Water Demand Management Policy Brief No

International Development Research Centre (IDRC) Digital Library (Canada)

Bob Stanley

Water demand management ― WDM ― can be hard to define. More an issue of policy than of technology, it is about managing and moderating our demands for good quality fresh water. It is less a matter of piping and pumps and more a tool ...

Identifying water price and population criteria for meeting future urban water demand targets

Science.gov (United States)

Ashoori, Negin; Dzombak, David A.; Small, Mitchell J.

2017-12-01

Predictive models for urban water demand can help identify the set of factors that must be satisfied in order to meet future targets for water demand. Some of the explanatory variables used in such models, such as service area population and changing temperature and rainfall rates, are outside the immediate control of water planners and managers. Others, such as water pricing and the intensity of voluntary water conservation efforts, are subject to decisions and programs implemented by the water utility. In order to understand this relationship, a multiple regression model fit to 44 years of monthly demand data (1970-2014) for Los Angeles, California was applied to predict possible future demand through 2050 under alternative scenarios for the explanatory variables: population, price, voluntary conservation efforts, and temperature and precipitation outcomes predicted by four global climate models with two CO2 emission scenarios. Future residential water demand in Los Angeles is projected to be largely driven by price and population rather than climate change and conservation. A median projection for the year 2050 indicates that residential water demand in Los Angeles will increase by approximately 36 percent, to a level of 620 million m3 per year. The Monte Carlo simulations of the fitted model for water demand were then used to find the set of conditions in the future for which water demand is predicted to be above or below the Los Angeles Department of Water and Power 2035 goal to reduce residential water demand by 25%. Results indicate that increases in price can not ensure that the 2035 water demand target can be met when population increases. Los Angeles must rely on furthering their conservation initiatives and increasing their use of stormwater capture, recycled water, and expanding their groundwater storage. The forecasting approach developed in this study can be utilized by other cities to understand the future of water demand in water-stressed areas

Long-term water demand for electricity, industry and households

NARCIS (Netherlands)

Bijl, David L.; Bogaart, Patrick W.; Kram, Tom; de Vries, Bert J M; van Vuuren, Detlef P.

2016-01-01

Better water demand projections are needed in order to better assess water scarcity. The focus in this paper is on non-agricultural water demand, as this is the fastest-growing and least well-modelled demand component. We describe an end use-oriented model for future water demand in the electricity,

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.

Water dynamics of vegetable using radiation

International Nuclear Information System (INIS)

Nakanishi, Tomoko

2000-01-01

Neutral ray is specifically adsorbed and scattered by hydrogen, which is construction element of water. We applied nondestructive visualization of water dynamics in vegetable using neutral ray. The neutron ray was produced by JRR-3M of JAERI. Water dynamics of epigeal part of vegetable, tree, seed, root and soil near root were observed. The distribution and behavior of water were seen by image. For examples, the dry process of cedar, water adsorption process of seed of broad beam, corn, morning glory, rice and wheat. The growing process of root in the soil was analyzed by CT images that constructed three-dimensional image. Water image of root-soil system made clear water dynamics of the optional site near root. The distribution of water in the cut carnation was observed before and after dry treatment. The change of distribution of water was observed. (S.Y.)

­­Drought, water conservation, and water demand rebound in California

Science.gov (United States)

Gonzales, P.; Ajami, N.

2017-12-01

There is growing recognition that dynamic community values, preferences, and water use behaviors are important drivers of water demand in addition to external factors such as temperature and precipitation. Water demand drivers have been extensively studied, yet they have traditionally been applied to models that assume static conditions and usually do not account for potential societal changes in response to increased scarcity awareness. For example, following a period of sustained low demand such as during a drought, communities often increase water use during a hydrologically wet period, a phenomenon known as "rebounding" water use. Yet previous experiences show the extent of this rebound is not a straightforward function of policy and efficiency improvements, but may also reflect short-term or long-lasting change in community behavior, which are not easily captured by models that assume stationarity. In this study we explore cycles of decreased water demand during drought and subsequent water use rebound observed in California in recent decades. We have developed a novel dynamic system model for water demand in three diverse but interconnected service areas in the San Francisco Bay Area, exposing local trends of changing water use behaviors and long-term impacts on water demand since 1980 to the present. In this model, we apply the concept of social memory, defined as a community's inherited knowledge about hazardous events or degraded environmental conditions from past experiences. While this concept has been applied to further conceptual understanding of socio-hydrologic systems in response to hydrological extremes, to the best of our knowledge this the first study to incorporate social memory to model the water demand rebound phenomenon and to use such a model in the examination of changing dynamics validated by historical data. In addition, we take a closer look at water demand during the recent historic drought in California from 2012-16, and relate our

Improving Water Demand Management by Addressing ...

International Development Research Centre (IDRC) Digital Library (Canada)

IDRC CRDI

Efforts to conserve water by improving water demand management policies .... First, ensure fair access to sustainable water supply, as well as, responsible water use. ... Water policy can also mandate reducing the loss of quantity or quality of ...

Water quality function of an extensive vegetated roof.

Science.gov (United States)

Todorov, Dimitar; Driscoll, Charles T; Todorova, Svetoslava; Montesdeoca, Mario

2018-06-01

In this paper we present the results of a four-year study of water quality in runoff from an extensive, sedum covered, vegetated roof on an urban commercial building. Monitoring commenced seven months after the roof was constructed, with the first growing season. Stormwater drainage quality function of the vegetated roof was compared to a conventional (impermeable, high-albedo) membrane roof in addition to paired measurements of wet and bulk depositions at the study site. We present concentrations and fluxes of nutrients and major solutes. We discuss seasonal and year-to-year variation in water quality of drainage from the vegetated roof and how it compares with atmospheric deposition and drainage from the impermeable roof. Drainage waters from the vegetated roof exhibited a high concentration of nutrients compared to atmospheric deposition, particularly during the warm temperature growing season. However, nutrient losses were generally low because of the strong retention of water by the vegetated roof. There was marked variation in the retention of nutrients by season due to variations in concentrations in drainage from the vegetated roof. The vegetated roof was a sink of nitrogen, total phosphorus and chloride, and a source of phosphate and dissolved inorganic and organic carbon. Chloride exhibited elevated inputs and leaching during the winter. The drainage from the vegetated and impermeable roofs met the United States Environmental Protection Agency freshwater standards for all parameters, except for total phosphorus. Copyright © 2017 Elsevier B.V. All rights reserved.

Conceptual Framework and Computational Research of Hierarchical Residential Household Water Demand

Directory of Open Access Journals (Sweden)

Baodeng Hou

2018-05-01

Full Text Available Although the quantity of household water consumption does not account for a huge proportion of the total water consumption amidst socioeconomic development, there has been a steadily increasing trend due to population growth and improved urbanization standards. As such, mastering the mechanisms of household water demand, scientifically predicting trends of household water demand, and implementing reasonable control measures are key focuses of current urban water management. Based on the categorization and characteristic analysis of household water, this paper used Maslow’s Hierarchy of Needs to establish a level and grade theory of household water demand, whereby household water is classified into three levels (rigid water demand, flexible water demand, and luxury water demand and three grades (basic water demand, reasonable water demand, and representational water demand. An in-depth analysis was then carried out on the factors that influence the computation of household water demand, whereby equations for different household water categories were established, and computations for different levels of household water were proposed. Finally, observational experiments on household water consumption were designed, and observation and simulation computations were performed on three typical households in order to verify the scientific outcome and rationality of the computation of household water demand. The research findings contribute to the enhancement and development of prediction theories on water demand, and they are of high theoretical and realistic significance in terms of scientifically predicting future household water demand and fine-tuning the management of urban water resources.

Estimation of water demand in water distribution systems using particle swarm optimization

CSIR Research Space (South Africa)

Letting, LK

2017-08-01

Full Text Available and an evolutionary algorithm is a potential solution to the demand estimation problem. This paper presents a detailed process simulation model for water demand estimation using the particle swarm optimization (PSO) algorithm. Nodal water demands and pipe flows...

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.

Integrated Modeling of Crop Growth and Water Resource Management to Project Climate Change Impacts on Crop Production and Irrigation Water Supply and Demand in African Nations

Science.gov (United States)

Dale, A. L.; Boehlert, B.; Reisenauer, M.; Strzepek, K. M.; Solomon, S.

2017-12-01

Climate change poses substantial risks to African agriculture. These risks are exacerbated by concurrent risks to water resources, with water demand for irrigation comprising 80 to 90% of water withdrawals across the continent. Process-based crop growth models are able to estimate both crop demand for irrigation water and crop yields, and are therefore well-suited to analyses of climate change impacts at the food-water nexus. Unfortunately, impact assessments based on these models generally focus on either yields or water demand, rarely both. For this work, we coupled a crop model to a water resource management model in order to predict national trends in the impact of climate change on crop production, irrigation water demand, and the availability of water for irrigation across Africa. The crop model FAO AquaCrop-OS was run at 2ox2o resolution for 17 different climate futures from the CMIP5 archive, nine for Representative Concentration Pathway (RCP) 4.5 and eight for RCP8.5. Percent changes in annual rainfed and irrigated crop production and temporal shifts in monthly irrigation water demand were estimated for the years 2030, 2050, 2070, and 2090 for maize, sorghum, rice, wheat, cotton, sugarcane, fruits & vegetables, roots & tubers, and legumes & soybeans. AquaCrop was then coupled to a water management model (WEAP) in order to project changes in the ability of seven major river basins (the Congo, Niger, Nile, Senegal, Upper Orange, Volta, and Zambezi) to meet irrigation water demand out to 2050 in both average and dry years in the face of both climate change and irrigation expansion. Spatial and temporal trends were identified and interpreted through the lens of potential risk management strategies. Uncertainty in model estimates is reported and discussed.

Vegetation Water Content Mapping for Agricultural Regions in SMAPVEX16

Science.gov (United States)

White, W. A.; Cosh, M. H.; McKee, L.; Berg, A. A.; McNairn, H.; Hornbuckle, B. K.; Colliander, A.; Jackson, T. J.

2017-12-01

Vegetation water content impacts the ability of L-band radiometers to measure surface soil moisture. Therefore it is necessary to quantify the amount of water held in surface vegetation for an accurate soil moisture remote sensing retrieval. A methodology is presented for generating agricultural vegetation water content maps using Landsat 8 scenes for agricultural fields of Iowa and Manitoba for the Soil Moisture Active Passive Validation Experiments in 2016 (SMAPVEX16). Manitoba has a variety of row crops across the region, and the study period encompasses the time frame from emergence to reproduction, as well as a forested region. The Iowa study site is dominated by corn and soybeans, presenting an easier challenge. Ground collection of vegetation biomass and water content were also collected to provide a ground truth data source. Errors for the resulting vegetation water content maps ranged depending upon crop type, but generally were less than 15% of the total plant water content per crop type. Interpolation is done between Landsat overpasses to produce daily vegetation water content maps for the summer of 2016 at a 30 meter resolution.

Water brief — Wastewater Reuse for Water Demand Management ...

International Development Research Centre (IDRC) Digital Library (Canada)

2011-01-04

Jan 4, 2011 ... Water Demand Management (WDM) is a water management approach that aims to ... WDM is simply defined as 'getting the most of the water that we have', while taking into ... Villages in Nepal prepare for weather extremes.

Water Demand Management ― Making the most of the water we ...

International Development Research Centre (IDRC) Digital Library (Canada)

2010-12-22

Dec 22, 2010 ... Water demand management ― WDM ― can be hard to define. More an issue of policy than of technology, it is about managing and moderating our demands for good quality fresh water. It is less a matter of piping and pumps and more a tool for changing the ways we use water and the rates at which we ...

Mercury concentration in vegetables of Pakistan irrigated by different water sources

International Nuclear Information System (INIS)

Shaheen, Q.; Mahmood, Z.; Imran, M.

2011-01-01

Mercury levels were determined in twenty samples of each vegetable i.e., Spinach (Spinacia oleracea), Lettuce (Lactuca sativa), Carrot (Daucus cariota), Capsicum (Capsicum fistulosus), Sweet pea (Lathyrus Odoratus), Potato (Solanum tuberosum) and Cabbage (Brassica oleracea), with a special reference of source of water of irrigation, i.e., tube well water, canal water and municipal sewage water. All the samples of vegetables were collected during the year 2006, 2007 and 2008 from the five districts of Pakistan viz Lahore, Kasur, Multan, Bahawalpur and R.Y. Khan. Statistical analysis such as Test of significance and multiple comparison were applied on the data obtained. The results showed that the concentration of Mercury in vegetables irrigated by canal water, sewage water and tube well water was in the range of 3.1-88.9 ppb and 9.0-130.6 ppb. It can be concluded from this study that the uptake of mercury by vegetables collected from above five districts of Pakistan was in the following order. Leafy vegetables > Root vegetables > seedy vegetables. (author)

Water advisory demand evaluation and resource toolkit

OpenAIRE

Paluszczyszyn, D.; Illya, S.; Goodyer, E.; Kubrycht, T.; Ambler, M.

2016-01-01

Cities are living organisms, 24h / 7day, with demands on resources and outputs. Water is a key resource whose management has not kept pace with modern urban life. Demand for clean water and loads on waste water no longer fit diurnal patterns; and they are impacted by events that are outside the normal range of parameters that are taken account of in water management. This feasibility study will determine how the application of computational intelligence can be used to analyse a mix of dat...

The influence of proximity on the potential demand for vegetable oil as a diesel substitute: A rural survey in West Africa

International Nuclear Information System (INIS)

Litvine, Dorian; Dabat, Marie-Helene; Gazull, Laurent

2013-01-01

Bio-energy demand is known to be influenced by geographical origin and social equity. This paper aims to highlight the influence of the proximity between biomass production and energy consumption on the demand for alternative bio-fuels. In the context of Burkina Faso, we explore potential demand for vegetable oil (Jatropha Curcas) as a diesel substitute among engine owners. Survey data are based on a between-groups design: one group of respondents experiencing a local supply chain, while the other a global one. Results show that proximity has a significant effect on potential demand itself and on the formation and strength of beliefs regarding vegetable oil. In a local supply chain context, the demand is superior and seems to be guided more by a certain economic and technical rationality. Conversely, the prospect of a vegetable oil produced outside the village restrains demand and this latter is more determined by contextual factors and social interaction. Our analysis confirms that demand does not only depend on technical and economic factors such as price but also on the integration of the biomass production and processing in the socioeconomic life of local rural populations. Understanding demand construction and assessing underlying beliefs are key success factors for bio-energy projects. (authors)

Potential for water salvage by removal of non-native woody vegetation from dryland river systems

Science.gov (United States)

Doody, T.M.; Nagler, P.L.; Glenn, E.P.; Moore, G.W.; Morino, K.; Hultine, K.R.; Benyon, R.G.

2011-01-01

Globally, expansion of non-native woody vegetation across floodplains has raised concern of increased evapotranspiration (ET) water loss with consequent reduced river flows and groundwater supplies. Water salvage programs, established to meet water supply demands by removing introduced species, show little documented evidence of program effectiveness. We use two case studies in the USA and Australia to illustrate factors that contribute to water salvage feasibility for a given ecological setting. In the USA, saltcedar (Tamarix spp.) has become widespread on western rivers, with water salvage programs attempted over a 50-year period. Some studies document riparian transpiration or ET reduction after saltcedar removal, but detectable increases in river base flow are not conclusively shown. Furthermore, measurements of riparian vegetation ET in natural settings show saltcedar ET overlaps the range measured for native riparian species, thereby constraining the possibility of water salvage by replacing saltcedar with native vegetation. In Australia, introduced willows (Salix spp.) have become widespread in riparian systems in the Murray-Darling Basin. Although large-scale removal projects have been undertaken, no attempts have been made to quantify increases in base flows. Recent studies of ET indicate that willows growing in permanently inundated stream beds have high transpiration rates, indicating water savings could be achieved from removal. In contrast, native Eucalyptus trees and willows growing on stream banks show similar ET rates with no net water salvage from replacing willows with native trees. We conclude that water salvage feasibility is highly dependent on the ecohydrological setting in which the non-native trees occur. We provide an overview of conditions favorable to water salvage. Copyright ?? 2011 John Wiley & Sons, Ltd.

The soil water balance in a mosaic of clumped vegetation

Science.gov (United States)

Pizzolla, Teresa; Manfreda, Salvatore; Caylor, Kelly; Gioia, Andrea; Iacobellis, Vito

2014-05-01

The spatio-temporal distribution of soil moisture influences the plant growth and the distribution of terrestrial vegetation. This effect is more evident in arid and semiarid ecosystems where the interaction between individuals and the water limited conditions play a fundamental role, providing environmental conditions which drive a variety of non-linear ecohydrological response functions (such as transpiration, photosynthesis, leakage). In this context, modeling vegetation patterns at multiple spatial aggregation scales is important to understand how different vegetation structures can modify the soil water distribution and the exchanged fluxes between soil and atmosphere. In the present paper, the effect of different spatial vegetation patterns, under different climatic scenarios, is investigated in a patchy vegetation mosaic generated by a random process of individual tree canopies and their accompanying root system. Vegetation pattern are generated using the mathematical framework proposed by Caylor et al. (2006) characterized by a three dimensional stochastic vegetation structure, based on the density, dispersion, size distribution, and allometry of individuals within a landscape. A Poisson distribution is applied to generate different distribution of individuals paying particular attention on the role of clumping on water distribution dynamics. The soil water balance is evaluated using the analytical expression proposed by Laio et al. (2001) to explore the influence of climate and vegetation patterns on soil water balance steady-state components (such as the average rates of evaporation, the root water uptake and leakage) and on the stress-weighted plant water uptake. Results of numerical simulations show that clumping may be beneficial for water use efficiency at the landscape scale. References Caylor, Kelly K., P. D'Odorico and I. Rodriguez Iturbe: On the ecohydrology of structurally heterogeneous semiarid landscape. Water Resour. Res., 28, W07424, 2006

A model to assess water tariffs as part of water demand management

African Journals Online (AJOL)

Keywords: water demand management, price elasticity, change in water tariff, block tariff, WC/WDM model. INTRODUCTION ... ever developed for a 6-block pricing structure and allows for limited available input data from ..... Payment Strategies and Price Elasticity of Demand for Water for. Different revenue Groups in Three ...

Water Demand Management Policy Brief No

International Development Research Centre (IDRC) Digital Library (Canada)

Bob Stanley

Fair share: Water Demand Management can help provide fair access to water for the poor. Water Policy. Brief no.2 ... management (WDM) can help spread water more equitably, providing a measure of opportunity, security and ... improving health and quality of life for families. WDM measures can improve the efficiency of.

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.

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.

Optimised control and pipe burst detection by water demand forecasting

NARCIS (Netherlands)

Bakker, M.

2014-01-01

Water demand forecasting The total water demand in an area is the sum of the water demands of all individual domestic and industrial consumers in that area. These consumers behave in repetitive daily, weekly and annual patterns, and the same repetitive patterns can be observed in the drinking water

Tapping Alternatives: The Benefits of Managing Urban Water Demands.

Science.gov (United States)

Dziegielewski, Benedykt; Baumann, Duane D.

1992-01-01

Presents the California plan for water demand management. Water conservation techniques are used to balance demand with supply. Discusses the implementation process: (1) water-use and service area analysis; (2) water-use forecasts; (3) benefit-cost analysis; (4) and development of a long-term water management plan. (17 references) (MCO)

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.

Resilience Through Disturbance: Effects of Wildfire on Vegetation and Water Balance in the Sierra Nevadas

Science.gov (United States)

Boisrame, G. F. S.; Thompson, S. E.; Stephens, S.; Collins, B.; Tague, N.

2015-12-01

A century of fire suppression in the Western United States has drastically altered the historically fire-adapated ecology in California's Sierra Nevada Mountains. Fire suppression is understood to have increased the forest cover, as well as the stem density, canopy cover and water demand of montane forests, reducing resilience of the forests to drought, and increasing the risk of catastrophic fire by drying the landscape and increasing fuel loads. The potential to reverse these trends by re-introducing fire into the Sierra Nevada is highly promising, but the likely effects on vegetation structure and water balance are poorly quantified. The Illilouette Creek Basin in Yosemite National Park represents a unique experiment in the Sierra Nevada, in which managers have moved from fire suppression to allowing a near-natural fire regime to prevail since 1972. Changes in vegetation structure in the Illilouette since the restoration of natural burning provides a unique opportunity to examine how frequent, mixed severity fires can reshape the Sierra Nevada landscape. We characterize these changes from 1969 to the present using a combination of Landsat products and high-resolution aerial imagery. We describe how the landscape structure has changed in terms of vegetation composition and its spatial organization, and explore the drivers of different post-fire vegetation type transitions (e.g. forest to shrubland vs. forest to meadow). By upscaling field data using vegetation maps and Landsat wetness indices, we explore how these vegetation transitions have impacted the water balance of the Illilouette Creek Basin, potentially increasing its resilience in the face of drought, climate change, and catastrophic fire. In a region that is adapted to frequent disturbance from fire, this work helps us understand how allowing such natural disturbances to take place can increase the sustainability of diverse landscapes in the long term.

Trading the Economic Value of Unsatisfied Municipal Water Demand

Science.gov (United States)

Telfah, Dua'a. B.; Minciardi, Riccardo; Roth, Giorgio

2018-06-01

Modelling and optimization techniques for water resources allocation are proposed to identify the economic value of the unsatisfied municipal water demand against demands emerging from other sectors. While this is always an important step in integrated water resource management perspective, it became crucial for water scarce Countries. In fact, since the competition for the resource is high, they are in crucial need to trade values which will help them in satisfying their policies and needs. In this framework, hydro-economic, social equity and environmental constraints need to be satisfied. In the present study, a hydro-economic decision model based on optimization schemes has been developed for water resources allocation, that enable the evaluation of the economic cost of a deficiency in fulfilling the municipal demand. Moreover, the model enables efficient water resources management, satisfying the demand and proposing additional water resources options. The formulated model is designed to maximize the demand satisfaction and minimize water production cost subject to system priorities, preferences and constraints. The demand priorities are defined based on the effect of demand dissatisfaction, while hydrogeological and physical characteristics of the resources are embedded as constraints in the optimization problem. The application to the City of Amman is presented. Amman is the Capital City of the Hashemite Kingdom of Jordan, a Country located in the south-eastern area of the Mediterranean, on the East Bank of the Jordan River. The main challenge for Jordan, that threat the development and prosperity of all sectors, is the extreme water scarcity. In fact, Jordan is classified as semi-arid to arid region with limited financial resources and unprecedented population growth. While the easy solution directly goes to the simple but expensive approach to cover the demand, case study results show that the proposed model plays a major role in providing directions to

Trading the Economic Value of Unsatisfied Municipal Water Demand

Directory of Open Access Journals (Sweden)

D. B. Telfah

2018-06-01

Full Text Available Modelling and optimization techniques for water resources allocation are proposed to identify the economic value of the unsatisfied municipal water demand against demands emerging from other sectors. While this is always an important step in integrated water resource management perspective, it became crucial for water scarce Countries. In fact, since the competition for the resource is high, they are in crucial need to trade values which will help them in satisfying their policies and needs. In this framework, hydro-economic, social equity and environmental constraints need to be satisfied. In the present study, a hydro-economic decision model based on optimization schemes has been developed for water resources allocation, that enable the evaluation of the economic cost of a deficiency in fulfilling the municipal demand. Moreover, the model enables efficient water resources management, satisfying the demand and proposing additional water resources options. The formulated model is designed to maximize the demand satisfaction and minimize water production cost subject to system priorities, preferences and constraints. The demand priorities are defined based on the effect of demand dissatisfaction, while hydrogeological and physical characteristics of the resources are embedded as constraints in the optimization problem. The application to the City of Amman is presented. Amman is the Capital City of the Hashemite Kingdom of Jordan, a Country located in the south-eastern area of the Mediterranean, on the East Bank of the Jordan River. The main challenge for Jordan, that threat the development and prosperity of all sectors, is the extreme water scarcity. In fact, Jordan is classified as semi-arid to arid region with limited financial resources and unprecedented population growth. While the easy solution directly goes to the simple but expensive approach to cover the demand, case study results show that the proposed model plays a major role in

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

Albedo and vegetation demand-side management options for warm climates

International Nuclear Information System (INIS)

Hall, Darwin C.

1997-01-01

For electric utilities, demand-side management (DSM) can reduce electric load and shift load from peak to off-peak periods. In general, the investor in DSM collects the reward with lower electric bills, excepting a positive externality because of reduced tropospheric and stratospheric air pollution from fossil fuel power plants. In warm climates, DSM options include increasing albedo and vegetation, respectively, by painting surfaces white and planting trees; these DSM options are distinguished from all other DSM options because of ecosystem effects. Ambient temperature falls, mitigating the urban 'heat island', which reduces electric load and ozone formation. The investor in albedo and vegetation DSM options does not collect all of the reward from lower electric bills, since the lower ambient temperature provides savings to all customers who use electricity for air conditioning and refrigeration. Similar to other DSM options, air pollution is also reduced as a result of lower power plant emissions. Complex airshed models and electric utility system dispatch models are applied in this paper to account for some of these ecosystem effects. Unaccounted ecosystem effects remain, stymieing cost effectiveness analysis

Information or prices, which is most powerful in increasing consumer demand for organic vegetables?

DEFF Research Database (Denmark)

Smed, Sinne; Andersen, Laura Mørch

2012-01-01

of consuming conventional vegetables on demand for organic foods for six different segments of Danish households. Three of these segments are positive towards organics whereas the remaining three segments are negative or indifferent. Using the double hurdle model we estimate partial effects of both directly...... and indirectly obtained information as well as prices. The results show, that there are larger effects of information for households where the information is in accordance with initial knowledge and attitudes, hence the positive segments react more to information whereas the negative segments react more......Based on a unique and very detailed panel dataset covering consumption of organically and conventionally produced vegetables in the years 2005 - 2007, we examine the effects of information about positive health effects of consuming organic vegetables and information about negative health effects...

Effects of submerged vegetation on water clarity across climates

NARCIS (Netherlands)

Kosten, S.; Lacerot, G.; Jeppesen, E.; Motta Marques, D.M.L.; Nes, van E.H.; Mazzeo, N.; Scheffer, M.

2009-01-01

A positive feedback between submerged vegetation and water clarity forms the backbone of the alternative state theory in shallow lakes. The water clearing effect of aquatic vegetation may be caused by different physical, chemical, and biological mechanisms and has been studied mainly in temperate

Remote sensing inputs to water demand modeling

Science.gov (United States)

Estes, J. E.; Jensen, J. R.; Tinney, L. R.; Rector, M.

1975-01-01

In an attempt to determine the ability of remote sensing techniques to economically generate data required by water demand models, the Geography Remote Sensing Unit, in conjunction with the Kern County Water Agency of California, developed an analysis model. As a result it was determined that agricultural cropland inventories utilizing both high altitude photography and LANDSAT imagery can be conducted cost effectively. In addition, by using average irrigation application rates in conjunction with cropland data, estimates of agricultural water demand can be generated. However, more accurate estimates are possible if crop type, acreage, and crop specific application rates are employed. An analysis of the effect of saline-alkali soils on water demand in the study area is also examined. Finally, reference is made to the detection and delineation of water tables that are perched near the surface by semi-permeable clay layers. Soil salinity prediction, automated crop identification on a by-field basis, and a potential input to the determination of zones of equal benefit taxation are briefly touched upon.

Short- and Long-Term Feedbacks on Vegetation Water Use: Unifying Evidence from Observations and Modeling

Science.gov (United States)

Mackay, D. S.

2001-05-01

Recent efforts to measure and model the interacting influences of climate, soil, and vegetation on soil water and nutrient dynamics have identified numerous important feedbacks that produce nonlinear responses. In particular, plant physiological factors that control rates of transpiration respond to soil water deficits and vapor pressure deficits (VPD) in the short-term, and to climate, nutrient cycling and disturbance in the long-term. The starting point of this presentation is the observation that in many systems, in particular forest ecosystems, conservative water use emerges as a result of short-term closure of stomata in response to high evaporative demand, and long-term vegetative canopy development under nutrient limiting conditions. Evidence for important short-term controls is presented from sap flux measurements of stand transpiration, remote sensing, and modeling of transpiration through a combination of physically-based modeling and Monte Carlo analysis. A common result is a strong association between stomatal conductance (gs) and the negative evaporative gain (∂ gs/∂ VPD) associated with the sensitivity of stomatal closure to rates of water loss. The importance of this association from the standpoint of modeling transpiration depends on the degree of canopy-atmosphere coupling. This suggests possible simplifications to future canopy component models for use in watershed and larger-scale hydrologic models for short-term processes. However, further results are presented from theoretical modeling, which suggest that feedbacks between hydrology and vegetation in current long-term (inter-annual to century) models may be too simple, as they do not capture the spatially variable nature of slow nutrient cycling in response to soil water dynamics and site history. Memory effects in the soil nutrient pools can leave lasting effects on more rapid processes associated with soil, vegetation, atmosphere coupling.

The MODIS Vegetation Canopy Water Content product

Science.gov (United States)

Ustin, S. L.; Riano, D.; Trombetti, M.

2008-12-01

Vegetation water stress drives wildfire behavior and risk, having important implications for biogeochemical cycling in natural ecosystems, agriculture, and forestry. Water stress limits plant transpiration and carbon gain. The regulation of photosynthesis creates close linkages between the carbon, water, and energy cycles and through metabolism to the nitrogen cycle. We generated systematic weekly CWC estimated for the USA from 2000-2006. MODIS measures the sunlit reflectance of the vegetation in the visible, near-infrared, and shortwave infrared. Radiative transfer models, such as PROSPECT-SAILH, determine how sunlight interacts with plant and soil materials. These models can be applied over a range of scales and ecosystem types. Artificial Neural Networks (ANN) were used to optimize the inversion of these models to determine vegetation water content. We carried out multi-scale validation of the product using field data, airborne and satellite cross-calibration. An Algorithm Theoretical Basis Document (ATBD) of the product is under evaluation by NASA. The CWC product inputs are 1) The MODIS Terra/Aqua surface reflectance product (MOD09A1/MYD09A1) 2) The MODIS land cover map product (MOD12Q1) reclassified to grassland, shrub-land and forest canopies; 3) An ANN trained with PROSPECT-SAILH; 4) A calibration file for each land cover type. The output is an ENVI file with the CWC values. The code is written in Matlab environment and is being adapted to read not only the 8 day MODIS composites, but also daily surface reflectance data. We plan to incorporate the cloud and snow mask and generate as output a geotiff file. Vegetation water content estimates will help predicting linkages between biogeochemical cycles, which will enable further understanding of feedbacks to atmospheric concentrations of greenhouse gases. It will also serve to estimate primary productivity of the biosphere; monitor/assess natural vegetation health related to drought, pollution or diseases

Semi-arid vegetation response to antecedent climate and water balance windows

Science.gov (United States)

Thoma, David P.; Munson, Seth M.; Irvine, Kathryn M.; Witwicki, Dana L.; Bunting, Erin

2016-01-01

Questions Can we improve understanding of vegetation response to water availability on monthly time scales in semi-arid environments using remote sensing methods? What climatic or water balance variables and antecedent windows of time associated with these variables best relate to the condition of vegetation? Can we develop credible near-term forecasts from climate data that can be used to prepare for future climate change effects on vegetation? Location Semi-arid grasslands in Capitol Reef National Park, Utah, USA. Methods We built vegetation response models by relating the normalized difference vegetation index (NDVI) from MODIS imagery in Mar–Nov 2000–2013 to antecedent climate and water balance variables preceding the monthly NDVI observations. We compared how climate and water balance variables explained vegetation greenness and then used a multi-model ensemble of climate and water balance models to forecast monthly NDVI for three holdout years. Results Water balance variables explained vegetation greenness to a greater degree than climate variables for most growing season months. Seasonally important variables included measures of antecedent water input and storage in spring, switching to indicators of drought, input or use in summer, followed by antecedent moisture availability in autumn. In spite of similar climates, there was evidence the grazed grassland showed a response to drying conditions 1 mo sooner than the ungrazed grassland. Lead times were generally short early in the growing season and antecedent window durations increased from 3 mo early in the growing season to 1 yr or more as the growing season progressed. Forecast accuracy for three holdout years using a multi-model ensemble of climate and water balance variables outperformed forecasts made with a naïve NDVI climatology. Conclusions We determined the influence of climate and water balance on vegetation at a fine temporal scale, which presents an opportunity to forecast vegetation

Terrestrial Water Storage and Vegetation Resilience to Drought

Science.gov (United States)

Meyer, V.; Reager, J. T., II; Konings, A. G.

2017-12-01

The expected increased occurrences of hydrologic extreme events such as droughts in the coming decades motivates studies to better understand and predict the response of vegetation to such extreme conditions. Previous studies have addressed vegetation resilience to drought, defined as its ability to recover from a perturbation (Hirota et al., 2011; Vicente-Serrano et al., 2012), but appear to only focus on precipitation and a couple of vegetation indices, hence lacking a key element: terrestrial water storage (TWS). In this study, we combine and compare multiple remotely-sensed hydro-ecological datasets providing information on climatic and hydrological conditions (Tropical Rainfall Measuring Mission (TRMM), Gravity Recovery and Climate Experiment (GRACE)) and indices characterizing the state of the vegetation (vegetation water content using Vegetation Optical Depth (VOD) from SMAP (Soil Moisture Active and Passive), Gross Primary Production (GPP) from FluxCom and Specific Fluorescence Intensity (SFI, from GOSat)) to assess the ability of vegetation to face and recover from droughts across the globe. Our results suggest that GRACE hydrological data bridge the knowledge gap between precipitation deficit and vegetation response. All products are aggregated at a 0.5º spatial resolution and a monthly temporal resolution to match the GRACE Mascon product. Despite these coarse spatiotemporal resolutions, we find that the relationship between existing remotely-sensed eco-hydrologic data varies spatially, both in terms of strength of relationship and time lag, showing the response time of vegetation characteristics to hydrological changes and highlighting the role of water storage. A special attention is given to the Amazon river basin, where two well documented droughts occurred in 2005 and 2010, and where a more recent drought occurred in 2015/2016. References : Hirota, Marina, et al. "Global resilience of tropical forest and savanna to critical transitions." Science

[Analysis of spectral features based on water content of desert vegetation].

Science.gov (United States)

Zhao, Zhao; Li, Xia; Yin, Ye-biao; Tang, Jin; Zhou, Sheng-bin

2010-09-01

By using HR-768 field-portable spectroradiometer made by the Spectra Vista Corporation (SVC) of America, the hyper-spectral data of nine types of desert plants were measured, and the water content of corresponding vegetation was determined by roasting in lab. The continuum of measured hyperspectral data was removed by using ENVI, and the relationship between the water content of vegetation and the reflectance spectrum was analyzed by using correlation coefficient method. The result shows that the correlation between the bands from 978 to 1030 nm and water content of vegetation is weak while it is better for the bands from 1133 to 1266 nm. The bands from 1374 to 1534 nm are the characteristic bands because of the correlation between them and water content is the best. By using cluster analysis and according to the water content, the vegetation could be marked off into three grades: high (>70%), medium (50%-70%) and low (<50%). The research reveals the relationship between water content of desert vegetation and hyperspectral data, and provides basis for the analysis of area in desert and the monitoring of desert vegetation by using remote sensing data.

Pollution source localization in an urban water supply network based on dynamic water demand.

Science.gov (United States)

Yan, Xuesong; Zhu, Zhixin; Li, Tian

2017-10-27

Urban water supply networks are susceptible to intentional, accidental chemical, and biological pollution, which pose a threat to the health of consumers. In recent years, drinking-water pollution incidents have occurred frequently, seriously endangering social stability and security. The real-time monitoring for water quality can be effectively implemented by placing sensors in the water supply network. However, locating the source of pollution through the data detection obtained by water quality sensors is a challenging problem. The difficulty lies in the limited number of sensors, large number of water supply network nodes, and dynamic user demand for water, which leads the pollution source localization problem to an uncertainty, large-scale, and dynamic optimization problem. In this paper, we mainly study the dynamics of the pollution source localization problem. Previous studies of pollution source localization assume that hydraulic inputs (e.g., water demand of consumers) are known. However, because of the inherent variability of urban water demand, the problem is essentially a fluctuating dynamic problem of consumer's water demand. In this paper, the water demand is considered to be stochastic in nature and can be described using Gaussian model or autoregressive model. On this basis, an optimization algorithm is proposed based on these two dynamic water demand change models to locate the pollution source. The objective of the proposed algorithm is to find the locations and concentrations of pollution sources that meet the minimum between the analogue and detection values of the sensor. Simulation experiments were conducted using two different sizes of urban water supply network data, and the experimental results were compared with those of the standard genetic algorithm.

Plants in water-controlled ecosystems: active role in hydrologic processes and response to water stress. III. Vegetation water stress

Science.gov (United States)

Porporato, A.; Laio, F.; Ridolfi, L.; Rodriguez-Iturbe, I.

