Next Issue
Volume 8, January
Previous Issue
Volume 7, November

Water, Volume 7, Issue 12 (December 2015) – 24 articles

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
Order results
Result details
Select all
Export citation of selected articles as:
Open AccessArticle
Combining Expert and Stakeholder Knowledge to Define Water Management Priorities in the Mékrou River Basin
Water 2015, 7(12), 7078-7094; https://doi.org/10.3390/w7126675 - 21 Dec 2015
Cited by 2 | Viewed by 2726
Abstract
Participatory approaches to water management, and specifically to transboundary river management, have been widely applied over recent decades. Regarding transboundary rivers, the active involvement of key actors in policy planning is of great importance. In this context, a participatory approach has been used [...] Read more.
Participatory approaches to water management, and specifically to transboundary river management, have been widely applied over recent decades. Regarding transboundary rivers, the active involvement of key actors in policy planning is of great importance. In this context, a participatory approach has been used to identify sectors of interest and priorities related to water and development in the Mékrou transboundary River Basin involving three countries: Benin, Burkina Faso and Niger. We conducted a web-based survey to quantify expert opinion on sectors of water management policy and priorities for the Mékrou River Basin. The same set of questions was then put to a sample of local stakeholders living in this river basin. Our analysis reveals some points of convergence and some discrepancies between the opinions of experts and local stakeholders. Overall, it provides a comparative analysis of how experts and local stakeholders prioritize water policy measures, which could influence decision-making. Full article
Show Figures

Figure 1

Open AccessArticle
Reducing Agricultural Water Footprints at the Farm Scale: A Case Study in the Beijing Region
Water 2015, 7(12), 7066-7077; https://doi.org/10.3390/w7126674 - 18 Dec 2015
Cited by 12 | Viewed by 3262
Abstract
Beijing is one of the most water-stressed regions in the world. Reducing agricultural water use has long been the basis of local policy for sustainable water use. In this article, the potential to reduce the life cycle (cradle to gate) water footprints of [...] Read more.
Beijing is one of the most water-stressed regions in the world. Reducing agricultural water use has long been the basis of local policy for sustainable water use. In this article, the potential to reduce the life cycle (cradle to gate) water footprints of wheat and maize that contribute to 94% of the local cereal production was assessed. Following ISO 14046, consumptive and degradative water use for the wheat-maize rotation system was modeled under different irrigation and nitrogen (N) application options. Reducing irrigation water volume by 33.3% compared to current practice did not cause a significant yield decline, but the water scarcity footprint and water eutrophication footprint were decreased by 27.5% and 23.9%, respectively. Similarly, reducing the N application rate by 33.3% from current practice did not cause a significant yield decline, but led to a 52.3% reduction in water eutrophication footprint while maintaining a similar water scarcity footprint. These results demonstrate that improving water and fertilizer management has great potential for reducing the crop water footprints at the farm scale. This situation in Beijing is likely to be representative of the challenge facing many of the water-stressed regions in China, where a sustainable means of agricultural production must be found. Full article
(This article belongs to the Special Issue Sustainable Water Consumption)
Show Figures

Figure 1

Open AccessArticle
Linear Trend Detection in Serially Dependent Hydrometeorological Data Based on a Variance Correction Spearman Rho Method
Water 2015, 7(12), 7045-7065; https://doi.org/10.3390/w7126673 - 17 Dec 2015
Cited by 10 | Viewed by 2655
Abstract
Hydrometeorological data are commonly serially dependent and thereby deviate from the assumption of independence that underlies the Spearman rho trend test. The presence of autocorrelation will influence the significance of observed trends. Specifically, the positive autocorrelation inflates Type І errors, while it deflates [...] Read more.
Hydrometeorological data are commonly serially dependent and thereby deviate from the assumption of independence that underlies the Spearman rho trend test. The presence of autocorrelation will influence the significance of observed trends. Specifically, the positive autocorrelation inflates Type І errors, while it deflates the power of trend detection in some cases. To address this issue, we derive a theoretical formula and recommend an appropriate empirical formula to calculate the rho variance of dependent series. The proposed procedure of the variance correction for the Spearman rho method is capable of mitigating the effect of autocorrelation on both, Type І error and power of the test. Similar to the Block Bootstrap method, it has the advantage that it does not require an initial knowledge of the autocorrelation structure or modification of the series. In comparison, the capability of the Pre-Whitening method is sensitive to model misspecification if the series are whitened by a parametric autocorrelation model. The Trend-Free Pre-Whitening method tends to lead to an overestimation of the statistical significance of trends, similar to the original Spearman rho test. The results of the study emphasize the importance of selecting a reliable method for trend detection in serially dependent data. Full article
Show Figures

