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Water, Volume 6, Issue 7 (July 2014), Pages 1873-2163

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Research

Jump to: Review

Open AccessArticle Marketing Household Water Treatment: Willingness to Pay Results from an Experiment in Rural Kenya
Water 2014, 6(7), 1873-1886; doi:10.3390/w6071873
Received: 29 April 2014 / Revised: 7 June 2014 / Accepted: 11 June 2014 / Published: 26 June 2014
Cited by 1 | PDF Full-text (258 KB) | HTML Full-text | XML Full-text
Abstract
Despite increasing availability of household water treatment products, demand in developing countries remains low. Willingness to pay for water treatment products and factors that affect demand are not well understood. In this study, we estimate willingness to pay for WaterGuard, a dilute chlorine
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Despite increasing availability of household water treatment products, demand in developing countries remains low. Willingness to pay for water treatment products and factors that affect demand are not well understood. In this study, we estimate willingness to pay for WaterGuard, a dilute chlorine solution for point-of-use water treatment, using actual purchase decisions at randomly assigned prices. Secondly, we identify household characteristics that are correlated with the purchase decision. Among a sample of 854 respondents from 107 villages in rural Kenya, we find that mean willingness to pay is approximately 80% of the market price. Although only 35% of sample households purchased WaterGuard at the market price, 67% of those offered a 50% discount purchased the product. A marketing message emphasizing child health did not have a significant effect on purchase behavior, overall or among the subset of households with children under five. These findings suggest that rural Kenyans are willing to pay for WaterGuard at low prices but are very sensitive to increasing price. Households with young children that could benefit the most from use of WaterGuard do not appear to be more likely to purchase the product, and a marketing message designed to target this population was ineffective. Full article
(This article belongs to the Special Issue Water Treatment and Human Health)
Open AccessArticle Pollutant Removal and Hydraulic Reduction Performance of Field Grassed Swales during Runoff Simulation Experiments
Water 2014, 6(7), 1887-1904; doi:10.3390/w6071887
Received: 27 March 2014 / Revised: 18 June 2014 / Accepted: 19 June 2014 / Published: 26 June 2014
Cited by 7 | PDF Full-text (1278 KB) | HTML Full-text | XML Full-text
Abstract
Four different field swales were tested in this study, using 24 standardised synthetic runoff simulation experiments to evaluate their performance in removing Total Suspended Solids (TSS), Total Nitrogen (TN) and Total Phosphorous (TP) from stormwater runoff. Hydraulic reduction capability of the swales was
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Four different field swales were tested in this study, using 24 standardised synthetic runoff simulation experiments to evaluate their performance in removing Total Suspended Solids (TSS), Total Nitrogen (TN) and Total Phosphorous (TP) from stormwater runoff. Hydraulic reduction capability of the swales was also assessed. The study demonstrated that a swale’s TSS removal performance is highly dependent on the inlet TSS concentrations. Results showed that between 50% and 80% of the TSS was generally removed within the first 10 m of the swale length. The study found no reduction in TN concentrations due to treatment by the swales. However, it did demonstrate a reduction in measured TP levels of between 20% and 23% between the inlet and the outlet. The study results demonstrated that swales can be successfully used to attenuate peak stormwater flow rates, reduce runoff volumes and to improve the quality of stormwater runoff, particularly in runoff with high concentrations of TSS and TP. The results from this study will assist designers to estimate the appropriate length of swale required to achieve specific TSS and TP pollution reductions in urban stormwater runoff and to reduce downstream runoff volumes. Full article
Open AccessArticle Using Remote Sensing to Identify Changes in Land Use and Sources of Fecal Bacteria to Support a Watershed Transport Model
Water 2014, 6(7), 1925-1944; doi:10.3390/w6071925
Received: 3 March 2014 / Revised: 2 June 2014 / Accepted: 20 June 2014 / Published: 4 July 2014
Cited by 1 | PDF Full-text (1653 KB) | HTML Full-text | XML Full-text
Abstract
The contamination of shellfish harvesting areas by fecal bacteria in the Annapolis Basin of Nova Scotia, Canada, is a recurring problem which has consequences for industry, government, and local communities. This study contributes to the development of an integrated water quality forecasting system
