Water Use Research Papers - Academia.edu (original) (raw)

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- Energy Economics, Land management, Behavioral Economics, Institutions

To improve water saving and conservation in irrigated agriculture, a range of field evaluation experiments was carried out with various furrow irrigation treatments in cotton fields to estimate the possibilities of improving furrow irrigation performances under conditions of Central Fergana Valley, Uzbekistan. The research consisted in comparing surge and continuous-flow in long furrows and adopting alternate-furrow irrigation. The best results were achieved with surge-flow irrigation applied to alternate furrows. Field data allowed the calibration of a surface irrigation model that was used to identify alternative management issues. Results identified the need to better adjust inflow rates to soil infiltration conditions, cutoff times to the soil water deficits and improving irrigation scheduling. The best irrigation water productivity (0.61 kg m À3) was achieved with surge-flow on alternate furrows, which reduced irrigation water use by 44% (390 mm) and led to high application efficiency, near 85%. Results demonstrated the possibility for applying deficit irrigation in this region.

Methodologies for end use analysis have been developed by different researchers in the energy and water fields and in different areas in the world over the last 20 years. While there are core features associated with the methodologies and models used, the differences can provide insight into the ways that they might be improved, as well as the differences that may be required in different regions and when models are used for different purposes.

- by Stuart White
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- Environmental Engineering, Chemical Engineering, Civil Engineering, Land Use Change

The minimisation of the water cost is examined in the framework of an integrated water resources planning and management model, implemented within the decision support system for the management of the Athens water supply system. The mathematical framework employs a simulation-optimisation scheme, where simulation is applied to faithfully represent the system operation, whereas optimisation is applied to derive the optimal management policy, which simultaneously minimises the risk and cost of decision-making. Real economic criteria in addition with virtual costs are appropriately assigned to preserve the physical constraints and water use priorities, ensuring also the lowest-cost transportation of water from the sources to the consumption. The proposed model is tested in the hydrosystem of Athens, in order to minimise the expected operational cost for several system configurations.

In recent years, the textile industry has been forced to develop new technologies to reduce energy and water consumption. The use of ultrasound in textile wet processing is one solution to this problem. The aim of this work was to investigate the effects of ultrasonic energy on the processing of cotton with a cationic softener. For this purpose, cotton fabric was treated with a fatty acid amide derivative cationic softener in water using ultrasonic energy during treatment. The physical properties of the fabrics treated under different conditions are discussed. The results show that the treatment of fabrics with softeners in an ultrasound bath is more effective compared to conventional methods and that it enhances the physical properties of the cotton.

- by Mohammad Shaver
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- Ultrasound, Surfactants, New Technology, Textile industry
- by David Goodrich
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- Earth Sciences, Environmental Science, Remote Sensing, Ecosystems Ecology

A field experiment was conducted in the western part of Saudi Arabia to optimize irrigation water use (IWU), yields and quality of the 'Nabbut-Saif' date palm grown in sandy loam soil under arid conditions. Four water regimes were investigated. The supplied amounts of irrigation water were 50, 65, 82 and 100% of date palm water requirements to the first (W1), second (W2), third (W3) and fourth (W4) water regimes, respectively. The daily water requirement was calculated using the Penman-Montieth equation for dry climates and applied to the trees three times a week through a drip irrigation system. Results indicated that giving 65% of total date palm water requirement maximized date yield by producing 46.1 kg per tree and resulted in the best IWU (0.8 m 3 kg À1 per tree). Increasing the water regime to 82 and 100% of total water requirement produced only 45.5 and 46 kg per tree respectively and reduced IWU. Generally, fruit quality characteristics were insignificantly affected by the water regimes investigated. The results suggested that supplying 34 m 3 yr À1 per tree for date palms grown under the conditions of the western part of Saudi Arabia is enough to maximize IWU, yield and quality of the 'Nabbut-Saif' date palm cultivar.

- by Saleh Ismail
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- Civil Engineering, Environmental Science, Agronomy, Agriculture

Several types of X-ray fluorescence (XRF) core scanners have been developed to fulfill the demands for high-resolution, rapid, chemical analysis of wet sediment cores. However, their application to quantitative analysis has been hampered by the difficulty of evaluating the XRF absorption effect of water in a water film on the sediment surface and interstitial water within the sediments, especially for lighter elements. In this study, we established a non-destructive, rapid, high-resolution, and quantitative chemical analysis method for wet fine-grained sediment samples using an XRF microscanner. Results of our experiments suggest that the degree of XRF absorption by the water film, which develops on the wet sample surface covered with Mylar film, shows a clear positive correlation with the water content of the sediments under the measurement area. A clear positive correlation also exists between the degree of XRF absorption by the interstitial water and the water content of the sediments under the measurement area. We evaluated the XRF absorption by the thin water film using the relationship between the water content and thickness of the thin water film, and the XRF absorption by the interstitial water using its relation with the water content. The water content under the measurement area is estimated from the average transmitted X-ray intensity that is measured on the same measurement area simultaneously with the measurement of XRF intensities. The dry sample equivalent XRF intensities of major elements (Al, Si, K, Ca, Ti, and Fe), which are the XRF intensities of wet samples corrected for the XRF absorption by the thin water film and the interstitial water, show better correlation with the major element concentrations determined by conventional XRF methods. Using this new method, it is possible to measure the average water content and average concentrations of the 6 major elements simultaneously for a square area as small as 0.5 × 0.5 mm on the wet fine-grained sediment within 6 min, which is nearly ten times faster than the conventional XRF method.