Graphical abstract

Open AccessArticle
Assessment of Suspended Sand Availability under Different Flow Conditions of the Lowermost Mississippi River at Tarbert Landing during 1973–2013
Water 2015, 7(12), 7022-7044; https://doi.org/10.3390/w7126672 - 15 Dec 2015
Cited by 22 | Viewed by 3615
Abstract
Rapid land loss in the Mississippi River Delta Plain has led to intensive efforts by state and federal agencies for finding solutions in coastal land restoration in the past decade. One of the proposed solutions includes diversion of the Mississippi River water into [...] Read more.
Rapid land loss in the Mississippi River Delta Plain has led to intensive efforts by state and federal agencies for finding solutions in coastal land restoration in the past decade. One of the proposed solutions includes diversion of the Mississippi River water into drowning wetland areas. Although a few recent studies have investigated flow-sediment relationships in the Lowermost Mississippi River (LmMR, defined as the 500 km reach from the Old River Control Structure to the river’s Gulf outlet), it is unclear how individual sediment fractions behave under varying flow conditions of the river. The information can be especially pertinent because the quantity of coarse sands plays a critical role for the Mississippi-Atchafalaya River deltaic development. In this study, we utilized long-term (1973–2013) records on discharge and sediments at Tarbert Landing of the LmMR to assess sand behavior and availability under different river flow regimes, and extreme sand transport events and their recurrence. We found an average annual sand load (SL) of 27.2 megatonnes (MT) during 1973 and 2013, varying largely from 3.37 to 52.30 MT. For the entire 41-year study period, a total of approximately 1115 MT sand were discharged at Tarbert Landing, half of which occurred during the peak 20% flow events. A combination of intermediate, high and peak flow stages (i.e., river discharge was ≥18,000 cubic meter per second) produced about 71% of the total annual SL within approximately 120 days of a year. Based on the long-term sediment assessment, we predict that the LmMR has a high likelihood to transport 4 to 446 thousand tonnes of sand every day over the next 40 years, during which annual sand loads could reach a maximum of 51.68 MT. Currently, no effective plan is in place to utilize this considerably high sand quantity and we suggest that river engineering and sediment management in the LmMR consider practices of hydrograph-based approach for maximally capturing riverine sediments. Full article
Show Figures

Figure 1

Open AccessArticle
Simulation of Water Use Dynamics by Salix Bush in a Semiarid Shallow Groundwater Area of the Chinese Erdos Plateau
Water 2015, 7(12), 6999-7021; https://doi.org/10.3390/w7126671 - 11 Dec 2015
Cited by 5 | Viewed by 2986
Abstract
This study analyzed the water use of the Salix psammophila bush in a semi-arid area in northwest China using a Hydrus-1D model. The model incorporated the effect of thermally driven water flow coupling liquid water, water vapor and heat transport. The model was [...] Read more.
This study analyzed the water use of the Salix psammophila bush in a semi-arid area in northwest China using a Hydrus-1D model. The model incorporated the effect of thermally driven water flow coupling liquid water, water vapor and heat transport. The model was calibrated and validated using hourly field measurements of soil water content and temperature at different depths for a growing season of 154 days. Furthermore, another Hydrus-1D model was established to simulate environments with decreased heat, rainfall or temperature and an increased leaf area index using calibrated and validated parameters. Our results show that upward and downward thermally driven water vapor fluxes account for 0.11% and 0.28%, respectively, of the corresponding direction of total water flux during the bush’s growing season. Although the vapor flux is very small, simulations incorporating heat flow revealed alterations in the temperature and pressure head gradients over the root zone, especially during dry periods. Consequently, the cumulative contributions of groundwater to evapotranspiration (ETg) with heat flow and without heat flow were 26.9% and 40.6%, respectively, during the simulation period. Therefore, the cumulative contribution of groundwater to ETg is overestimated when heat flow is excluded. Thus, we recommended that heat transport be incorporated when evaluating ETg in arid and semi-arid areas. Full article
(This article belongs to the Special Issue Water Resources Assessment and Management in Drylands)
Show Figures