The reduction of soil moisture content during droughts lowers the plant water potential and decreases transpiration; this in turn causes a reduction of cell turgor and relative water content which brings about a sequence of damages of increasing seriousness. A review of the literature on plant physiology and water stress shows that vegetation water stress can be assumed to start at the soil moisture level corresponding to incipient stomatal closure and reach a maximum intensity at the wilting point. The mean crossing properties of these soil moisture levels crucial for water stress are derived analytically for the stochastic model of soil moisture dynamics described in Part II (F. Laio, A. Porporato, L. Ridolfi, I. Rodriguez-Iturbe. Adv. Water Res. 24 (7) (2001) 707-723). These properties are then used to propose a measure of vegetation water stress which combines the mean intensity, duration, and frequency of periods of soil water deficit. The characteristics of vegetation water stress are then studied under different climatic conditions, showing how the interplay between plant, soil, and environment can lead to optimal conditions for vegetation.

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

Peatland Open-water Pool Biogeochemistry: The Influence of Hydrology and Vegetation

Science.gov (United States)

Arsenault, J.; Talbot, J.; Moore, T. R.

2017-12-01

Peatland open-water pools are net sources of carbon to the atmosphere. However, their interaction with the surrounding peat remains poorly known. In a previous study, we showed that shallow pools are richer in nutrients than deep pools. While depth was the main driver of biogeochemistry variations across time and space, analyses also showed that pool's adjacent vegetation may have an influence on water chemistry. Our goal is to understand the relationship between the biogeochemistry of open-water pools and their surroundings in a subboreal ombrotrophic peatland of southern Quebec (Canada). To assess the influence of vegetation on pool water chemistry, we compare two areas covered with different types of vegetation: a forested zone dominated by spruce trees and an open area mostly covered by Sphagnum spp. To evaluate the direction of water (in or out of the pools), we installed capacitance water level probes in transects linking pools in the two zones. Wells were also installed next to each probe to collect peat pore water samples. Samples were taken every month during summer 2017 and analyzed for dissolved organic carbon, nitrogen and phosphorus, pH and specific UV absorbance. Preliminary results show differences in peat water chemistry depending on the dominant vegetation. In both zones, water levels fluctuations are disconnected between peat and the pools, suggesting poor horizontal water movement. Pool water chemistry may be mostly influenced by the immediate surrounding vegetation than by the local vegetation pattern. Climate and land-use change may affect the vegetation structure of peatlands, thus affecting pool biogeochemistry. Considering the impact of pools on the overall peatland capacity to accumulate carbon, our results show that more focus must be placed on pools to better understand peatland stability over time.

Industrial water demand management and cleaner production ...

African Journals Online (AJOL)

Processes and systems using water today are being subjected to increasingly stringent environmental regulations on effluents and there is growing demand for fresh water. In Morocco, consumption of water by industries is estimated in 1994 at 1 billion m3, the drinking water constitutes 4%. Water used in the food and drink ...

Contamination level in vegetables grown around Peshawar using sewerage and canal water

International Nuclear Information System (INIS)

Mahmood, S.

2001-01-01

The level of contamination in vegetables grown around Peshawar using sewerage/canal water is reported. The vegetable samples were collected from three representative locations. The results indicated that vegetables grown with sewerage water contained higher levels of Cd, Cu and Pb than those with irrigation water. Maximum amount of Cd was in Qulfa (3.68 mu g/ g) followed by sponge gourd leaves (3.38 mu g/ g) the tomato leaves (93.32 mu g/ g). while Pb in tomato leaves (4.88 mu g / g), Cu content ranged between 2.08 and 7.5 mu g/g in these vegetables. In the vegetables grown with canal water the Cd ranged 0.82 - 2.88 mu g/g, Cu 2.38 mu g /g and Pb 0.84 - 1.88 mu g/ g. The concentration of Fe and P in the vegetables of sewerage water ranged 9.0-25.0 and 5.6-14.8 mg/100g respectively while those grown with canal water 9.0-11.0 mg/ 100 g and 8.4-12.8 mg/ 100 g respectively. (author)

Internalisation of microbes in vegetables: microbial load of Ghanaian vegetables and the relationship with different water sources of irrigation.

Science.gov (United States)

Donkor, Eric S; Lanyo, R; Kayang, Boniface B; Quaye, Jonathan; Edoh, Dominic A

2010-09-01

The occurrence of pathogens in the internal parts of vegetables is usually associated with irrigation water or contaminated soil and could pose risk to consumers as the internalised pathogens are unaffected by external washing. This study was carried out to assess the rate of internalisation of microbes in common Ghanaian vegetables. Standard microbiological methods were employed in microbial enumeration of vegetables collected at the market and farm levels, as well as irrigation water and soil samples. The overall mean counts of vegetables were 4.0 x 10(3) cfu g(-1); 8.1 x 10(2) cfu g(-1); 2.0 x 10(2) cfu g(-1); 3.5 x 10(2) cfu g(-1) for total bacteria, coliform counts, faecal coliform counts and yeast counts, respectively. The rate of internalisation of coliforms in vegetables irrigated with stream/well water was 2.7 times higher than those irrigated with pipe water. The mean coliform counts (4.7 x 10(7) cfu g(-1)) and faecal coliform counts (1.8 x 10(6) cfu g(-1)) of soil samples were similar to those of stream water suggesting both sources exerted similar contamination rates on the vegetables. Generally, there were no significant variations between the rates of internalisation of microbes at the market and farm levels at p vegetables mainly occurred at the farm level. The study has shown that microbial contamination of vegetables in Ghana is not limited to the external surface, but internal vegetable parts could harbour high microbial loads and pose risk to consumers. Safety practices associated with the commodity should therefore not be limited to external washing only. There is the additional need of heating vegetables to eliminate microbes both externally and internally before consumption.

Water demand and supply co-adaptation to mitigate climate change impacts in agricultural water management

Science.gov (United States)

Giuliani, Matteo; Mainardi, Matteo; Castelletti, Andrea; Gandolfi, Claudio

2013-04-01

Agriculture is the main land use in the world and represents also the sector characterised by the highest water demand. To meet projected growth in human population and per-capita food demand, agricultural production will have to significantly increase in the next decades. Moreover, water availability is nowadays a limiting factor for agricultural production, and is expected to decrease over the next century due to climate change impacts. To effectively face a changing climate, agricultural systems have therefore to adapt their strategies (e.g., changing crops, shifting sowing and harvesting dates, adopting high efficiency irrigation techniques). Yet, farmer adaptation is only one part of the equation because changes in water supply management strategies, as a response to climate change, might impact on farmers' decisions as well. Despite the strong connections between water demand and supply, being the former dependent on agricultural practices, which are affected by the water available that depends on the water supply strategies designed according to a forecasted demand, an analysis of their reciprocal feedbacks is still missing. Most of the recent studies has indeed considered the two problems separately, either analysing the impact of climate change on farmers' decisions for a given water supply scenario or optimising water supply for different water demand scenarios. In this work, we explicitly connect the two systems (demand and supply) by activating an information loop between farmers and water managers, to integrate the two problems and study the co-evolution and co-adaptation of water demand and water supply systems under climate change. The proposed approach is tested on a real-world case study, namely the Lake Como serving the Muzza-Bassa Lodigiana irrigation district (Italy). In particular, given an expectation of water availability, the farmers are able to solve a yearly planning problem to decide the most profitable crop to plant. Knowing the farmers

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...

Mitigating the impact of swimming pools on domestic water demand

African Journals Online (AJOL)

need to implement desalination schemes by ensuring water is used in in a 'fit for purpose' manner. This study therefore aims to better understand the impact that pools have on residential water demand through the analysis of metered water demand records and end-use modelling. The study site was the Liesbeek.

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.

The effect of vegetation and soil texture on the nature of organics in runoff from a catchment supplying water for domestic consumption

Energy Technology Data Exchange (ETDEWEB)

Awad, John [Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, South Australia 5095 (Australia); Leeuwen, John van, E-mail: John.VanLeeuwen@unisa.edu.au [Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, South Australia 5095 (Australia); State Key Laboratory for Environmental Aquatic Chemistry, CAS, Beijing (China); Barbara Hardy Institute, University of South Australia, South Australia 5095 (Australia); Abate, Dawit [Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, South Australia 5095 (Australia); Pichler, Markus; Bestland, Erick [School of the Environment, Flinders University, Bedford Park, South Australia 5042 (Australia); Chittleborough, David J. [School of Physical Sciences, University of Adelaide, North Terrace, South Australia 5005 (Australia); Fleming, Nigel [South Australian Research and Development Institute, P.O. Box 397, Adelaide, SA 5000 (Australia); Cohen, Jonathan; Liffner, Joel [Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, South Australia 5095 (Australia); Drikas, Mary [Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, South Australia 5095 (Australia); Australian Water Quality Centre, SA Water Corporation, 250 Victoria Square, Adelaide, South Australia 5000 (Australia); State Key Laboratory for Environmental Aquatic Chemistry, CAS, Beijing (China)

2015-10-01

The influence of vegetation and soil texture on the concentration and character of dissolved organic matter (DOM) present in runoff from the surface and sub-surface of zero order catchments of the Myponga Reservoir-catchment (South Australia) was investigated to determine the impacts of catchment characteristics and land management practices on the quality of waters used for domestic supply. Catchments selected have distinct vegetative cover (grass, native vegetation or pine) and contrasting texture of the surface soil horizon (sand or clay loam/clay). Water samples were collected from three slope positions (upper, middle, and lower) at soil depths of ~ 30 cm and ~ 60 cm in addition to overland flows. Filtered (0.45 μm) water samples were analyzed for dissolved organic carbon (DOC) and UV–visible absorbance and by F-EEM and HPSEC with UV and fluorescence detection to characterize the DOM. Surface and sub-surface runoff from catchments with clay soils and native vegetation or grass had lower DOC concentrations and lower relative abundances of aromatic, humic-like and high molecular weight organics than runoff from sandy soils with these vegetative types. Sub-surface flows from two catchments with Pinus radiata had similar DOC concentrations and DOM character, regardless of marked variation in surface soil texture. Runoff from catchments under native vegetation and grass on clay soils resulted in lower DOC concentrations and hence would be expected to have lower coagulant demand in conventional treatment for potable water supply than runoff from corresponding sandy soil catchments. However, organics in runoff from clay catchments would be more difficult to remove by coagulation. Surface waters from the native vegetation and grass catchments were generally found to have higher relative abundance of organic compounds amenable to removal by coagulation compared with sub-surface waters. Biophysical and land management practices combine to have a marked influence on

The effect of vegetation and soil texture on the nature of organics in runoff from a catchment supplying water for domestic consumption

International Nuclear Information System (INIS)

Awad, John; Leeuwen, John van; Abate, Dawit; Pichler, Markus; Bestland, Erick; Chittleborough, David J.; Fleming, Nigel; Cohen, Jonathan; Liffner, Joel; Drikas, Mary

2015-01-01

The influence of vegetation and soil texture on the concentration and character of dissolved organic matter (DOM) present in runoff from the surface and sub-surface of zero order catchments of the Myponga Reservoir-catchment (South Australia) was investigated to determine the impacts of catchment characteristics and land management practices on the quality of waters used for domestic supply. Catchments selected have distinct vegetative cover (grass, native vegetation or pine) and contrasting texture of the surface soil horizon (sand or clay loam/clay). Water samples were collected from three slope positions (upper, middle, and lower) at soil depths of ~ 30 cm and ~ 60 cm in addition to overland flows. Filtered (0.45 μm) water samples were analyzed for dissolved organic carbon (DOC) and UV–visible absorbance and by F-EEM and HPSEC with UV and fluorescence detection to characterize the DOM. Surface and sub-surface runoff from catchments with clay soils and native vegetation or grass had lower DOC concentrations and lower relative abundances of aromatic, humic-like and high molecular weight organics than runoff from sandy soils with these vegetative types. Sub-surface flows from two catchments with Pinus radiata had similar DOC concentrations and DOM character, regardless of marked variation in surface soil texture. Runoff from catchments under native vegetation and grass on clay soils resulted in lower DOC concentrations and hence would be expected to have lower coagulant demand in conventional treatment for potable water supply than runoff from corresponding sandy soil catchments. However, organics in runoff from clay catchments would be more difficult to remove by coagulation. Surface waters from the native vegetation and grass catchments were generally found to have higher relative abundance of organic compounds amenable to removal by coagulation compared with sub-surface waters. Biophysical and land management practices combine to have a marked influence on

China's rising hydropower demand challenges water sector

NARCIS (Netherlands)

Liu, Junguo; Zhao, Dandan; Gerbens-Leenes, Winnie; 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

Institutions for Effective Water Demand Management

International Development Research Centre (IDRC) Digital Library (Canada)

2010-12-14

Dec 14, 2010 ... The paper also describes the state of South African WDM to highlight ... Download the PDF: Working Paper 4: Institutions for Effective Water Demand Management ​ ... Managing flood risk through collaborative governance.

[Investigation of the distribution of water clusters in vegetables, fruits, and natural waters by flicker noise spectroscopy].

Science.gov (United States)

Zubov, A V; Zubov, K V; Zubov, V A

2007-01-01

The distribution of water clusters in fresh rain water and in rain water that was aged for 30 days (North Germany, 53 degrees 33' N, 12 degrees 47' E, 293 K, rain on 25.06.06) as well as in fresh vegetables and fruits was studied by flicker noise spectroscopy. In addition, the development of water clusters in apples and potatoes during ripening in 2006 was investigated. A different distribution of water clusters in irrigation water (river and rain) and in the biomatrix of vegetables (potatoes, onions, tomatoes, red beets) and fruits (apples, bananas) was observed. It was concluded that the cluster structure of irrigation water differs from that of water of the biomatrix of vegetables and fruits and depends on drought and the biomatrix nature. Water clusters in plants are more stable and reproducible than water clusters in natural water. The main characteristics of cluster formation in materials studied were given. The oscillation frequencies of water clusters in plants (biofield) are given at which they interact with water clusters of the Earth hydrosphere. A model of series of clusters 16(H2O)100 4(H2O)402 2(H2O)903 (H2O)1889 in the biomatrix of vegetables and fruits was discussed.

Influence of vegetation dynamic modeling on the allocation of green and blue waters

Science.gov (United States)

Ruiz-Pérez, Guiomar; Francés, Félix

2015-04-01

The long history of the Mediterranean region is dominated by the interactions and co-evolution between man and its natural environment. It is important to consider that the Mediterranean region is recurrently or permanently confronted with the scarcity of the water. The issue of climate change is (and will be) aggravating this situation. This raises the question of a loss of services that ecosystems provide to human and also the amount of available water to be used by vegetation. The question of the water cycle, therefore, should be considered in an integrated manner by taking into account both blue water (water in liquid form used for the human needs or which flows into the oceans) and green water (water having the vapor for resulting from evaporation and transpiration processes). In spite of this, traditionally, very few hydrological models have incorporated the vegetation dynamic as a state variable. In fact, most of them are able to represent fairly well the observed discharge, but usually including the vegetation as a static parameter. However, in the last decade, the number of hydrological models which explicitly take into account the vegetation development as a state variable has increased substantially. In this work, we want to analyze if it is really necessary to use a dynamic vegetation model to quantify adequately the distribution of water into blue and green water. The study site is located in the Public Forest Monte de la Hunde y Palomeras (Spain). The vegetation in the study area is dominated by Aleppo pine of high tree density with scant presence of other species. Two different daily models were applied (with static and dynamic vegetation representation respectively) in three different scenarios: dry year (2005), normal year (2008) and wet year (2010). The static vegetation model simulates the evapotranspiration considering the vegetation as a stationary parameter. Contrarily, the dynamic vegetation model connects the hydrological model with a

Assessing the significance of climate and community factors on urban water demand

OpenAIRE

Md Mahmudul Haque; Prasanna Egodawatta; Ataur Rahman; Ashantha Goonetilleke

2015-01-01

Ensuring adequate water supply to urban areas is a challenging task due to factors such as rapid urban growth, increasing water demand and climate change. In developing a sustainable water supply system, it is important to identify the dominant water demand factors for any given water supply scheme. This paper applies principal components analysis to identify the factors that dominate residential water demand using the Blue Mountains Water Supply System in Australia as a case study. The resul...

The effect of vegetation and soil texture on the nature of organics in runoff from a catchment supplying water for domestic consumption.

Science.gov (United States)

Awad, John; van Leeuwen, John; Abate, Dawit; Pichler, Markus; Bestland, Erick; Chittleborough, David J; Fleming, Nigel; Cohen, Jonathan; Liffner, Joel; Drikas, Mary

2015-10-01

The influence of vegetation and soil texture on the concentration and character of dissolved organic matter (DOM) present in runoff from the surface and sub-surface of zero order catchments of the Myponga Reservoir-catchment (South Australia) was investigated to determine the impacts of catchment characteristics and land management practices on the quality of waters used for domestic supply. Catchments selected have distinct vegetative cover (grass, native vegetation or pine) and contrasting texture of the surface soil horizon (sand or clay loam/clay). Water samples were collected from three slope positions (upper, middle, and lower) at soil depths of ~30 cm and ~60 cm in addition to overland flows. Filtered (0.45 μm) water samples were analyzed for dissolved organic carbon (DOC) and UV-visible absorbance and by F-EEM and HPSEC with UV and fluorescence detection to characterize the DOM. Surface and sub-surface runoff from catchments with clay soils and native vegetation or grass had lower DOC concentrations and lower relative abundances of aromatic, humic-like and high molecular weight organics than runoff from sandy soils with these vegetative types. Sub-surface flows from two catchments with Pinus radiata had similar DOC concentrations and DOM character, regardless of marked variation in surface soil texture. Runoff from catchments under native vegetation and grass on clay soils resulted in lower DOC concentrations and hence would be expected to have lower coagulant demand in conventional treatment for potable water supply than runoff from corresponding sandy soil catchments. However, organics in runoff from clay catchments would be more difficult to remove by coagulation. Surface waters from the native vegetation and grass catchments were generally found to have higher relative abundance of organic compounds amenable to removal by coagulation compared with sub-surface waters. Biophysical and land management practices combine to have a marked influence on the

Forecasting domestic water demand in the Haihe river basin under changing environment

Science.gov (United States)

Wang, Xiao-Jun; Zhang, Jian-Yun; Shahid, Shamsuddin; Xie, Yu-Xuan; Zhang, Xu

2018-02-01

A statistical model has been developed for forecasting domestic water demand in Haihe river basin of China due to population growth, technological advances and climate change. Historical records of domestic water use, climate, population and urbanization are used for the development of model. An ensemble of seven general circulation models (GCMs) namely, BCC-CSM1-1, BNU-ESM, CNRM-CM5, GISS-E2-R, MIROC-ESM, PI-ESM-LR, MRI-CGCM3 were used for the projection of climate and the changes in water demand in the Haihe River basin under Representative Concentration Pathways (RCPs) 4.5. The results showed that domestic water demand in different sub-basins of the Haihe river basin will gradually increase due to continuous increase of population and rise in temperature. It is projected to increase maximum 136.22 × 108 m3 by GCM BNU-ESM and the minimum 107.25 × 108 m3 by CNRM-CM5 in 2030. In spite of uncertainty in projection, it can be remarked that climate change and population growth would cause increase in water demand and consequently, reduce the gap between water supply and demand, which eventually aggravate the condition of existing water stress in the basin. Water demand management should be emphasized for adaptation to ever increasing water demand and mitigation of the impacts of environmental changes.

Stochastic soil water dynamics of phreatophyte vegetation with dimorphic root systems

NARCIS (Netherlands)

Vervoort, R.W.; Zee, van der S.E.A.T.M.

2009-01-01

As the direct uptake of deep groundwater by vegetation may be essential in semiarid regions, we incorporated this process in stochastic root zone water balance models. The direct water uptake by vegetation via deep tap roots is simulated using one additional empirical parameter. This is considered

Chemical oxygen demand (cod) attenuation of methyl red in water ...

African Journals Online (AJOL)

Chemical oxygen demand (cod) attenuation of methyl red in water using biocarbons obtained from Nipa palm leaves. ... eco-friendly and locally accessible biocarbon for mitigation of organic contaminants in water. Keywords: Chemical oxygen demand, biocarbon, methyl red, biodegradation, bioremediation, Nipa palm ...

Vegetative Propagule Pressure and Water Depth Affect Biomass and Evenness of Submerged Macrophyte Communities.

Science.gov (United States)

Li, Hong-Li; Wang, Yong-Yang; Zhang, Qian; Wang, Pu; Zhang, Ming-Xiang; Yu, Fei-Hai

2015-01-01

Vegetative propagule pressure may affect the establishment and structure of aquatic plant communities that are commonly dominated by plants capable of clonal growth. We experimentally constructed aquatic communities consisting of four submerged macrophytes (Hydrilla verticillata, Ceratophyllum demersum, Elodea nuttallii and Myriophyllum spicatum) with three levels of vegetative propagule pressure (4, 8 and 16 shoot fragments for communities in each pot) and two levels of water depth (30 cm and 70 cm). Increasing vegetative propagule pressure and decreasing water level significantly increased the growth of the submerged macrophyte communities, suggesting that propagule pressure and water depth should be considered when utilizing vegetative propagules to re-establish submerged macrophyte communities in degraded aquatic ecosystems. However, increasing vegetative propagule pressure and decreasing water level significantly decreased evenness of the submerged macrophyte communities because they markedly increased the dominance of H. verticillata and E. nuttallii, but had little impact on that of C. demersum and M. spicatum. Thus, effects of vegetative propagule pressure and water depth are species-specific and increasing vegetative propagule pressure under lower water level can facilitate the establishment success of submerged macrophyte communities.

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

Water use demand in the Crans-Montana-Sierre region (Switzerland)

Science.gov (United States)

Bonriposi, M.; Reynard, E.

2012-04-01

Crans-Montana-Sierre is an Alpine touristic region located in the driest area of Switzerland (Rhone River Valley, Canton of Valais), with both winter (ski) and summer (e.g. golf) tourist activities. Climate change as well as societal and economic development will in future significantly modify the supply and consumption of water and, consequently, may fuel conflicts of interest. Within the framework of the MontanAqua project (www.montanaqua.ch), we are researching more sustainable water management options based on the co-ordination and adaptation of water demand to water availability under changing biophysical and socioeconomic conditions. This work intends to quantify current water uses in the area and consider future scenarios (around 2050). We have focused upon the temporal and spatial characteristics of resource demand, in order to estimate the spatial footprint of water use (drinking water, hydropower production, irrigation and artificial snowmaking), in terms of system, infrastructure, and organisation of supply. We have then quantified these as precisely as possible (at the monthly temporal scale and at the municipality spatial scale). When the quantity of water was not measurable for practical reasons or for lack of data, as for the case for irrigation or snowmaking, an alternative approach was applied. Instead of quantifying how much water was used, the stress was put on the water needs for irrigating agricultural land or on the optimal meteorological conditions necessary to produce artificial snow. A huge summer peak and a smaller winter peak characterize the current regional water consumption estimation. The summer peak is mainly caused by irrigation and secondly by drinking water demand. The winter peak is essentially due to drinking water and snowmaking. Other consumption peaks exist at the municipality scale but they cannot be observed at the regional scale. The results show a major variation in water demand between the 11 concerned municipalities and

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.

Forecasting domestic water demand in the Haihe river basin under changing environment

Directory of Open Access Journals (Sweden)

X.-J. Wang

2018-02-01

Full Text Available A statistical model has been developed for forecasting domestic water demand in Haihe river basin of China due to population growth, technological advances and climate change. Historical records of domestic water use, climate, population and urbanization are used for the development of model. An ensemble of seven general circulation models (GCMs namely, BCC-CSM1-1, BNU-ESM, CNRM-CM5, GISS-E2-R, MIROC-ESM, PI-ESM-LR, MRI-CGCM3 were used for the projection of climate and the changes in water demand in the Haihe River basin under Representative Concentration Pathways (RCPs 4.5. The results showed that domestic water demand in different sub-basins of the Haihe river basin will gradually increase due to continuous increase of population and rise in temperature. It is projected to increase maximum 136.22  ×  108 m3 by GCM BNU-ESM and the minimum 107.25  ×  108 m3 by CNRM-CM5 in 2030. In spite of uncertainty in projection, it can be remarked that climate change and population growth would cause increase in water demand and consequently, reduce the gap between water supply and demand, which eventually aggravate the condition of existing water stress in the basin. Water demand management should be emphasized for adaptation to ever increasing water demand and mitigation of the impacts of environmental changes.

Evaluation of water demand in golf courses from southern Portugal during the last three decades

Science.gov (United States)

Gago Pedras, Celestina M.; Lança, Rui M.; Granja-Martins, Fernando M.; Neto-Paixão, Helena M.; Vieira, Cristina; Monteiro, José P.; Guerrero, Carlos

2014-05-01

Golf is an economic activity with a prominent position in the tourist-sport offer in the region of Algarve. Located in southern of Portugal, this region is the most suitable region for the growth of the golf industry. The climate is characterized by mild winters with slight rainfall and hot and dry summers. The region has an annual average temperature of 14oC and annual precipitation that rarely exceeds 500 mm year-1. Since most of the rainfall occurs concentrated in the winter, irrigation is needed during the remaining months of the year to meet the water demand from plants. A proper irrigation management will allow to optimize the use water, thus it constitutes a key issue for the sustainability of this activity in areas subjected to water scarcity. Currently, remote sensing provides the tools to assess the evolution of the greenish quality of the area in the golf courses. In this study, based on Landsat images, vegetation indices were calculated the Normalized Difference Vegetation Index (NDVI), for the spring and summer seasons during the last 30 years. For the same period, according the data collected from weather stations distributed in the region, maps of precipitation, temperature, solar radiation, relative humidity and wind were produced. According the current maintenance practices and irrigation cycles, maps of potential and real evapotranspiration and with basis on the water balance were calculated, and water deficit maps estimated. Upon crossing this information with the NDVI maps, trends were identified in the consumption of water for irrigation due to the growth of the occupied area by golf courses in the region of Algarve. Since drought problems tend to increase due to climate changes, it becomes relevant the need to conduct this study aiming the research of strategies to ensure the beneficial use of water on golf courses and other turfgrass areas.

Responding to increased needs and demands for water

Science.gov (United States)

Hans M. Gregersen; William K. Easter; J. Edward de Steiguer

2000-01-01

The nature of the increased needs and demands for water relate to water quantity and quality, bringing in the dimensions of timing and location of water flows. Some key past international activities related to water and watershed policy are reviewed. The common threads that are shaping likely future responses relate to technical vs. institutional means of addressing...

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

Vegetative Propagule Pressure and Water Depth Affect Biomass and Evenness of Submerged Macrophyte Communities.

Directory of Open Access Journals (Sweden)

Hong-Li Li

Full Text Available Vegetative propagule pressure may affect the establishment and structure of aquatic plant communities that are commonly dominated by plants capable of clonal growth. We experimentally constructed aquatic communities consisting of four submerged macrophytes (Hydrilla verticillata, Ceratophyllum demersum, Elodea nuttallii and Myriophyllum spicatum with three levels of vegetative propagule pressure (4, 8 and 16 shoot fragments for communities in each pot and two levels of water depth (30 cm and 70 cm. Increasing vegetative propagule pressure and decreasing water level significantly increased the growth of the submerged macrophyte communities, suggesting that propagule pressure and water depth should be considered when utilizing vegetative propagules to re-establish submerged macrophyte communities in degraded aquatic ecosystems. However, increasing vegetative propagule pressure and decreasing water level significantly decreased evenness of the submerged macrophyte communities because they markedly increased the dominance of H. verticillata and E. nuttallii, but had little impact on that of C. demersum and M. spicatum. Thus, effects of vegetative propagule pressure and water depth are species-specific and increasing vegetative propagule pressure under lower water level can facilitate the establishment success of submerged macrophyte communities.

Water Demand Management Policy Brief No

International Development Research Centre (IDRC) Digital Library (Canada)

Bob Stanley

Water demand management (WDM) programs have been widely implemented across the MENA region and elsewhere, with varying degrees of success. The criteria below are intended to help policymakers determine how best to develop institutions with the capacity and capability to design, implement and monitor WDM ...

Estimating the Determinants of Residential Water Demand in Italy

Directory of Open Access Journals (Sweden)

Giulia Romano

2014-09-01

Full Text Available The aim of this study was to estimate the determinants of residential water demand for chief towns of every Italian province, in the period 2007–2009, using the linear mixed-effects model estimated with the restricted-maximum-likelihood method. Results confirmed that the applied tariff had a negative effect on residential water consumption and that it was a relevant driver of domestic water consumption. Moreover, income per capita had a positive effect on water consumption. Among measured climatic and geographical features, precipitation and altitude exerted a strongly significant negative effect on water consumption, while temperature did not influence water demand. Further, data show that small towns in terms of population served were characterized by lower levels of consumption. Water utilities ownership itself did not have a significant effect on water consumption but tariffs were significantly lower and residential water consumption was higher in towns where the water service was managed by publicly owned water utilities. However, further research is needed to gain a better understanding of the connection between ownership of water utilities and water prices and water consumption.

Management of Water Demand in Africa and the Middle East ...

International Development Research Centre (IDRC) Digital Library (Canada)

Management of Water Demand in Africa and the Middle East : Current Practices and Future Needs. Couverture du livre Management of Water Demand in Africa and the Middle East : Current Practices. Directeur(s) : David B. Brooks, Eglal Rached et Maurice Saade. Maison(s) d'édition : CRDI. 1 janvier 1997. ISBN : Épuisé.

Management of Water Demand in Africa and the Middle East ...

International Development Research Centre (IDRC) Digital Library (Canada)

1997-01-01

Management of Water Demand in Africa and the Middle East : Current Practices and Future Needs. Couverture du livre Management of Water Demand in Africa and the Middle East : Current Practices. Editor(s):. David B. Brooks, Eglal Rached et Maurice Saade. Publisher(s):. CRDI. January 1, 1997. ISBN: Épuisé. 78 pages.

Linking marine resources to ecotonal shifts of water uptake by terrestrial dune vegetation.

Science.gov (United States)

Greaver, Tara L; Sternberg, Leonel L da S

2006-09-01

As evidence mounts that sea levels are rising, it becomes increasingly important to understand the role of ocean water within terrestrial ecosystem dynamics. Coastal sand dunes are ecosystems that occur on the interface of land and sea. They are classic ecotones characterized by zonal distribution of vegetation in response to strong gradients of environmental factors from the ocean to the inland. Despite the proximity of the dune ecosystem to the ocean, it is generally assumed that all vegetation utilizes only freshwater and that water sources do not change across the ecotone. Evidence of ocean water uptake by vegetation would redefine the traditional interpretation of plant-water relations in the dune ecosystem and offer new ideas for assessing maritime influences on function and spatial distribution of plants across the dune. The purpose of this study was to identify sources of water (ocean, ground, and rain) taken up by vegetation using isotopic analysis of stem water and to evaluate water uptake patterns at the community level based on the distribution and assemblage of species. Three coastal dune systems located in southern Florida, USA, and the Bahamian bank/platform system were investigated. Plant distributions across the dune were zonal for 61-94% of the 18 most abundant species at each site. Species with their highest frequency on the fore dune (nearest the ocean) indicate ocean water uptake as evidenced by delta 18O values of stem water. In contrast, species most frequent in the back dune show no evidence of ocean water uptake. Analysis of species not grouped by frequency, but instead sampled along a transect from the ocean toward the inland, indicates that individuals from the vegetation assemblage closest to the ocean had a mixed water-harvesting strategy characterized by plants that may utilize ocean, ground-, and/or rainwater. In contrast, the inland vegetation relies mostly on rainwater. Our results show evidence supporting ocean water use by dune

Assessing the adequacy of water storage infrastructure capacity under hydroclimatic variability and water demands in the United States

Science.gov (United States)

Ho, M. W.; Devineni, N.; Cook, E. R.; Lall, U.

2017-12-01

As populations and associated economic activity in the US evolve, regional demands for water likewise change. For regions dependent on surface water, dams and reservoirs are critical to storing and managing releases of water and regulating the temporal and spatial availability of water in order to meet these demands. Storage capacities typically range from seasonal storage in the east to multi-annual and decadal-scale storage in the drier west. However, most dams in the US were designed with limited knowledge regarding the range, frequency, and persistence of hydroclimatic extremes. Demands for water supplied by these dams have likewise changed. Furthermore, many dams in the US are now reaching or have already exceeded their economic design life. The converging issues of aging dams, improved knowledge of hydroclimatic variability, and evolving demands for dam services result in a pressing need to evaluate existing reservoir capacities with respect to contemporary water demands, long term hydroclimatic variability, and service reliability into the future. Such an effort is possible given the recent development of two datasets that respectively address hydroclimatic variability in the conterminous United States over the past 555 years and human water demand related water stress over the same region. The first data set is a paleoclimate reconstruction of streamflow variability across the CONUS region based on a tree-ring informed reconstruction of the Palmer Drought Severity Index. This streamflow reconstruction suggested that wet spells with shorter drier spells were a key feature of 20th century streamflow compared with the preceding 450 years. The second data set in an annual cumulative drought index that is a measure of water balance based on water supplied through precipitation and water demands based on evaporative demands, agricultural, urban, and industrial demands. This index identified urban and regional hotspots that were particularly dependent on water

A model to assess water tariffs as part of water demand management

African Journals Online (AJOL)

... to calculate the predicted change in water use and the associated income. The model takes into account variation in price elasticity per tariff block. The effectiveness of the model as a planning tool is illustrated through an appropriate example. Keywords: water demand management, price elasticity, change in water tariff, ...

Blue Water Trade-Offs With Vegetation in a CO2-Enriched Climate

Science.gov (United States)

Mankin, Justin S.; Seager, Richard; Smerdon, Jason E.; Cook, Benjamin I.; Williams, A. Park; Horton, Radley M.

2018-04-01

Present and future freshwater availability and drought risks are physically tied to the responses of surface vegetation to increasing CO2. A single-model large ensemble identifies the occurrence of colocated warming- and CO2-induced leaf area index increases with summer soil moisture declines. This pattern of "greening" and "drying," which occurs over 42% of global vegetated land area, is largely attributable to changes in the partitioning of precipitation at the land surface away from runoff and toward terrestrial vegetation ecosystems. Changes in runoff and ecosystem partitioning are inversely related, with changes in runoff partitioning being governed by changes in precipitation (mean and extremes) and ecosystem partitioning being governed by ecosystem water use and surface resistance to evapotranspiration (ET). Projections show that warming-influenced and CO2-enriched terrestrial vegetation ecosystems use water that historically would have been partitioned to runoff over 48% of global vegetated land areas, largely in Western North America, the Amazon, and Europe, many of the same regions with colocated greening and drying. These results have implications for how water available for people will change in response to anthropogenic warming and raise important questions about model representations of vegetation water responses to high CO2.

Using Demand Side Management to Adapt to Water Scarcity and ...

International Development Research Centre (IDRC) Digital Library (Canada)

The Saiss is a sub-basin of the Sebou basin in Northern Morocco. Due to decreased precipitation and increased water demand, the surface waters of the Saiss basin have been greatly reduced. At the current rate of exploitation, the aquifer will be depleted within 25 years. This project will examine whether demand-side ...

Vegetation Water Content Mapping in a Diverse Agricultural Landscape: National Airborne Field Experiment 2006

Science.gov (United States)

Cosh, Michael H.; Jing Tao; Jackson, Thomas J.; McKee, Lynn; O'Neill, Peggy

2011-01-01

Mapping land cover and vegetation characteristics on a regional scale is critical to soil moisture retrieval using microwave remote sensing. In aircraft-based experiments such as the National Airborne Field Experiment 2006 (NAFE 06), it is challenging to provide accurate high resolution vegetation information, especially on a daily basis. A technique proposed in previous studies was adapted here to the heterogenous conditions encountered in NAFE 06, which included a hydrologically complex landscape consisting of both irrigated and dryland agriculture. Using field vegetation sampling and ground-based reflectance measurements, the knowledge base for relating the Normalized Difference Water Index (NDWI) and the vegetation water content was extended to a greater diversity of agricultural crops, which included dryland and irrigated wheat, alfalfa, and canola. Critical to the generation of vegetation water content maps, the land cover for this region was determined from satellite visible/infrared imagery and ground surveys with an accuracy of 95.5% and a kappa coefficient of 0.95. The vegetation water content was estimated with a root mean square error of 0.33 kg/sq m. The results of this investigation contribute to a more robust database of global vegetation water content observations and demonstrate that the approach can be applied with high accuracy. Keywords: Vegetation, field experimentation, thematic mapper, NDWI, agriculture.

Dynamic modelling of water demand, water availability and adaptation strategies for power plants to global change

International Nuclear Information System (INIS)

Koch, Hagen; Voegele, Stefan

2009-01-01

According to the latest IPCC reports, the frequency of hot and dry periods will increase in many regions of the world in the future. For power plant operators, the increasing possibility of water shortages is an important challenge that they have to face. Shortages of electricity due to water shortages could have an influence on industries as well as on private households. Climate change impact analyses must analyse the climate effects on power plants and possible adaptation strategies for the power generation sector. Power plants have lifetimes of several decades. Their water demand changes with climate parameters in the short- and medium-term. In the long-term, the water demand will change as old units are phased out and new generating units appear in their place. In this paper, we describe the integration of functions for the calculation of the water demand of power plants into a water resources management model. Also included are both short-term reactive and long-term planned adaptation. This integration allows us to simulate the interconnection between the water demand of power plants and water resources management, i.e. water availability. Economic evaluation functions for water shortages are also integrated into the water resources management model. This coupled model enables us to analyse scenarios of socio-economic and climate change, as well as the effects of water management actions. (author)

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.