- by Ryuji Tada
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- Earth Sciences, Marine Geology, Quantitative analysis, X Rays

By 2025, it is estimated that around 5 billion people, out of a total population of around 8 billion, will be living in countries experiencing water stress (using more than 20% of their available resources). Climate change has the potential to impose additional pressures in some regions. This paper describes an assessment of the implications of climate change for global hydrological regimes and water resources. It uses climate change scenarios developed from Hadley Centre climate simulations (HadCM2 and HadCM3), and simulates global river #ows at a spatial resolution of 0.5;0.53 using a macro-scale hydrological model. Changes in national water resources are calculated, including both internally generated runo! and upstream imports, and compared with national water use estimates developed for the United Nations Comprehensive Assessment of the Freshwater Resources of the World. Although there is variation between scenarios, the results suggest that average annual runo! will increase in high latitudes, in equatorial Africa and Asia, and southeast Asia, and will decrease in mid-latitudes and most subtropical regions. The HadCM3 scenario produces changes in runo! which are often similar to those from the HadCM2 scenarios * but there are important regional di!erences. The rise in temperature associated with climate change leads to a general reduction in the proportion of precipitation falling as snow, and a consequent reduction in many areas in the duration of snow cover. This has implications for the timing of stream#ow in such regions, with a shift from spring snow melt to winter runo!. Under the HadCM2 ensemble mean scenario, the number of people living in countries with water stress would increase by 53 million by 2025 (relative to those who would be a!ected in the absence of climate change). Under the HadCM3 scenario, the number of people living in countries with water stress would rise by 113 million. However, by 2050 there would be a net reduction in populations in stressed countries under HadCM2 (of around 69 million), but an increase of 56 million under HadCM3. The study also showed that di!erent indications of the impact of climate change on water resource stresses could be obtained using di!erent projections of future water use. The paper emphasises the large range between estimates of`impacta, and also discusses the problems associated with the scale of analysis and the de"nition of indices of water resource impact.

- by javeria saher
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- Climate Change, United Nations, Southeast Asia, Global Environmental Change

When dealing with the planning and management of water uses in a river, the knowledge of the probabilistic structure of minima of daily or of multiple-day flows is often required. As a tool for straightforward determination of different levels of flow minima, flow duration curves (FDCs) are particularly suited for planning purposes. In this paper, FDCs referred to annual samples are interpolated with lognormal curves and their probabilistic structure is obtained through the statistical analysis of the two lognormal parameters. Distribution of these parameters is shown to be normal, so that the discharge with a given duration related to a return period T can be easily evaluated. To build FDCs in ungauged basins, relations between the moments of the parameters and catchment characteristics have been investigated, with reference to the data available in the Basilicata region (Italy). For both parameters, most of the variance of the first moment can be explained by the Base Flow Index (BFI), which can be estimated from geology. The second moment can be derived considering that the coefficient of variation is constant over the whole region. Since the curves are considered in dimensionless form, estimation of the mean annual runoff is finally needed to obtain the dimensional probabilistic FDCs in ungauged sites.

- by P. Claps
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- Statistical Analysis, Environmental Planning, Coefficient of Variation, Water Use

While the relations between climate variables and sectoral water demand have been well established in the literature, few studies have attempted to quantify changes in urban water usage with climate change. Concentrating on the city of Hamilton, New Zealand, we investigate possible water use and infrastructure needs for a range of climate and population projections. We find that water demand (at the monthly aggregate level) is largely driven by changes in population, and not significantly affected by changes in climate. However, as population increases, the effect of climate variables on per capita consumption will be magnified. Monthly aggregate changes may further mask potenially significant short-term shortages. In several scenarios, water supply shortages in 2030 occur with a 30-40% probability, suggesting needs for long-term capacity expansion or aggressive demand side management, rather than implementation of short-term management of water demand.

- by Matthias Ruth
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- Climate Change, Water resources, Climate variability, Water Resources Management

The study has investigated the feasibility of using siderite-coated quartz sand and/or hematite-coated quartz sand columns for removing As from water. Arsenic-spiked tap water and synthetic As solution with As concentrations from 200 to 500 μg/L were used for the experiments. Since three coating methods employed to prepare siderite-coated quartz sand and hematite-coated quartz sand had no significant impact on As adsorption in batch tests, the column fillings were produced by means of the simplest one involving mechanically mixing the Fe mineral with quartz sand. Fixed bed tests show that the combination of siderite-coated quartz sand and hematite-coated quartz sand greatly promoted the column performance in removing As and the presence of As(III) in the influent improved the removal efficiency of the column. The relatively low capacity in treating As-spiked tap water arose from the suppression of FeCO 3 dissolution in the presence of high HCO 3 − concentration (333 mg/L), which consequently limited the formation of fresh Fe(III) oxides. However, the H 2 O 2 -conditioning greatly increased As adsorption capacity of the column for remediating As-spiked tap water. The Toxicity Characteristic Leaching Procedure (TCLP) test shows that the spent adsorbents were not hazardous and could be safely disposed of to landfill.

- by Huaming Guo
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- Arsenic, Water Purification, Multidisciplinary, Adsorption

Increasing demands on limited water resources have made wastewater reclamation for municipal irrigation an attractive option for extending water supplies in the semiarid Southwest. However, public concerns remain about the potential risks of human contact with reclaimed water used for irrigating public and recreational areas. This study focused on identifying public perceptions regarding wastewater reuse and how these may affect

- by Kristine Uhlman
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- Wastewater Treatment, Water Reuse, Water Management, Water Supply