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The contamination of shellfish harvesting areas by fecal bacteria in the Annapolis Basin of Nova Scotia, Canada, is a recurring problem which has consequences for industry, government, and local communities. This study contributes to the development of an integrated water quality forecasting system to improve the efficiency and effectiveness of industry management. The proposed integrated forecasting framework is composed of a database containing contamination sources, hydrodynamics of the Annapolis Basin, Escherichia coli (E. coli) loadings and watershed hydrology scenarios, coupled with environmental conditions of the region (e.g., temperature, precipitation, evaporation, and ultraviolet light). For integration into this framework, this study presents a viable methodology for assessing the contribution of fecal bacteria originating from a watershed. The proposed methodology investigated the application of high resolution remote sensing, coupled with the commercially available product, MIKE 11, to monitor watershed land use and its impact on water quality. Remote sensing proved to be an extremely useful tool in the identification of sources of fecal bacteria contamination, as well as the detection of land use change over time. Validation of the MIKE 11 model produced very good agreement (R2 = 0.88, E = 0.85) between predicted and observed river flows, while model calibration of E. coli concentrations showed fair agreement (R2 = 0.51 and E = 0.38) between predicted and observed values. A proper evaluation of the MIKE 11 model was constrained due to limited water sampling. However, the model was very effective in predicting times of high contamination for use in the integrated forecasting framework, especially during substantial precipitation events. Full article
Open AccessArticle Utilization of Ion-Exclusion Chromatography for Water Quality Monitoring in a Suburban River in Jakarta, Indonesia
Water 2014, 6(7), 1945-1960; doi:10.3390/w6071945
Received: 21 January 2014 / Revised: 26 May 2014 / Accepted: 11 June 2014 / Published: 4 July 2014
Cited by 1 | PDF Full-text (666 KB) | HTML Full-text | XML Full-text
Abstract
We evaluated the use of ion-exclusion chromatographic systems for analyzing the behavior of inorganic ions (e.g., bicarbonate, sulfate, chloride, nitrate, phosphate, dissolved silicate, sodium, ammonium, potassium, magnesium, and calcium ions) in a suburban river located in Jakarta, Indonesia. Carbonate, phosphate, and silicate ion
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We evaluated the use of ion-exclusion chromatographic systems for analyzing the behavior of inorganic ions (e.g., bicarbonate, sulfate, chloride, nitrate, phosphate, dissolved silicate, sodium, ammonium, potassium, magnesium, and calcium ions) in a suburban river located in Jakarta, Indonesia. Carbonate, phosphate, and silicate ion concentrations were determined using ion-exclusion chromatography (IEC) on a weakly acidic cation-exchange resin column (WCX) in the H+-form with water eluent. Other ions were identified by ion-exclusion/cation-exchange chromatography (IEC/CEC) on a WCX column with tartaric acid eluent. The use of IEC systems for water quality monitoring was advantageous for the following reasons: (1) the concentrations of analyte ions, except NO3 and silicate ions, increased from upstream to downstream; and (2) the speciation of inorganic nitrogen ions could be analyzed by single injection into the IEC/CEC. The IEC approach provided beneficial information for the construction of sewage treatment facilities in our study area. Results showed that (1) the analyte concentrations for samples obtained in the downstream area were higher than those in the upstream area owing to contamination by domestic sewage; (2) the concentrations of NO3 and NH4+ correlated with the concentration of dissolved oxygen; and (3) bicarbonate concentrations increased downstream, likely due to respiration of bacteria and dissolution of concrete under low-oxygen conditions. Full article
Open AccessArticle Socio-Technological Influences on Future Water Demands
Water 2014, 6(7), 1961-1984; doi:10.3390/w6071961
Received: 30 January 2014 / Revised: 18 June 2014 / Accepted: 26 June 2014 / Published: 7 July 2014
Cited by 5 | PDF Full-text (1330 KB) | HTML Full-text | XML Full-text
Abstract
The traditional water supply management approach focuses on (perceived) community requirements that must be met, but not on community demands, which are variable. Therefore a paradigm-shift is required to the way water is considered. In this paper two fundamental management measures to influence