A System Dynamics Modeling of Water Supply and Demand in Las Vegas Valley

Science.gov (United States)

Parajuli, R.; Kalra, A.; Mastino, L.; Velotta, M.; Ahmad, S.

2017-12-01

The rise in population and change in climate have posed the uncertainties in the balance between supply and demand of water. The current study deals with the water management issues in Las Vegas Valley (LVV) using Stella, a system dynamics modeling software, to model the feedback based relationship between supply and demand parameters. Population parameters were obtained from Center for Business and Economic Research while historical water demand and conservation practices were modeled as per the information provided by local authorities. The water surface elevation of Lake Mead, which is the prime source of water supply to the region, was modeled as the supply side whereas the water demand in LVV was modeled as the demand side. The study was done from the period of 1989 to 2049 with 1989 to 2012 as the historical one and the period from 2013 to 2049 as the future period. This study utilizes Coupled Model Intercomparison Project data sets (2013-2049) (CMIP3&5) to model different future climatic scenarios. The model simulates the past dynamics of supply and demand, and then forecasts the future water budget for the forecasted future population and future climatic conditions. The results can be utilized by the water authorities in understanding the future water status and hence plan suitable conservation policies to allocate future water budget and achieve sustainable water management.

Relations between vegetation and water level in groundwater dependent terrestrial ecosystems (GWDTEs)

DEFF Research Database (Denmark)

Munch Johansen, Ole; Andersen, Dagmar Kappel; Ejrnæs, Rasmus

2018-01-01

, management and conservation of fens are constrained by limited knowledge on the relations between vegetation and measurable hydrological conditions. This study investigates the relations between vegetation and water level dynamics in groundwater dependent wetlands in Denmark. A total of 35 wetland sites...... across Denmark were included in the study. The sites represent a continuum of wetlands with respect to vegetation and hydrological conditions. Water level was measured continuously using pressure transducers at each site. Metrics expressing different hydrological characteristics, such as mean water level...... and low and high water level periods, were calculated based on the water level time series. A complete plant species list was recorded in plots covering 78.5 m2 at each site. Community metrics such as total number of species and the number of bryophytes were generated from the species lists and Ellenberg...

Changes in vegetative communities and water table dynamics following timber harvesting in small headwater streams

Science.gov (United States)

B. Choi; J.C. Dewey; J. A. Hatten; A.W. Ezell; Z. Fan

2012-01-01

In order to better understand the relationship between vegetation communities and water table in the uppermost portions (ephemeral–intermittent streams) of headwater systems, seasonal plot-based field characterizations of vegetation were used in conjunction with monthly water table measurements. Vegetation, soils, and water table data were examined to determine...

Analysis of grey-water used for irrigating vegetables and possible ...

African Journals Online (AJOL)

Analysis of grey-water used for irrigating vegetables and possible effects on soils in the ... The concentrations of nutrients and heavy metals found in the grey-water ... in order to lower the salt content and to improve the irrigation water quality.

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

Evaluation of golf courses water demand in southern of Portugal for the last three decades

Science.gov (United States)

Gago Pedras, Celestina M.; Lança, Rui M.; Martins, Fernando; Fernandez, Helena; Vieira, Cristina; Monteiro, José Paulo; Guerrero, Carlos

2014-05-01

Golf is an economic activity with a prominent position in the tourist-sport offer in the region of Algarve. Located in southern of Portugal, this region is the most suitable region for the growth of the golf industry. The climate is characterized by mild winters with slight rainfall and hot and dry summers. The region has an annual average temperature of 14oC and annual precipitation that rarely exceeds 500 mm year-1. Since most of the rainfall occurs concentrated in the winter, irrigation is needed during the remaining months of the year to meet the water demand from plants. A proper irrigation management will allow to optimize the use water, thus it constitutes a key issue for the sustainability of this activity in areas subjected to water scarcity. Currently, remote sensing provides the tools to assess the evolution of the greenish quality of the area in the golf courses. In this study, based on Landsat images, vegetation indices were calculated the Normalized Difference Vegetation Index (NDVI), for the spring and summer seasons during the last 30 years. For the same period, according the data collected from weather stations distributed in the region, maps of precipitation, temperature, solar radiation, relative humidity and wind were produced. According the current maintenance practices and irrigation cycles, maps of potential and real evapotranspiration and with basis on the water balance were calculated, and water deficit maps estimated. Upon crossing this information with the NDVI maps, trends were identified in the consumption of water for irrigation due to the growth of the occupied area by golf courses in the region of Algarve. Since drought problems tend to increase due to climate changes, it becomes relevant the need to conduct this study aiming the research of strategies to ensure the beneficial use of water on golf courses and other turfgrass areas. Keywords: evapotranspiration, golf, irrigation, NDVI, water deficit

Household Water Demand in Andorra: Impact of Individual Metering and Seasonality

Directory of Open Access Journals (Sweden)

Arnaud Reynaud

2018-03-01

Full Text Available Despite the large literature focused on residential water use, our knowledge of the impact of individual metering on household water consumption remains limited. Our work aims to fill this gap by providing the first estimate of the residential water demand function in the Principality of Andorra, where collective and individual metering coexists. Using a panel dataset covering the years 2006 to 2015, we propose estimating a domestic water demand function for the municipality of Andorra La Vella (the capital of Andorra. Our estimates reveal a price elasticity of the residential water demand equal to –0.7. Facing a price increase of 10 percent, households will react in the short run by reducing their water consumption by 7 percent. Interestingly, the price elasticity is found to be significantly different in single-family units compared to multi-family units. This may suggest a significant impact of individual metering on domestic water consumption in Andorra.

Handling Uncertain Gross Margin and Water Demand in Agricultural Water Resources Management using Robust Optimization

Science.gov (United States)

Chaerani, D.; Lesmana, E.; Tressiana, N.

2018-03-01

In this paper, an application of Robust Optimization in agricultural water resource management problem under gross margin and water demand uncertainty is presented. Water resource management is a series of activities that includes planning, developing, distributing and managing the use of water resource optimally. Water resource management for agriculture can be one of the efforts to optimize the benefits of agricultural output. The objective function of agricultural water resource management problem is to maximizing total benefits by water allocation to agricultural areas covered by the irrigation network in planning horizon. Due to gross margin and water demand uncertainty, we assume that the uncertain data lies within ellipsoidal uncertainty set. We employ robust counterpart methodology to get the robust optimal solution.

Open Source Tools for Assessment of Global Water Availability, Demands, and Scarcity

Science.gov (United States)

Li, X.; Vernon, C. R.; Hejazi, M. I.; Link, R. P.; Liu, Y.; Feng, L.; Huang, Z.; Liu, L.

2017-12-01

Water availability and water demands are essential factors for estimating water scarcity conditions. To reproduce historical observations and to quantify future changes in water availability and water demand, two open source tools have been developed by the JGCRI (Joint Global Change Research Institute): Xanthos and GCAM-STWD. Xanthos is a gridded global hydrologic model, designed to quantify and analyze water availability in 235 river basins. Xanthos uses a runoff generation and a river routing modules to simulate both historical and future estimates of total runoff and streamflows on a monthly time step at a spatial resolution of 0.5 degrees. GCAM-STWD is a spatiotemporal water disaggregation model used with the Global Change Assessment Model (GCAM) to spatially downscale global water demands for six major enduse sectors (irrigation, domestic, electricity generation, mining, and manufacturing) from the region scale to the scale of 0.5 degrees. GCAM-STWD then temporally downscales the gridded annual global water demands to monthly results. These two tools, written in Python, can be integrated to assess global, regional or basin-scale water scarcity or water stress. Both of the tools are extensible to ensure flexibility and promote contribution from researchers that utilize GCAM and study global water use and supply.

Designing cost effective water demand management programs in Australia.

Science.gov (United States)

White, S B; Fane, S A

2002-01-01

This paper describes recent experience with integrated resource planning (IRP) and the application of least cost planning (LCP) for the evaluation of demand management strategies in urban water. Two Australian case studies, Sydney and Northern New South Wales (NSW) are used in illustration. LCP can determine the most cost effective means of providing water services or alternatively the cheapest forms of water conservation. LCP contrasts to a traditional approach of evaluation which looks only at means of increasing supply. Detailed investigation of water usage, known as end-use analysis, is required for LCP. End-use analysis allows both rigorous demand forecasting, and the development and evaluation of conservation strategies. Strategies include education campaigns, increasing water use efficiency and promoting wastewater reuse or rainwater tanks. The optimal mix of conservation strategies and conventional capacity expansion is identified based on levelised unit cost. IRP uses LCP in the iterative process, evaluating and assessing options, investing in selected options, measuring the results, and then re-evaluating options. Key to this process is the design of cost effective demand management programs. IRP however includes a range of parameters beyond least economic cost in the planning process and program designs, including uncertainty, benefit partitioning and implementation considerations.

Characterization of antibiotic resistant and pathogenic Escherichia coli in irrigation water and vegetables in household farms.

Science.gov (United States)

Araújo, Susana; A T Silva, Isabel; Tacão, Marta; Patinha, Carla; Alves, Artur; Henriques, Isabel

2017-09-18

This study aimed to characterize Escherichia coli present in irrigation water and vegetables from 16 household farms. Isolates were obtained from 50% of water (n=210 isolates) and 38% of vegetable samples (n=239). Phylogroups B1 (56% of isolates) and A (22%) were the most prevalent both in water and vegetables. Diarrheagenic strains were detected in vegetables. Irrespective of the source (i.e. water or vegetables), the most common antibiotic resistance was against streptomycin (89% resistant isolates) and tetracycline (24%). Common acquired genes (e.g. bla TEM , tetA, tetB) were found in isolates from both sources. Class I integrons were detected in water (arrays dfrA1-aadA1 and dfr16-blaP1b-aadA2-ereA) and vegetables (unknown arrays). intI2 was detected in water (dfrA1-sat2-aadA1). Plasmids were detected in 14 isolates (IncFIC, IncFIB, IncFrep, IncI1 in both samples; IncY in vegetables). Plasmids from seven isolates were transferrable by conjugation, conferring resistance to antibiotics to the recipient strain. Multidrug-resistant (MDR) strains were isolated from water (12% of the unique isolates) and vegetables (21%). Predominant sequence types (STs) among MDR isolates were ST10, ST297 and ST2522. In some cases, the same STs and identical clones (as showed by rep-PCR typing) were detected in water and vegetables, suggesting cross-contamination. This study identified several risk factors in E. coli isolates from vegetables and irrigation water, raising health concerns. Also, results suggest that irrigation groundwater constitutes a source of E. coli that may enter the food chain through vegetables ingestion. Copyright © 2017. Published by Elsevier B.V.

Multi-Model Prediction for Demand Forecast in Water Distribution Networks

Directory of Open Access Journals (Sweden)

Rodrigo Lopez Farias

2018-03-01

Full Text Available This paper presents a multi-model predictor called Qualitative Multi-Model Predictor Plus (QMMP+ for demand forecast in water distribution networks. QMMP+ is based on the decomposition of the quantitative and qualitative information of the time-series. The quantitative component (i.e., the daily consumption prediction is forecasted and the pattern mode estimated using a Nearest Neighbor (NN classifier and a Calendar. The patterns are updated via a simple Moving Average scheme. The NN classifier and the Calendar are executed simultaneously every period and the most suited model for prediction is selected using a probabilistic approach. The proposed solution for water demand forecast is compared against Radial Basis Function Artificial Neural Networks (RBF-ANN, the statistical Autoregressive Integrated Moving Average (ARIMA, and Double Seasonal Holt-Winters (DSHW approaches, providing the best results when applied to real demand of the Barcelona Water Distribution Network. QMMP+ has demonstrated that the special modelling treatment of water consumption patterns improves the forecasting accuracy.

Potential climate change impacts on water availability and cooling water demand in the Lusatian Lignite Mining Region, Central Europe

Science.gov (United States)

Pohle, Ina; Koch, Hagen; Gädeke, Anne; Grünewald, Uwe; Kaltofen, Michael; Redetzky, Michael

2014-05-01

In the catchments of the rivers Schwarze Elster, Spree and Lusatian Neisse, hydrologic and socioeconomic systems are coupled via a complex water management system in which water users, reservoirs and water transfers are included. Lignite mining and electricity production are major water users in the region: To allow for open pit lignite mining, ground water is depleted and released into the river system while cooling water is used in the thermal power plants. In order to assess potential climate change impacts on water availability in the catchments as well as on the water demand of the thermal power plants, a climate change impact assessment was performed using the hydrological model SWIM and the long term water management model WBalMo. The potential impacts of climate change were considered by using three regional climate change scenarios of the statistical regional climate model STAR assuming a further temperature increase of 0, 2 or 3 K by the year 2050 in the region respectively. Furthermore, scenarios assuming decreasing mining activities in terms of a decreasing groundwater depression cone, lower mining water discharges, and reduced cooling water demand of the thermal power plants are considered. In the standard version of the WBalMo model cooling water demand is considered as static with regard to climate variables. However, changes in the future cooling water demand over time according to the plans of the local mining and power plant operator are considered. In order to account for climate change impacts on the cooling water demand of the thermal power plants, a dynamical approach for calculating water demand was implemented in WBalMo. As this approach is based on air temperature and air humidity, the projected air temperature and air humidity of the climate scenarios at the locations of the power plants are included in the calculation. Due to increasing temperature and decreasing precipitation declining natural and managed discharges, and hence a lower

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.

Demonstrating demand response from water distribution system through pump scheduling

International Nuclear Information System (INIS)

Menke, Ruben; Abraham, Edo; Parpas, Panos; Stoianov, Ivan

2016-01-01

Highlights: • Water distribution systems can profitably provide demand response energy. • STOR and FFR are financially viable under a wide range of operating conditions. • Viability depends on the pump utilisation and peak price of the electricity tariff. • Total GHG emissions caused by the provision of reserve energy are <300 gCO_2/kW h. • These are lower than those from the major reserve energy provision technologies. - Abstract: Significant changes in the power generation mix are posing new challenges for the balancing systems of the grid. Many of these challenges are in the secondary electricity grid regulation services and could be met through demand response (DR) services. We explore the opportunities for a water distribution system (WDS) to provide balancing services with demand response through pump scheduling and evaluate the associated benefits. Using a benchmark network and demand response mechanisms available in the UK, these benefits are assessed in terms of reduced green house gas (GHG) emissions from the grid due to the displacement of more polluting power sources and additional revenues for water utilities. The optimal pump scheduling problem is formulated as a mixed-integer optimisation problem and solved using a branch and bound algorithm. This new formulation finds the optimal level of power capacity to commit to the provision of demand response for a range of reserve energy provision and frequency response schemes offered in the UK. For the first time we show that DR from WDS can offer financial benefits to WDS operators while providing response energy to the grid with less greenhouse gas emissions than competing reserve energy technologies. Using a Monte Carlo simulation based on data from 2014, we demonstrate that the cost of providing the storage energy is less than the financial compensation available for the equivalent energy supply. The GHG emissions from the demand response provision from a WDS are also shown to be smaller than

The Role of Riparian Vegetation in Protecting and Improving Chemical Water Quality in Streams

Science.gov (United States)

Michael G. Dosskey; Philippe Vidon; Noel P. Gurwick; Craig J. Allan; Tim P. Duval; Richard Lowrance

2010-01-01

We review the research literature and summarize the major processes by which riparian vegetation influences chemical water quality in streams, as well as how these processes vary among vegetation types, and discuss how these processes respond to removal and restoration of riparian vegetation and thereby determine the timing and level of response in stream water quality...

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

Developing a water and nitrogen management model for greenhouse vegetable production in China

NARCIS (Netherlands)

Liang, Hao; Hu, Kelin; Batchelor, William D.; Qin, Wei; Li, Baoguo

2018-01-01

Excessive water and fertilizer inputs have led to a series of environmental problems in vegetable production areas in China. Identifying the fates of water and nutrients is crucial to develop best management strategies in intensive vegetable production systems. The objectives of this study were to

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.

Is the available cropland and water enough for food demand? A global perspective of the Land-Water-Food nexus

Science.gov (United States)

Ibarrola-Rivas, M. J.; Granados-Ramírez, R.; Nonhebel, S.

2017-12-01

Land and water are essential local resources for food production but are limited. The main drivers of increasing food demand are population growth and dietary changes, which depend on the socioeconomic situation of the population. These two factors affect the availability of local resources: population growth reduces the land and water per person; and adoption of affluent diets increases the demand for land and water per person. This study shows potentials of global food supply by linking food demand drivers with national land and water availability. Whether the available land and water is enough to meet national food demand was calculated for 187 countries. The calculations were performed for the past situation (1960 and 2010) and to assess four future scenarios (2050) to discuss different paths of diets, population numbers and agricultural expansion. Inclusion of the demand perspective in the analysis has shown stronger challenges for future global food supply than have other studies. The results show that with the "business as usual" scenario, 40% of the global population in 2050 will live in countries with not enough land nor water to meet the demands of their population. Restriction to basic diets will be the most effective in lowering both land and water constraints. Our results identify both food production and food demand factors, and the regions that may experience the strongest challenges in 2050.

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

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.

Intensified Vegetation Water Use due to Soil Calcium Leaching under Acid Deposition

Science.gov (United States)

Lanning, M.; Wang, L.; Scanlon, T. M.; Vadeboncoeur, M. A.; Adams, M. B.; Epstein, H. E.; Druckenbrod, D.

2017-12-01

Despite the important role vegetation plays in the global water cycle, the exact controls of vegetation water use, especially the role of soil biogeochemistry, remain elusive. Nitrate and sulfate deposition from fossil fuel burning has caused significant soil acidification, leading to the leaching of soil base cations. From a physiological perspective, plants require various soil cations as signaling and regulatory ions as well as integral parts of structural molecules; a depletion of soil cations can cause reduced productivity and abnormal responses to environmental change. A deficiency in calcium could also potentially prolong stomatal opening, leading to increased transpiration until enough calcium had been acquired to stimulate stomatal closure. Based on the plant physiology and the nature of acidic deposition, we hypothesize that depletion of the soil calcium supply, induced by acid deposition, would intensify vegetation water use at the watershed scale. We tested this hypothesis by analyzing a long-term and unique data set (1989-2012) of soil lysimeter data along with stream flow and evapotranspiration data at the Fernow Experimental Forest. We show that depletion of soil calcium by acid deposition can intensify vegetation water use ( 10% increase in evapotranspiration and depletion in soil water) for the first time. These results are critical to understanding future water availability, biogeochemical cycles, and surficial energy flux and may help reduce uncertainties in terrestrial biosphere models.

Mediterranean shrub vegetation: soil protection vs. water availability

Science.gov (United States)

García Estringana, Pablo; Nieves Alonso-Blázquez, M.; Alegre, Alegre; Cerdà, Artemi

2014-05-01

Soil Erosion and Land Degradation are closely related to the changes in the vegetation cover (Zhao et al., 2013). Although other factors such as rainfall intensiy or slope (Ziadat and Taimeh, 2013) the plant covers is the main factor that controls the soil erosion (Haregeweyn, 2013). Plant cover is the main factor of soil erosion processes as the vegetation control the infiltration and runoff generation (Cerdà, 1998a; Kargar Chigani et al., 2012). Vegetation cover acts in a complex way in influencing on the one hand on runoff and soil loss and on the other hand on the amount and the way that rainfall reaches the soil surface. In arid and semiarid regions, where erosion is one of the main degradation processes and water is a scant resource, a minimum percentage of vegetation coverage is necessary to protect the soil from erosion, but without compromising the availability of water (Belmonte Serrato and Romero Diaz, 1998). This is mainly controlled by the vegetation distribution (Cerdà, 1997a; Cammeraat et al., 2010; Kakembo et al., 2012). Land abandonment is common in Mediterranean region under extensive land use (Cerdà, 1997b; García-Ruiz, 2010). Abandoned lands typically have a rolling landscape with steep slopes, and are dominated by herbaceous communities that grow on pasture land interspersed by shrubs. Land abandonment use to trigger an increase in soil erosion, but the vegetation recovery reduces the impact of the vegetation. The goal of this work is to assess the effects of different Mediterranean shrub species (Dorycnium pentaphyllum Scop., Medicago strasseri, Colutea arborescens L., Retama sphaerocarpa, L., Pistacia Lentiscus L. and Quercus coccifera L.) on soil protection (runoff and soil losses) and on rainfall reaching soil surface (rainfall partitioning fluxes). To characterize the effects of shrub vegetation and to evaluate their effects on soil protection, two field experiments were carried out. The presence of shrub vegetation reduced runoff by

Hierarchical prediction of industrial water demand based on refined Laspeyres decomposition analysis.

Science.gov (United States)

Shang, Yizi; Lu, Shibao; Gong, Jiaguo; Shang, Ling; Li, Xiaofei; Wei, Yongping; Shi, Hongwang

2017-12-01

A recent study decomposed the changes in industrial water use into three hierarchies (output, technology, and structure) using a refined Laspeyres decomposition model, and found monotonous and exclusive trends in the output and technology hierarchies. Based on that research, this study proposes a hierarchical prediction approach to forecast future industrial water demand. Three water demand scenarios (high, medium, and low) were then established based on potential future industrial structural adjustments, and used to predict water demand for the structural hierarchy. The predictive results of this approach were compared with results from a grey prediction model (GPM (1, 1)). The comparison shows that the results of the two approaches were basically identical, differing by less than 10%. Taking Tianjin, China, as a case, and using data from 2003-2012, this study predicts that industrial water demand will continuously increase, reaching 580 million m 3 , 776.4 million m 3 , and approximately 1.09 billion m 3 by the years 2015, 2020 and 2025 respectively. It is concluded that Tianjin will soon face another water crisis if no immediate measures are taken. This study recommends that Tianjin adjust its industrial structure with water savings as the main objective, and actively seek new sources of water to increase its supply.

Environmental variation, vegetation distribution, carbon dynamics and water/energy exchange at high latitudes

Science.gov (United States)

McGuire, A.D.; Wirth, C.; Apps, M.; Beringer, J.; Clein, J.; Epstein, H.; Kicklighter, D.W.; Bhatti, J.; Chapin, F. S.; De Groot, B.; Efremov, D.; Eugster, W.; Fukuda, M.; Gower, T.; Hinzman, L.; Huntley, B.; Jia, G.J.; Kasischke, E.; Melillo, J.; Romanovsky, V.; Shvidenko, A.; Vaganov, E.; Walker, D.

2002-01-01

The responses of high latitude ecosystems to global change involve complex interactions among environmental variables, vegetation distribution, carbon dynamics, and water and energy exchange. These responses may have important consequences for the earth system. In this study, we evaluated how vegetation distribution, carbon stocks and turnover, and water and energy exchange are related to environmental variation spanned by the network of the IGBP high latitude transects. While the most notable feature of the high latitude transects is that they generally span temperature gradients from southern to northern latitudes, there are substantial differences in temperature among the transects. Also, along each transect temperature co-varies with precipitation and photosynthetically active radiation, which are also variable among the transects. Both climate and disturbance interact to influence latitudinal patterns of vegetation and soil carbon storage among the transects, and vegetation distribution appears to interact with climate to determine exchanges of heat and moisture in high latitudes. Despite limitations imposed by the data we assembled, the analyses in this study have taken an important step toward clarifying the complexity of interactions among environmental variables, vegetation distribution, carbon stocks and turnover, and water and energy exchange in high latitude regions. This study reveals the need to conduct coordinated global change studies in high latitudes to further elucidate how interactions among climate, disturbance, and vegetation distribution influence carbon dynamics and water and energy exchange in high latitudes.

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

NARCIS (Netherlands)

Hellegers, P.J.G.J.; Immerzeel, 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

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.

Residential water demand and water consumption: an econometric analysis on municipal panel data

International Nuclear Information System (INIS)

Musolesi, Antonio; Nosvelli, Mario

2005-01-01

This paper focuses on residential water demand estimation, a rather neglected issue in the Italian environmental economics literature as compared to other European countries and the USA. This may depend on the difficulties in gathering proper data and, most of all, panel data. In some cases statistical information are not suitably collected, while in other cases legal privacy ties put some obstacles to data set transfer. Our panel data set refers to 102 municipalities in Lombardy (Italy) for the period 1998-2002. When estimating the effect of water price, we control for other relevant variables such as: income, households demographical variables - (age structure, number of component for each family) number of firms in tertiary sector, water system length. In the considered period, the data show both an increase in population (1,5 %) and in the number of water consumers (7%) associated, on aggregate, with a slight reduction in water consumption (-1,1 %). Water demand models are estimated both in a static and in a dynamic framework. In the former, the emphasis is set on the sources of endogeneity in the average price by estimating a system of simultaneous equations and relevant variables for assessing consumer behaviour - such as socio demographic ones - are incorporated in the model. In the latter, econometric methods especially designed for endogeneity in panel data models (Arellano e Bond, 1991), are employed in order to estimate the long run elasticity of water demand with respect to average price. We find evidence both that consumers significantly respond to average price only in the long run with an elasticity of about - 0,3-0,4 and that income and demographic variables are crucial in explaining consumers' behaviour. Furthermore, water consumption presents a strong auto-regressive component, showing the emergence of inertia and path dependency in consumption habits. Such results suggest important implications for water policy planning. On one side demographic

On the sources of vegetation activity variation, and their relation with water balance in Mexico

Science.gov (United States)

F. Mora; L.R. Iverson

1998-01-01

Natural landscape surface processes are largely controlled by the relationship between climate and vegetation. Water balance integrates the effects of climate on patterns of vegetation distribution and productivity, and for that season, functional relationships can be established using water balance variables as predictors of vegetation response. In this study, we...

Interacting vegetative and thermal contributions to water movement in desert soil

Science.gov (United States)

Garcia, C.A.; Andraski, Brian J.; Stonestrom, David A.; Cooper, C.A.; Šimůnek, J.; Wheatcraft, S.W.

2011-01-01

Thermally driven water-vapor flow can be an important component of total water movement in bare soil and in deep unsaturated zones, but this process is often neglected when considering the effects of soil–plant–atmosphere interactions on shallow water movement. The objectives of this study were to evaluate the coupled and separate effects of vegetative and thermal-gradient contributions to soil water movement in desert environments. The evaluation was done by comparing a series of simulations with and without vegetation and thermal forcing during a 4.7-yr period (May 2001–December 2005). For vegetated soil, evapotranspiration alone reduced root-zone (upper 1 m) moisture to a minimum value (25 mm) each year under both isothermal and nonisothermal conditions. Variations in the leaf area index altered the minimum storage values by up to 10 mm. For unvegetated isothermal and nonisothermal simulations, root-zone water storage nearly doubled during the simulation period and created a persistent driving force for downward liquid fluxes below the root zone (total net flux ~1 mm). Total soil water movement during the study period was dominated by thermally driven vapor fluxes. Thermally driven vapor flow and condensation supplemented moisture supplies to plant roots during the driest times of each year. The results show how nonisothermal flow is coupled with plant water uptake, potentially influencing ecohydrologic relations in desert environments.

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

Forecasting Hourly Water Demands With Seasonal Autoregressive Models for Real-Time Application

Science.gov (United States)

Chen, Jinduan; Boccelli, Dominic L.

2018-02-01

Consumer water demands are not typically measured at temporal or spatial scales adequate to support real-time decision making, and recent approaches for estimating unobserved demands using observed hydraulic measurements are generally not capable of forecasting demands and uncertainty information. While time series modeling has shown promise for representing total system demands, these models have generally not been evaluated at spatial scales appropriate for representative real-time modeling. This study investigates the use of a double-seasonal time series model to capture daily and weekly autocorrelations to both total system demands and regional aggregated demands at a scale that would capture demand variability across a distribution system. Emphasis was placed on the ability to forecast demands and quantify uncertainties with results compared to traditional time series pattern-based demand models as well as nonseasonal and single-seasonal time series models. Additional research included the implementation of an adaptive-parameter estimation scheme to update the time series model when unobserved changes occurred in the system. For two case studies, results showed that (1) for the smaller-scale aggregated water demands, the log-transformed time series model resulted in improved forecasts, (2) the double-seasonal model outperformed other models in terms of forecasting errors, and (3) the adaptive adjustment of parameters during forecasting improved the accuracy of the generated prediction intervals. These results illustrate the capabilities of time series modeling to forecast both water demands and uncertainty estimates at spatial scales commensurate for real-time modeling applications and provide a foundation for developing a real-time integrated demand-hydraulic model.

Soil Water Balance and Vegetation Dynamics in two Water-limited Mediterranean Ecosystem on Sardinia under past and future climate change

Science.gov (United States)

Corona, R.; Montaldo, N.; Albertson, J. D.

2016-12-01

Water limited conditions strongly impacts soil and vegetation dynamics in Mediterranean regions, which are commonly heterogeneous ecosystems, characterized by inter-annual rainfall variability, topography variability and contrasting plant functional types (PFTs) competing for water use. Historical human influences (e.g., deforestation, urbanization) further altered these ecosystems. Sardinia island is a representative region of Mediterranean ecosystems. It is low urbanized except some plan areas close to the main cities where main agricultural activities are concentrated. Two contrasting case study sites are within the Flumendosa river basin (1700 km2). The first site is a typical grassland on an alluvial plan valley (soil depth > 2m) while the second is a patchy mixture of Mediterranean vegetation species (mainly wild olive trees and C3 herbaceous) that grow in a soil bounded from below by a rocky layer of basalt, partially fractured (soil depth 15 - 40 cm). In both sites land-surface fluxes and CO2 fluxes are estimated by the eddy correlation technique while soil moisture was continuously estimated with water content reflectometers, and periodically leaf area index (LAI) was estimated. The following objectives are addressed:1) pointing out the dynamics of land surface fluxes, soil moisture, CO2 and vegetation cover for two contrasting water-limited ecosystems; 2) assess the impact of the soil depth and type on the CO2 and water balance dynamics; 3) evaluate the impact of past and future climate change scenarios on the two contrasting ecosystems. For reaching the objectives an ecohydrologic model that couples a vegetation dynamic model (VDM), and a 3-component (bare soil, grass and woody vegetation) land surface model (LSM) has been used. Historical meteorological data are available from 1922 and hydro-meteorological scenarios are then generated using a weather generator. The VDM-LSM model predict soil water balance and vegetation dynamics for the generated

Deconstructing Demand: The Anthropogenic and Climatic Drivers of Urban Water Consumption.

Science.gov (United States)

Hemati, Azadeh; Rippy, Megan A; Grant, Stanley B; Davis, Kristen; Feldman, David

2016-12-06

Cities in drought prone regions of the world such as South East Australia are faced with escalating water scarcity and security challenges. Here we use 72 years of urban water consumption data from Melbourne, Australia, a city that recently overcame a 12 year "Millennium Drought", to evaluate (1) the relative importance of climatic and anthropogenic drivers of urban water demand (using wavelet-based approaches) and (2) the relative contribution of various water saving strategies to demand reduction during the Millennium Drought. Our analysis points to conservation as a dominant driver of urban water savings (69%), followed by nonrevenue water reduction (e.g., reduced meter error and leaks in the potable distribution system; 29%), and potable substitution with alternative sources like rain or recycled water (3%). Per-capita consumption exhibited both climatic and anthropogenic signatures, with rainfall and temperature explaining approximately 55% of the variance. Anthropogenic controls were also strong (up to 45% variance explained). These controls were nonstationary and frequency-specific, with conservation measures like outdoor water restrictions impacting seasonal water use and technological innovation/changing social norms impacting lower frequency (baseline) use. The above-noted nonstationarity implies that wavelets, which do not assume stationarity, show promise for use in future predictive models of demand.

Evaluation of sea water chlorine demand in condenser cooling water at TAPS 1 and 2

International Nuclear Information System (INIS)

Papachan, Deepa; Gupta, P.K.; Patil, D.P.; Save, C.B.; Anilkumar, K.R.

2008-01-01

To prevent microbiological growth in the condenser tubes, condenser cooling water chlorination is very important. For effective chlorination, chlorine dose rate and frequency of dosing has to be determined on the basis of sea water chlorine demand. TAPS 1 and 2 is located near Arabian sea and draws water from this sea for its condenser cooling. The present practice of chlorine dosing at TAPS 1 and 2, based on the analysis carried out by GE in 1969, is 2500 kg/day/CWpump and 90 kg/day/SSWpump for a contact period of 25 minutes. Normal frequency of dosing is once per 8 hour and booster dose is once in a week at the same rate for 1 hour. The criteria of effective chlorination is to get residual chlorine of 2-3 ppm at the condenser water box outlet during chlorination at water box inlet/CW pump suction header in the recommended dose rate. The other option of chlorination was continuous dosing to get 0.5 ppm residual chlorine. This option has its own limitations as it is more expensive and also that micro organisms get immune to chlorine eventually due to continuous dosing. Nevertheless higher chlorine dosing is detrimental to AI-brass condenser tubes. Therefore the second option was not adopted at TAPS 1 and 2. Tarapur Atomic Power Station-1 is in the process of replacement of condenser tubes due to frequent condenser tube failures in the recent years. It was essential to analyse the present sea water chlorine demand and re-determine the chlorine dose rate because of development of industries under Maharashtra Industrial Development Corporation (MIDC) and simultaneous population growth around this area over a period of three decades. This paper discusses the experimental observations regarding significant change in sea water chlorine demand over this period and the effect of seasonal changes on sea water chlorine demand. (author)

Correlation Analysis of Water Demand and Predictive Variables for Short-Term Forecasting Models

Directory of Open Access Journals (Sweden)

B. M. Brentan

2017-01-01

Full Text Available Operational and economic aspects of water distribution make water demand forecasting paramount for water distribution systems (WDSs management. However, water demand introduces high levels of uncertainty in WDS hydraulic models. As a result, there is growing interest in developing accurate methodologies for water demand forecasting. Several mathematical models can serve this purpose. One crucial aspect is the use of suitable predictive variables. The most used predictive variables involve weather and social aspects. To improve the interrelation knowledge between water demand and various predictive variables, this study applies three algorithms, namely, classical Principal Component Analysis (PCA and machine learning powerful algorithms such as Self-Organizing Maps (SOMs and Random Forest (RF. We show that these last algorithms help corroborate the results found by PCA, while they are able to unveil hidden features for PCA, due to their ability to cope with nonlinearities. This paper presents a correlation study of three district metered areas (DMAs from Franca, a Brazilian city, exploring weather and social variables to improve the knowledge of residential demand for water. For the three DMAs, temperature, relative humidity, and hour of the day appear to be the most important predictive variables to build an accurate regression model.

Development of water demand coefficients for power generation from renewable energy technologies

International Nuclear Information System (INIS)

Ali, Babkir; Kumar, Amit

2017-01-01

Highlights: • Water consumption and withdrawals coefficients for renewable power generation were developed. • Six renewable energy sources (biomass, nuclear, solar, wind, hydroelectricity, and geothermal) were studied. • Life cycle water footprints for 60 electricity generation pathways were considered. • Impact of cooling systems for some power generation pathways was assessed. - Abstract: Renewable energy technology-based power generation is considered to be environmentally friendly and to have a low life cycle greenhouse gas emissions footprint. However, the life cycle water footprint of renewable energy technology-based power generation needs to be assessed. The objective of this study is to develop life cycle water footprints for renewable energy technology-based power generation pathways. Water demand is evaluated through consumption and withdrawals coefficients developed in this study. Sixty renewable energy technology-based power generation pathways were developed for a comprehensive comparative assessment of water footprints. The pathways were based on the use of biomass, nuclear, solar, wind, hydroelectricity, and geothermal as the source of energy. During the complete life cycle, power generation from bio-oil extracted from wood chips, a biomass source, was found to have the highest water demand footprint and wind power the lowest. During the complete life cycle, the water demand coefficients for biomass-based power generation pathways range from 260 to 1289 l of water per kilowatt hour and for nuclear energy pathways from 0.48 to 179 l of water per kilowatt hour. The water demand for power generation from solar energy-based pathways ranges from 0.02 to 4.39 l of water per kilowatt hour, for geothermal pathways from 0.04 to 1.94 l of water per kilowatt hour, and for wind from 0.005 to 0.104 l of water per kilowatt hour. A sensitivity analysis was conducted with varying conversion efficiencies to evaluate the impact of power plant performance on

Water Demand Management for Social Justice | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

2012-01-18

Jan 18, 2012 ... Water Demand Management for Social Justice ... Women play larger role in Latin America's commercial urban waste management ... the management of solid waste in Latin America, according to research supported by IDRC.

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 ... The methodology for this study was developed as part of the ... Study' for the Vaal River system (DWAF, 2006; DWAF, 2009).

Variation of Vegetation Ecological Water Consumption and Its Response to Vegetation Coverage Changes in the Rocky Desertification Areas in South China.