Growth and water uptake both decreases when tomato plants are irrigated with saline water. To determine the relative contribution of physiological traits to these decreases plant fresh and dry weight, leaf area, leaf water (c w) and osmotic (c P) potentials, gas exchange parameters, stomatal density, leaf chlorophyll and Na content were investigated in the tomato (Lycopersicon esculentum) cultivars, Daniela and Moneymaker. Plants were grown in greenhouse, in sand culture, and irrigated with a complete nutrient solution supplied with 0 (control), 35 and 70 mM NaCl over a period of 2 months. Salinity reduced plant dry weight, height and number of leaves even at 35 mM NaCl. Leaf c w and c P decreased with salinity but leaf turgor pressures were significantly higher in salinised than in control plants which suggests that bulk tissue turgor did not limit growth under the saline conditions tested. Increasing salinity in the irrigation solution led to both morphological changes [(reduction of plant leaf area and stomatal density) and physiological changes [reduction of stomatal conductance, transpiration, and net CO 2 assimilation (A CO 2)] Plant water uptake, measured as the difference between volume of nutrient solution supplied and drainage collected, was closely related to transpiration, stomatal conductance, and stomatal density. Chlorophyll content per unit of leaf area increased with salinity. Reduction of net A CO 2 with salinity was explained in higher degree by stomatal conductance and stomatal density than by Na accumulation in the leaves. Although plant water uptake was similar for the two cultivars, Daniela transported, per unit of water uptake, more Na to the leaves than did Moneymaker. However, Daniela reduced leaf area less than did Moneymaker. Water use efficiency, calculated either as the ratio between total plant dry matter and total plant water uptake, or as the ratio between net A CO 2 and transpiration, did not change under our saline growth conditions. The contribution of the observed salt-responses to reduction in shoot water loss, plant water uptake and salt loading, while keeping water use efficiency, is discussed in relation to salt tolerance. Because some of these salt-responses take a long time to develop, growing seedlings in seedbeds with saline media could be of interest to better tolerate further salty conditions in the field or greenhouse.

- by remedios romero
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- Plant Biology, Biology, Salt Stress, Medicine

Water use concepts and performance descriptors that may be useful in defining conservation and saving of water are discussed with the aim of improving the overall performance and productivity of water use. New indicators are proposed which include consideration of water reuse and aim to assist in identifying and providing clear distinctions between beneficial and non-beneficial water uses. An analysis of productivity concepts useful both in irrigation and elsewhere is provided together with suggestions for where commonly used terms, such as the broadly used "water use efficiency" among others, would be better avoided in irrigation engineering and given much more narrowly defined meanings in agronomy and biological sciences. Particular attention is given to economic issues in water productivity. The analysis is completed with various case study applications at irrigation farm and system scales. It is recommended that a set of terms (not necessarily those developed here) be widely adopted that will provide a basis for easy, certain communication and provide widespread common understanding of the issues which must be faced to develop approaches to achieve efficient water use.

- by Luís Santos Pereira
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- Civil Engineering, Environmental Science, Chemistry, Water Reuse

In recent years, several ponds near Alviso, California, previously used in commercial salt production, were modified for wetland restoration and management as part of the South Bay Salt Pond Restoration Project. Algal growth and subsequent decay often leads to suboxic or anoxic water conditions in the ponds. Sampling trips were coordinated in the second half of 2008 to examine the interstitial water in the sediment and the overlying bottom waters of three shallow (average depth

- by Brent Topping
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- Environmental Science, Ground Water, Water Use, Dissolved Oxygen
- by Cesar Koppe Grisolia
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- Ecotoxicology, Reproduction, Multidisciplinary, Toxicity

The use of the compensation heat-pulse velocity (CHPV) technique to estimate sap flow in olive trees as a means of irrigation scheduling can be a difficult task because of the naturally heterogeneity of hydraulic functioning of sapwood area in this species. As a result, the monitoring of an unreasonably large number of both trees and CHPV gauges per tree is needed for accurate estimation of orchard transpiration. The approach used in this paper restricts the monitoring of a large number of both trees and gauges to a very short time (a day) and allows the long term estimation of transpiration of several olive trees by the continuous monitoring of a sole CHPV gauge installed in a single tree. In an experimental olive orchard in southern Italy, we monitored six CHPV gauges in three well irrigated trees (treatment T100) and six CHPV gauges in three rain-fed trees (treatment T0) at half hour intervals for 60 days during summer 1999. For each i th gauge at each day, we linearly regressed the sap flow (Q i , l h (1 ) against the mean sap flow of the all other n(/1 gauges of the same treatment (Qm i ). The regression parameters were used to obtain an estimation of Qm i (EQm i ) throughout the trial using the data of any single i th gauge. In order to test the prediction power of the model of i th gauge, the estimated mean sap flow (EQm i ) values were regressed day by day against the actually measured Qm i . The same procedure was also applied at the time scale of a day, that is to the daily cumulative value of Q i and Qm i . In all cases, we obtained high statistical significance of the models applied to data as confirmed by the high adjusted R 2 estimates. Our analyses show the feasibility of estimating the transpiration rate of many trees by monitoring sap flow in a single tree by the use of a sole CHPV gauge. The results of this work indicate that CHPV can be a useful and powerful method for irrigation scheduling for olive and other tree species. #

- by Pasquale Giorio
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- Biological Sciences, SAP, Environmental Sciences, Olea europaea
- by Daniela Baglio
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- Engineering, Technology, Mass Spectrometry, European Union

This paper reviews the application of a scenario for the 2015 agricultural policy and markets for the irrigated agriculture in Europe. Scenarios for irrigated agriculture 2015 are also described in detail including Reformed CAP and biomass demand. It is applied at the basin level for the Guadalquivir River in southern Spain. The methodology is based upon residual value of water and it combines budget and farm analysis at municipality level, with the Guadalquivir basin divided at 50 'comarcas'; in each of them 24 possible crops are selected with specific 'comarca' data bases. The 2015 scenario studies the present level of water use and value, and makes an analysis for 2015.This model allows the knowledge of water value and irrigated agriculture at 'comarca' level and 'aggregated basin level'.

- by Giacomo Giannoccaro
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- Energy Economics, Agricultural Policy, Food Policy, Water Pricing

Studies on nanoparticles have become the target of major interest in modern science. Fabrication and characterization of silver nanoparticles has attracted considerable attention as a result of their significant applications in nano-technology and nano-biotechnology. The unique physical, chemical and mechanical properties of nanoparticles are the effect, among other things, of the high ratio of total surface area to their volume.