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The traditional water supply management approach focuses on (perceived) community requirements that must be met, but not on community demands, which are variable. Therefore a paradigm-shift is required to the way water is considered. In this paper two fundamental management measures to influence daily water demand and therefore conservation are considered: (1) Technological efficiency measures (i.e., via adopting water-saving devices); and (2) User behaviour (i.e., how users interact with and use the technologies). Through a newly developed futures framework, the individual and combined impact of these approaches within residential and office buildings are examined. Results show each in isolation has similar impacts (i.e., 55% reduction) on domestic water consumption per capita, although the ranges over which user behaviour can operate appears to be far more diverse. Most strikingly, when these measures are considered in combination, greater impact (i.e., 80% reduction) could be achieved. Conclusions are drawn as to how far water demand management, through a dual track approach, can go in terms of reducing indoor water consumption of both residential and office users within the UK. The paper provides philosophical arguments for what else is needed in order to secure sufficient, sustainable water supplies within a “liveable” future. Full article
Open AccessArticle Water End-Uses in Low-Income Houses in Southern Brazil
Water 2014, 6(7), 1985-1999; doi:10.3390/w6071985
Received: 4 May 2014 / Revised: 13 June 2014 / Accepted: 18 June 2014 / Published: 8 July 2014
Cited by 5 | PDF Full-text (613 KB) | HTML Full-text | XML Full-text
Abstract
Knowing water consumption patterns in buildings is key information for water planning. This article aims to characterize the water consumption pattern and water end-uses in low-income houses in the region of Florianópolis, Southern Brazil. Data were collected by interviewing householders, as well as
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Knowing water consumption patterns in buildings is key information for water planning. This article aims to characterize the water consumption pattern and water end-uses in low-income houses in the region of Florianópolis, Southern Brazil. Data were collected by interviewing householders, as well as by measuring the flow rate of existing water fixtures and appliances. The results indicated that the shower was the fixture with the largest water consumption in households, i.e., about 30%–36% of total water consumption on average, followed by the toilet (18%–20%). The surveyed households consumed from 111 to 152 L/capita·day on average, based on different income ranges. No correlation was found between income and water consumption. The results of this study can be used to estimate the consumption of water for new buildings, as well as to develop integrated water management strategies in low-income developments, in Florianópolis, such as water-saving plumbing fixtures, rainwater harvesting, and greywater reuse. Likely, there would be a deferral of capital investments in new water assets for enhancing water and wastewater services by saving water in low-income houses. Full article
(This article belongs to the Special Issue Water Consumption and Water End-uses in Buildings)
Open AccessArticle Economic Assessment of Opportunities for Managed Aquifer Recharge Techniques in Spain Using an Advanced Geographic Information System (GIS)
Water 2014, 6(7), 2021-2040; doi:10.3390/w6072021
Received: 3 January 2014 / Revised: 20 May 2014 / Accepted: 5 June 2014 / Published: 17 July 2014
Cited by 3 | PDF Full-text (3190 KB) | HTML Full-text | XML Full-text
Abstract
This paper investigates the economic aspects of Managed Aquifer Recharge (MAR) techniques considered in the DINA-MAR (Depth Investigation of New Areas for Managed Aquifer Recharge in Spain) project. This project firstly identified the areas with potential for MAR for the whole of the
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This paper investigates the economic aspects of Managed Aquifer Recharge (MAR) techniques considered in the DINA-MAR (Depth Investigation of New Areas for Managed Aquifer Recharge in Spain) project. This project firstly identified the areas with potential for MAR for the whole of the Iberian Peninsula and Balearic Islands of Spain using characteristics derived from 23 GIS layers of physiographic features, spanning geology, topography, land use, water sources and including existing MAR sites. The work involved evaluations for 24 different types (techniques) of MAR projects, over this whole area accounting for the physiographic features that favor each technique. The scores for each feature for each type of technique were set based on practical considerations and scores were accumulated for each location. A weighting was assigned to each feature by “training” the