Science.gov (United States)

Wan, Long; Tong, Jing; Zhou, Jinxing; Guo, Hongyan; Cui, Ming; Liu, Yuguo; Ning, Like; Tang, Fukai

2016-01-01

Over the past several decades, rocky desertification has led to severe ecological problems in karst areas in South China. After a rocky desertification treatment project was completed, the vegetation coverage changed greatly and, consequently, increased the ecology water consumption (approximately equal to the actual evapotranspiration) of the regional vegetation. Thus, it intensified the regional water stresses. This study explored the changes in the actual evapotranspiration (ETa) response to the vegetation coverage changes in the rocky desertification areas in South China based on the precipitation (P), potential evapotranspiration (ETp) and NDVI (the normalized difference vegetation index) datasets. The revised Bagrov model was used to simulate the actual evapotranspiration changes with the supposed increasing NDVI. The results indicated that the average NDVI value was lower when the rocky desertification was more severe. The ETa, evapotranspiration efficiency (ETa/ETp) and potential humidity (P/ETp) generally increased with the increasing NDVI. The sensitivity of the ETa response to vegetation coverage changes varied due to different precipitation conditions and different rocky desertification severities. The ETa was more sensitive under drought conditions. When a drought occurred, the ETa exhibited an average increase of 40~60 mm with the NDVI increasing of 0.1 in the rocky desertification areas. Among the 5 different severity categories of rocky desertification, the ETa values' responses to NDVI changes were less sensitive in the severe rocky desertification areas but more sensitive in the extremely and potential rocky desertification areas. For example, with the NDVI increasing of 0.025, 0.05, 0.075, and 0.1, the corresponding ETa changes increased by an average of 2.64 mm, 10.62 mm, 19.19 mm, and 27.58 mm, respectively, in severe rocky desertification areas but by 4.94 mm, 14.99 mm, 26.80, and 37.13 mm, respectively, in extremely severe rocky

The determinants of domestic water demand. Empirical evidence from Emilia-Romagna municipal data

International Nuclear Information System (INIS)

Mazzanti, Massimiliano; Montini, Anna

2004-01-01

This paper presents empirical evidence on the determinants of water demand for domestic use in one Italian region, the Emilia Romagna, by using municipal data. Two main stems in urban/domestic demand analysis cab be found in the empirical literature. The first deals with the estimation of price or income demand elasticities in the short and the long run. The price demand elasticities can be used for water demand managements purpose while the income price elasticities can be useful in the forecasting process of the water requirements. The second one deals with the estimate of customer willingness to pay increasing in water service quality in holistic sense or concerning single characteristics of the service: safety, flavour, continuity, appearance, pollution rate and cost. The aim of the analysis in this case the elicitation of the direct use, indirect use and non-use values associated to the water resource consumption, by means of direct or indirect techniques. In this paper we focused the analysis in the first stem of the empirical literature in which a cross section data set is required. The paper explores the topic problems of the estimating process whit the analysis of the empirical literature (with particular regard to investigations that use municipal data) and with the analysis of the econometric problems related to the demand estimate. The theoretical model for the water demand analysis is also presented and discussed. Two datasets have been implemented: one with 125 municipalities and four years, the other with 40 municipalities and eleven years. Both the databases bring together municipal water consumption and tariffs data provided by local water utilities and other municipal data (inhabitants, surface, household, income, etc.) stemming from official sources. The econometric analysis is based on both fixed effects, performing better than random effects models, and dynamic panel models. The estimated coefficient of the tariff variable arises always

Woody riparian vegetation response to different alluvial water table regimes

Science.gov (United States)

Shafroth, P.B.; Stromberg, J.C.; Patten, D.T.

2000-01-01

Woody riparian vegetation in western North American riparian ecosystems is commonly dependent on alluvial groundwater. Various natural and anthropogenic mechanisms can cause groundwater declines that stress riparian vegetation, but little quantitative information exists on the nature of plant response to different magnitudes, rates, and durations of groundwater decline. We observed groundwater dynamics and the response of Populus fremontii, Salix gooddingii, and Tamarix ramosissima saplings at 3 sites between 1995 and 1997 along the Bill Williams River, Arizona. At a site where the lowest observed groundwater level in 1996 (-1.97 m) was 1.11 m lower than that in 1995 (-0.86 m), 92-100% of Populus and Salix saplings died, whereas 0-13% of Tamarix stems died. A site with greater absolute water table depths in 1996 (-2.55 m), but less change from the 1995 condition (0.55 m), showed less Populus and Salix mortality and increased basal area. Excavations of sapling roots suggest that root distribution is related to groundwater history. Therefore, a decline in water table relative to the condition under which roots developed may strand plant roots where they cannot obtain sufficient moisture. Plant response is likely mediated by other factors such as soil texture and stratigraphy, availability of precipitation-derived soil moisture, physiological and morphological adaptations to water stress, and tree age. An understanding of the relationships between water table declines and plant response may enable land and water managers to avoid activities that are likely to stress desirable riparian vegetation.

[Estimation of vegetation canopy water content using Hyperion hyperspectral data].

Science.gov (United States)

Song, Xiao-Ning; Ma, Jian-Wei; Li, Xiao-Tao; Leng, Pei; Zhou, Fang-Cheng; Li, Shuang

2013-10-01

Vegetation canopy water content (VCWC) has widespread utility in agriculture, ecology and hydrology. Based on the PROSAIL model, a novel model for quantitative inversion of vegetation canopy water content using Hyperion hyperspectral data was explored. Firstly, characteristics of vegetation canopy reflection were investigated with the PROSAIL radiative transfer model, and it was showed that the first derivative at the right slope (980 - 1 070 nm) of the 970 nm water absorption feature (D98-1 070) was closely related to VCWC, and determination coefficient reached to 0.96. Then, bands 983, 993, 1 003, 1 013, 1 023, 1 033, 1 043, 1 053 and 1 063 nm of Hyperion data were selected to calculate D980-1 070, and VCWC was estimated using the proposed method. Finally, the retrieval result was verified using field measured data in Yingke oasis of the Heihe basin. It indicated that the mean relative error was 12.5%, RMSE was within 0.1 kg x m(-2) and the proposed model was practical and reliable. This study provides a more efficient way for obtaining VCWC of large area.

Perceptions of using low-quality irrigation water in vegetable production in Morogoro, Tanzania

DEFF Research Database (Denmark)

Mayilla, Winfrida; Keraita, Bernard; Ngowi, Helena

2017-01-01

This study was conducted to examine perceptions of the farmers and key informants on the use of low-quality irrigation water for vegetable production in urban and peri-urban areas in Morogoro, Tanzania. The methods used to collect data were farmer surveys (n = 60), focus group discussions (n = 4)...... in formulating policies and creating health promotion awareness for safe use of low-quality water for benefit maximization and health risk reduction....... of buying commercial fertilizers, vegetable production all year round, sustainable income generation from selling vegetables and also jobs creation in the community among farmers and vegetable sellers. Findings from Mann–Whitney U test and Kruskal–Wallis test score on farmers perception scales indicate...

Dynamic modelling of a PV pumping system with special consideration on water demand

International Nuclear Information System (INIS)

Campana, Pietro Elia; Li, Hailong; Yan, Jinyue

2013-01-01

Highlights: ► Evaluation of water demand and solar energy is essential for PV pumping system. ► The design for a PV water pumping system has been optimized based on dynamic simulations. ► It is important to conduct dynamic simulations to check the matching between water demand and water supply. ► AC pump driven by the fixed PV array is the most cost-effective solution. - Abstract: The exploitation of solar energy in remote areas through photovoltaic (PV) systems is an attractive solution for water pumping for irrigation systems. The design of a photovoltaic water pumping system (PVWPS) strictly depends on the estimation of the crop water requirements and land use since the water demand varies during the watering season and the solar irradiation changes time by time. It is of significance to conduct dynamic simulations in order to achieve the successful and optimal design. The aim of this paper is to develop a dynamic modelling tool for the design of a of photovoltaic water pumping system by combining the models of the water demand, the solar PV power and the pumping system, which can be used to validate the design procedure in terms of matching between water demand and water supply. Both alternate current (AC) and direct current (DC) pumps and both fixed and two-axis tracking PV array were analyzed. The tool has been applied in a case study. Results show that it has the ability to do rapid design and optimization of PV water pumping system by reducing the power peak and selecting the proper devices from both technical and economic viewpoints. Among the different alternatives considered in this study, the AC fixed system represented the best cost effective solution

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

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.

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.

Estimating the Determinants of Residential Water Demand in Italy

OpenAIRE

Giulia Romano; Nicola Salvati; Andrea Guerrini

2014-01-01

The aim of this study was to estimate the determinants of residential water demand for chief towns of every Italian province, in the period 2007–2009, using the linear mixed-effects model estimated with the restricted-maximum-likelihood method. Results confirmed that the applied tariff had a negative effect on residential water consumption and that it was a relevant driver of domestic water consumption. Moreover, income per capita had a positive effect on water consumption. Among measured cli...

Water demand studies. [central and southern California regions

Science.gov (United States)

Bowden, L. W.; Estes, J. E.; Churchman, C. W.; Johnson, C. W.; Huning, J. R.; Rozelle, K.; Hamilton, J.; Washburn, G.; Tinney, L. R.; Thaman, R. R.

1973-01-01

The areas of focus of the Santa Barbara and Riverside groups in conducting water demand studies are the central and southern California regional test sites, respectively. Within each test site, sub-areas have been selected for use in the making of detailed investigations. Within each of these sub-areas an in-depth evaluation is being made as to the capability of remote sensing systems to provide pertinent data relative to water demand phenomena. These more limited sub-areas are: (1) Kern County and the San Joaquin Basin; (2) Chino-Riverside Basin; and (3) the Imperial Valley. Rational for the selection of these subareas included the following: Much of the previous remote sensing research had been conducted in these areas and therefore a great deal of remote sensing imagery and pertinent ground truth for the areas was already available.

Comprehensive Forecast of Urban Water-Energy Demand Based on a Neural Network Model

Directory of Open Access Journals (Sweden)

Ziyi Yin

2018-03-01

Full Text Available Water-energy nexus has been a popular topic of rese arch in recent years. The relationships between the demand for water resources and energy are intense and closely connected in urban areas. The primary, secondary, and tertiary industry gross domestic product (GDP, the total population, the urban population, annual precipitation, agricultural and industrial water consumption, tap water supply, the total discharge of industrial wastewater, the daily sewage treatment capacity, total and domestic electricity consumption, and the consumption of coal in industrial enterprises above the designed size were chosen as input indicators. A feedforward artificial neural network model (ANN based on a back-propagation algorithm with two hidden layers was constructed to combine urban water resources with energy demand. This model used historical data from 1991 to 2016 from Wuxi City, eastern China. Furthermore, a multiple linear regression model (MLR was introduced for comparison with the ANN. The results show the following: (a The mean relative error values of the forecast and historical urban water-energy demands are 1.58 % and 2.71%, respectively; (b The predicted water-energy demand value for 2020 is 4.843 billion cubic meters and 47.561 million tons of standard coal equivalent; (c The predicted water-energy demand value in the year 2030 is 5.887 billion cubic meters and 60.355 million tons of standard coal equivalent; (d Compared with the MLR, the ANN performed better in fitting training data, which achieved a more satisfactory accuracy and may provide a reference for urban water-energy supply planning decisions.

Water availability, water quality water governance: the future ahead

Science.gov (United States)

Tundisi, J. G.; Matsumura-Tundisi, T.; Ciminelli, V. S.; Barbosa, F. A.

2015-04-01

The major challenge for achieving a sustainable future for water resources and water security is the integration of water availability, water quality and water governance. Water is unevenly distributed on Planet Earth and these disparities are cause of several economic, ecological and social differences in the societies of many countries and regions. As a consequence of human misuse, growth of urbanization and soil degradation, water quality is deteriorating continuously. Key components for the maintenance of water quantity and water quality are the vegetation cover of watersheds, reduction of the demand and new water governance that includes integrated management, predictive evaluation of impacts, and ecosystem services. Future research needs are discussed.

A novel approach for examining future US 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 policy makers’ abilities to meet essential domestic drinking water needs for future generations. Using Bayesian statistic...

Regional effects of vegetation restoration on water yield across the Loess Plateau, China

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X. M. Feng

2012-08-01

Full Text Available The general relationships between vegetation and water yield under different climatic regimes are well established at a small watershed scale in the past century. However, applications of these basic theories to evaluate the regional effects of land cover change on water resources remain challenging due to the complex interactions of vegetation and climatic variability and hydrologic processes at the large scale. The objective of this study was to explore ways to examine the spatial and temporal effects of a large ecological restoration project on water yield across the Loess Plateau region in northern China. We estimated annual water yield as the difference between precipitation input and modelled actual evapotranspiration (ET output. We constructed a monthly ET model using published ET data derived from eddy flux measurements and watershed streamflow data. We validated the ET models at a watershed and regional levels. The model was then applied to examine regional water yield under land cover change and climatic variability during the implementation of the Grain-for-Green (GFG project during 1999–2007. We found that water yield in 38% of the Loess Plateau area might have decreased (1–48 mm per year as a result of land cover change alone. However, combined with climatic variability, 37% of the study area might have seen a decrease in water yield with a range of 1–54 mm per year, and 35% of the study area might have seen an increase with a range of 1–10 mm per year. Across the study region, climate variability masked or strengthened the water yield response to vegetation restoration. The absolute annual water yield change due to vegetation restoration varied with precipitation regimes with the highest in wet years, but the relative water yield changes were most pronounced in dry years. We concluded that the effects of land cover change associated with ecological restoration varied greatly over time and space and were strongly influenced

Electric Water Heater Modeling and Control Strategies for Demand Response

Energy Technology Data Exchange (ETDEWEB)

Diao, Ruisheng; Lu, Shuai; Elizondo, Marcelo A.; Mayhorn, Ebony T.; Zhang, Yu; Samaan, Nader A.

2012-07-22

Abstract— Demand response (DR) has a great potential to provide balancing services at normal operating conditions and emergency support when a power system is subject to disturbances. Effective control strategies can significantly relieve the balancing burden of conventional generators and reduce investment on generation and transmission expansion. This paper is aimed at modeling electric water heaters (EWH) in households and tests their response to control strategies to implement DR. The open-loop response of EWH to a centralized signal is studied by adjusting temperature settings to provide regulation services; and two types of decentralized controllers are tested to provide frequency support following generator trips. EWH models are included in a simulation platform in DIgSILENT to perform electromechanical simulation, which contains 147 households in a distribution feeder. Simulation results show the dependence of EWH response on water heater usage . These results provide insight suggestions on the need of control strategies to achieve better performance for demand response implementation. Index Terms— Centralized control, decentralized control, demand response, electrical water heater, smart grid

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

Shallow water table effects on water, sediment, and pesticide transport in vegetative filter strips - Part 1: nonuniform infiltration and soil water redistribution

OpenAIRE

Munoz Carpena, R.; Lauvernet, C.; Carluer, N.

2018-01-01

Vegetation buffers like vegetative filter strips (VFSs) are often used to protect water bodies from surface runoff pollution from disturbed areas. Their typical placement in floodplains often results in the presence of a seasonal shallow water table (WT) that can decrease soil infiltration and increase surface pollutant transport during a rainfall-runoff event. Simple and robust components of hydrological models are needed to analyze the impacts of WT in the landscape. To si...

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.

2011-08-01

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-induced. In those countries, it can be seen

Spectral entropy as a mean to quantify water stress history for natural vegetation and irrigated agriculture in a water-stressed tropical environment

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Kim, Y.; Johnson, M. S.

2017-12-01

Spectral entropy (Hs) is an index which can be used to measure the structural complexity of time series data. When a time series is made up of one periodic function, the Hs value becomes smaller, while Hs becomes larger when a time series is composed of several periodic functions. We hypothesized that this characteristic of the Hs could be used to quantify the water stress history of vegetation. For the ideal condition for which sufficient water is supplied to an agricultural crop or natural vegetation, there should be a single distinct phenological cycle represented in a vegetation index time series (e.g., NDVI and EVI). However, time series data for a vegetation area that repeatedly experiences water stress may include several fluctuations that can be observed in addition to the predominant phenological cycle. This is because the process of experiencing water stress and recovering from it generates small fluctuations in phenological characteristics. Consequently, the value of Hs increases when vegetation experiences several water shortages. Therefore, the Hs could be used as an indicator for water stress history. To test this hypothesis, we analyzed Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data for a natural area in comparison to a nearby sugarcane area in seasonally-dry western Costa Rica. In this presentation we will illustrate the use of spectral entropy to evaluate the vegetative responses of natural vegetation (dry tropical forest) and sugarcane under three different irrigation techniques (center pivot irrigation, drip irrigation and flood irrigation). Through this comparative analysis, the utility of Hs as an indicator will be tested. Furthermore, crop response to the different irrigation methods will be discussed in terms of Hs, NDVI and yield.

Historical effects of CO2 and climate trends on global crop water demand

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Urban, Daniel W.; Sheffield, Justin; Lobell, David B.

2017-12-01

A critical question for agricultural production and food security is how water demand for staple crops will respond to climate and carbon dioxide (CO2) changes1, especially in light of the expected increases in extreme heat exposure2. To quantify the trade-offs between the effects of climate and CO2 on water demand, we use a `sink-strength' model of demand3,4 which relies on the vapour-pressure deficit (VPD), incident radiation and the efficiencies of canopy-radiation use and canopy transpiration; the latter two are both dependent on CO2. This model is applied to a global data set of gridded monthly weather data over the cropping regions of maize, soybean, wheat and rice during the years 1948-2013. We find that this approach agrees well with Penman-Monteith potential evapotranspiration (PM) for the C3 crops of soybean, wheat and rice, where the competing CO2 effects largely cancel each other out, but that water demand in maize is significantly overstated by a demand measure that does not include CO2, such as the PM. We find the largest changes in wheat, for which water demand has increased since 1981 over 86% of the global cropping area and by 2.3-3.6 percentage points per decade in different regions.

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 statistical mo...

Relationships between aquatic vegetation and water turbidity: A field survey across seasons and spatial scales

OpenAIRE

Austin, ?sa N.; Hansen, Joakim P.; Donadi, Serena; Ekl?f, Johan S.

2017-01-01

Field surveys often show that high water turbidity limits cover of aquatic vegetation, while many small-scale experiments show that vegetation can reduce turbidity by decreasing water flow, stabilizing sediments, and competing with phytoplankton for nutrients. Here we bridged these two views by exploring the direction and strength of causal relationships between aquatic vegetation and turbidity across seasons (spring and late summer) and spatial scales (local and regional), using causal model...

Advances in estimation methods of vegetation water content based on optical remote sensing techniques

Institute of Scientific and Technical Information of China (English)

无

2010-01-01

Quantitative estimation of vegetation water content(VWC) using optical remote sensing techniques is helpful in forest fire as-sessment,agricultural drought monitoring and crop yield estimation.This paper reviews the research advances of VWC retrieval using spectral reflectance,spectral water index and radiative transfer model(RTM) methods.It also evaluates the reli-ability of VWC estimation using spectral water index from the observation data and the RTM.Focusing on two main definitions of VWC-the fuel moisture content(FMC) and the equivalent water thickness(EWT),the retrieval accuracies of FMC and EWT using vegetation water indices are analyzed.Moreover,the measured information and the dataset are used to estimate VWC,the results show there are significant correlations among three kinds of vegetation water indices(i.e.,WSI,NDⅡ,NDWI1640,WI/NDVI) and canopy FMC of winter wheat(n=45).Finally,the future development directions of VWC detection based on optical remote sensing techniques are also summarized.

Hygienic-sanitary conditions of vegetables and irrigation water from kitchen gardens in the municipality of Campinas, SP

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Simões Marise

2001-01-01

Full Text Available We examined samples of irrigation water and vegetables from kitchen gardens in Campinas, Brazil. The bacterial analysis condemned 22.3% of the vegetable samples, and the parasitological examination condemned 14.5%. The criteria established by the Brazilian legislation condemned 11.8% of the irrigation water samples. Parasites were significantly more frequent in vegetables in the rainy season, while excessive fecal coliforms were more frequent in the dry season. A proper monitoring of the irrigation water supply is important to avoid the contamination of vegetables.

Water Footprints of Vegetable Crop Wastage along the Supply Chain in Gauteng, South Africa

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Betsie le Roux

2018-04-01

Full Text Available Food production in water-scarce countries like South Africa will become more challenging in the future because of the growing population and intensifying water shortages. Reducing food wastage is one way of addressing this challenge. The wastage of carrots, cabbage, beetroot, broccoli and lettuce, produced on the Steenkoppies Aquifer in Gauteng, South Africa, was estimated for each step along the supply chain from the farm to the consumer. Water footprints for these vegetables were used to determine the volume of water lost indirectly as a result of this wastage. Highest percentage wastage occurs at the packhouse level, which is consistent with published literature. Some crops like lettuce have higher average wastage percentages (38% compared to other crops like broccoli (13% and cabbage (14%, and wastage varied between seasons. Care should therefore be taken when applying general wastage values reported for vegetables. The classification of “waste” presented a challenge, because “wasted” vegetables are often used for other beneficial purposes, including livestock feed and composting. It was estimated that blue water lost on the Steenkoppies Aquifer due to vegetable crop wastage (4 Mm3 year−1 represented 25% of the estimated blue water volume that exceeded sustainable limits (17 Mm3 year−1.

Influence of Hudiara Drain Water Irrigation on Trace Elements Load ...

African Journals Online (AJOL)

... Drain Water Irrigation on Trace Elements Load In Soil And Uptake By Vegetables. ... This polluted water not only contains organic matter and crop nutrients but also ... Plant samples were collected at maturity from all the monitoring points. ... (DO), Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) ...

Household demand for water in Sweden with implications of a potential tax on water use

Science.gov (United States)

HöGlund, Lena

1999-12-01

The purpose of this paper is to estimate empirically the effects of a water tax on water use and on the size and stability of the tax revenues. A tax exceeding value-added tax can be motivated on efficiency grounds when there are environmental external costs of water use and when water is a scarce resource. A household demand function for water is estimated using community level data for 282 (out of 286) Swedish communities studied annually over the period 1980-1992. Static and dynamic demand functions are estimated using panel data methods. The results show a long-run price elasticity of -0.10 in marginal price models and -0.20 in average price models. The findings imply that a tax of 1 Swedish Kronor (SEK) m-3 of water used (corresponding to a 5% increase in the mean average price) would generate ˜600 million SEK in tax revenues per year when levied on all households in Sweden. The water consumption would, however, only be reduced by ˜1%.

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

NARCIS (Netherlands)

Blokker, E.J.M.; Vreeburg, J.H.G.; Beverloo, H.; Klein Arfman, M.; Van Dijk, J.C.

2010-01-01

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

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

KAUST Repository

Ghaffour, NorEddine; Missimer, Thomas M.; Amy, Gary L.

2013-01-01

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

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

Ready-to-eat vegetables production with low-level water chlorination. An evaluation of water quality, and of its impact on end products.

Science.gov (United States)

D'Acunzo, Francesca; Del Cimmuto, Angela; Marinelli, Lucia; Aurigemma, Caterina; De Giusti, Maria

2012-01-01

We evaluated the microbiological impact of low-level chlorination (1 ppm free chlorine) on the production of ready-to-eat (RTE) vegetables by monitoring the microbiological quality of irrigation and processing water in two production plants over a 4-season period, as well as the microbiological quality of unprocessed vegetables and RTE product. Water samples were also characterized in terms of some chemical and physico-chemical parameters of relevance in chlorination management. Both producers use water with maximum 1 ppm free chlorine for vegetables rinsing, while the two processes differ by the number of washing cycles. Salmonella spp and Campylobacter spp were detected once in two different irrigation water samples out of nine from one producer. No pathogens were found in the vegetable samples. As expected, the procedure encompassing more washing cycles performed slightly better in terms of total mesophilic count (TMC) when comparing unprocessed and RTE vegetables of the same batch. However, data suggest that low-level chlorination may be insufficient in preventing microbial build-up in the washing equipment and/or batch-to batch cross-contamination.

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

Analysis of soil and vegetation patterns in semi-arid Mediterranean landscapes by way of a conceptual water balance model

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I. Portoghese

2008-06-01

Full Text Available This paper investigates the impact of various vegetation types on water balance variability in semi-arid Mediterranean landscapes, and the different strategies they may have developed to succeed in such water-limited environments. The existence of preferential associations between soil water holding capacity and vegetation species is assessed through an extensive soil geo-database focused on a study region in Southern Italy. Water balance constraints that dominate the organization of landscapes are investigated by a conceptual bucket approach. The temporal water balance dynamics are modelled, with vegetation water use efficiency being parameterized through the use of empirically obtained crop coefficients as surrogates of vegetation behavior in various developmental stages. Sensitivity analyses with respect to the root zone depth and soil water holding capacity are carried out with the aim of explaining the existence of preferential soil-vegetation associations and, hence, the spatial distribution of vegetation types within the study region. Based on these sensitivity analyses the degrees of suitability and adaptability of each vegetation type to parts of the study region are explored with respect of the soil water holding capacity, and the model results were found consistent with the observed affinity patterns.

Phenological characteristics of the main vegetation types on the Tibetan Plateau based on vegetation and water indices

International Nuclear Information System (INIS)

Peng, D L; Huang, W J; Zhou, B; Li, C J; Wu, Y P; Yang, X H

2014-01-01

Plant phenology is considered one of the most sensitive and easily observable natural indicators of climate change, though few studies have focused on the heterogeneities of phenology across the different vegetation types. In this study, we tried to find the phenological characteristics of the main vegetation types on the Tibetan Plateau. MCD12Q1 images over the Tibetan Plateau from 2001 to 2010 were used to extract the main vegetation types. The Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Land Surface Water Index (LSWI) were calculated using surface reflectance values from the blue, red, near-infrared, short-wave infrared (SWIR) 6 (for LSIW6), and SWIR7 (for LSIW7) bands derived from MOD09A1 and used to explore the phenological characteristics of the main vegetation types on the Tibetan Plateau. The results showed that there were eight constant vegetation types on the Tibetan Plateau from 2001 to 2010 demonstrating multiple phenological characteristics. Evergreen needleleaf forest, evergreen broadleaf forest, and permanent wetland had the minimum NDVI values during the summer season, while open shrubland and grassland had the maximum NDVI/EVI values during this period. NDVI and EVI of cropland/natural vegetation had two peaks for their seasonal variations. EVI showed a more significant correlation with LSWI6/LSWI7 than NDVI. Compared to LSWI7, larger EVI values occurred in evergreen needleleaf forest, evergreen broadleaf forest, mixed forest, and permanent wetland, while smaller values occurred in shrubland and barren or sparsely vegetated cover, and nearly equal values occurred in grassland and cropland

Assessing the impact of climate variability on catchment water balance and vegetation cover

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X. Xu

2012-01-01

Full Text Available Understanding the interactions among climate, vegetation cover and the water cycle lies at the heart of the study of watershed ecohydrology. Recently, considerable attention is being paid to the effect of climate variability on catchment water balance and also associated vegetation cover. In this paper, we investigate the general pattern of long-term water balance and vegetation cover (as reflected by fPAR among 193 study catchments in Australia through statistical analysis. We then employ the elasticity analysis approach for quantifying the effects of climate variability on hydrologic partitioning (including total, surface and subsurface runoff and on vegetation cover (including total, woody and non-woody vegetation cover. Based on the results of statistical analysis, we conclude that annual runoff (R, evapotranspiration (E and runoff coefficient (R/P increase with vegetation cover for catchments in which woody vegetation is dominant and annual precipitation is relatively high. Control of water available on annual evapotranspiration in non-woody dominated catchments is relatively stronger compared to woody dominated ones. The ratio of subsurface runoff to total runoff (R_g/R also increases with woody vegetation cover. Through the elasticity analysis of catchment runoff, it is shown that precipitation (P in current year is the most important factor affecting the change in annual total runoff (R, surface runoff (R_s and subsurface runoff (R_g. The significance of other controlling factors is in the order of annual precipitation in previous years (P₋₁ and P₋₂, which represents the net effect of soil moisture and annual mean temperature (T in current year. Change of P by +1% causes a +3.35% change of R, a +3.47% change of R_s and a +2.89% change of

Stable oxygen isotope analysis reveal vegetation influence on soil water movement and ecosystem water fluxes in a semi-arid oak woodland

Science.gov (United States)

Piayda, Arndt; Dubbert, Maren; Werner, Christiane; Cuntz, Matthias

2015-04-01

Mechanistically disentangling the role and function of vegetation within the hydrological cycle is one of the key questions in the interdisciplinary field of ecohydrology. The presence of vegetation can have various impacts on soil water relations: transpiration of active vegetation causes great water losses, rainfall is intercepted, soil evaporation can be reduced and infiltration, hydraulic redistribution and translatory flow might be altered. In drylands, covering around 40% of the global land surface, the carbon cycle is closely coupled to water availability due to (seasonal) droughts. Specifically savannah type ecosystems, which cover large areas worldwide, are, due to their bi-layered structure, very suitable to study the effects of distinct vegetation types on the ecosystem water cycle. Oxygen isotope signatures (δ18O) have been used to partition ecosystem evapotranspiration (ET ) because of the distinct isotopic compositions of water transpired by leaves relative to soil evaporated vapor. Recent developments in laser spectroscopy enable measurements of δ18O in the vapor phase with high temporal resolution in the field and bear a novel opportunity to trace water movement within the ecosystem. In the present study, the effects of distinct vegetation layers (i.e. trees and herbaceous vegetation) on soil water infiltration and redistribution as well as ecosystem water fluxes in a Mediterranean cork-oak woodland are disentangled. An irrigation experiment was carried out using δ18O labeled water to quantify the distinct effects of trees and herbaceous vegetation on 1) infiltration and redistribution of water in the soil profile and 2) to disentangle the effects of tree cover on the contribution of unproductive soil evaporation and understory transpiration to total ET . First results proof that stable δ18O isotopes measured onsite with laser spectroscopy is a valuable tool to trace water movement in the soil showing a much higher sensitivity than common TDR

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

The Impact of Vegetative Slope on Water Flow and Pollutant Transport through Embankments

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Liting Sheng

2017-06-01

Full Text Available Embankments are common structures along rivers or lakes in riparian zones in plain areas. They should have natural slopes instead of slopes covered by concrete or other hard materials, in order to rebuild sustainable ecosystems for riparian zones. This study was conducted to evaluate the effects of vegetative slopes on water flow and pollutant transport through the embankments. Three embankments with different slope treatments (a bare slope, a slope covered in centipede grass, a slope covered in tall fescue were examined, and three inflow applications of pollute water with different concentration of total nitrogen (TN and total phosphorus (TP used to simulate different agricultural non-point pollution levels. The results showed that the water flux rates of the three embankments were relatively stable under all inflow events, and almost all values were higher than 80%. The embankments with vegetative slopes had better nitrogen removal than the bare slope under all events, and the one with tall fescue slope was best, but the benefits of vegetative slopes decreased with increasing inflow concentration. Moreover, there were no significant differences between the embankments on phosphorus removal, for which the reductions were all high (above 90% with most loads remaining in the front third of embankment bodies. Overall, the embankments with vegetative slopes had positive effects on water exchange and reducing non-point pollutant into lake or river water, which provides a quantitative scientific basis for the actual layout of lakeshores.

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

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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

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.

Climate change and water supply and demand in western Canada

International Nuclear Information System (INIS)

Lawford, R.G.

1990-01-01

There is reason to be concerned that water resources on the Canadian Prairies could be at considerable risk due to climatic change. The Canadian Prairies frequently experience variations in the climate, which can reduce crop production by 25-50% and annual volumetric river flows by 70-90%. The potential impacts of climatic change on the Prairies are discussed. Consumptive water uses on the Prairies are dominated by irrigation and the water demands arising from thermal power generation. The overall effect of climatic change on water supplies will depend on the ways in which the various components of the hydrological cycle are affected. At the present time it is unsure whether complementary equations are more realistic in estimating evaporation than mass balance techniques. There is a need to obtain good baseline data which will allow the unequivocal resolution of the most accurate technique for estimating evaporation on the Prairies. Climate change could lead to a decrease in spring runoff, and would also lead to earlier snowmelt and peak flows. This could lead to a longer period of low flows during the summer and fall and a further drawdown of moisture reserves. Some appropriate strategies for adapting to climate change would be: encouraging water conservation; reductions in agricultural water use by developing/utilizing strains of plants with lower water demand; controlling new water developments; and enhancing on-farm retention. 10 refs

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

Demand Estimation for Irrigation Water in the Moroccan Drâa Valley using Contingent Valuation

OpenAIRE

Storm, Hugo; Heckelei, Thomas; Heidecke, Claudia

2010-01-01

Irrigation water management is crucial for agricultural production and livelihood security in Morocco as in many other parts of the world. For the implementation of an effective water management knowledge about farmers’ irrigation water demand is crucial to assess demand reactions of a water pricing policy, to establish a cost-benefit analysis of water supply investments or to determine the optimal water allocation between different users. Previously used econometric methods providing this in...

Groundwater discharge by evapotranspiration, flow of water in unsaturated soil, and stable isotope water sourcing in areas of sparse vegetation, Amargosa Desert, Nye County, Nevada

Science.gov (United States)

Moreo, Michael T.; Andraski, Brian J.; Garcia, C. Amanda

2017-08-29

This report documents methodology and results of a study to evaluate groundwater discharge by evapotranspiration (GWET) in sparsely vegetated areas of Amargosa Desert and improve understanding of hydrologic-continuum processes controlling groundwater discharge. Evapotranspiration and GWET rates were computed and characterized at three sites over 2 years using a combination of micrometeorological, unsaturated zone, and stable-isotope measurements. One site (Amargosa Flat Shallow [AFS]) was in a sparse and isolated area of saltgrass (Distichlis spicata) where the depth to groundwater was 3.8 meters (m). The second site (Amargosa Flat Deep [AFD]) was in a sparse cover of predominantly shadscale (Atriplex confertifolia) where the depth to groundwater was 5.3 m. The third site (Amargosa Desert Research Site [ADRS]), selected as a control site where GWET is assumed to be zero, was located in sparse vegetation dominated by creosote bush (Larrea tridentata) where the depth to groundwater was 110 m.Results indicated that capillary rise brought groundwater to within 0.9 m (at AFS) and 3 m (at AFD) of land surface, and that GWET rates were largely controlled by the slow but relatively persistent upward flow of water through the unsaturated zone in response to atmospheric-evaporative demands. Greater GWET at AFS (50 ± 20 millimeters per year [mm/yr]) than at AFD (16 ± 15 mm/yr) corresponded with its shallower depth to the capillary fringe and constantly higher soil-water content. The stable-isotope dataset for hydrogen (δ2H) and oxygen (δ18O) illustrated a broad range of plant-water-uptake scenarios. The AFS saltgrass and AFD shadscale responded to changing environmental conditions and their opportunistic water use included the time- and depth-variable uptake of unsaturated-zone water derived from a combination of groundwater and precipitation. These results can be used to estimate GWET in other areas of Amargosa Desert where hydrologic conditions are similar.

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

Relationships between aquatic vegetation and water turbidity: A field survey across seasons and spatial scales.

Science.gov (United States)

Austin, Åsa N; Hansen, Joakim P; Donadi, Serena; Eklöf, Johan S

2017-01-01

Field surveys often show that high water turbidity limits cover of aquatic vegetation, while many small-scale experiments show that vegetation can reduce turbidity by decreasing water flow, stabilizing sediments, and competing with phytoplankton for nutrients. Here we bridged these two views by exploring the direction and strength of causal relationships between aquatic vegetation and turbidity across seasons (spring and late summer) and spatial scales (local and regional), using causal modeling based on data from a field survey along the central Swedish Baltic Sea coast. The two best-fitting regional-scale models both suggested that in spring, high cover of vegetation reduces water turbidity. In summer, the relationships differed between the two models; in the first model high vegetation cover reduced turbidity; while in the second model reduction of summer turbidity by high vegetation cover in spring had a positive effect on summer vegetation which suggests a positive feedback of vegetation on itself. Nitrogen load had a positive effect on turbidity in both seasons, which was comparable in strength to the effect of vegetation on turbidity. To assess whether the effect of vegetation was primarily caused by sediment stabilization or a reduction of phytoplankton, we also tested models where turbidity was replaced by phytoplankton fluorescence or sediment-driven turbidity. The best-fitting regional-scale models suggested that high sediment-driven turbidity in spring reduces vegetation cover in summer, which in turn has a negative effect on sediment-driven turbidity in summer, indicating a potential positive feedback of sediment-driven turbidity on itself. Using data at the local scale, few relationships were significant, likely due to the influence of unmeasured variables and/or spatial heterogeneity. In summary, causal modeling based on data from a large-scale field survey suggested that aquatic vegetation can reduce turbidity at regional scales, and that high

Relationships between aquatic vegetation and water turbidity: A field survey across seasons and spatial scales.