- by Robert Tien
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- Materials Science, Water Use, Spectrum, Surface Area

Introduction The water and energy interdependence Water is essential for all life. There are no substitutes. Water is not renewable, so we have to take care of the same amount of fresh water that was available for the dinosaurs. So the water is reused. The problem is that a growing population, climate change, increasing standard of living, food production and industrialization will put a lot of pressure on water resources. Pollution and contamination of available fresh water sources will further decrease available water. Still we witness so much misuse of water. Too often it is considered to be ubiquitous and taken for granted and the water is not given its true value. Water is not just an environmental issue. It is a fundamental issue at the very heart of justice, development, economics and human rights. As stated by the UN Committee on Economic, Cultural and Social Rights (2002): '.. . Water is fundamental to life and health. The human right to water is indispensable for leading a healthy life in human dignity. It is a prerequisite to the realization of all other human rights.' Water is certainly needed for life. Still it is a great killer. Floodings and contaminations kill millions of people every year. Most often we can do something about this. Water has been and still is a source of con ict between people, between regions and nations. Water can be considered synonymous with human power and in uence. During the history the most powerful nations and kingdoms were established around fresh water sources-rivers or lakes. Civilizations have collapsed as a result of sustained droughts, exempli ed by the Tang (907 AD) and Yuan dynasties in China, the Maya empire (900 AD) in Meso America and the Khmer Empire in Cambodia that peaked in the 13th century. Energy is a fundamental condition for a decent life. Energy is needed to extract, treat and distribute drinking water as well as to collect and treat the wastewater. It is less apparent that energy depends so much on water. Water is needed to extract primary energy, to re ne the fuel, and to generate electric power. Energy production also has a large impact on water quality.

- by Gustaf Olsson
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- Engineering, Water resources, Energy, Water Use

The consumption of a cotton product is connected to a chain of impacts on the water resources in the countries where cotton is grown and processed. The aim of this paper is to assess the 'water footprint' of worldwide cotton consumption, identifying both the location and the character of the impacts. The study distinguishes between three types of impact: evaporation of infiltrated rainwater for cotton growth (green water use), withdrawal of ground-or surface water for irrigation or processing (blue water use) and water pollution during growth or processing. The latter impact is quantified in terms of the dilution volume necessary to assimilate the pollution. For the period 1997-2001 the study shows that the worldwide consumption of cotton products requires 256 Gm 3 of water per year, out of which about 42% is blue water, 39% green water and 19% dilution water. Impacts are typically cross-border. About 84% of the water footprint of cotton consumption in the EU25 region is located outside Europe, with major impacts particularly in India and Uzbekistan. Given the general lack of proper water pricing mechanisms or other ways of transmitting productioninformation, cotton consumers have little incentive to take responsibility for the impacts on remote water systems.

- by Arjen Hoekstra
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- Ecological Economics, Water Pollution, Applied Economics, Water Pricing

The continuous high demand of water resources for agricultural uses in Jordan is leading to a water crisis. A possible partial solution may be to import food which requires large amounts of water to grow instead of cultivating high water consuming crops. Crops such as banana and citrus cause a huge virtual water loss, which can be reduced by cultivating other less water-demanding crops. This paper focuses on analyzing the economic value of cultivating tree fruit from a virtual water perspective. The virtual water calculations in this study depend on the average rainfall, water quota, and the crops' water requirements (CWR). The gross profit to the water use ratio showed that banana has the lowest value 0.085 JD/m 3 , while lemon has the highest value 1.65 JD/m 3 . The calculations show that the average embedded water in fruits varies from about 470 m 3 /ton for grapes to about 2,500 m 3 /ton for dates. Banana and citrus plantations consume about 21 and 71 million cubic meters (MCM) annually, respectively, which represent about 85% of the total water consumption in fruit tree plantation. The virtual water flow estimation embedded in fruits shows that Jordan imports about 77 MCM per year. However it exports about 29 MCM per year. The results were analyzed from an integrated water resources management (IWRM) perspective. The analysis shows that a way to recover some of the water costs involved in, e.g., banana production would be

- by Hartmut Gaese and +1
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- Water, Water resources, Consumption, Water Resources Management

to investigate the spatial distribution of fine roots and its correlation with selected soil properties on an artificial ecosystem dominated by woody vegetation species, and (2) to compare the root distribution to that predicted using... more
to investigate the spatial distribution of fine roots and its correlation with selected soil properties on an artificial ecosystem dominated by woody vegetation species, and (2) to compare the root distribution to that predicted using a global model for natural ecosystems. Root diameter distribution (≤5 mm), root biomass density (RBD), root length density (RLD), soil pH, soil electrical conductivity and dry soil bulk density were measured on soil core samples (217) collected from a trench wall using a 20×20-cm grid sampling. Approximately 90% of the RBD (mean ± standard error: 0.27±0.027 kg m −3 ) and RLD (1.57±0.023 cm cm −3 ) occurred in the top 40 cm, decreasing exponentially to a maximum rooting depth of 150 cm. RBD exhibited a vertical spatial structure associated with soil pH (p<0.05; r 2 = 0.48), and a random lateral distribution. Coefficients of variation (CV) of RBD were high irrespective of orientation (vertical: 79-200%, lateral: 50-236%). The root extinction parameter β (0.944) for the global model was lower (p<0.05) than that of woodlands (β= 0.964-0.976), indicating a shallow root distribution resembling that of grasslands (β=0.943). The superficial root distribution indicated subsoil chemical constraints to root growth, while high lateral variability was attributed to sparse vegetation. The findings stress the need to account for both vertical and lateral variability of roots for accurate modelling of water use and productivity on certain artificial ecosystems with sparse vegetation.