integrated score for each technique across all the features with the existing MAR sites overlay, so that opportunities for each technique could be more reliably predicted. It was found that there were opportunities for MAR for 16% of the area evaluated and that the additional storage capacity of aquifers in these areas was more than 2.5 times the total storage capacity of all existing surface water dams in Spain. The second part of this work, which is considered internationally unique, was to use this GIS methodology to evaluate the economics of the various MAR techniques across the region. This involved determining an economic index related to key physiographic features and applying this as an additional GIS overlay. Again this was trained by use of economic information for each of the existing MAR sites for which economic data and supply or storage volume were available. Two simpler methods were also used for comparison. Finally, the mean costs of MAR facilities and construction projects were determined based on the origin of the water. Maps of potential sites for Managed Aquifer Recharge (or “MAR zones”) in the Iberian Peninsula and Balearic Islands of Spain and the results of the previous economic studies developed at the beginning of the project were used as the foundation for the economic analysis. Based on these data, a new specific mapping of the total expected costs for all “MAR zones” (€/m3) was proposed based on the techniques that were considered most appropriate for each Spanish study case. Capital costs ranged from Euro 0.08–0.58 per m3/year. Overall, this study investigates the opportunity and economic feasibility of implementing new MAR projects and provides support to decision makers in Spain. The novel mapping provides valuable guidance for the future development of Managed Aquifer Recharge projects for water managers and practitioners. Full article
Figures

Open AccessArticle Characteristics of Water Budget Components in Paddy Rice Field under the Asian Monsoon Climate: Application of HSPF-Paddy Model
Water 2014, 6(7), 2041-2055; doi:10.3390/w6072041
Received: 14 May 2014 / Revised: 26 June 2014 / Accepted: 9 July 2014 / Published: 17 July 2014
Cited by 4 | PDF Full-text (603 KB) | HTML Full-text | XML Full-text
Abstract
The HSPF-Paddy model was applied to the Bochung watershed in Korea to compare water budget components by the land use types under the Asian monsoon climate. The calibration of HSPF-Paddy during 1992–2001 with PEST, a package program to optimize HSPF, and validation during
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The HSPF-Paddy model was applied to the Bochung watershed in Korea to compare water budget components by the land use types under the Asian monsoon climate. The calibration of HSPF-Paddy during 1992–2001 with PEST, a package program to optimize HSPF, and validation during 1985–1991 were carried out. The model efficiencies for monthly stream flow are 0.85 for calibration and 0.84 for validation. The simulation of annual mean runoff met the criteria of water budget analysis with the acceptable error level (less than 10 percent mean error). The simulation of the movement of water from paddy rice field to watershed was successful, and application of HSPF-Paddy coupled with PEST was able to improve accuracy of model simulation with reduced time and efforts for model calibration. The results of water budget analysis show that most of the outflow (86%) for the urban area occurred through surface runoff, showing the highest rate among the land use types compared. Significant amounts of water are irrigated to paddy rice fields, and the runoff depth as well as evapotranspiration from paddy rice field is higher than other land use types. Hydrological characteristic of paddy rice field is that most of water movement occurred at the surface area, resulting from the low infiltration rate and manning’s coefficient, as well as ponded water throughout the growing season. Major impact on input and output of water were precipitation and runoff, respectively, influenced by an Asian monsoon climate. Full article
Open AccessArticle Experimental Assessment of the Use of a Novel Superabsorbent polymer (SAP) for the Optimization ofWater Consumption in Agricultural Irrigation Process
Water 2014, 6(7), 2056-2069; doi:10.3390/w6072056
Received: 14 April 2014 / Revised: 12 June 2014 / Accepted: 9 July 2014 / Published: 18 July 2014
Cited by 7 | PDF Full-text (5175 KB) | HTML Full-text | XML Full-text
Abstract
In this work, an innovative cellulose-based superabsorbent polymer (SAP) was experimentally assessed as an environmentally friendly alternative to acrylate-based SAPs, for the optimization of water consumption in agriculture. The cellulose-based SAP was synthesized and tested for its swelling capability in different aqueous media.