Directory of Open Access Journals (Sweden)

Åsa N Austin

Full Text Available Field surveys often show that high water turbidity limits cover of aquatic vegetation, while many small-scale experiments show that vegetation can reduce turbidity by decreasing water flow, stabilizing sediments, and competing with phytoplankton for nutrients. Here we bridged these two views by exploring the direction and strength of causal relationships between aquatic vegetation and turbidity across seasons (spring and late summer and spatial scales (local and regional, using causal modeling based on data from a field survey along the central Swedish Baltic Sea coast. The two best-fitting regional-scale models both suggested that in spring, high cover of vegetation reduces water turbidity. In summer, the relationships differed between the two models; in the first model high vegetation cover reduced turbidity; while in the second model reduction of summer turbidity by high vegetation cover in spring had a positive effect on summer vegetation which suggests a positive feedback of vegetation on itself. Nitrogen load had a positive effect on turbidity in both seasons, which was comparable in strength to the effect of vegetation on turbidity. To assess whether the effect of vegetation was primarily caused by sediment stabilization or a reduction of phytoplankton, we also tested models where turbidity was replaced by phytoplankton fluorescence or sediment-driven turbidity. The best-fitting regional-scale models suggested that high sediment-driven turbidity in spring reduces vegetation cover in summer, which in turn has a negative effect on sediment-driven turbidity in summer, indicating a potential positive feedback of sediment-driven turbidity on itself. Using data at the local scale, few relationships were significant, likely due to the influence of unmeasured variables and/or spatial heterogeneity. In summary, causal modeling based on data from a large-scale field survey suggested that aquatic vegetation can reduce turbidity at regional scales

Quantitative variation in water-use efficiency across water regimes and its relationship with circadian, vegetative, reproductive, and leaf gas-exchange traits.

Science.gov (United States)

Edwards, Christine E; Ewers, Brent E; McClung, C Robertson; Lou, Ping; Weinig, Cynthia

2012-05-01

Drought limits light harvesting, resulting in lower plant growth and reproduction. One trait important for plant drought response is water-use efficiency (WUE). We investigated (1) how the joint genetic architecture of WUE, reproductive characters, and vegetative traits changed across drought and well-watered conditions, (2) whether traits with distinct developmental bases (e.g. leaf gas exchange versus reproduction) differed in the environmental sensitivity of their genetic architecture, and (3) whether quantitative variation in circadian period was related to drought response in Brassica rapa. Overall, WUE increased in drought, primarily because stomatal conductance, and thus water loss, declined more than carbon fixation. Genotypes with the highest WUE in drought expressed the lowest WUE in well-watered conditions, and had the largest vegetative and floral organs in both treatments. Thus, large changes in WUE enabled some genotypes to approach vegetative and reproductive trait optima across environments. The genetic architecture differed for gas-exchange and vegetative traits across drought and well-watered conditions, but not for floral traits. Correlations between circadian and leaf gas-exchange traits were significant but did not vary across treatments, indicating that circadian period affects physiological function regardless of water availability. These results suggest that WUE is important for drought tolerance in Brassica rapa and that artificial selection for increased WUE in drought will not result in maladaptive expression of other traits that are correlated with WUE.

Water retention techniques for vegetation establishment in TxDOT West Texas districts.

Science.gov (United States)

2010-03-01

Water harvesting is the collection of runoff for its productive use and may aid in the germination and : establishment of vegetation seeded in the roadside. This project is a synthesis study on the feasibility and : implications of adapting water har...

Green Walls as an Approach in Grey Water Treatment

Science.gov (United States)

Rysulova, Martina; Kaposztasova, Daniela; Vranayova, Zuzana

2017-10-01

Grey water contributes significantly to waste water parameters such as biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total phosphorus (Ptotal), total nitrogen (Ntotal), ammonium, boron, metals, salts, surfactants, synthetic chemicals, oils and greases, xenobiotic substances and microorganisms. Concentration of these pollutants and the water quality highlights the importance of treatment process in grey water systems. Treatment technologies operating under low energy and maintenance are usually preferred, since they are more cost effective for users. Treatment technologies based on natural processes represent an example of such technology including vegetated wall. Main aim of this paper is to introduce the proposal of vegetated wall managing grey water and brief characteristic of proposed system. Is expected that prepared experiment will establish the purifying ability and the potential of green wall application as an efficient treatment technology.

Chlorinated and ultraviolet radiation -treated reclaimed irrigation water is the source of Aeromonas found in vegetables used for human consumption

Energy Technology Data Exchange (ETDEWEB)

Latif-Eugenín, Fadua; Beaz-Hidalgo, Roxana; Silvera-Simón, Carolina [Unidad de Microbiología, Facultad de Medicina y Ciencias de la Salud, IISPV, Universidad Rovira i Virgili, Reus (Spain); Fernandez-Cassi, Xavi [Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona, Barcelona (Spain); Figueras, María J., E-mail: mariajose.figueras@urv.cat [Unidad de Microbiología, Facultad de Medicina y Ciencias de la Salud, IISPV, Universidad Rovira i Virgili, Reus (Spain)

2017-04-15

Wastewater is increasingly being recognized as a key water resource, and reclaimed water (or treated wastewater) is used for irrigating vegetables destined for human consumption. The aim of the present study was to determine the diversity and prevalence of Aeromonas spp. both in reclaimed water used for irrigation and in the three types of vegetables irrigated with that water. Seven of the 11 (63.6%) samples of reclaimed water and all samples of vegetables were positive for the presence of Aeromonas. A total of 216 Aeromonas isolates were genotyped and corresponded to 132 different strains that after identification by sequencing the rpoD gene belonged to 10 different species. The prevalence of the species varied depending on the type of sample. In the secondary treated reclaimed water A. caviae and A. media dominated (91.4%) while A. salmonicida, A. media, A. allosaccharophila and A. popoffii represented 74.0% of the strains in the irrigation water. In vegetables, A. caviae (75.0%) was the most common species, among which a strain isolated from lettuce had the same genotype (ERIC pattern) as a strain recovered from the irrigation water. Furthermore, the same genotype of the species A. sanarellii was recovered from parsley and tomatoes demonstrating that irrigation water was the source of contamination and confirming the risk for public health. - Highlights: • Reclaimed water (= treated wastewater) is used for the irrigation of vegetables. • Aeromonas was found in reclaimed water and irrigated vegetables with this water. • The prevalence of Aeromonas spp. varied between irrigation water and vegetables. • Epidemiological relationships were found between irrigation water and vegetables. • The water was the source of contamination which means a risk for the public health.

Chlorinated and ultraviolet radiation -treated reclaimed irrigation water is the source of Aeromonas found in vegetables used for human consumption

International Nuclear Information System (INIS)

Latif-Eugenín, Fadua; Beaz-Hidalgo, Roxana; Silvera-Simón, Carolina; Fernandez-Cassi, Xavi; Figueras, María J.

2017-01-01

Wastewater is increasingly being recognized as a key water resource, and reclaimed water (or treated wastewater) is used for irrigating vegetables destined for human consumption. The aim of the present study was to determine the diversity and prevalence of Aeromonas spp. both in reclaimed water used for irrigation and in the three types of vegetables irrigated with that water. Seven of the 11 (63.6%) samples of reclaimed water and all samples of vegetables were positive for the presence of Aeromonas. A total of 216 Aeromonas isolates were genotyped and corresponded to 132 different strains that after identification by sequencing the rpoD gene belonged to 10 different species. The prevalence of the species varied depending on the type of sample. In the secondary treated reclaimed water A. caviae and A. media dominated (91.4%) while A. salmonicida, A. media, A. allosaccharophila and A. popoffii represented 74.0% of the strains in the irrigation water. In vegetables, A. caviae (75.0%) was the most common species, among which a strain isolated from lettuce had the same genotype (ERIC pattern) as a strain recovered from the irrigation water. Furthermore, the same genotype of the species A. sanarellii was recovered from parsley and tomatoes demonstrating that irrigation water was the source of contamination and confirming the risk for public health. - Highlights: • Reclaimed water (= treated wastewater) is used for the irrigation of vegetables. • Aeromonas was found in reclaimed water and irrigated vegetables with this water. • The prevalence of Aeromonas spp. varied between irrigation water and vegetables. • Epidemiological relationships were found between irrigation water and vegetables. • The water was the source of contamination which means a risk for the public health.

Estimation of area and income elasticities of water demand in a number of cities and towns in Gauteng

OpenAIRE

2012-01-01

M.Ing. Water demand prediction can be useful for future planning and has a significant economic effect on a city, town or suburb. There are numerous factors influencing water demand and therefore influencing the prediction thereof. The effect of each of these factors on the water demand is called the elasticity of that factor. The main aim of this study is to determine area and income elasticities of demand. This will enable the reader to predict water demand by taking stand size (area) an...

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

Interactions of Vegetation and Climate: Remote Observations, Earth System Models, and the Amazon Forest

Science.gov (United States)

Quetin, Gregory R.

The natural composition of terrestrial ecosystems can be shaped by climate to take advantage of local environmental conditions. Ecosystem functioning, e.g. interaction between photosynthesis and temperature, can also acclimate to different climatological states. The combination of these two factors thus determines ecological-climate interactions. The ecosystem functioning also plays a key role in predicting the carbon cycle, hydrological cycle, terrestrial surface energy balance, and the feedbacks in the climate system. Predicting the response of the Earth's biosphere to global warming requires the ability to mechanistically represent the processes controlling ecosystem functioning through photosynthesis, respiration, and water use. The physical environment in a place shapes the vegetation there, but vegetation also has the potential to shape the environment, e.g. increased photosynthesis and transpiration moisten the atmosphere. These two-way ecoclimate interactions create the potential for feedbacks between vegetation at the physical environment that depend on the vegetation and the climate of a place, and can change throughout the year. In Chapter 1, we derive a global empirical map of the sensitivity of vegetation to climate using the response of satellite-observed greenness to interannual variations in temperature and precipitation. We infer mechanisms constraining ecosystem functioning by analyzing how the sensitivity of vegetation to climate varies across climate space. Our analysis yields empirical evidence for multiple physical and biological mediators of the sensitivity of vegetation to climate at large spatial scales. In hot and wet locations, vegetation is greener in warmer years despite temperatures likely exceeding thermally optimum conditions. However, sunlight generally increases during warmer years, suggesting that the increased stress from higher atmospheric water demand is offset by higher rates of photosynthesis. The sensitivity of vegetation

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. Copyright © 2016 Elsevier B.V. All rights reserved.

Chlorine demand and residual chlorine decay kinetics of Kali river water at Kaiga project area

International Nuclear Information System (INIS)

Krishna Bhat, D.; Prakash, T.R.; Thimme Gowda, B.; Sherigara, B.S.; Khader, A.M.A.

1995-01-01

The nuclear power plant at Kaiga would use Kali river water for condenser cooling. This necessitated studies on the chemistry of chlorination such as chlorine demand, kinetics of chlorination and other water characteristics aimed at obtaining base line data. The study revealed significant seasonal variation of chlorine demand ranging from 0.5 ppm to 1.7 ppm (3.0 ppm dose, 30 min contact time) and total consumption of 5.0 ppm (10.0 ppm dose, 48 hours contact time). The reaction follows first order kinetics in chlorine. High correlation of chlorine demand with chlorophyll a, suspended matter, turbidity, silica, nitrite, phosphate and sulphate indicated that chlorine demand is greatly influenced by water quality. (author). 3 refs., 1 tab

Topographic, edaphic, and vegetative controls on plant-available water

Science.gov (United States)

Salli F. Dymond; John B. Bradford; Paul V. Bolstad; Randall K. Kolka; Stephen D. Sebestyen; Thomas M. DeSutter

2017-01-01

Soil moisture varies within landscapes in response to vegetative, physiographic, and climatic drivers, which makes quantifying soil moisture over time and space difficult. Nevertheless, understanding soil moisture dynamics for different ecosystems is critical, as the amount of water in a soil determines a myriad ecosystem services and processes such as net primary...

Water resources adaptation to climate and demand change in the Potomac river

Science.gov (United States)

The effects of climate change are increasingly considered in conjunction with changes in water demand and reservoir sedimentation in forecasts of water supply vulnerability. Here, the relative effects of these factors are evaluated for the Washington, DC metropolitan area water supply for the near f...

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.

Impact of water-level changes to aquatic vegetation in small oligotrophic lakes

Directory of Open Access Journals (Sweden)

Egert VANDEL

2016-06-01

Full Text Available This study demonstrates the effect of drastic water-level changes to the aquatic vegetation in three small oligotrophic lakes situated in Kurtna Kame Field in north-eastern Estonia. The area holds around 40 lakes in 30 km2 of which 18 lakes are under protection as Natura Habitat lakes (Natura 2000 network. The area is under a strong human impact as it is surrounded by oil shale mines, sand quarry, peat harvesting field etc. The most severe impact comes from the groundwater intake established in 1972 in the vicinity of three studied lakes. The exploitation of groundwater led to drastic water-level drops. In 1980s the water-level drops were measured to be up to 3 to 4 meters compared to the levels of 1946. Lake Martiska and Lake Kuradijärv were severely affected and only 29% and 45% of lake area respectively and 21% of initial volume remained. Both lakes were described as oligotrophic lakes before severe human impact and held characteristic macrophytes such as Isoëtes lacustris L., Sparganium angustifolium Michx and Lobelia dortmanna L. As the water level declined the lakes lost their rare characteristic species and can now be described more as a meso- or even eutrophic lakes. When the volume of groundwater abstraction decreased in the 1990s the water levels started to recover but did not reach the natural levels of pre-industrialized era. Also the vegetation did not show any signs of recovery. In 2012 the pumping rates increased again causing a new rapid decline in water levels which almost exceed the previous minimum levels. The water-level monitoring alongside with the macrophyte monitoring data gives us a good case study on how the long term abrupt water-level changes can affect the aquatic vegetation

Estimating irrigation water demand in the Moroccan Drâa Valley using contingent valuation.

Science.gov (United States)

Storm, Hugo; Heckelei, Thomas; Heidecke, Claudia

2011-10-01

Irrigation water management is crucial for agricultural production and livelihood security in Morocco as in many other parts of the world. For the implementation of an effective water management, knowledge about farmers' demand for irrigation water is crucial to assess reactions to water pricing policy, to establish a cost-benefit analysis of water supply investments or to determine the optimal water allocation between different users. Previously used econometric methods providing this information often have prohibitive data requirements. In this paper, the Contingent Valuation Method (CVM) is adjusted to derive a demand function for irrigation water along farmers' willingness to pay for one additional unit of surface water or groundwater. An application in the Middle Drâa Valley in Morocco shows that the method provides reasonable results in an environment with limited data availability. For analysing the censored survey data, the Least Absolute Deviation estimator was found to be a more suitable alternative to the Tobit model as errors are heteroscedastic and non-normally distributed. The adjusted CVM to derive demand functions is especially attractive for water scarce countries under limited data availability. Copyright © 2011 Elsevier Ltd. All rights reserved.

A multi-scale relevance vector regression approach for daily urban water demand forecasting

Science.gov (United States)

Bai, Yun; Wang, Pu; Li, Chuan; Xie, Jingjing; Wang, Yin

2014-09-01

Water is one of the most important resources for economic and social developments. Daily water demand forecasting is an effective measure for scheduling urban water facilities. This work proposes a multi-scale relevance vector regression (MSRVR) approach to forecast daily urban water demand. The approach uses the stationary wavelet transform to decompose historical time series of daily water supplies into different scales. At each scale, the wavelet coefficients are used to train a machine-learning model using the relevance vector regression (RVR) method. The estimated coefficients of the RVR outputs for all of the scales are employed to reconstruct the forecasting result through the inverse wavelet transform. To better facilitate the MSRVR forecasting, the chaos features of the daily water supply series are analyzed to determine the input variables of the RVR model. In addition, an adaptive chaos particle swarm optimization algorithm is used to find the optimal combination of the RVR model parameters. The MSRVR approach is evaluated using real data collected from two waterworks and is compared with recently reported methods. The results show that the proposed MSRVR method can forecast daily urban water demand much more precisely in terms of the normalized root-mean-square error, correlation coefficient, and mean absolute percentage error criteria.

Assessment of water availability and its relationship with vegetation distribution over a tropical montane system

Science.gov (United States)

Streher, A. S.; Sobreiro, J. F. F.; Silva, T. S. F.

2017-12-01

Water availability is one of the main drivers of vegetation distribution, but assessing it over mountainous regions is difficult given the effects of rugged topography on hydroclimatic dynamics (orographic rainfall, soil water, and runoff). We assessed how water availability may influence the distribution of vegetation types in the Espinhaço Range, a South American tropical mountain landscape comprised of savannas, grasslands, rock outcrops, cloud forests, and semi-deciduous/deciduous forests. For precipitation, we used CHIRPS monthly and daily products (1981- 2016) and 112 rain gauge ground stations, and assessed potential evapotranspiration (PET) using the MODIS MOD16A3 (2000-2013) product. Vegetation types were classified according to the Global Ecoregions by WWF. We show that rainfall has well-defined rainy and dry seasons with a strong latitudinal pattern, there is evidence for local orographic effects. Dry forests (907 mm/yr; 8% cv) and caatinga vegetation (795 mm/yr; 7% cv) had the lowest average annual precipitation and low variance, whilst Atlantic tropical forest in the southeast (1267 mm/yr; 15% cv), cerrado savanna vegetation in the west (1086 mm/yr; 15% cv) and rupestrian grasslands above 800m (1261 mm/yr; 20% cv) received the highest annual precipitation, with the largest observed variance due to their wide latitudinal distribution. Forests and rupestrian grasslands in the windward side of the mountain had a higher frequency of intense rainfall events (> 20mm), accounting for 6% of the CHIRPS daily time series, suggesting orographic effects on precipitation. Annual average PET was highest for dry forests (2437 mm/yr) and caatinga (2461 mm/yr), intermediate for cerrado (2264 mm/yr) and lowest for Atlantic tropical forest (2083 mm/yr) and rupestrian grasslands (2136 mm/yr). All vegetation types received less rainfall than its PET capacity based on yearly data, emphasizing the need for ecophysiological adaptations to water use. Climate change threatens

A statistical analysis of the freshness of postharvest leafy vegetables with application of water based on chlorophyll fluorescence measurement

Directory of Open Access Journals (Sweden)

Yichen Qiu

2017-12-01

Full Text Available Vegetable freshness is very important for both restaurant and home consumers. In market, sellers frequently apply water to leafy vegetables to make them not lose weight and look fresh; however, these vegetables may not be stored for a long time as they appear. After a time limit, they may be quickly rotten. It is thus meaningful to investigate early and simple detection tools to measure leafy vegetable freshness while they are frequently applied water in selling. In this work, three types of newly harvested leafy vegetables were bought from a local farmer market and stored in the air with room temperature and roots submerging in water. Chlorophyll a fluorescence (ChlF from the vegetables was measured each half a day for three days. The obtained ChlF data were analyzed statistically and the correlation of ChlF parameters and vegetable freshness/storage time was obtained. The k-mean classification was also performed. It is found that Fo, Fj, Fm/Fo, and Fv/Fm can be used as an early detection tool to differentiate the freshness of leafy vegetables on which water is constantly applied in storage without visible difference. Keywords: Vegetable freshness, Chlorophyll fluorescence, Food measurement

Effects of sulphuric acid and acidifying ammonium deposition on water quality and vegetation of simulated soft water ecosystem

Energy Technology Data Exchange (ETDEWEB)

Schuurkes, J.A.A.R.; Heck, I.C.C; Hesen, P.L.G.M.; Leuven, R.S.E.W.; Roelofs, J.G.M.

1986-11-01

In a greenhouse, seven identical mini-ecosystems, simulating soft water ponds, were exposed to different types of artificial rain water. The effects of rain water containing H/sub 2/SO/sub 4/ and nitrate, and rain water containing ammonium sulphate on water quality and vegetation were studied and compared. Causal relations were established between rain water quality, water chemistry and changes in floristic composition. Ammonium sulphate deposition, particularly, strongly affected water quality and vegetation development. Although ammonium sulphate deposition was only slightly acid, due to nitrification it acted as an important acid source, causing acidification to pH 3.8. Under acidified conditions, ammonium sulphate deposition led to a luxuriant growth of Juncus bulbosus and Agrostis canina. In the mini-ecosystems, H/sub 2/SO/sub 4/ deposition with a pH of 3.5 only decreased the pH of the water to 5.1 within 1 yr, the acidification of water appeared to be coupled with changes in alkalinity, sulphate, Al, Cd, Ca, Mg, K and inorganic-N. It is concluded that in NH/sub 3/-affected regions in The Netherlands, the high atmospheric deposition of ammonium sulphate probably contributes to a large extent in the acidification, eutrophication and floristic changes of oligotrophic soft waters. 10 references.

Effects of sulphuric acid and acidifying ammonium deposition on water quality and vegetation of simulated soft water ecosystems

Energy Technology Data Exchange (ETDEWEB)

Schuurkes, J.A.; Heck, I.C.; Hesen, P.L.; Leuven, R.S.; Roelofs, J.G.

1986-11-01

In a greenhouse, seven identical mini-ecosystems, simulating soft water ponds, were exposed to different types of artificial rain water. The effects of rain water containing H/sub 2/SO/sub 4/ and nitrate, and rain water containing ammonium sulfate on water quality and vegetation were studied and compared. Causal relations were established between rain water quality, water chemistry and changes in floristic composition. Ammonium sulfate deposition, particularly, strongly affected water quality and vegetation development. Although ammonium sulfate deposition was only slightly acid, due to nitrification it acted as an important acid source, causing acidification to pH = 3.8. Under acidified conditions, ammonium sulfate deposition lead to a luxuriant growth of Juncus bulbosus and Agrostis canina. In the mini-ecosystems, H/sub 2/SO/sub 4/ deposition with a pH of 3.5 only decreased the pH of the water to 5.1 within 1 yr. The acidification of water appeared to be coupled with changes in alkalinity, sulfate, Al, Cd, Ca, Mg, K and inorganic-N. It is concluded that in NH/sub 3/-affected regions in The Netherlands, the high atmospheric deposition of ammonium sulfate probably contributes to a large extent in the acidification, eutrophication and floristic changes of oligotrophic soft waters. 10 refs.

The Role of Different Plant Soil-Water Feedbacks in Models of Dryland Vegetation Patterns

Science.gov (United States)

Silber, M.; Bonetti, S.; Gandhi, P.; Gowda, K.; Iams, S.; Porporato, A. M.

2017-12-01

Understanding the processes underlying the formation of regular vegetation patterns in arid and semi-arid regions is important to assessing desertification risk under increasing anthropogenic pressure. Various modeling frameworks have been proposed, which are all capable of generating similar patterns through self-organizing mechanisms that stem from assumptions about plant feedbacks on surface/subsurface water transport. We critically discuss a hierarchy of hydrology-vegetation models for the coupled dynamics of surface water, soil moisture, and vegetation biomass on a hillslope. We identify distinguishing features and trends for the periodic traveling wave solutions when there is an imposed idealized topography and make some comparisons to satellite images of large-scale banded vegetation patterns in drylands of Africa, Australia and North America. This work highlights the potential for constraining models by considerations of where the patterns may lie on a landscape, such as whether on a ridge or in a valley.

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.

Environmental protection: private vegetable gardens on water protected areas in Ljubljana

Directory of Open Access Journals (Sweden)

Sara Strajnar

2008-12-01

Full Text Available The areas of allotment gardens and private vegetable gardens are two types of ‘small-scale agriculture’ on water protected areas in Ljubljana and surroundings. From the environmental protection point of view, these gardens are important for the intensity of production and large number of gardeners. In author’s graduation thesis the gardening habits have been investigated in detail. We combined data from fi eld work with numerous measurements of phytopharmaceutical products and nutrients in soil and vegetables.

Optimum Returns from Greenhouse Vegetables under Water Quality and Risk Constraints in the United Arab Emirates

Directory of Open Access Journals (Sweden)

Eihab Fathelrahman

2017-04-01

Full Text Available Greenhouses have been used in the United Arab Emirates (UAE to produce vegetables that contribute toward UAE food security, including offering fresh vegetable produce in the off-season. However, to manage such greenhouses, farmers face both technical and environmental limitations (i.e., high water scarcity, as well as vegetable market price instability. The objective of this study is to explore tradeoffs between returns (i.e., gross margin of selected vegetables (tomato, pepper, and cucumber, risk (deviation from gross margin means, and an environmental constraint (water salinity using a unique target MOTAD (minimization of total absolute deviations approach to support UAE farmer decision-making processes. The optimal target MOTAD solution included all three vegetables and no corner solution. The results showed tradeoffs between returns and risks, and confirmed that product diversification reduces overall risk. The analysis was consistent with farmer perceptions based on a survey of 78 producers in the region. The search for the optimal mix of vegetable production under UAE greenhouse conditions revealed that reduction in tomato production should be offset by an increase in cucumber production while maintaining a constant level of pepper production. In other words, risk is reduced as cucumber production increases due to the high level of tomato and lettuce price volatility as the alternative to cucumber. The results also demonstrated the importance of the water salinity environmental constraint, as it was found to have a positive marginal value in the optimal vegetable mix solution (i.e., important factor. Thus the optimal solution was highly sensitive to changes in the crop water salinity constraint. The study results also demonstrate that the target MOTAD approach is a suitable optimization methodology. As a practical approach, a decision-maker in the UAE can consider gross margin (total revenue-variable costs maximization with risk and water

LOW WATER DEMAND CEMENTS - WAY OF EFFICIENT USE OF CLINKER AND MINERAL FILLERS IN CONCRETES

Directory of Open Access Journals (Sweden)

Khokhryakov Oleg Viktorovich

2017-10-01

Full Text Available Subject: the provisions in the updated edition of the technical specifications for cements are analyzed. A trend to decrease the clinker volume in Portland cement due to the wider use of mineral additives, up to 95%, was observed. Research objectives: substantiation of the most complete and efficient use of Portland cement and mineral additives in the composition of low water demand cements. Materials and methods: portland cement, mineral additives and superplasticizer were used as raw materials for obtaining cements of low water demand. The experimental methods comply with the current standards. Results: comparative properties of low water demand cements and cements with mineral additives are presented. The properties of cement-water suspensions of these binders have been studied, and, on their basis, heavy concretes have been made. The results of the grindability of Portland cement and mineral components with a superplasticizer are given. Conclusions: it is shown that the cement of low water demand, in which the advantages of both Portland cement and mineral additives are more fully and efficiently presented, complies with the tendency to decrease the clinker volume to the greatest degree. It is established that the clinker volume index for heavy concrete prepared on low water demand cement is almost four times lower than that for heavy concrete based on common Portland cement.

Selection of a Vegetable Water-Retaining Material and Its Effects on the Growth and Quality of Cucumber under Drought Stress Part 1 : Selection of a Vegetable Water-Retaining Material

OpenAIRE

Yang, Shang-Dong; Wang, Rui; Li, Gang; Egashira, Kazuhiko

2008-01-01

Water-retention capacities of moss, common water hyacinth and Late　Juncellus were compared with that of SAP (super absorbent polymers), a presently used chemical water-retaining material. Moss was highest in the amount of water retained per unit weight among the three vegetable materials and showed a somewhat higher water-retention capacity than did SAP. However, it is difficult to collect moss enough for use as a water-retaining material, and collection of a large amount of moss easily lea...

Hygienic-sanitary conditions of vegetables and irrigation water from kitchen gardens in the municipality of Campinas, SP

OpenAIRE

Simões,Marise; Pisani,Beatriz; Marques,Eneida Gonçalves Lemes; Prandi,Maria Angela Garnica; Martini,Maria Helena; Chiarini,Paulo Flávio Teixeira; Antunes,José Leopoldo Ferreira; Nogueira,Ana Paula

2001-01-01

We examined samples of irrigation water and vegetables from kitchen gardens in Campinas, Brazil. The bacterial analysis condemned 22.3% of the vegetable samples, and the parasitological examination condemned 14.5%. The criteria established by the Brazilian legislation condemned 11.8% of the irrigation water samples. Parasites were significantly more frequent in vegetables in the rainy season, while excessive fecal coliforms were more frequent in the dry season. A proper monitoring of the irri...

Life cycle water demand coefficients for crude oil production from five North American locations.

Science.gov (United States)

Ali, Babkir; Kumar, Amit

2017-10-15

The production of liquid fuels from crude oil requires water. There has been limited focus on the assessment of life cycle water demand footprints for crude oil production and refining. The overall aim of this paper is address this gap. The objective of this research is to develop water demand coefficients over the life cycle of fuels produced from crude oil pathways. Five crude oil fields were selected in the three North American countries to reflect the impact of different spatial locations and technologies on water demand. These include the Alaska North Slope, California's Kern County heavy oil, and Mars in the U.S.; Maya in Mexico; and Bow River heavy oil in Alberta, Canada. A boundary for an assessment of the life cycle water footprint was set to cover the unit operations related to exploration, drilling, extraction, and refining. The recovery technology used to extract crude oil is one of the key determining factors for water demand. The amount of produced water that is re-injected to recover the oil is essential in determining the amount of fresh water that will be required. During the complete life cycle of one barrel of conventional crude oil, 1.71-8.25 barrels of fresh water are consumed and 2.4-9.51 barrels of fresh water are withdrawn. The lowest coefficients are for Bow River heavy oil and the highest coefficients are for Maya crude oil. Of all the unit operations, exploration and drilling require the least fresh water (less than 0.015 barrel of water per barrel of oil produced). A sensitivity analysis was conducted and uncertainty in the estimates was determined. Copyright © 2017 Elsevier Ltd. All rights reserved.

Contribution of vegetation and water table on isoprene emission from boreal peatland microcosms

DEFF Research Database (Denmark)

Tiiva, Päivi; Faubert, Patrick; Räty, Sanna

2009-01-01

emission in these naturally wet ecosystems, although water table is predicted to decline due to climate warming. We studied the relative contribution of mosses vs. vascular plants to isoprene emission in boreal peatland microcosms in growth chambers by removing either vascular vegetation or both vascular...... hollows with intact vegetation, 45 ± 6 µg m-2 h-1, was decreased by 25% under water table drawdown. However, water table drawdown reduced net ecosystem carbon dioxide (CO2) exchange more dramatically than isoprene emission. Isoprene emission strongly correlated with both CO2 exchange and methane emission......Boreal peatlands are substantial sources of isoprene, a reactive hydrocarbon. However, it is not known how much mosses, vascular plants and peat each contribute to isoprene emission from peatlands. Furthermore, there is no information on the effects of declining water table depth on isoprene...

Evaluation of water demand and supply in the south of Iraq

NARCIS (Netherlands)

Al-Furaiji, Mustafa; Karim, Usama F.A.; Augustijn, Dionysius C.M.; Waisi, Basma; Hulscher, Suzanne 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

A Novel Approach for Analyzing Water Diffusion in Mineral and Vegetable Oil-Paper Insulation

Directory of Open Access Journals (Sweden)

Bin Du

2014-04-01

Full Text Available Water diffusion characteristics of mineral and vegetable oil-paper insulation systems are important for insulation condition evaluation of oil-filled transformers. In this paper, we describe a novel application method of in situ attenuated total reflection Fourier transform infrared (ATR-FTIR approach for analyzing the diffusion process of water molecules in oil-immersed insulating paper. Two-dimensional correlation was used to analyze the 3700 cm-1 to 3000 cm- 1 hydroxyl peak. The observed results indicated that water molecules form two types of hydroxyl (OH with oil-impregnated paper in the diffusion process are weak and strong hydrogen bonds, respectively. 2D infrared correlation analysis revealed that three OH stretching vibration spectra absorption peaks was existed in hygroscopic vegetable oil-immersed insulating paper. And there are four OH stretching vibration spectra absorption peaks in mineral oil-immersed insulation paper. Furthermore, mineral oil-impregnated paper and vegetable oil-impregnated paper diffusion coefficients were obtained by nonlinear fitting.

Macauba: a promising tropical palm for the production of vegetable oil

Directory of Open Access Journals (Sweden)

Colombo Carlos Augusto

2018-01-01

Full Text Available The growing global demand for vegetable oils for food and for replacing fossil fuels leads to increased oilseeds production. Almost 122 of the current 187 million tons of vegetable oils produced in the world correspond to palm and soybean oils. The oil palm is cultivated in the tropical zone, in areas formerly occupied by forests, and soybean oil is a by-product of protein meal production. The diversification of raw materials for the vegetable oil market is thus strategic for both food and non-food sectors. Sources for vegetable oil should be economically competitive and provide sustainability indexes higher than that provided by oil palm and soybean. In this context, we describe the potential of Acrocomia aculeata, popularly known as macauba. Macauba is an American palm from the tropical zones which presents oil productivity and quality similar to that of the oil palm. It grows spontaneously in a wide range of environments and it is not very water demanding. Macauba palm has a high potential for oil production and for diversification of co-products with some potential of value aggregation. Such a perennial and sustainable species will probably fulfill the requirements to become an important new commercial oilseed crop.

Expanded ethanol production: Implications for agriculture, water demand, and water quality

International Nuclear Information System (INIS)

De La Torre Ugarte, Daniel G.; He, Lixia; Jensen, Kimberly L.; English, Burton C.

2010-01-01

Feedstock production for large scale development of the U.S. ethanol industry and introduction of cellulose-to-ethanol technology will require extensive changes in land use and field management. Hence, this production will likely have significant impact on water demand and quality. This study compares two 'what if' scenarios for attaining a 227.1 hm 3 of ethanol by 2030 and 3.8 hm 3 of biodiesel by 2012. In the first scenario cellulose-to-ethanol technology is introduced in 2012, while in the second scenario the technology is delayed until 2015. Results show that the timing of introduction of cellulose-to-ethanol technology will affect the water use and water quality related input use in primarily in the eastern part of the nation. Results also suggest policy emphasis on reduced and no-till practices needs to be complementary to increased crop residue use. (author)

Effects of Misasa hot spring water on the growth of vegetables (Joint research)

International Nuclear Information System (INIS)

Yamada, Satoshi; Kita, Makoto; Goto, Yukari; Ishimori, Yuu

2011-11-01

Tottori University and Japan Atomic Energy Agency started a joint study to investigate the effect of hot spring water on the growth of vegetable plants in 2009. The aim of the study is to examine a feasibility of producing a regionally special vegetable with considering the characteristics of the Misasa district, where radon hot springs are historically famous. This report illustrates the intermediate results obtained from the study carried out from 2009 to 2010. (1) Screening test: Eighteen plants were examined for screening. As the results, Misasa hot spring water used in the water culture enlarged the growths of 14 plants. Lastly, 9 plants were selected as candidate plants for further examinations. (2) Sample preparation: Plants sampled in the water culture were lyophilized and stored in a freezer for nutrio-physiological analyses to select the suitable plant from the 9 plants. (3) Examination in labor-saving cultivation: Preliminary examinations were performed with a large-scale system to establish a practical labor-saving water culture system. (author)

Correlates of potable water demand among farming households in ...

African Journals Online (AJOL)

This study estimated the correlates of potable water demand among farming households through the use of cross-sectional data collected from 100 households in Abak, Nigeria. Based on the fact that heterogeneity and homogeneity exist within and among the clans and also to ensure equal representation of people from all ...

Transpiration Demand in Southern California Oak Woodlands: Making the Leap from Lab and Individual Tree to Watershed Scale

Science.gov (United States)

Weinberger, J. L.; Quinlan, P. T.; Martin, J.; Tartakovsky, D. M.

2013-12-01

Watershed scale estimates of evapotranspiration (ET) have proven difficult to quantify in areas of native vegetation with uncertain or unknown crop coefficients. In this study, we evaluate the water use in Quercus engelmanni and Quercus agrifolia, two species of oak native to Southern California. Thermal dissipation probes (TDPs) were installed at four locations within a 14,500 acre watershed, comprising 770 acres of Q. agrifolia woodland and 2440 acres of Q. engelmanni woodland. Installation duration ranged from 6 weeks to 14 months. The TDPs were calibrated to each species in the laboratory using limbs ranging from 2 to 5 inches in diameter. Dye was run through each limb at the end of the calibration test in order to establish a relationship between active sapwood area and limb diameter. ET measured in the field for each species was 0.15 to 0.3 times that of the reference evapotranspiration (ETo) derived from the Penman-Monteith equation, with the primary variability in the demand related to measured incident solar radiation. The total water demand for each species is estimated using the laboratory determined relationship between the active sapwood area and the diameter of the limb, and a survey of the tree diameter breast height (DBH) of each tree in the watershed. This study provides new insight into the actual water demand of two native tree species in Southern California and has serious implications for conservation plans, which are often developed using watershed models that apply ETo to all vegetation communities, regardless of actual water demand.

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

African Journals Online (AJOL)

AADD) in South Africa are based on residential plot size. This paper presents a novel, robust method for estimating suburban water demand as a function of the suburb area. Seventy suburbs, identified as being predominantly residential, were ...

Optimal and Learning-Based Demand Response Mechanism for Electric Water Heater System

Directory of Open Access Journals (Sweden)

Bo Lin

2017-10-01

Full Text Available This paper investigates how to develop a learning-based demand response approach for electric water heater in a smart home that can minimize the energy cost of the water heater while meeting the comfort requirements of energy consumers. First, a learning-based, data-driven model of an electric water heater is developed by using a nonlinear autoregressive network with external input (NARX using neural network. The model is updated daily so that it can more accurately capture the actual thermal dynamic characteristics of the water heater especially in real-life conditions. Then, an optimization problem, based on the NARX water heater model, is formulated to optimize energy management of the water heater in a day-ahead, dynamic electricity price framework. A genetic algorithm is proposed in order to solve the optimization problem more efficiently. MATLAB (R2016a is used to evaluate the proposed learning-based demand response approach through a computational experiment strategy. The proposed approach is compared with conventional method for operation of an electric water heater. Cost saving and benefits of the proposed water heater energy management strategy are explored.