- by Willis Gwenzi
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- Spatial Analysis, Biological Sciences, Environmental Sciences, Root Distribution

Hydrogen is a renewable and non-polluting fuel. Its production from water using renewable energy is an attractive challenge. In this work we report some results on the preparation of titanium oxide TiO 2 thin films for environmental applications such as water photosplitting. TiO 2 thin films have been prepared by spin coating technique of sol precursor onto glass substrates. The deposited films were annealed at different temperatures in air. The X-ray diffraction (XRD) experiments show that the two well-known anatase and rutile phases were observed depending both on the conditions of deposition and on the temperature of annealing. The best conditions of crystallization were found to be around 400 C in air. The influence of the number of deposited layer on the crystalline quality of the films was investigated. The surface morphology of the deposited film was characterized by atomic force microscopy (AFM) and scanning electronic microscopy (SEM). The UVeViseNIR spectroscopy shows that the film exhibits a high transmission around 90%. The best layers were obtained when concentrated (HCl) was added to the sol solutions. The direct band gap of the films was found to be around 3.7 eV, and their refractive index was found to vary from 2 to 2.4. (A. Elfanaoui).

- by Laanab Larbi
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- Engineering, Renewable Energy, Scanning Electron Microscopy, Atomic Force Microscopy
- by David Cocke
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- Engineering, Chemistry, Radiation Chemistry, Technology Assessment

RESUMO-Existe uma controvérsia histórica sobre o uso de água em plantações de eucalipto em vários países onde estas plantações vêm se expandindo. Este trabalho apresenta os resultados de um monitoramento hidrológico intensivo que vem sendo realizado desde 1994 em uma microbacia no município de Aracruz-ES, Brasil. As medições realizadas nos plantios de eucalipto (Eucalyptus grandis W. Hill ex Maiden) e em uma floresta nativa (Mata Atlântica) e as estimativas a partir de modelos hidrológicos para o cálculo de balanço hídrico demonstram que as plantações de eucalipto se comparam à floresta nativa quanto à evapotranspiração anual e ao uso de água do solo. Considerando o ciclo de crescimento do eucalipto para produção de celulose, o uso de água pela plantação pode ser inferior ao da floresta nativa, principalmente no início do ciclo. A análise da relação entre evapotranspiração e precipitação mostrou que em anos em que a precipitação é próxima à média anual existe um equilíbrio entre a perda e a entrada de água através da precipitação pluviométrica. Palavras-chave: Eucalipto, Mata Atlântica, uso de água, modelos hidrológicos, balanço hídrico e evapotranspiração.

- by João Vianei Soares
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- Evapotranspiration, Water balance, Water Use, Forestry Sciences

Fouling is a major obstacle for maintaining efficient membrane-based drinking water treatment processes. Natural organic matter (NOM) components such as humic substances (HS)-and protein-like matter as well as colloidal/particulate matter are known to be the major membrane foulants in ultrafiltration-based drinking water processes. In this study, a fluorescence excitation-emission matrix (EEM) approach was used for characterization of these major membrane foulants. Unlike most NOM and colloidal/particulate matter characterization techniques, this method can provide fast and consistent analyses with high instrumental sensitivity. Principal component analysis (PCA) of fluorescence EEM measurements collected during cross-flow ultrafiltration of river water was used to extract principal components (PCs) that contained information relevant to membrane fouling. These PCs were related to the major membrane foulants, HS, protein-like and colloidal/particulate matter present in natural water. PC score analysis revealed that colloidal/particulate matter mostly contributed to reversible fouling. HSand protein-like matter were largely responsible for irreversible fouling behaviour. Fluorescence EEMs of the foulants extracted from the membranes also revealed different rejection characteristics for two different membranes, 60 kDa and 20 kDa. The proposed method proved suitable for identifying the major foulant components and their contribution to reversible and irreversible membrane fouling, illustrating its potential for monitoring and controlling membrane fouling in drinking water treatment applications.

- by Ian Makin
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- Water quality, Sri Lanka, Soil ecology, Water Supply

Laboratory-accelerated ageing tests have been conducted to examine the depletion of antioxidants from highdensity polyethylene (HDPE) geomembranes as a result of their exposure to various environments. Samples of 2.0 mm thick geomembrane were exposed to air, water, and municipal solid waste (MSW) leachate at temperatures of 22, 40, 55, 70, and 85°C. At various time intervals, samples were collected and the oxidative induction time (OIT) was evaluated. The results indicated that the antioxidants are depleted at rates 1.6 to 2.4 times faster for samples in water than for air-exposed samples. For samples in leachate, the depletion is about 4 times faster than that in air and 1.6-3.2 times faster than that in water. Using these rates, it is estimated that if the geomembrane examined were used as an MSW landfill primary liner, it would take at least 40 years to deplete the antioxidants from the geomembrane at a temperature of 33°C and over 150 years at a temperature of 13°C.

- by henri Sangam
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- Environmental Engineering, Civil Engineering, Water, Municipal Solid Waste

The article details the development and uses of the water poverty index (WPI). The index was developed as a holistic tool to measure water stress at the household and community levels, designed to aid national decision makers, at... more

- by Ian Smout
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- Environmental Science, Development Studies, Water, Natural Resources

A hydrogen peroxide (H 2 O 2) auto-analyzer was developed to continuously detect H 2 O 2 present in water, using a flow injection analysis (FIA) technique, during several advanced oxidation processes (AOPs) involving H 2 O 2 , such as ozone/H 2 O 2 , UV/H 2 O 2 , and ozone/UV, and an electrochemical process. The analytical method was based on a fluorometric method, using the reaction of p-hydroxyphenyl acetic acid and H 2 O 2 in the presence of peroxidase enzyme. H 2 O 2 was analyzed within the high (100-2,000 lg/L) and low (0-500 lg/L) concentration ranges, using both long and short reaction coils, respectively. The standard deviation and detection limit were 0.5 and 1.6 lg/L, respectively, and the coefficient of variation at 1 lg/L was 7.8%. This study also investigated the effects of Na 2 S 2 O 3 and NH 4 Cl, which were used to quench the ozone and hypochlorous acid (HOCl) present in the samples, on the measurement of H 2 O 2 during the ozone-based AOPs and electrochemical process.