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In this work, an innovative cellulose-based superabsorbent polymer (SAP) was experimentally assessed as an environmentally friendly alternative to acrylate-based SAPs, for the optimization of water consumption in agriculture. The cellulose-based SAP was synthesized and tested for its swelling capability in different aqueous media. The effectiveness of the SAP in agricultural applications was then evaluated by analyzing its performance after several absorption/desorption cycles, over a period of approximately 80 days, upon addition to different types of soil, i.e., white and red soil, for the cultivation of two varieties of plants typical of the Mediterranean area (tomatoes and chicory). The results confirmed that SAP-amended soil can store a considerable amount of water and can release it gradually to the plant roots when needed. The adoption of the proposed SAP in cultivations could thus represent a promising solution for the rationalization of water resources, especially in desert areas. Full article
Open AccessArticle Evaluating the Infiltration Performance of Eight Dutch Permeable Pavements Using a New Full-Scale Infiltration Testing Method
Water 2014, 6(7), 2070-2083; doi:10.3390/w6072070
Received: 14 May 2014 / Revised: 25 June 2014 / Accepted: 8 July 2014 / Published: 21 July 2014
Cited by 2 | PDF Full-text (1202 KB) | HTML Full-text | XML Full-text
Abstract
Permeable pavements are a type of sustainable urban drainage system (SUDS) technique that are used around the world to infiltrate and treat urban stormwater runoff and to minimize runoff volumes. Urban stormwater runoff contains significant concentrations of suspended sediments that can cause clogging
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Permeable pavements are a type of sustainable urban drainage system (SUDS) technique that are used around the world to infiltrate and treat urban stormwater runoff and to minimize runoff volumes. Urban stormwater runoff contains significant concentrations of suspended sediments that can cause clogging and reduce the infiltration capacity and effectiveness of permeable pavements. It is important for stormwater managers to be able to determine when the level of clogging has reached an unacceptable level, so that they can schedule maintenance or replacement activities as required. Newly-installed permeable pavements in the Netherlands must demonstrate a minimum infiltration capacity of 194 mm/h (540 l/s/ha). Other commonly used permeable pavement guidelines in the Netherlands recommend that maintenance is undertaken on permeable pavements when the infiltration falls below 0.50 m/d (20.8 mm/h). This study used a newly-developed, full-scale infiltration test procedure to evaluate the infiltration performance of eight permeable pavements in five municipalities that had been in service for over seven years in the Netherlands. The determined infiltration capacities vary between 29 and 342 mm/h. Two of the eight pavements show an infiltration capacity higher than 194 mm/h, and all infiltration capacities are higher than 20.8 mm/h. According to the guidelines, this suggests that none of the pavements tested in this study would require immediate maintenance. Full article
(This article belongs to the Special Issue Sustainable Drainage Systems) Print Edition available
Open AccessArticle Multilayer Numerical Modeling of Flows through Vegetation Using a Mixing-Length Turbulence Model
Water 2014, 6(7), 2084-2103; doi:10.3390/w6072084
Received: 14 January 2014 / Revised: 5 July 2014 / Accepted: 17 July 2014 / Published: 21 July 2014
Cited by 1 | PDF Full-text (1166 KB) | HTML Full-text | XML Full-text
Abstract
This work focuses on the effects of vegetation on a fluid flow pattern. In this numerical research, we verify the applicability of a simpler turbulence model than the commonly used k-" model to predict the mean flow through vegetation. The novel characteristic of
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This work focuses on the effects of vegetation on a fluid flow pattern. In this numerical research, we verify the applicability of a simpler turbulence model than the commonly used k-" model to predict the mean flow through vegetation. The novel characteristic of this turbulence model is that the horizontal mixing-length is explicitly calculated and coupled with a multi-layer approach for the vertical mixing-length, within a general three-dimensional eddy-viscosity formulation. This mixing-length turbulence model has been validated in previous works for different kinds of non-vegetated flows. The hydrodynamic numerical model used for simulations is based on the Reynolds-averaged Navier–Stokes equations for shallow water flows, where a vegetation shear stress term is considered to reproduce the effects of drag forces on flow. A second-order approximation is used for spatial discretization and a semi-implicit Lagrangian–Eulerian scheme is used for time discretization. In order to validate the numerical results, we compare them against experimental data reported in the literature. The comparisons are carried out for two cases of study: submerged vegetation and submerged and emergent vegetation, both within an open channel flow. Full article