Effect of water stress in soil-water-vegetation relationships, along a rainfall gradient in southern Spain

International Nuclear Information System (INIS)

Ruiz-Sinoga, J. D.; Ferre Bueno, E.; Martinez-Murillo, J. F.; Gabarron-Galeote, M. A.

2009-01-01

The Andalusian Mediterranean Watershed, in the South of the Iberian Peninsula, shows a climatic gradient from the Straits of Gibraltar (1,600 mm year - 1) to the Cabo de Gata (150 mm year 1 ). Climate conditions differences are translating into variations in the elements of the eco-geomorphologic system at hillslope scale. In this study has been analysed the immediate consequences of a period of two years drought (2004-06) on several elements of the Mediterranean eco-geomorphologic system at three hillslopes (sub-humid, dry Mediterranean and semi-arid). the soil water content, the pattern of vegetation and some soil properties (organic matter content, aggregate stability and permeability) were analysed before (Nov-2003) and during (Nov-2005) the drought period. Final results have shown: i) reduction in soil water content which reached in the wet seasons values below wilting point, affecting negatively to the water available for vegetation and especially in the wettest sites; ii) reduction in vegetation cover and in the number of plants, especially at semi-arid field site; iii) changes in the organic matter content which aggravates the loss of stability of soil aggregates, a process seen more clearly under more arid conditions; and iv) reduction of soil permeability in all situations in the climate gradient studied, which supposes a priori an increase in erosive processes due to surface runoff. These results indicate increased vulnerability of the eco-geomorphologic system because of the rainfall drought situation. (Author) 14 refs.

Vegetation cover, avoided erosion and water quality in high Andean wetlands, Yeso River Basin

Science.gov (United States)

León, Alejandro; Soto, Jorge; Seguel, Oscar; Pérez, Javier; Osses, Daniela; Leiva, Nicolás; Zerega, Linka

2017-04-01

Wetlands on the high Andes mountains near Santiago de Chile have been impacted by overgrazing and off-road tourists. We studied wetlands in El Yeso River basin. In February 2015 we established 36 exclusions and measured vegetation cover and height, biomass production in and out the exclusions starting in October. Water and undisturbed soil samples were collected. Data were analyzed statistically to estimate i) the recovery of vegetation, and ii) the influence of grazing and vehicle traffic on vegetation loss, and iii) impacts on soil and water quality. In areas with less intense traffic, the difference in vegetation coverage in and out the exclusions is 22% (± 11.4%); in areas with more intense traffic this difference is 16% (± 16%). Height of vegetation, in the less intense traffic areas, ranges from 6.25 cm (± 2.8) to 13.32 cm (± 6.3). With higher traffic it varies between 6.9 cm (± 3.1) and 13.6 cm (± 5.4). Biomass varies between 0.06 kg DM/m2 to 0.57 kg DM/m2 depending on botanical composition and date. After water circulates through the wetlands its content of nitrogen increases 37.33% to 0.37 mg N/l and the fecal coliforms 66.67% to 0.67 MPN/100 ml, because of cattle. On the contrary, turbidity decreases 20.67% to 0.21 UNT because sediments are captured by vegetation. We also estimated an avoided erosion rate, ranging between 1.23% and 31.87% (depending on the slope) due to the increase in coverage within the exclusions.

Development of life cycle water-demand coefficients for coal-based power generation technologies

International Nuclear Information System (INIS)

Ali, Babkir; Kumar, Amit

2015-01-01

Highlights: • We develop water consumption and withdrawals coefficients for coal power generation. • We develop life cycle water footprints for 36 coal-based electricity generation pathways. • Different coal power generation technologies were assessed. • Sensitivity analysis of plant performance and coal transportation on water demand. - Abstract: This paper aims to develop benchmark coefficients for water consumption and water withdrawals over the full life cycle of coal-based power generation. This study considered not only all of the unit operations involved in the full electricity generation life cycle but also compared different coal-based power generating technologies. Overall this study develops the life cycle water footprint for 36 different coal-based electricity generation pathways. Power generation pathways involving new technologies of integrated gasification combined cycle (IGCC) or ultra supercritical technology with coal transportation by conventional means and using dry cooling systems have the least complete life cycle water-demand coefficients of about 1 L/kW h. Sensitivity analysis is conducted to study the impact of power plant performance and coal transportation on the water demand coefficients. The consumption coefficient over life cycle of ultra supercritical or IGCC power plants are 0.12 L/kW h higher when conventional transportation of coal is replaced by coal-log pipeline. Similarly, if the conventional transportation of coal is replaced by its transportation in the form of a slurry through a pipeline, the consumption coefficient of a subcritical power plant increases by 0.52 L/kW h

Hyperspectral detection of a subsurface CO2 leak in the presence of water stressed vegetation.

Directory of Open Access Journals (Sweden)

Gabriel J Bellante

Full Text Available Remote sensing of vegetation stress has been posed as a possible large area monitoring tool for surface CO2 leakage from geologic carbon sequestration (GCS sites since vegetation is adversely affected by elevated CO2 levels in soil. However, the extent to which remote sensing could be used for CO2 leak detection depends on the spectral separability of the plant stress signal caused by various factors, including elevated soil CO2 and water stress. This distinction is crucial to determining the seasonality and appropriateness of remote GCS site monitoring. A greenhouse experiment tested the degree to which plants stressed by elevated soil CO2 could be distinguished from plants that were water stressed. A randomized block design assigned Alfalfa plants (Medicago sativa to one of four possible treatment groups: 1 a CO2 injection group; 2 a water stress group; 3 an interaction group that was subjected to both water stress and CO2 injection; or 4 a group that received adequate water and no CO2 injection. Single date classification trees were developed to identify individual spectral bands that were significant in distinguishing between CO2 and water stress agents, in addition to a random forest classifier that was used to further understand and validate predictive accuracies. Overall peak classification accuracy was 90% (Kappa of 0.87 for the classification tree analysis and 83% (Kappa of 0.77 for the random forest classifier, demonstrating that vegetation stressed from an underground CO2 leak could be accurately discerned from healthy vegetation and areas of co-occurring water stressed vegetation at certain times. Plants appear to hit a stress threshold, however, that would render detection of a CO2 leak unlikely during severe drought conditions. Our findings suggest that early detection of a CO2 leak with an aerial or ground-based hyperspectral imaging system is possible and could be an important GCS monitoring tool.

Hyperspectral detection of a subsurface CO2 leak in the presence of water stressed vegetation.

Science.gov (United States)

Bellante, Gabriel J; Powell, Scott L; Lawrence, Rick L; Repasky, Kevin S; Dougher, Tracy

2014-01-01

Remote sensing of vegetation stress has been posed as a possible large area monitoring tool for surface CO2 leakage from geologic carbon sequestration (GCS) sites since vegetation is adversely affected by elevated CO2 levels in soil. However, the extent to which remote sensing could be used for CO2 leak detection depends on the spectral separability of the plant stress signal caused by various factors, including elevated soil CO2 and water stress. This distinction is crucial to determining the seasonality and appropriateness of remote GCS site monitoring. A greenhouse experiment tested the degree to which plants stressed by elevated soil CO2 could be distinguished from plants that were water stressed. A randomized block design assigned Alfalfa plants (Medicago sativa) to one of four possible treatment groups: 1) a CO2 injection group; 2) a water stress group; 3) an interaction group that was subjected to both water stress and CO2 injection; or 4) a group that received adequate water and no CO2 injection. Single date classification trees were developed to identify individual spectral bands that were significant in distinguishing between CO2 and water stress agents, in addition to a random forest classifier that was used to further understand and validate predictive accuracies. Overall peak classification accuracy was 90% (Kappa of 0.87) for the classification tree analysis and 83% (Kappa of 0.77) for the random forest classifier, demonstrating that vegetation stressed from an underground CO2 leak could be accurately discerned from healthy vegetation and areas of co-occurring water stressed vegetation at certain times. Plants appear to hit a stress threshold, however, that would render detection of a CO2 leak unlikely during severe drought conditions. Our findings suggest that early detection of a CO2 leak with an aerial or ground-based hyperspectral imaging system is possible and could be an important GCS monitoring tool.

Test results on vegetable cultivation using fish breeding water; Yogyosui riyo ni yoru yasai saibai shikenkekka ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Nishida, S. [Hokuriku Electric Power Co. Inc., Toyama (Japan)

1997-10-30

Although a part of the entrails of fishes, birds and livestock is used for food, most of them are treated by costly combustion because of their bad odor and looking, and International Environment and Welfare Laboratory, Toyama prefecture in Japan is studying their profitable treatment. As a part of such study, possibility of hydroponic cultivation of vegetable was tested using fish breeding water including excretions of fishes and residual feeds after use of waste as feed, and the growth condition, safety and effectiveness of cultured vegetable were verified. Three-hundred and fifty viviparous Oryzias were released into a breeding water area with no controlled pH and EC (electric conductivity). For comparison a culture solution area of 6.0 in pH and 1.2ms/cm in EC was prepared. The result on cultivation of 6 kinds of vegetable in culture beds supported by circulation of these water showed that hydroponic cultivation of vegetable using fish breeding water is possible, and average growth of 68% is obtained although difference in growth for every vegetable is found. 8 figs., 5 tabs.

The role of ice dynamics in shaping vegetation in flowing waters.

Science.gov (United States)

Lind, Lovisa; Nilsson, Christer; Polvi, Lina E; Weber, Christine

2014-11-01

Ice dynamics is an important factor affecting vegetation in high-altitude and high-latitude streams and rivers. During the last few decades, knowledge about ice in streams and rivers has increased significantly and a respectable body of literature is now available. Here we review the literature on how ice dynamics influence riparian and aquatic vegetation. Traditionally, plant ecologists have focused their studies on the summer period, largely ignoring the fact that processes during winter also impact vegetation dynamics. For example, the freeze-up period in early winter may result in extensive formation of underwater ice that can restructure the channel, obstruct flow, and cause flooding and thus formation of more ice. In midwinter, slow-flowing reaches develop a surface-ice cover that accumulates snow, protecting habitats under the ice from formation of underwater ice but also reducing underwater light, thus suppressing photosynthesis. Towards the end of winter, ice breaks up and moves downstream. During this transport, ice floes can jam up and cause floods and major erosion. The magnitudes of the floods and their erosive power mainly depend on the size of the watercourse, also resulting in different degrees of disturbance to the vegetation. Vegetation responds both physically and physiologically to ice dynamics. Physical action involves the erosive force of moving ice and damage caused by ground frost, whereas physiological effects - mostly cell damage - happen as a result of plants freezing into the ice. On a community level, large magnitudes of ice dynamics seem to favour species richness, but can be detrimental for individual plants. Human impacts, such as flow regulation, channelisation, agriculturalisation and water pollution have modified ice dynamics; further changes are expected as a result of current and predicted future climate change. Human impacts and climate change can both favour and disfavour riverine vegetation dynamics. Restoration of streams

Better Water Demand and Pipe Description Improve the Distribution Network Modeling Results

Science.gov (United States)

Distribution system modeling simplifies pipe network in skeletonization and simulates the flow and water quality by using generalized water demand patterns. While widely used, the approach has not been examined fully on how it impacts the modeling fidelity. This study intends to ...

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

Nigerian women reap benefits from indigenous vegetables | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

2016-06-06

Jun 6, 2016 ... Demand for fresh indigenous vegetables in Nigeria has increased ... greater returns from indigenous vegetables compared to conventional vegetables. ... In Kolli Hills, Tamil Nadu, monocropping of a single, non-edible variety ...

Hydrologic responses to restored wildfire regimes revealed by soil moisture-vegetation relationships

Science.gov (United States)

Boisramé, Gabrielle; Thompson, Sally; Stephens, Scott

2018-02-01

Many forested mountain watersheds worldwide evolved with frequent fire, which Twentieth Century fire suppression activities eliminated, resulting in unnaturally dense forests with high water demand. Restoration of pre-suppression forest composition and structure through a variety of management activities could improve forest resilience and water yields. This study explores the potential for "managed wildfire", whereby naturally ignited fires are allowed to burn, to alter the water balance. Interest in this type of managed wildfire is increasing, yet its long-term effects on water balance are uncertain. We use soil moisture as a spatially-distributed hydrologic indicator to assess the influence of vegetation, fire history and landscape position on water availability in the Illilouette Creek Basin in Yosemite National Park. Over 6000 manual surface soil moisture measurements were made over a period of three years, and supplemented with continuous soil moisture measurements over the top 1m of soil in three sites. Random forest and linear mixed effects models showed a dominant effect of vegetation type and history of vegetation change on measured soil moisture. Contemporary and historical vegetation maps were used to upscale the soil moisture observations to the basin and infer soil moisture under fire-suppressed conditions. Little change in basin-averaged soil moisture was inferred due to managed wildfire, but the results indicated that large localized increases in soil moisture had occurred, which could have important impacts on local ecology or downstream flows.

Managing Water Demand : Policies, Practices and Lessons from the ...

International Development Research Centre (IDRC) Digital Library (Canada)

30 août 2005 ... Managing Water Demand : Policies, Practices and Lessons from the Middle East and North Africa Forums. Couverture du livre ... L'organisation HarassMap, soutenue par le CRDI, a une fois de plus incité à apporter des changements progressifs dans le domaine de la lutte contre le harcèlement sexuel.

Field measurement of soil water repellency and its impact on water flow under different vegetation

Czech Academy of Sciences Publication Activity Database

Lichner, Ľ.; Hallett, P. D.; Feeney, D. S.; Ďugová, O.; Šír, Miloslav; Tesař, Miroslav

2007-01-01

Roč. 62, č. 5 (2007), s. 537-541 ISSN 0006-3088 R&D Projects: GA ČR GA205/05/2312 Institutional research plan: CEZ:AV0Z20600510 Keywords : vegetation * sandy soil * water repellency * hydraulic conductivity Subject RIV: DA - Hydrology ; Limnology Impact factor: 0.207, year: 2007

Canopy Modeling of Aquatic Vegetation: Construction of Submerged Vegetation Index

Science.gov (United States)

Ma, Z.; Zhou, G.

2018-04-01

The unique spectral characteristics of submerged vegetation in wetlands determine that the conventional terrestrial vegetation index cannot be directly employed to species identification and parameter inversion of submerged vegetation. Based on the Aquatic Vegetation Radiative Transfer model (AVRT), this paper attempts to construct an index suitable for submerged vegetation, the model simulated data and a scene of Sentinel-2A image in Taihu Lake, China are utilized for assessing the performance of the newly constructed indices and the existent vegetation indices. The results show that the angle index composed by 525 nm, 555 nm and 670 nm can resist the effects of water columns and is more sensitive to vegetation parameters such as LAI. Furthermore, it makes a well discrimination between submerged vegetation and water bodies in the satellite data. We hope that the new index will provide a theoretical basis for future research.

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.

Impact of oil prices, economic diversification policies and energy conservation programs on the electricity and water demands in Kuwait

International Nuclear Information System (INIS)

Wood, Michael; Alsayegh, Osamah A.

2014-01-01

This paper describes the influences of oil revenue and government's policies toward economic developments and energy efficiency on the electricity and water demands. A Kuwait-specific electricity and water demand model was developed based on historic data of oil income, gross domestic product (GDP), population and electric load and water demand over the past twelve years (1998–2010). Moreover, the model took into account the future mega projects, annual new connected loads and expected application of energy conservation programs. It was run under six circumstances representing the combinations of three oil income scenarios and two government action policies toward economic diversification and energy conservation. The first government policy is the status quo with respect to economic diversification and applying energy conservation programs. The second policy scenario is the proactive strategy of raising the production of the non-oil sector revenue and enforcing legislations toward energy demand side management and conservation. In the upcoming 20 years, the average rates of change of the electric load and water demand increase are 0.13 GW and 3.0 MIGD, respectively, per US dollar oil price increase. Moreover, through proactive policy, the rates of average load and water demand decrease are 0.13 GW and 2.9 MIGD per year, respectively. - Highlights: • Kuwait-specific electricity and water demand model is presented. • Strong association between oil income and electricity and water demands. • Rate of change of electric load per US dollar oil price change is 0.13 GW. • Rate of change of water demand per US dollar oil price change is 3.0 MIGD. • By 2030, efficiency lowers electric load and water demand by 10 and 6%, respectively

Assessing water stress of desert vegetation using remote sensing : the case of the Tamarugo forest in the Atacama Desert (Northern Chile)

NARCIS (Netherlands)

Chávez Oyanadel, R.O.

2014-01-01

Water stress assessment of natural vegetation plays a key role in water management of desert ecosystems. It allows scientists and managers to relate water extraction rates to changes in vegetation water condition, and consequently to define safe water extraction rates for maintaining a healthy

Controlled laboratory experiments and modeling of vegetative filter strips with shallow water tables

Science.gov (United States)

Fox, Garey A.; Muñoz-Carpena, Rafael; Purvis, Rebecca A.

2018-01-01

Natural or planted vegetation at the edge of fields or adjacent to streams, also known as vegetative filter strips (VFS), are commonly used as an environmental mitigation practice for runoff pollution and agrochemical spray drift. The VFS position in lowlands near water bodies often implies the presence of a seasonal shallow water table (WT). In spite of its potential importance, there is limited experimental work that systematically studies the effect of shallow WTs on VFS efficacy. Previous research recently coupled a new physically based algorithm describing infiltration into soils bounded by a water table into the VFS numerical overland flow and transport model, VFSMOD, to simulate VFS dynamics under shallow WT conditions. In this study, we tested the performance of the model against laboratory mesoscale data under controlled conditions. A laboratory soil box (1.0 m wide, 2.0 m long, and 0.7 m deep) was used to simulate a VFS and quantify the influence of shallow WTs on runoff. Experiments included planted Bermuda grass on repacked silt loam and sandy loam soils. A series of experiments were performed including a free drainage case (no WT) and a static shallow water table (0.3-0.4 m below ground surface). For each soil type, this research first calibrated VFSMOD to the observed outflow hydrograph for the free drainage experiments to parameterize the soil hydraulic and vegetation parameters, and then evaluated the model based on outflow hydrographs for the shallow WT experiments. This research used several statistical metrics and a new approach based on hypothesis testing of the Nash-Sutcliffe model efficiency coefficient (NSE) to evaluate model performance. The new VFSMOD routines successfully simulated the outflow hydrographs under both free drainage and shallow WT conditions. Statistical metrics considered the model performance valid with greater than 99.5% probability across all scenarios. This research also simulated the shallow water table experiments with

The biophysical link between climate, water, and vegetation in bioenergy agro-ecosystems

International Nuclear Information System (INIS)

Bagley, Justin E.; Davis, Sarah C.; Georgescu, Matei; Hussain, Mir Zaman; Miller, Jesse; Nesbitt, Stephen W.; VanLoocke, Andy; Bernacchi, Carl J.

2014-01-01

Land use change for bioenergy feedstocks is likely to intensify as energy demand rises simultaneously with increased pressure to minimize greenhouse gas emissions. Initial assessments of the impact of adopting bioenergy crops as a significant energy source have largely focused on the potential for bioenergy agroecosystems to provide global-scale climate regulating ecosystem services via biogeochemical processes. Such as those processes associated with carbon uptake, conversion, and storage that have the potential to reduce global greenhouse gas emissions (GHG). However, the expansion of bioenergy crops can also lead to direct biophysical impacts on climate through water regulating services. Perturbations of processes influencing terrestrial energy fluxes can result in impacts on climate and water across a spectrum of spatial and temporal scales. Here, we review the current state of knowledge about biophysical feedbacks between vegetation, water, and climate that would be affected by bioenergy-related land use change. The physical mechanisms involved in biophysical feedbacks are detailed, and interactions at leaf, field, regional, and global spatial scales are described. Locally, impacts on climate of biophysical changes associated with land use change for bioenergy crops can meet or exceed the biogeochemical changes in climate associated with rising GHG's, but these impacts have received far less attention. Realization of the importance of ecosystems in providing services that extend beyond biogeochemical GHG regulation and harvestable yields has led to significant debate regarding the viability of various feedstocks in many locations. The lack of data, and in some cases gaps in knowledge associated with biophysical and biochemical influences on land–atmosphere interactions, can lead to premature policy decisions. - Highlights: • The physical basis for biophysical impacts of expanding bioenergy agroecosystems on climate and water is described. • We

Water demand management: A policy response to climate change

International Nuclear Information System (INIS)

Rivers, R.; Tate, D.

1990-01-01

The impacts of climate change on the water resources of the Great Lakes region are discussed. It is predicted that there will be a relative water scarcity in the Great Lakes basin of Ontario as climate changes occur over the next two decades. Declines in water supply will be accompanied by deterioration in the quality of fresh water as higher temperatures and higher relative quantities of discharged wastewater to water bodies reduce both assimilative and dilutive capacity. The most cost effective policy is to encourage water conservation through programs of water demand management. Water should be priced at the point at which its marginal cost is equal to its marginal product, ie. if priced any higher, less efficient substitutes would be used. Not only would water usage, and subsequent degradation of used water, be reduced, but energy and other cost savings would be achieved. The additional costs that apply to water users could be returned to the communities as additional revenue to be applied against sewage treatment upgrades and other environmental enhancements. Communities involved in water study should consider the development of water use analysis models to assist with decision making about allocation, pricing and availability of water supplies. 10 refs

Water availability and demand in the development regions of South Africa

Directory of Open Access Journals (Sweden)

A. B. de Villiers

1988-03-01

Full Text Available The availability of water data in the development regions is at present insufficient. This is due to the fact that water supply and demand is calculated for the physical drainage regions (watersheds, while the development regions do not correspond with the drainage regions. The necessary calculations can accordingly presently not be made. In this paper this problem is addressed.

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.

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.

Evaluating water controls on vegetation growth in the semi-arid sahel using field and earth observation data

DEFF Research Database (Denmark)

Abdi, Abdulhakim M.; Boke-Olen, Niklas; Tenenbaum, David E.

2017-01-01

Water loss is a crucial factor for vegetation in the semi-arid Sahel region of Africa. Global satellite-driven estimates of plant CO2 uptake (gross primary productivity, GPP) have been found to not accurately account for Sahelian conditions, particularly the impact of canopy water stress. Here, we...... identify the main biophysical limitations that induce canopy water stress in Sahelian vegetation and evaluate the relationships between field data and Earth observation-derived spectral products for up-scaling GPP. We find that plant-available water and vapor pressure deficit together control the GPP...

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

International Nuclear Information System (INIS)

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

2013-01-01

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

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

High Resolution Map of Water Supply and Demand for North East United States

Science.gov (United States)

Ehsani, N.; Vorosmarty, C. J.; Fekete, B. M.

2012-12-01

Accurate estimates of water supply and demand are crucial elements in water resources management and modeling. As part of our NSF-funded EaSM effort to build a Northeast Regional Earth System Model (NE-RESM) as a framework to improve our understanding and capacity to forecast the implications of planning decisions on the region's environment, ecosystem services, energy and economic systems through the 21st century, we are producing a high resolution map (3' x 3' lat/long) of estimated water supply and use for the north east region of United States. Focusing on water demand, results from this study enables us to quantify how demand sources affect the hydrology and thermal-chemical water pollution across the region. In an attempt to generate this 3-minute resolution map in which each grid cell has a specific estimated monthly domestic, agriculture, thermoelectric and industrial water use. Estimated Use of Water in the United States in 2005 (Kenny et al., 2009) is being coupled to high resolution land cover and land use, irrigation, power plant and population data sets. In addition to water demands, we tried to improve estimates of water supply from the WBM model by improving the way it controls discharge from reservoirs. Reservoirs are key characteristics of the modern hydrologic system, with a particular impact on altering the natural stream flow, thermal characteristics, and biogeochemical fluxes of rivers. Depending on dam characteristics, watershed characteristics and the purpose of building a dam, each reservoir has a specific optimum operating rule. It means that literally 84,000 dams in the National Inventory of Dams potentially follow 84,000 different sets of rules for storing and releasing water which must somehow be accounted for in our modeling exercise. In reality, there is no comprehensive observational dataset depicting these operating rules. Thus, we will simulate these rules. Our perspective is not to find the optimum operating rule per se but to find

Phase 1 summaries of radionuclide concentration data for vegetation, river water, drinking water, and fish

International Nuclear Information System (INIS)

Denham, D.H.; Dirkes, R.L.; Hanf, R.W.; Poston, T.M.; Thiede, M.E.; Woodruff, R.K.

1993-06-01

The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at the Hanford Site since 1944. As part of the HEDR Project, the Environmental Monitoring Data Task (Task 05) staff assemble, evaluate, and summarize key historical measurements of radionuclide concentrations in the environment as a result of Hanford operations. The scope of work performed during Phase I included initiating the search, recovery, and inventory of environmental reports. Summaries of the environmental monitoring data that were recovered and evaluated are presented for specific periods of interest. These periods include vegetation monitoring data (primarily sagebrush) for the years 1945 through 1947, Columbia River water and drinking water monitoring data for the years 1963 through 1966, and fish monitoring data for the years 1964 through 1966. Concern was limited to those radionuclides identified as the most likely major contributors to the dose potentially received by the public during the times of interest: phosphorous-32, copper-64, zinc-65, arsenic-76, and neptunium-239 in Columbia River fish and drinking water taken from the river, and iodine-131 in vegetation. This report documents the achievement of the Phase I objectives of the Environmental Monitoring Data Task

Interacting Effects of Leaf Water Potential and Biomass on Vegetation Optical Depth

Science.gov (United States)

Momen, M.; Wood, J. D.; Novick, K. A.; Pockman, W.; Konings, A. G.

2017-12-01

Remotely-sensed microwave observations of vegetation optical depth (VOD) have been widely used to examine vegetation responses to climate. Such studies have alternately found that VOD is sensitive to both biomass and canopy water content. However, the relative impacts of changes in phenology or water stress on VOD have not been disentangled. In particular, understanding whether leaf water potential (LWP) affects VOD may permit the assimilation of satellite observations into new large-scale plant hydraulic models. Despite extensive validation of the relationship between satellite-derived VOD estimates and vegetation density, relatively few studies have explicitly sought to validate the sensitivity of VOD to canopy water status, and none have studied the effect of variations in LWP on VOD. In this work, we test the sensitivity of VOD to variations in LWP, and present a conceptual framework which relates VOD to a combination of leaf water potential and total biomass including leaves, whose dynamics can be measured through leaf area index, and woody biomass. We used in-situ measurements of LWP data to validate the conceptual model in mixed deciduous forests in Indiana and Missouri, as well as a pinion-juniper woodland in New Mexico. Observed X-band VOD from the AMSR-E and AMSR2 satellites showed dynamics similar to those reconstructed VOD signals based on the new conceptual model which employs in-situ LWP data (R2=0.60-0.80). Because LWP data are not available at global scales, we further estimated ecosystem LWP based on remotely sensed surface soil moisture to better understand the sensitivity of VOD across ecosystems. At the global scale, incorporating a combination of biomass and water potential in the reconstructed VOD signal increased correlations with VOD about 15% compared to biomass alone and about 30% compared to water potential alone. In wetter regions with denser and taller canopy heights, VOD has a higher correlation with leaf area index than with water

Water Resource Assessment, Gaps, and Constraints of Vegetable Production in Robit and Dangishta Watersheds, Upper Blue Nile Basin, Ethiopia

Science.gov (United States)

Worqlul, A. W.; Dile, Y.; Jeong, J.; Schmitter, P.; Bizimana, J. C.; Gerik, T.; Srinivasan, R.; Richardson, J. W.; Clarke, N.

2017-12-01

Rainfed agriculture supports the majority of the poor in sub-Saharan Africa. However, rainfall variability, land degradation and low soil fertility lessen their effectiveness for feeding the growing population. This study aims to estimate the water resources potential to sustain small-scale irrigation (SSI) in Ethiopia into the dry season to expand the food supply by growing vegetable and to understand the gaps and constraints of irrigated vegetable production. The case studies were located in Robit and Dangishta watersheds of the Ethiopian highlands near Lake Tana, where detailed field-level data were collected. The study focused on data from 18 households who have been cultivating tomato and onion during the dry season using irrigation in each watershed. The two components of the Integrated Decision Support System (IDSS) - the Soil and Water Assessment Tool (SWAT) and Agricultural Policy Environmental eXtender (APEX) - were used to assess impacts of SSI at multiple scales. Results suggest that there is a substantial amount of surface runoff and shallow groundwater recharge at watershed scale. The field-scale analysis within the Robit watershed indicated that optimal tomato yield could be obtained with 450 mm of irrigation and 200 to 250 kg/ha of urea with 50 kg/ha of diammonium phosphate (DAP). In Dangishta, optimum onion yield can be obtained by applying 550 mm irrigation and 120 to 180 kg/ha of urea with 50 kg/ha of DAP. Studying field scale water balance, the average shallow groundwater recharge (after accounting other groundwater users such as household and livestock uses) was not sufficient to meet tomato and onion water demand. The field-scale analysis also indicated that soil evaporation attributed a significant proportion of evapotranspiration (i.e. 60% of the evapotranspiration for onion and 40% for tomato). Use of mulching or other soil and water conservation interventions could increase water for cropping by reducing soil evaporation thereby enhancing

Experimental and theoretical study of the influence of water on hydrolyzed product formation during the feruloylation of vegetable oil.

Science.gov (United States)

Compton, David L; Evans, Kervin O; Appell, Michael

2017-07-01

Feruloylated vegetable oil is a valuable green bioproduct that has several cosmeceutical applications associated with its inherent anti-oxidant and ultraviolet-absorption properties. Hydrolyzed vegetable oil by-products can influence product quality and consistency. The formation of by-products by residual water in the enzymatic synthesis of feruloylated vegetable oil was investigated using chemical theory and experimental studies by monitoring the reaction over a 22-day period. The hydrolysis of vegetable oil is thermodynamically favored over the hydrolysis of the ethyl ferulate starting material. These results suggest that hydrolyzed vegetable oil products will be experimentally observed in greater concentrations compared to hydrolyzed ethyl ferulate products. Quantum chemical studies identified several reaction mechanisms that explain the formation of side products by water, suggesting that residual water influences product quality. Efforts to reduce residual water can improve product consistency and reduce purification costs. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Modeling of Residential Water Demand Using Random Effect Model,Case Study: Arak City

Directory of Open Access Journals (Sweden)

Seyed Hossein Sajadifar

2011-10-01

Full Text Available The present study tries to apply the “Partial Adjustment Model” and “Random Effect Model” techniques to the Stone-Greay’s linear expenditure system, in order to estimate the "Residential Seasonal Demand" for water in Arak city. Per capita water consumption of family residences is regressed on marginal price, per capita income, price of other goods, average temperature and average rainfall. Panel data approaches based on a sample of 152 observations from Arak city referred to 1993-2003. From the estimation of the Elasticity-price of the residential water demand, we want to know how a policy of responsive pricing can lead to more efficient household water consumption inArakcity. Results also indicated that summer price elasticity was twice the winter and price and income elasticity was less than 1 in all cases.

Effects of vegetation structure on biomass accumulation in a Balanced Optimality Structure Vegetation Model (BOSVM v1.0

Directory of Open Access Journals (Sweden)

Z. Yin

2014-05-01

Full Text Available A myriad of interactions exist between vegetation and local climate for arid and semi-arid regions. Vegetation function, structure and individual behavior have large impacts on carbon–water–energy balances, which consequently influence local climate variability that, in turn, feeds back to the vegetation. In this study, a conceptual vegetation structure scheme is formulated and tested in the new Balanced Optimality Structure Vegetation Model (BOSVM to explore the importance of vegetation structure and vegetation adaptation to water stress on equilibrium biomass states. Surface energy, water and carbon fluxes are simulated for a range of vegetation structures across a precipitation gradient in West Africa and optimal vegetation structures that maximize biomass for each precipitation regime are determined. Two different strategies of vegetation adaptation to water stress are included. Under dry conditions vegetation tries to maximize the water use efficiency and leaf area index as it tries to maximize carbon gain. However, a negative feedback mechanism in the vegetation–soil water system is found as the vegetation also tries to minimize its cover to optimize the surrounding bare ground area from which water can be extracted, thereby forming patches of vertical vegetation. Under larger precipitation, a positive feedback mechanism is found in which vegetation tries to maximize its cover as it then can reduce water loss from bare soil while having maximum carbon gain due to a large leaf area index. The competition between vegetation and bare soil determines a transition between a "survival" state to a "growing" state.

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....

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

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...

The evaluation and determination of heavy metals pollution in edible vegetables, water and soil in the south of Tehran province by GIS

Directory of Open Access Journals (Sweden)

Shirkhanloo Hamid

2015-06-01

Full Text Available In this study, heavy metals pollutions in waters, soils and vegetables were investigated from farms, near oil refinery in south of Tehran city, Iran (Shahre Ray. The most important heavy metals in Iranian oil are vanadium, cobalt, nickel, arsenic and mercury (V, Co, Ni, As, Hg. In this region, the concentration of heavy metals in soils, well waters and leafy edible vegetables were evaluated in ten different points of farms. Geographic information systems (GIS were used to estimate the levels of heavy metals concentration at unmeasured locations. After sample preparation, concentrations of heavy metals in vegetables, soils and waters were determined by atomic absorption spectrometry (AAS. Five different leafy edible vegetables from farms, i.e., Persian leek, dill, parsley, spinach and radish were sampled in spring, summer and autumn 2012. In vegetables and well water samples, the concentrations of V, Ni and Co were above the permissible limit of heavy metals as compared to WHO guidelines and the concentrations of these metals in agricultural soils were found to be lower in accordance to soil references. The industrial waste waters had high concentration of heavy metals in this area. In consequence, the results of this study indicate that industrial waste water can cause pollution in well waters and edible vegetables. So, this region is not suitable for cultivation and growing vegetables.

Economic Value Approach to Industrial Water Demand Management, A Case Study of Chemical Plants

Directory of Open Access Journals (Sweden)

morteza tahami pour zarandi

2017-03-01

Full Text Available Limitations in water supply to meet the increasing demand have encouraged both planners and researchers to focus attention on water demand management, in which such economic tools as the water pricing system play a major role. A fundamental component of the pricing system is the estimation of the economic value of water, which reflects a firm’s maximum affordable water price or the ultimate elasticity of industrial water. The present study was conducted to estimate the economic value of water for basic chemical plants, excluding fertilizers and nitrogen compounds (code 2411, representing the four-digit ISIC industrial codes which account for about 14% of the total industrial water consumption. The econometric method of production function within the framework of panel data and the residual method were used. Data were collected from the Census of medium-sized businesses carried out by the Statistical Center of Iran over the period 1997–2013.  Results showed that one cubic meter of water allocated to the plants surveyed creates a value of 3,7071 Rials, which shows a large gap with the current purchase price of 5685 Rials. Moreover, it was found that the present water prices account for only about 1.3 percent of the total production cost of basic chemicals, excluding fertilizers and nitrogen compounds. It may, thus, be concluded that it is reasonable to increase the present water tariffs and discriminate among the various manufacturing codes by differences in tariffs in order to achieve water demand management goals. Finally, the information emerging from the study may be exploited to improve the revenues earned by water authorities or to carry out feasibility studies of industrial water development projects.

Consumption of arsenic and other elements from vegetables and drinking water from an arsenic-contaminated area of Bangladesh

International Nuclear Information System (INIS)

Rahman, Mohammad Mahmudur; Asaduzzaman, Md.; Naidu, Ravi

2013-01-01

Highlights: ► Concentrations of As and other elements in vegetables and drinking water. ► Concentrations of As and other elements in garden soils. ► Daily dietary intake of As and other elements for adults from vegetables and water. ► Potential health risk was estimated comparing with the FAO/WHO values of metals. ► Vegetables alone contribute the elemental intake below the PMTDI values. -- Abstract: The study assesses the daily consumption by adults of arsenic (As) and other elements in drinking water and home-grown vegetables in a severely As-contaminated area of Bangladesh. Most of the examined elements in drinking water were below the World Health Organization (WHO) guideline values except As. The median concentrations of As, cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), lead (Pb), Mn, nickel (Ni), and zinc (Zn) in vegetables were 90 μg kg −1 , 111 μg kg −1 , 0.80 mg kg −1 , 168 μg kg −1 , 13 mg kg −1 , 2.1 mg kg −1 , 65 mg kg −1 , 1.7 mg kg −1 , and 50 mg kg −1 , respectively. Daily intakes of As, Cd, Cr, Co, Cu, Pb, manganese (Mn), Ni, and Zn from vegetables and drinking water for adults were 839 μg, 2.9 μg, 20.8 μg, 5.5 μg, 0.35 mg, 56.4 μg, 2.0 mg, 49.1 μg, and 1.3 mg, respectively. The health risks from consuming vegetables were estimated by comparing these figures with the WHO/FAO provisional tolerable weekly or daily intake (PTWI or PTDI). Vegetables alone contribute 0.05 μg of As and 0.008 mg of Cu per kg of body weight (bw) daily; 0.42 μg of Cd, 8.77 mg of Pb, and 0.03 mg of Zn per kg bw weekly. Other food sources and particularly dietary staple rice need to be evaluated to determine the exact health risks from such foods

Toward Estimating Wetland Water Level Changes Based on Hydrological Sensitivity Analysis of PALSAR Backscattering Coefficients over Different Vegetation Fields

Directory of Open Access Journals (Sweden)

Ting Yuan

2015-03-01

Full Text Available Synthetic Aperture Radar (SAR has been successfully used to map wetland’s inundation extents and types of vegetation based on the fact that the SAR backscatter signal from the wetland is mainly controlled by the wetland vegetation type and water level changes. This study describes the relation between L-band PALSAR  and seasonal water level changes obtained from Envisat altimetry over the island of Île Mbamou in the Congo Basin where two distinctly different vegetation types are found. We found positive correlations between and water level changes over the forested southern Île Mbamou whereas both positive and negative correlations were observed over the non-forested northern Île Mbamou depending on the amount of water level increase. Based on the analysis of sensitivity, we found that denser vegetation canopy leads to less sensitive  variation with respect to the water level changes regardless of forested or non-forested canopy. Furthermore, we attempted to estimate water level changes which were then compared with the Envisat altimetry and InSAR results. Our results demonstrated a potential to generate two-dimensional maps of water level changes over the wetlands, and thus may have substantial synergy with the planned Surface Water and Ocean Topography (SWOT mission.