- by Minhwan Kwon
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- Environmental Engineering, Chemical Engineering, Civil Engineering, Chemistry

The environmental consequences of replacing fish meal and fish oil with plant-based sources in salmonid feeds were investigated using Life Cycle Assessment (LCA). Two scenarios of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) farming were compared. The first scenario used a Standard Diet (STD) with high levels of fish meal and fish oil, and the second a Low Marine-Fishery-Capture Diet (LFD) in which fish meal and fish oil were replaced by plant protein and oil sources. Environmental impacts assessed were: acidification, eutrophication, climate change, terrestrial ecotoxicity, net primary production use (biotic resource use), water use, land occupation and total cumulative energy demand. The assessment confirmed the substantial contribution of feed to the environmental burdens of fish production and the LFD scenario led to a significant decrease in biotic resource use compared to the STD scenario with the same total energy demand. Environmental impacts of feeds depended highly on the geographic origins of feed ingredients from fishery (e.g., fish oil from Norway or Peru) and from terrestrial agricultural crop species (e.g., palm oil or rapeseed oil). This study demonstrated the importance of a multicriteria method to give stakeholders the most accurate information on the potential consequences of replacing fishery products with plant-based sources in aquafeeds.

- by Hayo van der Werf
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- Zoology, Climate Change, Life Cycle Assessment, Environmental Impact Assessment

A method based on solid-phase extraction (SPE) and capillary zone electrophoresis-tandem mass spectrometry (CZE-MS/MS) is described for the separation and determination of six cytokinin nucleotides in coconut water. The best CZE separation for the six cytokinin nucleotide standards was achieved using a 25 mM ammonium formate/formic acid buffer (pH 3.8) and 2% (v/v) methanol with an applied gradient separation voltage (25 kV for 32 min, and then a linear gradient to 30 kV in 5 min, finally 30 kV to the end of separation) in less than 60 min. MS/MS with multiple reaction monitoring (MRM) detection was carried out to obtain sufficient selectivity and sensitivity for the cytokinin nucleotides. The combined use of on-line sample stacking and CZE-MS/MS achieved limits of detection (LODs) in the range of 0.06-0.19 M for the six cytokinin nucleotides at a signal-to-noise ratio of 3. Furthermore, a novel dual-step SPE procedure was developed for the pre-concentration and purification of cytokinin nucleotides using Oasis HLB and Oasis MAX cartridges. The recoveries of the cytokinin nucleotides after the dual-step SPE were in the range of 44-71%. The combination of off-line SPE, on-line sample stacking and CZE-MS/MS approach was successfully applied to screen for endogenous cytokinin nucleotides present in coconut water sample. trans-Zeatin riboside-5 -monophosphate (ZMP) was detected and quantified in coconut water by CZE-MS/MS after SPE and on-line sample stacking.

- by Jean Yong
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- Engineering, Technology, Mass Spectrometry, Capillary electrophoresis

Transpiration-use efficiency, the ratio of biomass (Y) produced per unit of water transpired (T) by a crop, depends on crop characteristics and on the environment in which crops develop. Transpiration-use efficiency has been described as Y/T=kc/Da, where kc is a crop dependent constant and Da is the daytime air vapor pressure deficit. Our objectives were to determine Y/T and kc

- by Armen Kemanian and +1
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- Earth Sciences, Biophysics, Biomass, Ecophysiology

Water use in vineyards is controlled by energy absorbed by plants and the soil surface. An 8 day field experiment was conducted in a commercial vineyard near Lamesa, TX, to evaluate soil and canopy energy balances, and to examine energy exchange between canopy and soil. Grapevines in the vineyard were wrapped tightly to trellis wires, creating compact hedgerows that were 3 m apart and of 1.6 m height and 0.4 m width, with little foliage below 1 m above the soil surface. The Bowen ratio method was used to measure the vineyard energy balance including total latent heat flux (AE). Latent heat flux from the canopy (,~Ec) was determined from sap flow measurements of transpiration. Soil latent heat flux (AEs) was calculated as the difference between AE and AE c. These measurements were combined with measurements of soil net irradiance to partition the vineyard energy balance into soil and canopy components. During the study, AEs accounted for 44-68% of AE. Unstable conditions predominated during the study, with the soil generating sensible heat that was transferred to the canopy, producing values of AE c that were greater than canopy net irradiance. Within-row advection of sensible heat was 17-36% of AEc. Although the canopy was cooler than within-and above-canopy air, it was not a strong enough sink for sensible heat to produce stable conditions above the canopy. The narrow hedgerows created an unusual diurnal pattern of canopy net irradiance, having midmorning and midafternoon peaks, and a low midday plateau. Morning and afternoon peaks occurred during times of maximum direct beam irradiance on east and west sides of the hedgerows. Results also showed that within-canopy wind speed and air temperature were affected by wind direction.

- by Michael Savage
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- Earth Sciences, Biological Sciences, Energy Balance, Field Experiment

Developing new and improved grazing systems for crop–livestock farms where crop production is the major driver of farm management decisions presents a unique research and development challenge. In southern Australia, a substantial proportion of animal production from grazing comes from regions and farms where cropping is the major enterprise. In this paper, we describe a multi-disciplinary farming-systems research approach (EverCrop) aimed at improving farm profitability, risk management and environmental impacts through the development and integration of new grazing options with an emphasis on perennial species. It has been used to analyse and target new opportunities for farmers to benefit from perennial species across dry Mediterranean-type and temperate regions of southern Australia. It integrates field experimentation, on-farm trialling, farmer participatory research, soil–plant–climate biophysical modelling, whole-farm bioeconomic analysis and evaluations of adoptability. Mult...