Open AccessArticle Sensitivity of Subjective Decisions in the GLUE Methodology for Quantifying the Uncertainty in the Flood Inundation Map for Seymour Reach in Indiana, USA
Water 2014, 6(7), 2104-2126; doi:10.3390/w6072104
Received: 30 May 2014 / Revised: 4 July 2014 / Accepted: 10 July 2014 / Published: 23 July 2014
Cited by 4 | PDF Full-text (2407 KB) | HTML Full-text | XML Full-text
Abstract
Generalized likelihood uncertainty estimation (GLUE) is one of the widely-used methods for quantifying uncertainty in flood inundation mapping. However, the subjective nature of its application involving the definition of the likelihood measure and the criteria for defining acceptable versus unacceptable models can lead
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Generalized likelihood uncertainty estimation (GLUE) is one of the widely-used methods for quantifying uncertainty in flood inundation mapping. However, the subjective nature of its application involving the definition of the likelihood measure and the criteria for defining acceptable versus unacceptable models can lead to different results in quantifying uncertainty bounds. The objective of this paper is to perform a sensitivity analysis of the effect of the choice of likelihood measures and cut-off thresholds used in selecting behavioral and non-behavioral models in the GLUE methodology. By using a dataset for a reach along the White River in Seymour, Indiana, multiple prior distributions, likelihood measures and cut-off thresholds are used to investigate the role of subjective decisions in applying the GLUE methodology for uncertainty quantification related to topography, streamflow and Manning’s n. Results from this study show that a normal pdf produces a narrower uncertainty bound compared to a uniform pdf for an uncertain variable. Similarly, a likelihood measure based on water surface elevations is found to be less affected compared to other likelihood measures that are based on flood inundation area and width. Although the findings from this study are limited due to the use of a single test case, this paper provides a framework that can be utilized to gain a better understanding of the uncertainty while applying the GLUE methodology in flood inundation mapping. Full article
Open AccessArticle Rainfall Enhances Vegetation Growth but Does the Reverse Hold?
Water 2014, 6(7), 2127-2143; doi:10.3390/w6072127
Received: 7 March 2014 / Revised: 9 July 2014 / Accepted: 14 July 2014 / Published: 23 July 2014
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Abstract
In the literature, there is substantial evidence presented of enhancement of vegetation growth and regrowth with rainfall. There is also much research presented on the decline in rainfall with land clearance. This article deals with the well documented decline in rainfall in southwestWestern
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In the literature, there is substantial evidence presented of enhancement of vegetation growth and regrowth with rainfall. There is also much research presented on the decline in rainfall with land clearance. This article deals with the well documented decline in rainfall in southwestWestern Australia and discusses the literature that has been presented as to the rationale for the decline. The original view was that it was the result of climate change. More recent research points to the compounding effect of land use change. In particular, one study estimated, through simulation work with atmospheric models, that up to 50% of the decline could be attributed to land use change. For South Australia, there is an examination the pattern of rainfall decline in one particular region, using Cummins on the Eyre Peninsula as an example location. There is a statistically significant decrease in annual rainfall over time in that location. This is mirrored for the vast majority of locations studied in South Australia, most probably having the dual drivers of climate and land use change. Conversely, it is found that for two locations, Murray Bridge and Callington, southeast of Adelaide, there is marginal evidence for an increase in annual rainfall over the last two decades, during which, incidentally, Australia experienced the most severe drought in recorded history. The one feature common to these two locations is the proximity to the Monarto plateau, which lies between them. It was the site of extensive revegetation in the 1970s. It is conjectured that there could be a connection between the increase in rainfall and the revegetation, and there is evidence presented from a number of studies for such a connection, though not specifically relating to this location. Full article
Open AccessArticle Seasonal Accumulation and Depletion of Local Sediment Stores of Four Headwater Catchments
Water 2014, 6(7), 2144-2163; doi:10.3390/w6072144
Received: 1 May 2014 / Revised: 8 July 2014 / Accepted: 8 July 2014 / Published: 23 July 2014
Cited by 2 | PDF Full-text (2002 KB) | HTML Full-text | XML Full-text
Abstract
Seasonal turbidity patterns and event-level hysteresis analysis of turbidity verses discharge in four 1 km2 headwater catchments in California’s Sierra Nevada indicate localized in-channel sediment sources and seasonal accumulation-depletion patterns of stream sediments. Turbidity signals were analyzed for three years in order
