funded by the Norwegian Research Council (NFR. This paper gives a brief presentation of the two models. Results from independent model calculations show that MARKAL gives a signficant lower residential energy demand than MSG-EE does. This is explained by major differences in modelling approach. A first attempt of coordinating the residential energy demand in the models is reported. This attempt shows that implementing results from MARKAL, in MSG-EE for the residential sector alone gives little impact on the general economy. A further development of an iteration procedure between the models should include all energy using sectors.

  1. Reduction of large-scale numerical ground water flow models

    NARCIS (Netherlands)

    Vermeulen, P.T.M.; Heemink, A.W.; Testroet, C.B.M.

    2002-01-01

    Numerical models are often used for simulating ground water flow. Written in state space form, the dimension of these models is of the order of the number of model cells and can be very high (> million). As a result, these models are computationally very demanding, especially if many different scena

  2. Demand Model Combining Stated And Revealed Preference Data

    Directory of Open Access Journals (Sweden)

    Luciana Londero Brandli

    2007-10-01

    Full Text Available The revealed and stated preference methods have been contributing a lot for the development of the econometric literature in the attempt of determining the variables that influence the individual decision in a choice process. This article combines preference data, with the objective of obtaining the advantages of the complementarity of the forces and frankness of both types of data. The approach involves the estimate of a model only with RP data, only with SP data and combining RP and SP data. The application is in the housing market, where it is observed, through the literature, that most of the papers of the consumer's choice has restricted the only one approaches. The utility functions obtained show the relative importance of the attributes, the tendency of behavior through the signs and its significance statistical. The results analysis of the models indicates differences and similarities about the attribute’s behavior.

  3. MODELLING CONSUMERS' DEMAND FOR ORGANIC FOOD PRODUCTS: THE SWEDISH EXPERIENCE

    OpenAIRE

    Manuchehr Irandoust

    2016-01-01

    This paper attempts to examine a few factors characterizing consumer preferences and behavior towards organic food products in the south of Sweden using a proportional odds model which captures the natural ordering of dependent variables and any inherent nonlinearities. The findings show that consumer's choice for organic food depends on perceived benefits of organic food (environment, health, and quality) and consumer's perception and attitudes towards labelling system, message framing, and ...

  4. Equilibrium Model of Discrete Dynamic Supply Chain Network with Random Demand and Advertisement Strategy

    Directory of Open Access Journals (Sweden)

    Guitao Zhang

    2014-01-01

    Full Text Available The advertisement can increase the consumers demand; therefore it is one of the most important marketing strategies in the operations management of enterprises. This paper aims to analyze the impact of advertising investment on a discrete dynamic supply chain network which consists of suppliers, manufactures, retailers, and demand markets associated at different tiers under random demand. The impact of advertising investment will last several planning periods besides the current period due to delay effect. Based on noncooperative game theory, variational inequality, and Lagrange dual theory, the optimal economic behaviors of the suppliers, the manufactures, the retailers, and the consumers in the demand markets are modeled. In turn, the supply chain network equilibrium model is proposed and computed by modified project contraction algorithm with fixed step. The effectiveness of the model is illustrated by numerical examples, and managerial insights are obtained through the analysis of advertising investment in multiple periods and advertising delay effect among different periods.

  5. Model documentation report: Residential sector demand module of the National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    This report documents the objectives, analytical approach, and development of the National Energy Modeling System (NEMS) Residential Sector Demand Module. The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, and FORTRAN source code. This document serves three purposes. First, it is a reference document that provides a detailed description for energy analysts, other users, and the public. Second, this report meets the legal requirement of the Energy Information Administration (EIA) to provide adequate documentation in support of its statistical and forecast reports according to Public Law 93-275, section 57(b)(1). Third, it facilitates continuity in model development by providing documentation from which energy analysts can undertake model enhancements, data updates, and parameter refinements.

  6. Model documentation report: Residential sector demand module of the National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    This report documents the objectives, analytical approach, and development of the National Energy Modeling System (NEMS) Residential Sector Demand Module. The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, and FORTRAN source code. This document serves three purposes. First, it is a reference document providing a detailed description for energy analysts, other users, and the public. Second, this report meets the legal requirement of the Energy Information Administration (EIA) to provide adequate documentation in support of its statistical and forecast reports according to Public Law 93-275, section 57(b)(1). Third, it facilitates continuity in model development by providing documentation from which energy analysts can undertake model enhancements, data updates, and parameter refinements.