- by Rick Llewellyn
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- Agronomy, Interaction, Sustainable, Climate

Agriculture is highly dependent on the social sustainability inherent in rural communities. Yet too often we focus on the economic and environmental drivers relating to agricultural production, ignoring the social and community aspects that make rural livelihood not only possible but also rewarding and nurturing. In this paper I focus on climate change as yet another factor associated with rural restructuring that defrays community wellbeing. I argue that attention to social factors and a stronger role for government in assisting communities will enable greater adaptation and enhance resilience in what are essentially very uncertain times.

- by Margaret Alston
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- Agronomy, Interaction, Sustainable, Climate

There is growing interest in managing water demand in the UK. A series of waste minimization clubs have been set up within the country and this paper identifies the effectiveness of these clubs in reducing the demand for water within industry. Membership of these clubs is voluntary and the only incentive for industry to reduce water consumption, and consequently the production of effluent, is the almost immediate fmancial saving made by the company, often achieved by accounting for the water consumption and loss within site from the point of input from the water supplier to output in the form of effluent. On average, companies are able to reduce water consumption by up to 30 percent. If the entire industrial sector within the UK were to achieve this degree of savings, it is possible that approximately l300MlId could be saved.

- by Christopher P Holt
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- Environmental Engineering, Civil Engineering, Consumption, Industry

Scarcity and competition for water are matters of increasing concern, as are potential shortages of food. These issues intersect both within the agricultural sector and across all water using sectors. Irrigation is by far the largest user of water in most water-scarce countries, and is under pressure to reduce utilisation (to release water to other sectors, including the environment) and use water more productively to meet demands for food and fibre. The terminology for such intra-and inter-sectoral analysis must be unambiguous across sectors so that interventions and their impacts are properly understood. Such terminology, based on previous work and debate, is set out. Implications for a better understanding of the scope for improved productivity of water in agriculture are traced, and some examples are given using data from recent research submissions, demonstrating the benefits of precise water accounting.

The paper analyses and discusses the concept of integrated water resources management (IWRM) and its application in South Africa. The central characteristics of IWRM are discussed and another feature, good governance, is highlighted as being crucial for effective IWRM. The paper focuses on those features that distinguish water management challenges in developing countries from those experienced in developed countries (where most of the current definitions of IWRM originated). The case study discussed in this paper, the Mhlatuze Catchment in South Africa, was selected as being representative of a catchment situated in one of the country's 19 water management areas (WMAs) where attempts are being made to implement IWRM. The available evidence indicates that three sets of reasons are responsible for the failure to achieve full implementation of IWRM in the Mhlatuze Catchment. First, the national custodian of water resources-DWAF-continues to experience severe internal (technical capacity) problems that hinder its efforts to successfully manage the Usutu to Mhlatuze WMA (of which the Mhlatuze Catchment forms a part) as a unit. Secondly, while IWRM is, on paper, a key part of national policy, the concept has not been fully accepted and practiced by local water managers. Thirdly, a range of institutional challenges persist because there is insufficient alignment and cooperation between the policies of different government departments and the practices of different water use sectors that impact on water.

- by Anthony R Turton
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- Geology, Geochemistry, Geophysics, Integrated Water Resources Management

Disinfection by-products (DBPs) are produced as a result of disinfecting water using various treatment methods. Over the years, chlorine has remained the most popular disinfecting agent due to its ability to kill pathogens. However, in 1974, it was discovered that the superchlorination of drinking water resulted in the production of chloroform and other trihalomethanes. Since then hundreds of additional DBPs have been identified, including haloacetic acids and haloacetonitriles with very little or no toxicological data available, thus necessitating the use of additional methods for hazard estimation. Quantitative Structure Toxicity Relationship (QSTR) is one such method and utilizes a computer-based technology to predict the toxicity of a chemical solely from its molecular attributes. The current research was conducted utilizing the TOPKAT ® /QSTR software package which is comprised of robust, cross-validated QSTR models for assessing mutagenicity, rodent carcinogenicity (female/male; rat/mouse), developmental toxicity, skin sensitization, lowest-observed-adverse-effect level (LOAEL), fathead minnow LC 50 , rat oral LD 50 and Daphia magna EC 50 . A total of 252 DBPs were analyzed for the likelihood that they would produce tumors and developmental effects using the carcinogenicity and developmental toxicity submodels of TOPKAT ® . The model predictions were evaluated to identify generalizations between the functional groups (e.g. alcohols, acids, etc.) and specific toxic endpoints. Developmental toxicity was identified as an endpoint common to the majority of aliphatic mono-and dicarboxylic acids, aliphatic halogenated and non-halogenated ketones, and aliphatic haloacetonitriles. In the case of the carcinogenicity submodels, most aliphatic aldehydes were identified as carcinogens only in the female mouse submodel. The majority of the aliphatic and aromatic dicarboxylic acids were identified as carcinogens in the female rat submodel. All other functional groups examined were largely predicted as non-carcinogens in all the cancer submodels (i.e. male/female rats and mice). The QSTR results should aid in the prioritization for evaluation of toxic endpoints in the absence of in vivo bioassays.

- by C. Moudgal
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- Algorithms, Toxicology, Water Supply, Mice

The paper analyses and discusses the implications that are inherent in the most widely accepted definition of the concept of Integrated Water Resources Management (IWRM). The most salient aspects of IWRM are discussed and another dimension, namely good governance, is then defined and added because it is argued that this is crucial for effective IWRM. The paper focuses in particular on those features that distinguish water management challenges in developing countries from those in developed countries (where most of the current definitions of IWRM originated), to provide a specific focus on IWRM in the Global South.