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Seasonal turbidity patterns and event-level hysteresis analysis of turbidity verses discharge in four 1 km2 headwater catchments in California’s Sierra Nevada indicate localized in-channel sediment sources and seasonal accumulation-depletion patterns of stream sediments. Turbidity signals were analyzed for three years in order to look at the relationships between seasonal turbidity trends, event turbidity patterns, and precipitation type to stream sediment production and transport. Seasonal patterns showed more turbidity events associated with fall and early to mid- winter events than with peak snow-melt. No significant turbidity patterns emerged for periods of snow melt vs. rain. Single event hysteresis loops showed clockwise patterns were dominant suggesting local sediment sources. In successive discharge events, the largest turbidity spike was often associated with the first but not necessarily the largest discharge event-indicating seasonal depletion of local sediment stores. In multi-peaked discharge events, hysteresis loops shifted from clockwise to linear or random patterns suggesting that localized sediment stores are being used up and sufficient flow energy must be reached to start entraining the more consolidated bank/bed sediment or that dominant sediment sources may be shifting to less localized areas such as hill slopes. A conceptual model with phases of accumulation and transport is proposed. Full article

Review

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Open AccessReview The Effect of Influent Characteristics and Operational Conditions over the Performance and Microbial Community Structure of Partial Nitritation Reactors
Water 2014, 6(7), 1905-1924; doi:10.3390/w6071905
Received: 11 April 2014 / Revised: 13 June 2014 / Accepted: 19 June 2014 / Published: 26 June 2014
Cited by 10 | PDF Full-text (1141 KB) | HTML Full-text | XML Full-text
Abstract
Nitrogen is a main contaminant of wastewater worldwide. Novel processes for nitrogen removal have been developed over the last several decades. One of these is the partial nitritation process. This process includes the oxidation of ammonium to nitrite without the generation of nitrate.
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Nitrogen is a main contaminant of wastewater worldwide. Novel processes for nitrogen removal have been developed over the last several decades. One of these is the partial nitritation process. This process includes the oxidation of ammonium to nitrite without the generation of nitrate. The partial nitritation process has several advantages over traditional nitrification-denitrification processes for nitrogen removal from wastewaters. In addition, partial nitritation is required for anammox elimination of nitrogen from wastewater. Partial nitritation is affected by operational conditions and substances present in the influent, such as quinolone antibiotics. In this review, the impact that several operational conditions, such as temperature, pH, dissolved oxygen concentration, hydraulic retention time and solids retention time, have over the partial nitritation process is covered. The effect of quinolone antibiotics and other emerging contaminants are discussed. Finally, future perspectives for the partial nitritation process are commented upon. Full article
Open AccessReview Challenges of Integrated Water Resources Management in Indonesia
Water 2014, 6(7), 2000-2020; doi:10.3390/w6072000
Received: 26 May 2014 / Revised: 8 July 2014 / Accepted: 9 July 2014 / Published: 17 July 2014
Cited by 3 | PDF Full-text (488 KB) | HTML Full-text | XML Full-text
Abstract
The increased demands for water and land in Indonesia as a consequence of the population growth and economic development has reportedly have been accelerated from the year to year. The spatial and temporal variability of human induced hydrological changes in a river basin
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The increased demands for water and land in Indonesia as a consequence of the population growth and economic development has reportedly have been accelerated from the year to year. The spatial and temporal variability of human induced hydrological changes in a river basin could affect quality and quantity of water. The challenge is that integrated water resources management (IWRM) should cope with complex issues of water in order to maximize the resultant economic and social welfare in an equitable manner, without compromising the sustainability of vital ecosystems. Even though the government of Indonesia has adopted new paradigm for water resources management by the enactment of Law No. 7/2004 on water resources, the implementation of IWRM may face the technical and managerial challenges. This paper briefly reviews the implementation of IWRM and related principles and provides an overview of potential water-related issues and progress towards implementation of IWRM in Indonesia. The availability of water and a broader range of water-related issues are identified. The recommended actions for improving the future IWRM are suggested. Challenges to improve the capacity buildings of IWRM related to enabling environment, institutional frameworks and management instruments are verified to contribute to the future directions for efficient problem-solving ability. Full article

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