  7. MODELLING CONSUMERS' DEMAND FOR ORGANIC FOOD PRODUCTS: THE SWEDISH EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Manuchehr Irandoust

    2016-07-01

    Full Text Available This paper attempts to examine a few factors characterizing consumer preferences and behavior towards organic food products in the south of Sweden using a proportional odds model which captures the natural ordering of dependent variables and any inherent nonlinearities. The findings show that consumer's choice for organic food depends on perceived benefits of organic food (environment, health, and quality and consumer's perception and attitudes towards labelling system, message framing, and local origin. In addition, high willingness to pay and income level will increase the probability to buy organic food, while the cultural differences and socio-demographic characteristics have no effect on consumer behaviour and attitudes towards organic food products. Policy implications are offered.

  8. Demand modelling of passenger air travel: An analysis and extension, volume 2

    Science.gov (United States)

    Jacobson, I. D.

    1978-01-01

    Previous intercity travel demand models in terms of their ability to predict air travel in a useful way and the need for disaggregation in the approach to demand modelling are evaluated. The viability of incorporating non-conventional factors (i.e. non-econometric, such as time and cost) in travel demand forecasting models are determined. The investigation of existing models is carried out in order to provide insight into their strong points and shortcomings. The model is characterized as a market segmentation model. This is a consequence of the strengths of disaggregation and its natural evolution to a usable aggregate formulation. The need for this approach both pedagogically and mathematically is discussed. In addition this volume contains two appendices which should prove useful to the non-specialist in the area.

  9. Modeling the effects of demand response on generation expansion planning in restructured power systems

    Institute of Scientific and Technical Information of China (English)

    Mahdi SAMADI; Mohammad Hossein JAVIDI; Mohammad Sadegh GHAZIZADEH

    2013-01-01

    Demand response is becoming a promising field of study in operation and planning of restructured power systems. More attention has recently been paid to demand response programs. Customers can contribute to the operation of power sys-tems by deployment demand response. The growth of customers’ participation in such programs may affect the planning of power systems. Therefore, it seems necessary to consider the effects of demand response in planning approaches. In this paper, the impact of demand responsiveness on decision making in generation expansion planning is modeled. Avoidance or deferment in installation of new generating units is comprehensively investigated and evaluated by introducing a new simple index. The effects of demand responsiveness are studied from the points of view of both customers and generation companies. The pro-posed model has been applied to a modified IEEE 30-bus system and the results of the study are discussed. Simulation results show that reducing just 3%of the customers’ demand (due to price elasticity) may result in a benefit of about 10%for customers in the long term.

  10. A model of the demand for Islamic banks debt-based financing instrument

    Science.gov (United States)

    Jusoh, Mansor; Khalid, Norlin

    2013-04-01

    This paper presents a theoretical analysis of the demand for debt-based financing instruments of the Islamic banks. Debt-based financing, such as through baibithamanajil and al-murabahah, is by far the most prominent of the Islamic bank financing and yet it has been largely ignored in Islamic economics literature. Most studies instead have been focusing on equity-based financing of al-mudharabah and al-musyarakah. Islamic bank offers debt-based financing through various instruments derived under the principle of exchange (ukud al-mu'awadhat) or more specifically, the contract of deferred sale. Under such arrangement, Islamic debt is created when goods are purchased and the payments are deferred. Thus, unlike debt of the conventional bank which is a form of financial loan contract to facilitate demand for liquid assets, this Islamic debt is created in response to the demand to purchase goods by deferred payment. In this paper we set an analytical framework that is based on an infinitely lived representative agent model (ILRA model) to analyze the demand for goods to be purchased by deferred payment. The resulting demand will then be used to derive the demand for Islamic debt. We also investigate theoretically, factors that may have an impact on the demand for Islamic debt.

  11. Demonstration study of biofilm reactor based rapid biochemical oxygen demand determination of surface water

    Directory of Open Access Journals (Sweden)

    Changyu Liu

    2016-05-01

    Full Text Available Application investigations of rapid biochemical oxygen demand (BOD online analyzer for surface water in Wuxi, China were carried out since 2013. The analyzer adopted a novel working principle, that is, the oxygen concentration of the sample to be tested was regarded as a reference, and the oxygen consumption by the biofilm reactor (BFR was calculated according to the difference between the reference and sample effluent from BFR. The BFR was fabricated via a cultivation process using naturally occurring microbial seeds from in site surface water. This analytical principle was first presented and clearly clarified, and the impact of microbial endogenous respiration to the measured values was also proposed and analyzed. The improved analyzers were equipped in three application sites with significant differences in BOD concentration, for the purpose of evaluating the feasibility and applicability of the proposed method. This study revealed that the online analyzer could continually operate over 30 days without human intervention and additional chemical reagent consumption. The obtained rapid BOD trend line showed that this analyzer could track the fluctuation of the biodegradable organic compound level timely and accurately. The innovative analytical method, as well as the outstanding adaptation and well accuracy rating, provided the highlights for wide applications in the future.