- by Nikki Funke and +2
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- Geology, Geochemistry, Geophysics, Water Management

Steady state and dynamic responses of two tree fern species of contrasting origins, Dicksonia antarctica (of Gondwanan origin) and Cyathea australis (Pan-tropical), were studied over two consecutive years under field conditions in a wet sclerophyll forest of south-east Australia. Irrespective of their different origins, there were no significant differences in photosynthetic performance between the two species. Growth irradiance and leaf temperature, but not plant water status, was significantly related to photosynthetic and morphological traits. At a common leaf temperature, maximum light-use efficiency of photosystem II (F v /F m ) was significantly lower in winter than in summer, suggesting some limitation to PSII efficiency potentially associated with cold winter mornings. Both species displayed seasonal acclimation in a number of measured photosynthetic parameters and frond traits (i.e. F v /F m , A sat , g s , N A , total chlorophyll, SLA). Acclimation of stomatal density to spatial variation in growth irradiance seemed limited in both species, although stomatal pattern differed between species. Because there were no significant differences between the two species in photosynthetic parameters, both species can be described by common carbon gain and water use models at the leaf scale.

- by Josep Penuelas
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- Biological Sciences, Seasonality, Environmental Sciences, Seasonal variation

The effects of pre-anthesis water deficit and cycle length were examined in Papaver somniferum L., cultivated for alkaloid production, in two locations in southern Spain. The vegetative period was shortened by extending the photoperiod through supplemental lighting in the field, while water deficit in pre-anthesis was induced by avoiding irrigations and installing rain shelters. The treatments were: IN (irrigated-normal photoperiod), IL (irrigated-hastened flowering), DN (water deficit in pre-anthesisnormal photoperiod) and DL (water deficit in pre-anthesis and hastened flowering). The artificial photoperiod hastened the flowering by 15 and 21 days, for irrigated and deficit treatments respectively. Seasonal evapotranspiration (ET) ranged from 398 (DN) to 505 mm (IN). There was evidence of root water uptake deeper than 1.5 m. Stomatal conductance was reduced (16%) during water stress, and did not recover in post-anthesis after resuming irrigation. Head yields (capsule + seeds + 7 cm stem) ranged between 3.8 and 4.3 t ha −1 ; water deficit and short vegetative period both reduced the biomass accumulated, although the effect on yields in these treatments was counterbalanced by a higher harvest index. Early flowering had a detrimental effect on alkaloid concentration in the capsule. Alkaloids yield ranged between 27 and 37 kg ha −1 . Water use efficiency (WUE) ranged between 0.78 and 0.96 kg m −3 ET for yield and between 63.4 and 73.7 g m −3 ET for alkaloids. Water stress increased slightly the Water Use Efficiency. A shorter vegetative phase had no effect on WUE for biomass or yield, but decreased the WUE for alkaloids production.

A carbon paste electrode modified with cobalt phthalocyanine (CPECoPc) was developed and applied to the determination of hydrazine [N 2 H 4 ] in industrial boiler feed water. The CPECoPc exhibited good electrocatalytical activity for hydrazine oxidation at pH 13. A linear correlation was obtained between anodic peak current (I ap ) and hydrazine concentration in the range of 1.25 Â 10 À4 to 9.80 Â 10 À4 mol L À1 , fit by the equation I ap ¼ 1.47 þ 4.90 Â 10 5 [N 2 H 4 ] with a correlation coefficient of 0.9967. A detection limit of 7.35 Â 10 À5 mol L À1 was obtained. Recovery of hydrazine from three samples ranged between 99.0% and 102.9%. The modified electrode showed no interference by cations commonly present in boiler water, such as K þ , Na þ , Ca 2þ , Mg 2þ , Al 3þ , Pb 2þ , and Zn 2þ . The results obtained for hydrazine in boiler water using the proposed modified electrode are in agreement with the data obtained by a standard spectrophotometric method, at the 95% confidence level.

- by Auro Tanaka and +1
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- Analytical Chemistry, Biomedical Engineering, Carbon, Titanium

The use of square wave voltammetry in conjunction with a boron-doped diamond electrode for the analytical determination of pentachlorophenol is described. After optimization of the experimental conditions, that model molecule was analyzed in pure and natural waters using a Britton-Robinson buffer (pHs5.5) as the supporting electrolyte. Oxidation occurs at 0.80 V vs. AgyAgCl in a two-electron process controlled by adsorption of the species. The detection limits obtained were 5.5 in pure water and 15.5 mg l for polluted water taken from a local creek. The combination of square wave voltammetry and diamond electrodes is an y1 interesting and desirable alternative for analytical determinations. ᮊ

The reclamation of effluent from wastewater treatment plants to be applied as an alternative water source is usually linked to reasons of water scarcity in the sense of unmatched temporary or structural water demand. Uneven spatial distribution and seasonal variations in water demand and in the hydrological cycle make the semi-arid coastal planes and islands of the Mediterranean particularly indicated for the use of reclaimed water as a useful droughtproof conservation measure. In the moderate climates of northern Europe, however, at first sight, one may think that there should be sufficient amounts of water available to support all possible water uses. However, the reuse of water in northern Europe can be an important asset to preserve or improve the quality of the existing water bodies. In simplified terms, 'reuse' of water in Northern Europe is dictated by quality aspects rather than by quantity. The main reason for the use of reclaimed water today is to conserve good quality (ground)water resources to applications requiring high-quality water such as the make-up of potable water. The water management in Flanders, the northern region of Belgium, is a good example of this situation, and will be discussed in the following paper.

- by Emmanuel Van Houtte
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- Water Availability, Water Reuse, Water Management, Water Demand