Examining Severe Drought-Induced Vegetation Change and its Influence on Water Resources

Science.gov (United States)

White, A. B.; Springer, E. P.; Vivoni, E. R.

2007-12-01

A "global-change-type" drought that occurred in the southwestern U.S. from 2000 to 2003, accompanied by increased temperatures and bark beetle infestations, induced large-scale woodland overstory mortality, the consequent redistribution of water, radiation, and nutrients, as well as modification of the ecosystem phenology. Our objectives in this research are to examine these vegetation changes in detail and to determine whether they translated to changes in hydrological processes. We chose the Rio Ojo Caliente, a subbasin of the Rio Grande, as a study site since a significant portion of the woodland ecosystem (piñon-juniper) was affected. Examining a remotely-sensed vegetation index (1-km AVHRR NDVI from 1989 to 2006), there is an increasing trend in the mean NDVI from 1989 to 1998 (pre-drought period), a decreasing trend from 1999 to 2003 (drought period), and a dramatic increasing trend from 2004 to 2006 (post-drought period) in which the mean NDVI rebounds to pre- drought magnitudes. Streamflow records from 1932 to 2006 show the watershed to be primarily spring snowmelt-driven, although monsoonal summer precipitation also plays a significant role. We compare the temporal variability in the streamflow to the NDVI, including the mean, anomalies from the mean, and seasonally- based duration curves, and find significant correlations (correlation coefficient ρ = -0.61) between the streamflow and NDVI at approximately a three-month lag (NDVI lagging streamflow). In analyzing the three phases of the drought, the correlation is slightly stronger during the pre-drought (ρ = -0.64) and drought (ρ = -0.65) periods, yet markedly stronger during the post-drought period (ρ = -0.74). This suggests that the coupling between vegetation water use and streamflow is tighter after the drought. This may be attributable to the reduction in the less-responsive overstory (pinñon mortality) and increase in the more-responsive understory (grasses and shrubs exploiting newly

Vegetation water stress monitoring with remote sensing-based energy balance modelling

Science.gov (United States)

González-Dugo, Maria P.; Andreu, Ana; Carpintero, Elisabet; Gómez-Giráldez, Pedro; José Polo, María

2014-05-01

Drought is one of the major hazards faced by agroforestry systems in southern Europe, and an increase in frequency is predicted under the conditions of climate change for the region. Timely and accurate monitoring of vegetation water stress using remote sensing time series may assist early-warning services, helping to assess drought impacts and the design of management actions leading to reduce the economic and environmental vulnerability of these systems. A holm oak savanna, known as dehesa in Spain and montado in Portugal, is an agro-silvo-pastoral system occupying more than 3 million hectares the Iberian Peninsula and Greece. It consists of widely-spaced oak trees (mostly Quercus ilex L.), combined with crops, pasture and Mediterranean shrubs, and it is considered an example of sustainable land use, with great importance in the rural economy. Soil water dynamics is known to have a central role in current tree decline and the reduction of the forested area that is threatening its conservation. A two-source thermal-based evapotranspiration model (TSEB) has been applied to monitor the effect on vegetation water use of soil moisture stress in a dehesa located in southern Spain. The TSEB model separates the soil and canopy contributions to the radiative temperature and to the exchange of surface energy fluxes, so it is especially suited for partially vegetated landscapes. The integration of remotely sensed data in this model may support an evaluation of the whole ecosystem state at a large scale. During two consecutive summers, in 2012 and 2013, time series of optical and thermal MODIS images, with 250m and 1 km of spatial resolution respectively, have been combined with meteorological data provided by a ground station to monitor the evapotranspiration (ET) of the system. An eddy covariance tower (38°12' N; 4°17' W, 736 m a.s.l), equipped with instruments to measure all the components of the energy balance and 1 km of homogeneous fetch in the predominant wind

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...

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...

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

OpenAIRE

Yalçıntaş, Murat; Bulu, Melih; Küçükvar, Murat; Samadi, Hamidreza

2015-01-01

Yayın, Endüstri Mühendisliği Bölümü ile ortak hazırlanmıştır; ancak tekrara düşmemek için ilk yazarın bölümü alınmıştır. 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, usi...

Importance of vegetation, topography and flow paths for water transit times of base flow in alpine headwater catchments

Directory of Open Access Journals (Sweden)

M. H. Mueller

2013-04-01

Full Text Available The mean transit time (MTT of water in a catchment gives information about storage, flow paths, sources of water and thus also about retention and release of solutes in a catchment. To our knowledge there are only a few catchment studies on the influence of vegetation cover changes on base flow MTTs. The main changes in vegetation cover in the Swiss Alps are massive shrub encroachment and forest expansion into formerly open habitats. Four small and relatively steep headwater catchments in the Swiss Alps (Ursern Valley were investigated to relate different vegetation cover to water transit times. Time series of water stable isotopes were used to calculate MTTs. The high temporal variation of the stable isotope signals in precipitation was strongly dampened in stream base flow samples. MTTs of the four catchments were 70 to 102 weeks. The strong dampening of the stable isotope input signal as well as stream water geochemistry points to deeper flow paths and mixing of waters of different ages at the catchments' outlets. MTTs were neither related to topographic indices nor vegetation cover. The major part of the quickly infiltrating precipitation likely percolates through fractured and partially karstified deeper rock zones, which increases the control of bedrock flow paths on MTT. Snow accumulation and the timing of its melt play an important role for stable isotope dynamics during spring and early summer. We conclude that, in mountainous headwater catchments with relatively shallow soil layers, the hydrogeological and geochemical patterns (i.e. geochemistry, porosity and hydraulic conductivity of rocks and snow dynamics influence storage, mixing and release of water in a stronger way than vegetation cover or topography do.

Testing water demand management scenarios in a water-stressed basin in South Africa: application of the WEAP model

Science.gov (United States)

Lévite, Hervé; Sally, Hilmy; Cour, Julien

Like many river basins in South Africa, water resources in the Olifants river basin are almost fully allocated. Respecting the so-called “reserve” (water flow reservation for basic human needs and the environment) imposed by the Water Law of 1998 adds a further dimension, if not difficulty, to water resources management in the basin, especially during the dry periods. Decision makers and local stakeholders (i.e. municipalities, water users’ associations, interest groups), who will soon be called upon to work together in a decentralized manner within Catchment Management Agencies (CMAs) and Catchment Management Committees (CMCs), must therefore be able to get a rapid and simple understanding of the water balances at different levels in the basin. This paper seeks to assess the pros and cons of using the Water Evaluation and Planning (WEAP) model for this purpose via its application to the Steelpoort sub-basin of the Olifants river. This model allows the simulation and analysis of various water allocation scenarios and, above all, scenarios of users’ behavior. Water demand management is one of the options discussed in more detail here. Simulations are proposed for diverse climatic situations from dry years to normal years and results are discussed. It is evident that the quality of data (in terms of availability and reliability) is very crucial and must be dealt with carefully and with good judgment. Secondly, credible hypotheses have to be made about water uses (losses, return flow) if the results are to be meaningfully used in support of decision-making. Within the limits of data availability, it appears that some water users are not able to meet all their requirements from the river, and that even the ecological reserve will not be fully met during certain years. But the adoption of water demand management procedures offers opportunities for remedying this situation during normal hydrological years. However, it appears that demand management alone will not

Optimum returns from greenhouse vegetables under water quality and risk constraints in the United Arab Emirates

Science.gov (United States)

Greenhouses have been used in the United Arab Emirates (UAE) to produce vegetables that contribute toward UAE food security, including offering fresh vegetable produce in the off-season. However, to manage such greenhouses farmers face both technical and environmental limitations (i.e., high water s...

Evaluation of Ensemble Water Supply and Demands Forecasts for Water Management in the Klamath River Basin

Science.gov (United States)

Broman, D.; Gangopadhyay, S.; McGuire, M.; Wood, A.; Leady, Z.; Tansey, M. K.; Nelson, K.; Dahm, K.

2017-12-01

The Upper Klamath River Basin in south central Oregon and north central California is home to the Klamath Irrigation Project, which is operated by the Bureau of Reclamation and provides water to around 200,000 acres of agricultural lands. The project is managed in consideration of not only water deliveries to irrigators, but also wildlife refuge water demands, biological opinion requirements for Endangered Species Act (ESA) listed fish, and Tribal Trust responsibilities. Climate change has the potential to impact water management in terms of volume and timing of water and the ability to meet multiple objectives. Current operations use a spreadsheet-based decision support tool, with water supply forecasts from the National Resources Conservation Service (NRCS) and California-Nevada River Forecast Center (CNRFC). This tool is currently limited in its ability to incorporate in ensemble forecasts, which offer the potential for improved operations by quantifying forecast uncertainty. To address these limitations, this study has worked to develop a RiverWare based water resource systems model, flexible enough to use across multiple decision time-scales, from short-term operations out to long-range planning. Systems model development has been accompanied by operational system development to handle data management and multiple modeling components. Using a set of ensemble hindcasts, this study seeks to answer several questions: A) Do a new set of ensemble streamflow forecasts have additional skill beyond what?, and allow for improved decision making under changing conditions? B) Do net irrigation water requirement forecasts developed in this project to quantify agricultural demands and reservoir evaporation forecasts provide additional benefits to decision making beyond water supply forecasts? C) What benefit do ensemble forecasts have in the context of water management decisions?

Watershed evapotranspiration increased due to changes in vegetation composition and structure under a subtropical climate

Science.gov (United States)

Ge Sun; Changqing Zuo; Shiyu Liu; Mingliang Liu; Steven G McNulty; James M. Vose

2008-01-01

Natural forests in southern China have been severely logged due to high human demand for timber, food, and fuels during the past century, but are recovering in the past decade. The objective of this study was to investigate how vegetation cover changes in composition and structure affected the water budgets of a 9.6-km2 Dakeng watershed located...

A Novel approach for predicting monthly water demand by combining singular spectrum analysis with neural networks

Science.gov (United States)

Zubaidi, Salah L.; Dooley, Jayne; Alkhaddar, Rafid M.; Abdellatif, Mawada; Al-Bugharbee, Hussein; Ortega-Martorell, Sandra

2018-06-01

Valid and dependable water demand prediction is a major element of the effective and sustainable expansion of municipal water infrastructures. This study provides a novel approach to quantifying water demand through the assessment of climatic factors, using a combination of a pretreatment signal technique, a hybrid particle swarm optimisation algorithm and an artificial neural network (PSO-ANN). The Singular Spectrum Analysis (SSA) technique was adopted to decompose and reconstruct water consumption in relation to six weather variables, to create a seasonal and stochastic time series. The results revealed that SSA is a powerful technique, capable of decomposing the original time series into many independent components including trend, oscillatory behaviours and noise. In addition, the PSO-ANN algorithm was shown to be a reliable prediction model, outperforming the hybrid Backtracking Search Algorithm BSA-ANN in terms of fitness function (RMSE). The findings of this study also support the view that water demand is driven by climatological variables.

Flume experiments on wind induced flow in static water bodies in the presence of protruding vegetation

Science.gov (United States)

Banerjee, Tirtha; Muste, Marian; Katul, Gabriel

2015-02-01

The problem of wind-induced flow in inland waters is drawing significant research attention given its relevance to a plethora of applications in wetlands including treatment designs, pollution reduction, and biogeochemical cycling. The present work addresses the role of wind induced turbulence and waves within an otherwise static water body in the presence of rigid and flexible emergent vegetation through flume experimentation and time series analysis. Because no prior example of Particle Imaging Velocimetry (PIV) experiments involving air-water and flexible oscillating components have been found in the literature, a spectral analysis framework is needed and proposed here to guide the analysis involving noise, wave and turbulence separation. The experiments reveal that wave and turbulence effects are simultaneously produced at the air-water interface and the nature of their coexistence is found to vary with different flow parameters including water level, mean wind speed, vegetation density and its flexibility. For deep water levels, signature of fine-scaled inertial turbulence is found at deeper layers of the water system. The wave action appears stronger close to the air-water interface and damped by the turbulence deeper inside the water system. As expected, wave action is found to be dominated in a certain frequency range driven by the wind forcing, while it is also diffused to lower frequencies by means of (wind-induced) oscillations in vegetation. Regarding the mean water velocity, existence of a counter-current flow and its switching to fully forward flow in the direction of the wind under certain combinations of flow parameters were studied. The relative importance of wave and turbulence to the overall energy, degree of anisotropy in the turbulent energy components, and turbulent momentum transport at different depths from the air-water interface and flow combinations were then quantified. The flume experiments reported here differ from previous laboratory

Forecasting the Water Demand in Chongqing, China Using a Grey Prediction Model and Recommendations for the Sustainable Development of Urban Water Consumption.

Science.gov (United States)

Wu, Hua'an; Zeng, Bo; Zhou, Meng

2017-11-15

High accuracy in water demand predictions is an important basis for the rational allocation of city water resources and forms the basis for sustainable urban development. The shortage of water resources in Chongqing, the youngest central municipality in Southwest China, has significantly increased with the population growth and rapid economic development. In this paper, a new grey water-forecasting model (GWFM) was built based on the data characteristics of water consumption. The parameter estimation and error checking methods of the GWFM model were investigated. Then, the GWFM model was employed to simulate the water demands of Chongqing from 2009 to 2015 and forecast it in 2016. The simulation and prediction errors of the GWFM model was checked, and the results show the GWFM model exhibits better simulation and prediction precisions than those of the classical Grey Model with one variable and single order equation GM(1,1) for short and the frequently-used Discrete Grey Model with one variable and single order equation, DGM(1,1) for short. Finally, the water demand in Chongqing from 2017 to 2022 was forecasted, and some corresponding control measures and recommendations were provided based on the prediction results to ensure a viable water supply and promote the sustainable development of the Chongqing economy.

A Water Demand Management Strategy For The Namibian Tourism Sector

Science.gov (United States)

Schachtschneider, K.; Winter, K.

The arid conditions of Namibia are forcing its decision-makers to resort to new wa- ter resource management approaches, including Water Demand Management (WDM). When Namibia achieved its independence from South Africa 1990, a new opportunity arose to rewrite certain restrictive laws and policies in order to bring about redress, development and transformation. The new Water Policy is one example in which the mindset is changed from a supply to a demand oriented water management ap- proach. Legal support for WDM within the new Water Act is a critical component that will support the implementation of WDM in all economic sectors, such as agri- culture, mining and tourism. It is argued that an appropriate WDM strategy should be designed specifically for each sector, once the typical water use patterns in a sec- tor are understood and key water resource managers at all levels are identified. The Namibian tourism sector is geographically dispersed and control over its operations is compounded by the fact that it is frequently located in extremely remote areas that are arid and ecologically sensitive. In general, WDM is rarely practised, because it is not yet supported by law and there are currently no institutional arrangements to con- trol water use in this geographically dispersed industrial sector through which WDM could be enforced either through metering and/or payments. Managers of tourist en- terprises undertake most of the water management themselves, and have been identi- fied as being crucial to the implementation of WDM strategies. A study of six tourist facilities determined the willingness and motivation of these managers to undertake various WDM initiatives. The study identified three factors which appear to influence the actions of managers, namely external controls, economics and company ethics. It is recommended that a tourism sector WDM strategy should focus on these three factors in order to transform the WDM aims and objectives on the policy level into

Robustness of the Drinking Water Distribution Network under Changing Future Demand

NARCIS (Netherlands)

Agudelo-Vera, C.; Blokker, M.; Vreeburg, J.; Bongard, T.; Hillegers, S.; Van der Hoek, J.P.

2014-01-01

A methodology to determine the robustness of the drinking water distribution system is proposed. The performance of three networks under ten future demand scenarios was tested, using head loss and residence time as indicators. The scenarios consider technological and demographic changes. Daily

[Method for optimal sensor placement in water distribution systems with nodal demand uncertainties].

Science.gov (United States)

Liu, Shu-Ming; Wu, Xue; Ouyang, Le-Yan

2013-08-01

The notion of identification fitness was proposed for optimizing sensor placement in water distribution systems. Nondominated Sorting Genetic Algorithm II was used to find the Pareto front between minimum overlap of possible detection times of two events and the best probability of detection, taking nodal demand uncertainties into account. This methodology was applied to an example network. The solutions show that the probability of detection and the number of possible locations are not remarkably affected by nodal demand uncertainties, but the sources identification accuracy declines with nodal demand uncertainties.

Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff.

Science.gov (United States)

Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Cahn, Michael

2017-05-15

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

Nitrate removal from polluted water by using a vegetated floating system.

Science.gov (United States)

Bartucca, Maria Luce; Mimmo, Tanja; Cesco, Stefano; Del Buono, Daniele

2016-01-15

Nitrate (NO3(-)) water pollution is one of the most prevailing and relevant ecological issues. For instance, the wide presence of this pollutant in the environment is dramatically altering the quality of superficial and underground waters. Therefore, we set up a floating bed vegetated with a terrestrial herbaceous species (Italian ryegrass) with the aim to remediate hydroponic solutions polluted with NO3(-). The floating bed allowed the plants to grow and achieve an adequate development. Ryegrass was not affected by the treatments. On the contrary, plant biomass production and total nitrogen content (N-K) increased proportionally to the amount of NO3(-) applied. Regarding to the water cleaning experiments, the vegetated floating beds permitted to remove almost completely all the NO3(-) added from the hydroponic solutions with an initial concentration of 50, 100 and 150 mg L(-1). Furthermore, the calculation of the bioconcentration factor (BCF) indicated this species as successfully applicable for the remediation of solutions polluted by NO3(-). In conclusion, the results highlight that the combination of ryegrass and the floating bed system resulted to be effective in the remediation of aqueous solutions polluted by NO3(-). Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of vegetation removal and water table drawdown on the non-methane biogenic volatile organic compound emissions in boreal peatland microcosms

Science.gov (United States)

Faubert, Patrick; Tiiva, Päivi; Rinnan, Åsmund; Räty, Sanna; Holopainen, Jarmo K.; Holopainen, Toini; Rinnan, Riikka

2010-11-01

Biogenic volatile organic compound (BVOC) emissions are important in the global atmospheric chemistry and their feedbacks to global warming are uncertain. Global warming is expected to trigger vegetation changes and water table drawdown in boreal peatlands, such changes have only been investigated on isoprene emission but never on other BVOCs. We aimed at distinguishing the BVOCs released from vascular plants, mosses and peat in hummocks (dry microsites) and hollows (wet microsites) of boreal peatland microcosms maintained in growth chambers. We also assessed the effect of water table drawdown (-20 cm) on the BVOC emissions in hollow microcosms. BVOC emissions were measured from peat samples underneath the moss surface after the 7-week-long experiment to investigate whether the potential effects of vegetation and water table drawdown were shown. BVOCs were sampled using a conventional chamber method, collected on adsorbent and analyzed with GC-MS. In hummock microcosms, vascular plants increased the monoterpene emissions compared with the treatment where all above-ground vegetation was removed while no effect was detected on the sesquiterpenes, other reactive VOCs (ORVOCs) and other VOCs. Peat layer from underneath the surface with intact vegetation had the highest sesquiterpene emissions. In hollow microcosms, intact vegetation had the highest sesquiterpene emissions. Water table drawdown decreased monoterpene and other VOC emissions. Specific compounds could be closely associated to the natural/lowered water tables. Peat layer from underneath the surface of hollows with intact vegetation had the highest emissions of monoterpenes, sesquiterpenes and ORVOCs whereas water table drawdown decreased those emissions. The results suggest that global warming would change the BVOC emission mixtures from boreal peatlands following changes in vegetation composition and water table drawdown.

Demand side management for commercial buildings using an in line heat pump water heating methodology

International Nuclear Information System (INIS)

Rankin, Riaan; Rousseau, Pieter G.; Eldik, Martin van

2004-01-01

Most of the sanitary hot water used in South African buildings is heated by means of direct electrical resistance heaters. This is one of the major contributors to the undesirably high morning and afternoon peaks imposed on the national electricity supply grid. For this reason, water heating continues to be of concern to the electricity supplier, ESCOM. Previous studies, conducted by the Potchefstroom University for Christian Higher Education in South Africa, indicated that extensive application of the so called inline heat pump water heating methodology in commercial buildings could result in significant demand side management savings to ESKOM. Furthermore, impressive paybacks can be obtained by building owners who choose to implement the design methodology on existing or new systems. Currently, a few examples exist where the design methodology has been successfully implemented. These installations are monitored with a fully web centric monitoring system that allows 24 h access to data from each installation. Based on these preliminary results, a total peak demand reduction of 108 MW can be achieved, which represents 18% of the peak load reduction target set by ESKOM until the year 2015. This represents an avoided cost of approximately MR324 (ZAR) [Int J Energy Res 25(4) (1999) 2000]. Results based on actual data from the monitored installations shows a significant peak demand reduction for each installation. In one installation, a hotel with an occupancy of 220 people, the peak demand contribution of the hot water installation was reduced by 86%, realizing a 36% reduction in peak demand for the whole building. The savings incurred by the building owner also included significant energy consumption savings due to the superior energy efficiency of the heat pump water heater. The combined savings result in a conservatively calculated straight payback period of 12.5 months, with an internal rate of return of 98%. The actual cost of water heating is studied by

Relationships demand-supply of water and the rate of water shortage as tools for evaluating water resources in Colombia

International Nuclear Information System (INIS)

Dominguez Calle, Efrain Antonio; Gonzalo Rivera, Hebert; Vanegas, Sarmiento Raquel; Moreno, Pedro

2008-01-01

This paper shows updated results about Colombian water resources and their requirements by the economic sectors. Water demand water availability relationship is used as a pressure index on water resources. This relationship is expressed through the water scarcity index, which applies constraints over water availability; due to the runoff temporal variability and to the low levels of water during the dry season each year and for each geographic region to characterize average and low runoff years. Different water availability scenarios were building. One for modal runoff values and another for 95 percents for 2025 also were prepared. To the results call our attention to problems caused by the concentration of high density settlements and the presence of economics sectors in regions with low water availability. The infrastructure lag for management of a scarce high variable and over pressured resources emerges as a key factor to avoid a looming crisis in the process of water management

Interannual water-level fluctuations and the vegetation of prairie potholes: Potential impacts of climate change

Science.gov (United States)

van der Valk, Arnold; Mushet, David M.

2016-01-01

Mean water depth and range of interannual water-level fluctuations over wet-dry cycles in precipitation are major drivers of vegetation zone formation in North American prairie potholes. We used harmonic hydrological models, which require only mean interannual water depth and amplitude of water-level fluctuations over a wet–dry cycle, to examine how the vegetation zones in a pothole would respond to small changes in water depth and/or amplitude of water-level fluctuations. Field data from wetlands in Saskatchewan, North Dakota, and South Dakota were used to parameterize harmonic models for four pothole classes. Six scenarios in which small negative or positive changes in either mean water depth, amplitude of interannual fluctuations, or both, were modeled to predict if they would affect the number of zones in each wetland class. The results indicated that, in some cases, even small changes in mean water depth when coupled with a small change in amplitude of water-level fluctuations can shift a prairie pothole wetland from one class to another. Our results suggest that climate change could alter the relative proportion of different wetland classes in the prairie pothole region.

Water availability as a driver of spatial and temporal variability in vegetation in the La Mancha plain (Spain): Implications for the land-surface energy, water and carbon budget

Science.gov (United States)

Los, Sietse

2017-04-01

Vegetation is water limited in large areas of Spain and therefore a close link exists between vegetation greenness observed from satellite and moisture availability. Here we exploit this link to infer spatial and temporal variability in moisture from MODIS NDVI data and thermal data. Discrepancies in the precipitation - vegetation relationship indicate areas with an alternative supply of water (i.e. not rainfall), this can be natural where moisture is supplied by upwelling groundwater, or can be artificial where crops are irrigated. As a result spatial and temporal variability in vegetation in the La Mancha Plain appears closely linked to topography, geology, rainfall and land use. Crop land shows large variability in year-to-year vegetation greenness; for some areas this variability is linked to variability in rainfall but in other cases this variability is linked to irrigation. The differences in irrigation treatment within one plant functional type, in this case crops, will lead to errors in land surface models when ignored. The magnitude of these effects on the energy, carbon and water balance are assessed at the scale of 250 m to 200 km. Estimating the water balance correctly is of particular important since in some areas in Spain more water is used for irrigation than is supplemented by rainfall.

A production planning model considering uncertain demand using two-stage stochastic programming in a fresh vegetable supply chain context.

Science.gov (United States)

Mateo, Jordi; Pla, Lluis M; Solsona, Francesc; Pagès, Adela

2016-01-01

Production planning models are achieving more interest for being used in the primary sector of the economy. The proposed model relies on the formulation of a location model representing a set of farms susceptible of being selected by a grocery shop brand to supply local fresh products under seasonal contracts. The main aim is to minimize overall procurement costs and meet future demand. This kind of problem is rather common in fresh vegetable supply chains where producers are located in proximity either to processing plants or retailers. The proposed two-stage stochastic model determines which suppliers should be selected for production contracts to ensure high quality products and minimal time from farm-to-table. Moreover, Lagrangian relaxation and parallel computing algorithms are proposed to solve these instances efficiently in a reasonable computational time. The results obtained show computational gains from our algorithmic proposals in front of the usage of plain CPLEX solver. Furthermore, the results ensure the competitive advantages of using the proposed model by purchase managers in the fresh vegetables industry.

Pollution Status of Pakistan: A Retrospective Review on Heavy Metal Contamination of Water, Soil, and Vegetables

Directory of Open Access Journals (Sweden)

Amir Waseem

2014-01-01

Full Text Available Trace heavy metals, such as arsenic, cadmium, lead, chromium, nickel, and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. In addition to these metals, copper, manganese, iron, and zinc are also important trace micronutrients. The presence of trace heavy metals in the atmosphere, soil, and water can cause serious problems to all organisms, and the ubiquitous bioavailability of these heavy metal can result in bioaccumulation in the food chain which especially can be highly dangerous to human health. This study reviews the heavy metal contamination in several areas of Pakistan over the past few years, particularly to assess the heavy metal contamination in water (ground water, surface water, and waste water, soil, sediments, particulate matter, and vegetables. The listed contaminations affect the drinking water quality, ecological environment, and food chain. Moreover, the toxicity induced by contaminated water, soil, and vegetables poses serious threat to human health.

Consumption of arsenic and other elements from vegetables and drinking water from an arsenic-contaminated area of Bangladesh

Energy Technology Data Exchange (ETDEWEB)

Rahman, Mohammad Mahmudur; Asaduzzaman, Md. [Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, Mawson Lakes, South Australia, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), P.O. Box 486, Salisbury South, SA 5106 (Australia); Naidu, Ravi, E-mail: ravi.naidu@crccare.com [Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, Mawson Lakes, South Australia, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), P.O. Box 486, Salisbury South, SA 5106 (Australia)

2013-11-15

Highlights: ► Concentrations of As and other elements in vegetables and drinking water. ► Concentrations of As and other elements in garden soils. ► Daily dietary intake of As and other elements for adults from vegetables and water. ► Potential health risk was estimated comparing with the FAO/WHO values of metals. ► Vegetables alone contribute the elemental intake below the PMTDI values. -- Abstract: The study assesses the daily consumption by adults of arsenic (As) and other elements in drinking water and home-grown vegetables in a severely As-contaminated area of Bangladesh. Most of the examined elements in drinking water were below the World Health Organization (WHO) guideline values except As. The median concentrations of As, cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), lead (Pb), Mn, nickel (Ni), and zinc (Zn) in vegetables were 90 μg kg{sup −1}, 111 μg kg{sup −1}, 0.80 mg kg{sup −1}, 168 μg kg{sup −1}, 13 mg kg{sup −1}, 2.1 mg kg{sup −1}, 65 mg kg{sup −1}, 1.7 mg kg{sup −1}, and 50 mg kg{sup −1}, respectively. Daily intakes of As, Cd, Cr, Co, Cu, Pb, manganese (Mn), Ni, and Zn from vegetables and drinking water for adults were 839 μg, 2.9 μg, 20.8 μg, 5.5 μg, 0.35 mg, 56.4 μg, 2.0 mg, 49.1 μg, and 1.3 mg, respectively. The health risks from consuming vegetables were estimated by comparing these figures with the WHO/FAO provisional tolerable weekly or daily intake (PTWI or PTDI). Vegetables alone contribute 0.05 μg of As and 0.008 mg of Cu per kg of body weight (bw) daily; 0.42 μg of Cd, 8.77 mg of Pb, and 0.03 mg of Zn per kg bw weekly. Other food sources and particularly dietary staple rice need to be evaluated to determine the exact health risks from such foods.

The annual number of days that solar heated water satisfies a specified demand temperature

Energy Technology Data Exchange (ETDEWEB)

Yohanis, Y.G. [Thermal Systems Engineering Group, Faculty of Engineering, University of Ulster, BT37 0QB Northern Ireland (United Kingdom); Popel, O.; Frid, S.E. [Non-traditional Renewable Energy Sources, Institute for High Temperatures, Russian Academy of Sciences, 13/19 Izhorskaya str., IVTAN, Moscow 127412 (Russian Federation); Norton, B. [Dublin Institute of Technology, Aungier Street, Dublin 2 (Ireland)

2006-08-15

An analysis of solar water heating systems determines the number of days in each month when solar heated water wholly meets demand above a set temperature. The approach has been used to investigate the potential contribution to water heating loads of solar water heating in two UK locations. Correlations between the approach developed and the use of solar fractions are discussed. (author)

Consumer attitudes towards vegetable attributes: potential buyers of pesticide-free vegetables in Accra and Kumasi, Ghana.

Science.gov (United States)

Probst, Lorenz; Aigelsperger, Lisa; Hauser, Michael

2010-01-01

Considering the inappropriate use of synthetic pesticides on vegetables in West Africa, the rationale behind this research was to assess the extent to which consumers can function as demanders of risk reduced vegetables and hence act as innovators towards vegetable safety. Using the cases of Kumasi and Accra in Ghana, the study examined possible consumer responses to product certification that communicates freedom from pesticides (e.g., organic certification). Generally, search attributes such as the fresh and healthy appearance of a vegetable were found to be central to consumer choice. While consumers stress the importance of health value, they are mostly unaware of agro-chemical risks related to vegetable consumption.

Assessment of the water supply:demand ratios in a Mediterranean basin under different global change scenarios and mitigation alternatives.

Science.gov (United States)

Boithias, Laurie; Acuña, Vicenç; Vergoñós, Laura; Ziv, Guy; Marcé, Rafael; Sabater, Sergi

2014-02-01

Spatial differences in the supply and demand of ecosystem services such as water provisioning often imply that the demand for ecosystem services cannot be fulfilled at the local scale, but it can be fulfilled at larger scales (regional, continental). Differences in the supply:demand (S:D) ratio for a given service result in different values, and these differences might be assessed with monetary or non-monetary metrics. Water scarcity occurs where and when water resources are not enough to meet all the demands, and this affects equally the service of water provisioning and the ecosystem needs. In this study we assess the value of water in a Mediterranean basin under different global change (i.e. both climate and anthropogenic changes) and mitigation scenarios, with a non-monetary metric: the S:D ratio. We computed water balances across the Ebro basin (North-East Spain) with the spatially explicit InVEST model. We highlight the spatial and temporal mismatches existing across a single hydrological basin regarding water provisioning and its consumption, considering or not, the environmental demand (environmental flow). The study shows that water scarcity is commonly a local issue (sub-basin to region), but that all demands are met at the largest considered spatial scale (basin). This was not the case in the worst-case scenario (increasing demands and decreasing supply), as the S:D ratio at the basin scale was near 1, indicating that serious problems of water scarcity might occur in the near future even at the basin scale. The analysis of possible mitigation scenarios reveals that the impact of global change may be counteracted by the decrease of irrigated areas. Furthermore, the comparison between a non-monetary (S:D ratio) and a monetary (water price) valuation metrics reveals that the S:D ratio provides similar values and might be therefore used as a spatially explicit metric to valuate the ecosystem service water provisioning. © 2013.

Response of vegetation indices to changes in three measures of leaf water stress

Science.gov (United States)

Cohen, Warren B.

1991-01-01

The responses of vegetation indices to changes in water stress were evaluated in two separate laboratory experiments. In one experiment the normalized difference vegetation index (NDVI), the near-IR to red ratio (near-IR/red), the Infrared Index (II), and the Moisture Stress Index (MSI) were more highly correlated to leaf water potential in lodgepole pine branches than were the Leaf Water Content Index (LWCI), the mid-IR ratio (Mid-IR), or any of the single Thematic Mapper (TM) bands. In the other experiment, these six indices and the TM Tasseled Cap brightness, greenness, and wetness indices responded to changes in leaf relative water content (RWC) differently than they responded to changes in leaf water content (WC) of three plant species, and the responses were dependent on how experimental replicates were pooled. With no pooling, the LWCI was the most highly correlated index to both RWC and WC among replications, followed by the II, MSI, and wetness. Only the LWCI was highly correlated to RWC and WC when replications were pooled within species. With among species pooling the LWCI was the only index highly correlated with RWC, while the II, MSI, Mid-IR, and wetness were most highly correlated with WC.

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...

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.

Irrigation Requirement Estimation using MODIS Vegetation Indices and Inverse Biophysical Modeling; A Case Study for Oran, Algeria

Science.gov (United States)

Bounoua, L.; Imhoff, M.L.; Franks, S.

2008-01-01

Human demand for food influences the water cycle through diversion and extraction of fresh water needed to support agriculture. Future population growth and economic development alone will substantially increase water demand and much of it for agricultural uses. For many semi-arid lands, socio-economic shifts are likely to exacerbate changes in climate as a driver of future water supply and demand. For these areas in particular, where the balance between water supply and demand is fragile, variations in regional climate can have potentially predictable effect on agricultural production. Satellite data and biophysically-based models provide a powerful method to quantify the interactions between local climate, plant growth and water resource requirements. In irrigated agricultural lands, satellite observations indicate high vegetation density while the precipitation amount indicates otherwise. This inconsistency between the observed precipitation and the observed canopy leaf density triggers the possibility that the observed high leaf density is due to an alternate source of water, irrigation. We explore an inverse process approach using observations from the Moderate Resolution Imaging Spectroradiometer (MODIS), climatological data, and the NASA's Simple Biosphere model, SiB2, to quantitatively assess water demand in a semi-arid agricultural land by constraining the carbon and water cycles modeled under both equilibrium (balance between vegetation and prevailing local climate) and nonequilibrium (water added through irrigation) conditions. We postulate that the degree to which irrigated lands vary from equilibrium conditions is related to the amount of irrigation water used. We added water using two distribution methods: The first method adds water on top of the canopy and is a proxy for the traditional spray irrigation. The second method allows water to be applied directly into the soil layer and serves as proxy for drip irrigation. Our approach indicates that over

Environmental controls over carbon dioxide and water vapor exchange of terrestrial vegetation

DEFF Research Database (Denmark)

Law, B.E.; Falge, E.; Gu, L.

2002-01-01

The objective of this research was to compare seasonal and annual estimates of CO2 and water vapor exchange across sites in forests, grasslands, crops, and tundra that are part of an international network called FLUXNET, and to investigating the responses of vegetation to environmental variables....

Change in the southern U.S. water demand and supply over the next forty years

Science.gov (United States)

Steven C. McNulty; Ge Sun; Erika C. Cohen; Jennifer A. Moore Myers

2008-01-01

Water shortages are often considered a problem in the western United States, where water supply is limited compared to the eastern half of the country. However, periodic water shortages are also common in the southeastern United States due to high water demand and periodic drought. Southeastern U.S. municipalities spend billions of dollars to develop water storage...

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.