  12. Comparing exponential and exponentiated models of drug demand in cocaine users.

    Science.gov (United States)

    Strickland, Justin C; Lile, Joshua A; Rush, Craig R; Stoops, William W

    2016-12-01

    Drug purchase tasks provide rapid and efficient measurement of drug demand. Zero values (i.e., prices with zero consumption) present a quantitative challenge when using exponential demand models that exponentiated models may resolve. We aimed to replicate and advance the utility of using an exponentiated model by demonstrating construct validity (i.e., association with real-world drug use) and generalizability across drug commodities. Participants (N = 40 cocaine-using adults) completed Cocaine, Alcohol, and Cigarette Purchase Tasks evaluating hypothetical consumption across changes in price. Exponentiated and exponential models were fit to these data using different treatments of zero consumption values, including retaining zeros or replacing them with 0.1, 0.01, or 0.001. Excellent model fits were observed with the exponentiated model. Means and precision fluctuated with different replacement values when using the exponential model but were consistent for the exponentiated model. The exponentiated model provided the strongest correlation between derived demand intensity (Q0) and self-reported free consumption in all instances (Cocaine r = .88; Alcohol r = .97; Cigarette r = .91). Cocaine demand elasticity was positively correlated with alcohol and cigarette elasticity. Exponentiated parameters were associated with real-world drug use (e.g., weekly cocaine use) whereas these correlations were less consistent for exponential parameters. Our findings show that selection of zero replacement values affects demand parameters and their association with drug-use outcomes when using the exponential model but not the exponentiated model. This work supports the adoption of the exponentiated demand model by replicating improved fit and consistency and demonstrating construct validity and generalizability. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  13. A Conceptual Model for Water Sensitive City in Surabaya

    Science.gov (United States)

    Pamungkas, A.; Tucunan, K. P.; Navastara, A.; Idajati, H.; Pratomoatmojo, N. A.

    2017-08-01

    Frequent inundated areas, low quality of water supply, highly dependent water sources from external are some key problems in Surabaya water balance. Many aspects of urban development have stimulated those problems. To uncover the complexity of water balance in Surabaya, a conceptual model for water sensitive city is constructed to find the optimum solution. A system dynamic modeling is utilized to assist and enrich the idea of conceptual model. A secondary analysis to a wide range data directs the process in making a conceptual model. FGD involving many experts from multidiscipline are also used to finalize the conceptual model. Based on those methods, the model has four main sub models that are; flooding, land use change, water demand and water supply. The model consists of 35 key variables illustrating challenges in Surabaya urban water.

  14. The primary demand for beer in the Netherlands; an application of ARMAX model specification

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans)

    1991-01-01

    textabstractThe central issue in the application of econometric and time series analysis (ETS) to market response models is the model-building process. The author proposes a specification strategy for ETS modeling and applies it to the primary demand for beer in The Netherlands.

  15. A comparison between the effort-reward imbalance and demand control models.

    Science.gov (United States)

    Ostry, Aleck S; Kelly, Shona; Demers, Paul A; Mustard, Cameron; Hertzman, Clyde

    2003-02-27

    To compare the predictive validity of the demand/control and reward/imbalance models, alone and in combination with each other, for self-reported health status and the self-reported presence of any chronic disease condition. Self-reports for psychosocial work conditions were obtained in a sample of sawmill workers using the demand/control and effort/reward imbalance models. The relative predictive validity of task-level control was compared with effort/reward imbalance. As well, the predictive validity of a model developed by combining task-level control with effort/reward imbalance was determined. Logistic regression was utilized for all models. The demand/control and effort/reward imbalance models independently predicted poor self-reported health status. The effort-reward imbalance model predicted the presence of a chronic disease while the demand/control model did not. A model combining effort-reward imbalance and task-level control was a better predictor of self-reported health status and any chronic condition than either model alone. Effort reward imbalance modeled with intrinsic effort had marginally better predictive validity than when modeled with extrinsic effort only. Future work should explore the combined effects of these two models of psychosocial stress at work on health more thoroughly.