2014-09-01

Water availability for a range of human uses will increasingly be affected by climate change, especially in the arid and semiarid tropics. The main objective of this study is to evaluate the infrastructure sufficiency in meeting water demand under climate-induced socio-hydrological transition in the Capibaribe River basin (CRB). The basin has experienced spatial and sectoral (agriculture-to-urban) reconfiguration of water demands. Human settlements that were once dispersed, relying on intermittent sources of surface water, are now larger and more spatially concentrated, which increases water-scarcity effects. Based on the application of linked hydrologic and water-resources models using precipitation and temperature projections of the IPCC SRES (Special Report: Emissions Scenarios) A1B scenario, a reduction in rainfall of 26.0% translated to streamflow reduction of 60.0%. We used simulations from four members of the HadCM3 (UK Met Office Hadley Centre) perturbed physics ensemble, in which a single model structure is used and perturbations are introduced to the physical parameterization schemes in the model (Chou et al., 2012). We considered that the change of the water availability in the basin in the future scenarios must drive the water management and the development of adaptation strategies that will manage the water demand. Several adaptive responses are considered, including water-loss reductions, wastewater collection and reuse, and rainwater collection cisterns, which together have potential to reduce future water demand by 23.0%. 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 simulations showed that the measures proposed and the water from interbasin transfer project of the São Francisco River had a positive

Detection of crop water status in mature olive orchards using vegetation spectral measurements

Science.gov (United States)

Rallo, Giovanni; Ciraolo, Giuseppe; Farina, Giuseppe; Minacapilli, Mario; Provenzano, Giuseppe

2013-04-01

Leaf/stem water potentials are generally considered the most accurate indicators of crop water status (CWS) and they are quite often used for irrigation scheduling, even if costly and time-consuming. For this reason, in the last decade vegetation spectral measurements have been proposed, not only for environmental monitoring, but also in precision agriculture, to evaluate crop parameters and consequently for irrigation scheduling. Objective of the study was to assess the potential of hyperspectral reflectance (450-2400 nm) data to predict the crop water status (CWS) of a Mediterranean olive orchard. Different approaches were tested and particularly, (i) several standard broad- and narrow-band vegetation indices (VIs), (ii) specific VIs computed on the basis of some key wavelengths, predetermined by simple correlations and finally, (iii) using partial least squares (PLS) regression technique. To this aim, an intensive experimental campaign was carried out in 2010 and a total of 201 reflectance spectra, at leaf and canopy level, were collected with an ASD FieldSpec Pro (Analytical Spectral Devices, Inc.) handheld field spectroradiometer. CWS was contemporarily determined by measuring leaf and stem water potentials with the Scholander chamber. The results indicated that the considered standard vegetation indices were weakly correlated with CWS. On the other side, the prediction of CWS can be improved using VIs pointed to key-specific wavelengths, predetermined with a correlation analysis. The best prediction accuracy, however, can be achieved with models based on PLS regressions. The results confirmed the dependence of leaf/canopy optical features from CWS so that, for the examined crop, the proposed methodology can be considered a promising tool that could also be extended for operational applications using multispectral aerial sensors.

Benefits of improved water quality: a discrete choice analysis of freshwater recreational demands

OpenAIRE

R S Tay; P S McCarthy

1994-01-01

Discrete choice methodologies are increasingly being used to estimate multiple-sites recreational demands and evaluate the welfare effects of alternative environmental policies aimed at water quality improvements. In this study the authors use 1985 data on Indiana anglers to estimate a multinomial logit model of destination choice and compute the benefits of alternative water quality improvements. In general, the results indicate that anglers are reasonably sensitive to changes in water quali...

Cs-137 in milk, vegetation, soil, and water near the former Soviet Union's Semipalatinsk Nuclear Test Site.

Science.gov (United States)

Kakimov, Aitbek; Yessimbekov, Zhanibek; Kakimova, Zhainagul; Bepeyeva, Aigerim; Stuart, Marilyne

2016-03-01

The present study was carried out to evaluate Cs-137 activity concentration in soil, water, vegetation, and cow's milk at 10 locations within three regions (Abai, Ayaguz, and Urdzhar) to the southeast of the Semipalatinsk Nuclear Test Site (SNTS) in Kazakhstan. Cs-137 activity concentrations, determined using a pure Ge gamma-ray spectrometer, showed that, all samples collected did not exceed the National maximum allowable limits of 10,000 Bq/kg for soil, 100 Bq/kg for cow's milk, 74 Bq/kg for vegetation, and 11 Bq/kg for water. Cs-137 is, therefore, not considered a health hazard in these regions. The highest levels of contamination were found in the Abai region, where the highest activity concentration of Cs-137 was 18.0 ± 1.0 Bq/kg in soil, 7.60 ± 0.31 Bq/kg in cow's milk, 4.00 ± 0.14 Bq/kg in the vegetation, and 3.00 ± 0.24 Bq/kg in water. The lowest levels were measured within the Urdzhar region, where 4.00 ± 0.14 Bq/kg was found in the soil, 0.30 ± 0.02 Bq/kg in the cow's milk, 1.00 ± 0.03 Bq/kg in the vegetation, and 0.20 ± 0.02 Bq/kg in the water.

Hydrogen and Oxygen stable isotope analysis of water in fruits and vegetables by using cavity ring-down spectrometry

International Nuclear Information System (INIS)

Suzuki, Yaeko

2016-01-01

We determined oxygen and hydrogen stable isotope ratios (δ"1"8O and δD) of water in fruits (citrus) and vegetables (ginger) using cavity ring-down spectrometry (CRDS) for assessment of their authenticity. The δ"1"8O and δD values of fruits and straight juice had higher than those of concentrated juice. The citrus fruits from Japan had relatively lower δ"1"8O and δD values of than those from Australia, South Africa and the United States. The δD values and d-excess of ginger samples from Japan were relatively higher than those of ginger samples from China. The δ"1"8O and δD values of water in fruits and vegetables would be representative of the ambient water, depending on geographical parameters such as the latitude and altitude. These results suggested that δ"1"8O and δD values of water in fruits and vegetables by using CRDS would be potentially useful for assessment of their authenticity. (author)

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.

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

Impacts of changes in vegetation cover on soil water heat coupling in an alpine meadow of the Qinghai-Tibet Plateau, China

Directory of Open Access Journals (Sweden)

W. Genxu

2009-03-01

Full Text Available Alpine meadow is one of the most widespread grassland types in the permafrost regions of the Qinghai-Tibet Plateau, and the transmission of coupled soil water heat is one of the most crucial processes influencing cyclic variations in the hydrology of frozen soil regions, especially under different vegetation covers. The present study assesses the impact of changes in vegetation cover on the coupling of soil water and heat in a permafrost region. Soil moisture (θ_v, soil temperature (T_s, soil heat content, and differences in θ_v−T_s coupling were monitored on a seasonal and daily basis under three different vegetation covers (30, 65, and 93% on both thawed and frozen soils. Regression analysis of θ_v vs. T_s plots under different levels of vegetation cover indicates that soil freeze-thaw processes were significantly affected by the changes in vegetation cover. The decrease in vegetation cover of an alpine meadow reduced the difference between air temperature and ground temperature (ΔT_a−s, and it also resulted in a decrease in T_s at which soil froze, and an increase in the temperature at which it thawed. This was reflected in a greater response of soil temperature to changes in air temperature (T_a. For ΔT_a−s outside the range of −0.1 to 1.0°C, root zone soil-water temperatures showed a significant increase with increasing ΔT_a−s; however, the magnitude of this relationship was dampened with increasing vegetation cover. At the time of maximum water content in the thawing season, the soil temperature decreased with increasing vegetation. Changes in vegetation cover also led to variations in θ_v−T_s coupling. With the increase in vegetation cover, the surface heat flux decreased. Soil heat storage at 20 cm in

Modeling and Clustering Water Demand Patterns from Real-World Smart Meter Data

OpenAIRE

CHEIFETZ , Nicolas; Noumir , Zineb; Same , Allou; SANDRAZ , Anne-Claire; FELIERS , Cédric; HEIM , Véronique

2017-01-01

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 identif...

Heavy metal contamination in water, soil and a potential vegetable garlic (Allium sativum L.) in Punjab, Pakistan

International Nuclear Information System (INIS)

Khan, Z.I.; Ahmad, K.; Yasmeen, S.; Mehmood, N.

2017-01-01

Heavy metal contamination in soil, water, and garlic (Allium sativum L.) (watered with canal, ground and sewage waters) in a semi-arid region was investigated in this study. A sub-urban area of district Khushab, Pakistan was chosen as the study site to assess the risks associated with the consumption of this vegetable supplied with three different types of water for irrigation. Sewage water had higher contents of metals and metalloids (Cu, Ni, Se, Mo, As, Fe and Zn) than in other waters. Mean metal concentrations were below the permissible values, but those of Pb and Mo exceeded their respective limits. Metal correlation for the vegetable and soil was significantly positive except for Cu. The range of bio-concentration factor varied between 0.06-20.51 mg/kg. The sewage water had the highest pollution load index. Zinc had the highest daily intake value (0.199), while Se had the lowest value (0.003). The range for health index stood between 0.261-73.44 mg/kg. Metals like Zn, Ni and Cu had enrichment factor higher than 1.0 which raised serious health concerns. It has been a routine to irrigate crops with sewage water but proper management of wastewater is required prior to its supply to the fields. Hazardous quotient (HQ) indicated alarming levels of different metals with respect to public health due to utilization of this vegetable receiving wastewater irrigation. (author)

Analysis of water supply and demand in high mountain cities of Bolivia under growing population and changing climate

Science.gov (United States)

Kinouchi, T.; Mendoza, J.; Asaoka, Y.; Fuchs, P.

2017-12-01

Water resources in La Paz and El Alto, high mountain capital cities of Bolivia, strongly depend on the surface and subsurface runoff from partially glacierized catchments located in the Cordillera Real, Andes. Due to growing population and changing climate, the balance between water supply from the source catchments and demand for drinking, agriculture, industry and hydropower has become precarious in recent years as evidenced by a serious drought during the 2015-2016 El Nino event. To predict the long-term availability of water resources under changing climate, we developed a semi-distributed glacio-hydrological model that considers various runoff pathways from partially glacierized high-altitude catchments. Two GCM projections (MRI-AGCM and INGV-ECHAM4) were used for the prediction with bias corrected by reanalysis data (ERA-INTERIM) and downscaled to target areas using data monitored at several weather stations. The model was applied to three catchments from which current water resources are supplied and eight additional catchments that will be potentially effective in compensating reduced runoff from the current water resource areas. For predicting the future water demand, a cohort-component method was used for the projection of size and composition of population change, considering natural and social change (birth, death and transfer). As a result, total population is expected to increase from 1.6 million in 2012 to 2.0 million in 2036. The water demand was predicted for given unit water consumption, non-revenue water rate (NWR), and sectorial percentage of water consumption for domestic, industrial and commercial purposes. The results of hydrological simulations and the analysis of water demand indicated that water supply and demand are barely balanced in recent years, while the total runoff from current water resource areas will continue to decrease and unprecedented water shortage is likely to occur since around 2020 toward the middle of 21st century even

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.

Effect of water cooking on antioxidant capacity of carotenoid-rich vegetables in Taiwan

Directory of Open Access Journals (Sweden)

Fuh-Juin Kao

2014-06-01

Full Text Available Carotenoid-rich green leafy vegetables including cilantro, Thai basil leaves, sweet potato leaves, and choy sum were selected to evaluate the effects of water cooking or boiling on their total carotenoid content (TCC, total phenolic content (TPC, and total antioxidant capacity (TAC. The percentage inhibition of peroxidation (%IP, Trolox equivalent antioxidant capacity (TEAC, and metal-chelating effect were used to evaluate TAC. The results indicated that TCC reached the maximum after boiling cilantro, Thai basil leaves, and sweet potato leaves for 10 minutes, 5 minutes, and 5 minutes, respectively, and choy sum remained almost unchanged after 30 minutes of boiling. Boiling cilantro and choy sum had a negative effect on their TPC, whereas there was a significant increase in TPC of Thai basil leaf and sweet potato leaf at 1 minute and 5 minutes of boiling, respectively. During water cooking, TAC of the vegetables did not demonstrate a consistent trend. However, TCC was a vital contributor to %IP, whereas TPC showed a strong association with TEAC. Our findings suggest that a boiling time of ≤5 minutes would be better for preserving or enhancing TCC and TPC as well as revealing a higher %IP, TEAC, or metal-chelating effect for the four vegetables investigated in this study.

STOMP Sparse Vegetation Evapotranspiration Model for the Water-Air-Energy Operational Mode

Energy Technology Data Exchange (ETDEWEB)

Ward, Anderson L.; White, Mark D.; Freeman, Eugene J.; Zhang, Z. F.

2005-09-15

The Water-Air-Energy (WAE) Operational Mode of the Subsurface Transport Over Multiple Phases (STOMP) numerical simulator solves the coupled conservation equations for water mass, air mass, and thermal energy in multiple dimensions. This addendum describes the theory, input file formatting, and application of a soil-vegetation-atmosphere transfer (SVAT) scheme for STOMP that is based on a sparse vegetation evapotranspiration model. The SVAT scheme is implemented as a boundary condition on the upper surface of the computational domain and has capabilities for simulating evaporation from bare surfaces as well as evapotranspiration from sparsely vegetated surfaces populated with single or multiple plant species in response to meteorological forcings. With this extension, the model calculates water mass, air mass and thermal energy across a boundary surface in addition to root-water transport between the subsurface and atmosphere. This mode represents the barrier extension of the WAE mode and is designated as STOMP-WAE-B. Input for STOMP-WAE-B is specified via three input cards and include: atmospheric conditions through the Atmospheric Conditions Card; time-invariant plant species data through the Plant Properties Card; and time varying plant species data through the Boundary Conditions Card. Two optional cards, the Observed Data and UCODE Control Cards allow use of STOMP-WAE with UCODE in an inverse mode to estimate model parameters. STOMP-WAE was validated by solving a number of test problems from the literature that included experimental observations as well as analytical or numerical solutions. Several of the UNSAT-H verification problems are included along with a benchmark simulation derived from a recently published intercode comparison for barrier design tools. Results show that STOMP is able to meet, and in most cases, exceed performance of other commonly used simulation codes without having to resort to may of their simplifying assumptions. Use of the fully

Response of nutrients, minerals, antioxidant leaf pigments, vitamins, polyphenol, flavonoid and antioxidant activity in selected vegetable amaranth under four soil water content.

Science.gov (United States)

Sarker, Umakanta; Oba, Shinya

2018-06-30

Four selected vegetable amaranths were grown under four soil water content to evaluate their response in nutrients, minerals, antioxidant leaf pigments, vitamins, polyphenol, flavonoid and total antioxidant activity (TAC). Vegetable amaranth was significantly affected by variety, soil water content and variety × soil water content interactions for all the traits studied. Increase in water stress, resulted in significant changes in proximate compositions, minerals (macro and micro), leaf pigments, vitamin, total polyphenol content (TPC), and total flavonoid content (TFC) of vegetable amaranth. Accessions VA14 and VA16 performed better for all the traits studied. Correlation study revealed a strong antioxidant scavenging activity of leaf pigments, ascorbic acid, TPC and TFC. Vegetable amaranth can tolerate soil water stress without compromising the high quality of the final product in terms of nutrients and antioxidant profiles. Therefore, it could be a promising alternative crop in semi-arid and dry areas and also during dry seasons. Copyright © 2018. Published by Elsevier Ltd.

Demand side management in South Africa at industrial residence water heating systems using in line water heating methodology

International Nuclear Information System (INIS)

Rankin, R.; Rousseau, P.G.

2008-01-01

The South African electrical utility, ESKOM, currently focuses its demand side management (DSM) initiatives on controlling electrical load between 18:00 and 20:00 each day, which is the utility's peak demand period. Funding is provided to energy service companies (ESCo's) to implement projects that can achieve load shifting out of this period. This paper describes how an improved in line water heating concept developed in previous studies was implemented into several real life industrial sanitary water heating systems to obtain the DSM load shift required by ESKOM. Measurements from a selection of these plants are provided to illustrate the significant load reductions that are being achieved during 18:00-20:00. The measured results also show that the peak load reduction is achieved without adversely affecting the availability of sufficient hot water to the persons using the showering and washing facilities served by the water heating system. A very good correlation also exists between these measured results and simulations that were done beforehand to predict the DSM potential of the project. The in line water heater concept provides an improved solution for DSM at sanitary water heating systems due to the stratified manner in which hot water is supplied to the tanks. This provides an improved hot water supply to users when compared to conventional in tank heating systems, even with load shifting being done. It also improves the storage efficiency of a plant, thereby allowing the available storage capacity of a plant to be utilized to its full extent for load shifting purposes

Feasibility of Rainwater Harvesting to fulfill potable water demand using quantitative water management in low-lying delta regions of Asia

Science.gov (United States)

Mahmood, A.; Hossain, F.

2016-12-01

Low-lying deltas of Asian region are usually densely populated and located in developing countries situated at the downstream end of major rivers. Extensive dam construction by the upstream countries has now caused water scarcity in large portions of low-lying deltas. Most inhabitants depend on shallow tube well for safe drinking water that tend to suffer from water quality issues (e.g. Arsenic contamination). In addition, people also get infected from water borne diseases like Cholera and Typhoid due to lack of safe drinking water. Developing a centralized piped network based water supply system is often not a feasible option in rural regions. Due to social acceptability, environment friendliness, lower capital and maintenance cost, rainwater harvesting can be the most sustainable option to supply safe drinking water in rural areas. In this study, first we estimate the monthly rainfall variability using long precipitation climatology from satellite precipitation data. The upper and lower bounds of monthly harvestable rainwater were estimated for each satellite precipitation grid. Taking this lower bound of monthly harvestable rainwater as input, we use quantitative water management concept to determine the percent of the time of the year potable water demand can be fulfilled. Analysis indicates that a 6 m³ reservoir tank can fulfill the potable water demand of a 6 person family throughout a year in almost all parts of this region.

Metal accumulation in a potential winter vegetable mustard (Brassica campestris L.) irrigated with different types of waters in Punjab, Pakistan

International Nuclear Information System (INIS)

Khan, Z. I.; Ahmad, K.; Yasmeen, S.; Ashfaq, A.

2016-01-01

Considering the harmful effects of metal-enriched vegetables a comprehensive study was conducted to appraise the extent of accumulation of different metals in mustard (Brassica campestris L.). The vegetable was treated with ground water, sewage water and canal water irrigation in areas of Punjab, Pakistan. Metals and metalloids observed in all three sites treated with sewage, canal and ground water were As, Cu, Fe, Ni, Pb, Mo, Se and Zn were observed in the sites treated with ground, sewage and canal waters as well as the vegetable grown therein. The metal concentration observed in water samples was: Fe>Zn >Pb> Ni> Mo> Cu> As> Se, the order in the soil was: As >Pb> Fe > Ni > Mo > Cu > Zn > Se, while the order in the vegetable was: Zn > Fe> Cu> Ni> Mo>Pb> As> Se. The values of bio-concentration factor varied from 0.09-15.47 mg kg-1. Correlation was positively significant for Brassica campestris and soil except Ni and Se which showed positive non significant correlation. Pollution load index was observed to be in the following order: As >Pb> Ni > Mo >Fe > Cu > Se > Zn in the sites GWI, CWI and CWI. Fe and Zn (0.169) showed highest value of daily intake of metal (DIM), while Se (0.003) showed lowest value in crop of all three sites GWI, CWI and CWI. The health risk index and EF ranged from 0.24-69.86 mg day/sup -1/and 0.134-14.12 mg day/sup -1/, respectively. Overall, the vegetable treated with sewage water may have considerable impact on food quality and in turn on the health of people consuming it. (author)

The Effect of Aquatic Vegetation on Water Quality in the Everglades Agricultural Area Canals

Science.gov (United States)

Gomez, S. M.; Bhadha, J. H.; Lang, T. A.; Josan, M. S.; Daroub, S. H.

2011-12-01

The canals in the Everglades Agricultural Area contain an abundance of floating aquatic vegetation (FAV) and submerged aquatic vegetation (SAV). These FAV flourish in waters with high phosphorus (P) concentrations and prevent the co-precipitation of P with the limestone bedrock (CaCO3). To test the effects of FAV and SAV and the presence of sediments on water quality in the canals, a lysimeter study was set up and stocked with FAV (water lettuce) and SAV (filamentous algae). There were four treatments with four replicates Treatment one contained limerock, sediment from the canals, and FAV. Treatment two contained limerock, sediment, and SAV. Treatment three contained limerock and FAV, while treatment four had limerock and SAV. After 7 days, the buckets were drained and replaced the water with new, high P canal water. Water samples were taken at 0, 0.25, 1, 3, and 7 days after each weekly water exchange. To test water quality soluble reactive P, total P, total dissolved P, Ca, and total organic carbon were analyzed. The impact of FAV and SAV and canal sediments on water quality will be discussed. We hypothesize water lettuce treatments will initially result in a reduction in P-concentration in all species, but will only serve as a short-term sink because of their high turn-over rate and production of labile high-P sediment (floc). In addition, we hypothesize the treatments with no sediment will have more P reduction because of the availability for P to co-precipitate with CaCO3.

Dependence of Wetland Vegetation on Hydrological Regime in a Large Floodplain Lake (Poyang Lake) in the Middle Yangtze River

Science.gov (United States)

Zhang, Q.; Tan, Z.; Xu, X.

2017-12-01

Exemplified in the Yangtze River floodplain lake, Poyang Lake, investigations were carried out to examine the dependence of vegetation on hydrological variables. The Lake is one of the few lakes that remain naturally connected to the Yangtze River. The Lake surface expanses to 4000 km2 in wet seasons, and reduces to less than 1000 km2 in dry seasons, creating some 3000 km2 vital wetland habitats for many animals. Remote sensing was used to obtain the spatial distribution of wetland vegetations. A lake hydrodynamic model using MIKE 21 was employed to determine the variability of wetland inundation. In-situ high time frequency observations of climate, soil moisture, and groundwater depth were also conducted in a typical wetland transect of 1 km long. Vegetations were sampled periodically to obtain species composition, diversity and biomass. Results showed that the spatial distribution of vegetation highly depended on the inundation duration and depth. Optimal hydrological variables existed for the typical vegetations in Poyang Lake wetland. Numerical simulations using HYDRUS-1D further demonstrated that both groundwater depth and soil moisture had significant effects on the growth of vegetation and the water demand in terms of transpiration, even in a wet climate zone such as middle Yangtze River. It was found that the optimal groundwater depths existed for both above- and belowground biomass. Simulation scenarios indicated that climate changes and human modification of hydrology would affect the water usage of vegetation and may cause a strategic adaptation of the vegetation to the stressed hydrological conditions. The study revealed new knowledge on the high dependence of wetland vegetation on both surface water regime and groundwater depths, in wet climate zone. Outcomes of this study may provide support for an integrated management of balancing water resources development and wetland sustainability maintenance in Poyang Lake, and other floodplain wetlands, with

Disentangling the Effects of Water Stress on Carbon Acquisition, Vegetative Growth, and Fruit Quality of Peach Trees by Means of the QualiTree Model

Directory of Open Access Journals (Sweden)

Mitra Rahmati

2018-01-01

Full Text Available Climate change projections predict warmer and drier conditions. In general, moderate to severe water stress reduce plant vegetative growth and leaf photosynthesis. However, vegetative and reproductive growths show different sensitivities to water deficit. In fruit trees, water restrictions may have serious implications not only on tree growth and yield, but also on fruit quality, which might be improved. Therefore, it is of paramount importance to understand the complex interrelations among the physiological processes involved in within-tree carbon acquisition and allocation, water uptake and transpiration, organ growth, and fruit composition when affected by water stress. This can be studied using process-based models of plant functioning, which allow assessing the sensitivity of various physiological processes to water deficit and their relative impact on vegetative growth and fruit quality. In the current study, an existing fruit-tree model (QualiTree was adapted for describing the water stress effects on peach (Prunus persica L. Batsch vegetative growth, fruit size and composition. First, an energy balance calculation at the fruit-bearing shoot level and a water transfer formalization within the plant were integrated into the model. Next, a reduction function of vegetative growth according to tree water status was added to QualiTree. Then, the model was parameterized and calibrated for a late-maturing peach cultivar (“Elberta” under semi-arid conditions, and for three different irrigation practices. Simulated vegetative and fruit growth variability over time was consistent with observed data. Sugar concentrations in fruit flesh were well simulated. Finally, QualiTree allowed for determining the relative importance of photosynthesis and vegetative growth reduction on carbon acquisition, plant growth and fruit quality under water constrains. According to simulations, water deficit impacted vegetative growth first through a direct effect on

Disentangling the Effects of Water Stress on Carbon Acquisition, Vegetative Growth, and Fruit Quality of Peach Trees by Means of the QualiTree Model.

Science.gov (United States)

Rahmati, Mitra; Mirás-Avalos, José M; Valsesia, Pierre; Lescourret, Françoise; Génard, Michel; Davarynejad, Gholam H; Bannayan, Mohammad; Azizi, Majid; Vercambre, Gilles

2018-01-01

Climate change projections predict warmer and drier conditions. In general, moderate to severe water stress reduce plant vegetative growth and leaf photosynthesis. However, vegetative and reproductive growths show different sensitivities to water deficit. In fruit trees, water restrictions may have serious implications not only on tree growth and yield, but also on fruit quality, which might be improved. Therefore, it is of paramount importance to understand the complex interrelations among the physiological processes involved in within-tree carbon acquisition and allocation, water uptake and transpiration, organ growth, and fruit composition when affected by water stress. This can be studied using process-based models of plant functioning, which allow assessing the sensitivity of various physiological processes to water deficit and their relative impact on vegetative growth and fruit quality. In the current study, an existing fruit-tree model (QualiTree) was adapted for describing the water stress effects on peach ( Prunus persica L. Batsch) vegetative growth, fruit size and composition. First, an energy balance calculation at the fruit-bearing shoot level and a water transfer formalization within the plant were integrated into the model. Next, a reduction function of vegetative growth according to tree water status was added to QualiTree. Then, the model was parameterized and calibrated for a late-maturing peach cultivar ("Elberta") under semi-arid conditions, and for three different irrigation practices. Simulated vegetative and fruit growth variability over time was consistent with observed data. Sugar concentrations in fruit flesh were well simulated. Finally, QualiTree allowed for determining the relative importance of photosynthesis and vegetative growth reduction on carbon acquisition, plant growth and fruit quality under water constrains. According to simulations, water deficit impacted vegetative growth first through a direct effect on its sink strength

Flume Experiments for Optimizing the Hydraulic Performance of a Deep-Water Wetland Utilizing Emergent Vegetation and Obstructions

Directory of Open Access Journals (Sweden)

Shang-Shu Shih

2016-06-01

Full Text Available Constructed ponds and wetlands are widely used in urban areas for stormwater management, ecological conservation, and pollution treatment. The treatment efficiency of these systems is strongly related to the hydrodynamics and hydraulic residence time. In this study, we developed a physical model and used rhodamine-WT as a tracer to conduct flume experiments. An equivalent Reynolds number was assumed, and the flume was a 1/25-scale model. Emergent obstructions (EOs, submerged obstructions (SOs, and high- and low-density emergent vegetation were placed along the sides of the flume, and 49 tracer tests were performed. We altered the density, spatial extent, aspect ratio, and configurations of the obstructions and emergent vegetation to observe changes in the hydraulic efficiency of a deep-water wetland. In the cases of low-aspect-ratio obstructions, the effects of the EOs on the hydraulic efficiency were significantly stronger than those of the SOs. In contrast, in the cases of high-aspect-ratio obstructions, the improvement effects of the EOs were weaker than those of the SOs. The high-aspect-ratio EOs altered the flow direction and constrained the water conveyance area, which apparently caused a short-circuited flow phenomenon, resulting in a decrease in hydraulic efficiency. Most cases revealed that the emergent vegetation improved the hydraulic efficiency more than the EOs. The high-density emergent vegetation (HEV improved the hydraulic efficiency more than the low-density emergent vegetation (LEV. Three cases involving HEV, two cases involving LEV, and one case involving EOs attained a good hydraulic efficiency (λ > 0.75. To achieve greater water purification, aquatic planting in constructed wetlands should not be overly dense. The HEV configuration in case 3-1 achieved optimum hydraulic performance for compliance with applicable water treatment standards.

Fresh Vegetables in the food service Industry its purchasing system; Gaishoku sangyo ni okeru seisen seikabutsu no chotatsu shisutemu

Energy Technology Data Exchange (ETDEWEB)

Oda, K. [Food Service Industry Survey and Research Center, Tokyo (Japan)

1999-09-05

The environment which surrounds production, distribution, consumption of vegetables changes. A demand for the business a household economy demand of vegetables stagnates by the increase of eating out and lunches demand in the food consumption as a long-term tendency, and the tendency as vigorousness continues. In addition, a demand for domestic organic and special cultivation vegetables from the increase of the healthy and safe orientation of the consumer heightens. In this paper, what kind of new movement occurs in environmental change which surrounds these vegetables is arranged. (NEDO)

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.

Evolution of evapotranspiration and water stress of oak savanna vegetation in the Iberian Peninsula (2001-2015

Directory of Open Access Journals (Sweden)

M. P. González-Dugo

2017-12-01

Full Text Available The objective of this work is to provide new insights about the effect of soil water deficit on the vegetation of Mediterranean oak savanna. The evolution of evapotranspiration (ET and vegetation water stress over this ecosystem, in the Iberian Peninsula, has been monitored for fifteen years through the application of a remote sensing thermal-based energy balance model. The Surface Energy Balance System (SEBS has been applied, on a monthly timescale from January 2001 to December 2015, using input satellite and meteorological reanalysis databases. The model performance has been evaluated under these conditions by comparison with field measurements. The estimation of energy fluxes yielded reasonable agreements with observations (RMSD=14-20 W·m–2 for the radiative fluxes and RMSD=26-29 W·m–2 for the turbulent ones and have led to characterize the main drought events occurred during the study period, and to quantify their effects on the vegetation coverage and production. The most generalized and severe events (2004/2005 and 2011/2012 and their impact on different vegetation strata, oaks and grasslands, are further analyzed.

Spatial distribution of heavy metals in soil, water, and vegetables of farms in Sanandaj, Kurdistan, Iran.

Science.gov (United States)

Maleki, Afshin; Amini, Hassan; Nazmara, Shahrokh; Zandi, Shiva; Mahvi, Amir Hossein

2014-01-01

Heavy metals are ubiquitous elsewhere in nature and their measurement in environment is necessary to develop health management strategies. In this study, we aimed to find out concentrations and spatial patterns of heavy metals in main farms of Sanandaj in Kurdistan, Iran. Over May to October 2012, six farms were selected to analyze concentrations and spatial patterns of several heavy metals, namely aluminum (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) in their soil, irrigation water, and edible vegetables. Overall, 36 samples of soil and water and 72 samples of vegetables including coriander (Coriandrum sativum), dill (Anethum graveolens), radish (Raphanus sativus) root and radish leaf were collected. The concentrations of metals were determined by inductively coupled plasma optical emission spectrometry. The spatial surfaces of heavy metals were created using geospatial information system. The order of metals in soil was Al > Zn > Ni > Cu > Cr > Pb > Co > As > Cd while in water it was Cr > Co > Zn > Pb > Cu > Ni > Al = As = Cd. The order of heavy metals in vegetables was Al > Zn > Cu > Cr > Ni > Pb > Co > As > Cd. Totally, the minimum concentrations of Al, Cu, Pb, and Zn were found in radish root while the maximum of Al, Co, Cr, and Ni were found in radish leaf. The minimum concentrations of Cd and Cr and maximum concentrations of Cu and Zn were also deciphered in dill. Noteworthy, coriander had the minimum concentrations of Co and Ni. The concentrations of Cr and Pb in vegetables were more than maximum allowable limits of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). In summary, albeit the concentrations of heavy metals in soil and water samples were below FAO and the WHO standards, vegetables were contaminated by chromium and lead.

The role of riparian vegetation density, channel orientation and water velocity in determining river temperature dynamics

Science.gov (United States)

Garner, Grace; Malcolm, Iain A.; Sadler, Jonathan P.; Hannah, David M.

2017-10-01

A simulation experiment was used to understand the importance of riparian vegetation density, channel orientation and flow velocity for stream energy budgets and river temperature dynamics. Water temperature and meteorological observations were obtained in addition to hemispherical photographs along a ∼1 km reach of the Girnock Burn, a tributary of the Aberdeenshire Dee, Scotland. Data from nine hemispherical images (representing different uniform canopy density scenarios) were used to parameterise a deterministic net radiation model and simulate radiative fluxes. For each vegetation scenario, the effects of eight channel orientations were investigated by changing the position of north at 45° intervals in each hemispheric image. Simulated radiative fluxes and observed turbulent fluxes drove a high-resolution water temperature model of the reach. Simulations were performed under low and high water velocity scenarios. Both velocity scenarios yielded decreases in mean (≥1.6 °C) and maximum (≥3.0 °C) temperature as canopy density increased. Slow-flowing water resided longer within the reach, which enhanced heat accumulation and dissipation, and drove higher maximum and lower minimum temperatures. Intermediate levels of shade produced highly variable energy flux and water temperature dynamics depending on the channel orientation and thus the time of day when the channel was shaded. We demonstrate that in many reaches relatively sparse but strategically located vegetation could produce substantial reductions in maximum temperature and suggest that these criteria are used to inform future river management.

Mapping of Temporal Surface-water Resources Availability and Agricultural Adaptability due to Climate Change and Anthropogenic Activity in a Hot Semi-arid Region of Maharashtra State, India

Science.gov (United States)

Roy, A.; Inamdar, A. B.

2016-12-01

Major part of Godavari River Basin is intensely drought prone and climate vulnerable in the Western Maharashtra State, India. The economy of the state depends on the agronomic productivity of this region. So, it is necessary to regulate the effects of existing and upcoming hydro-meteorological advances in various strata. This study investigates and maps the surface water resources availability and vegetation, their decadal deviations with multi-temporal LANDSAT images; and finally quantifies the agricultural adaptations. This work involves the utilization of Remote Sensing and GIS with Hydrological modeling. First, climatic trend analysis is carried out with NCEP dataset. Then, multi-temporal LANDSAT images are classified to determine the decadal LULC changes and correlated to the community level hydrological demand. Finally, NDVI, NDWI and SWAT model analysis are accomplished to determine irrigated and non-irrigated cropping area for identifying the agricultural adaptations. The analysis shows that the mean value of annual and monsoon rainfall is significantly decreasing, whereas the mean value of annual and summer temperature is increasing significantly and the winter temperature is decreasing. The analysis of LANDSAT images shows that the surface water availability is highly dependent on climatic conditions. Barren-lands are most dynamic during the study period followed by, vegetation, and water bodies. The spatial extent of barren-lands is increased drastically during the climate vulnerable years replacing the vegetation and surface water bodies. Hence, the barren lands are constantly increasing and the vegetation cover is linearly decreasing, whereas the water extent is changing either way in a random fashion. There appears a positive correlation between surface water and vegetation occurrence; as they are fluctuating in a similar fashion in all the years. The vegetation cover is densely replenished around the dams and natural water bodies which serve as the

THE ANALYSIS OF THE TIME-SERIES FLUCTUATION OF WATER DEMAND FOR THE SMALL WATER SUPPLY BLOCK

Science.gov (United States)

Koizumi, Akira; Suehiro, Miki; Arai, Yasuhiro; Inakazu, Toyono; Masuko, Atushi; Tamura, Satoshi; Ashida, Hiroshi

The purpose of this study is to define one apartment complex as "the water supply block" and to show the relationship between the amount of water supply for an apartment house and its time series fluctuation. We examined the observation data which were collected from 33 apartment houses. The water meters were installed at individual observation points for about 20 days in Tokyo. This study used Fourier analysis in order to grasp the irregularity in a time series data. As a result, this paper demonstrated that the smaller the amount of water supply became, the larger irregularity the time series fluctuation had. We also found that it was difficult to describe the daily cyclical pattern for a small apartment house using the dominant periodic components which were obtained from a Fourier spectrum. Our research give useful information about the design for a directional water supply system, as to making estimates of the hourly fluctuation and the maximum daily water demand.

Experimental study on influence of vegetation coverage on runoff in wind-water erosion crisscross region

Science.gov (United States)

Wang, Jinhua; Zhang, Ronggang; Sun, Juan

2018-02-01

Using artificial rainfall simulation method, 23 simulation experiments were carried out in water-wind erosion crisscross region in order to analyze the influence of vegetation coverage on runoff and sediment yield. The experimental plots are standard plots with a length of 20m, width of 5m and slope of 15 degrees. The simulation experiments were conducted in different vegetation coverage experimental plots based on three different rainfall intensities. According to the experimental observation data, the influence of vegetation coverage on runoff and infiltration was analyzed. Vegetation coverage has a significant impact on runoff, and the higher the vegetation coverage is, the smaller the runoff is. Under the condition of 0.6mm/min rainfall intensity, the runoff volume from the experimental plot with 18% vegetation coverage was 1.2 times of the runoff from the experimental with 30% vegetation coverage. What’s more, the difference of runoff is more obvious in higher rainfall intensity. If the rainfall intensity reaches 1.32mm/min, the runoff from the experimental plot with 11% vegetation coverage is about 2 times as large as the runoff from the experimental plot with 53%vegetation coverage. Under the condition of small rainfall intensity, the starting time of runoff in the experimental plot with higher vegetation coverage is later than that in the experimental plot with low vegetation coverage. However, under the condition of heavy rainfall intensity, there is no obvious difference in the beginning time of runoff. In addition, the higher the vegetation coverage is, the deeper the rainfall infiltration depth is.The results can provide reference for ecological construction carried out in wind erosion crisscross region with serious soil erosion.

A model exploring whether the coupled effects of plant water supply and demand affect the interpretation of water potentials and irrigation management