Figure 1

Open AccessArticle
Blending the Analytic Hierarchy Process and Fuzzy Logical Systems in Scenic Beauty Assessment of Check Dams in Streams
Water 2015, 7(12), 6983-6998; https://doi.org/10.3390/w7126670 - 11 Dec 2015
Cited by 9 | Viewed by 3044
Abstract
With Taiwan’s steep terrain and fracture geology, natural disasters are likely to occur after heavy rainfall. To reduce the effects of upstream sediment on human surroundings, check dams are an essential transverse structure for streams in watersheds. However, there is likely to be [...] Read more.
With Taiwan’s steep terrain and fracture geology, natural disasters are likely to occur after heavy rainfall. To reduce the effects of upstream sediment on human surroundings, check dams are an essential transverse structure for streams in watersheds. However, there is likely to be a detrimental visual impact on the landscape without consideration of the integration of dams with the environment. Based on previous studies of landscape assessment, this paper considers the factors of texture, color, and form, often used as part of expert paradigms, as the major aesthetic aspects of check dams. These factors are used to construct an expert questionnaire using the Delphi Method and Analytic Hierarchy Process (AHP). The preliminary criteria and weights for Scenic Beauty Assessment of check dams are determined based on the results of AHP. A Fuzzy Logical System is further applied to solve the linguistic fuzziness of landscape assessment so as to establish a complete expert scenic beauty assessment model. Five cases are further tested for comparison with 224 public samples with Scenic Beauty Estimation (SBE). Results demonstrate that the model presents the validity of expert paradigm and the reliability of the psychophysical paradigm. These results can provide a reference for engineering designers seeking to integrate check dams with the natural landscape. The results indicate that the present method can efficiently assess the scenic beauty of check dams as established by a scientific method. Full article
Show Figures

Figure 1

Open AccessArticle
Experimental Measurement of Diffusive Extinction Depth and Soil Moisture Gradients in a Dune Sand Aquifer in Western Saudi Arabia: Assessment of Evaporation Loss for Design of an MAR System
Water 2015, 7(12), 6967-6982; https://doi.org/10.3390/w7126669 - 10 Dec 2015
Cited by 5 | Viewed by 3165
Abstract
A component of designing a managed aquifer recharge system in a dune aquifer is the control of diffusive evaporative loss of water which is governed by the physical properties of the sediments and the position of the water table. A critical water table [...] Read more.
A component of designing a managed aquifer recharge system in a dune aquifer is the control of diffusive evaporative loss of water which is governed by the physical properties of the sediments and the position of the water table. A critical water table position is the “extinction depth”, below which no further loss of water occurs via diffusion. Field experiments were conducted to measure the extinction depth of sediments taken from a typical dune field in the region. The soil grain size characteristics, laboratory porosity, and saturated hydraulic conductivity were measured. The sand is classified as well-sorted, very fine sand with a mean grain diameter of 0.15 mm. Soil moisture gradients and diffusion loss rates were measured using sensors in a non-weighing lysimeter that was placed below land surface. The sand was saturated carefully with water from the bottom to the top and was exposed to the natural climate for a period of about two months. The moisture gradient showed a gradual decline during measurement until extinction depth was reached at about 100 cm below surface after 56 days. Diurnal temperature changes were observed in the upper 75 cm of the column and were negligible at greater depth. Full article
(This article belongs to the Special Issue Water Resources Assessment and Management in Drylands)
Show Figures

Figure 1

Open AccessArticle
Estimating Costs and Effectiveness of Upgrades in Forestry Best Management Practices for Stream Crossings
Water 2015, 7(12), 6946-6966; https://doi.org/10.3390/w7126668 - 08 Dec 2015
Cited by 18 | Viewed by 3409
Abstract
Forestry Best Management Practices (BMPs) are used for protection of water quality at forest stream crossings, yet effects and costs for gradients of BMPs are not well documented. We evaluated forty-two truck road and skid trail stream crossings using three surrogates of BMP [...] Read more.
Forestry Best Management Practices (BMPs) are used for protection of water quality at forest stream crossings, yet effects and costs for gradients of BMPs are not well documented. We evaluated forty-two truck road and skid trail stream crossings using three surrogates of BMP adequacy: (1) potential erosion rates for stream crossing approaches; (2) adequacy of stream crossing BMPs; and (3) overall BMP rating (BMP−, BMP-standard, and BMP+). Subsequently, BMP upgrades were recommended for enhancing BMP− or BMP-standard stream crossings. Costs for BMP upgrades were estimated using an existing road and skid trail cost method. The majority of truck road stream crossings were culverts, while skid trail stream crossings were primarily portable bridges. Potential erosion estimates, BMP audit scores, and BMP ratings all indicated that skid crossings have lower BMP implementation than truck road crossings. BMP improvements commonly identified for skid trail and truck crossings included addition of cover and water control structures. Improved BMPs at skid trail crossings were less expensive than those at truck road crossings. Current BMP guidelines provide economical and effective techniques for reducing erosion, and BMP upgrades have the potential to reduce erosion rates to similar levels found in undisturbed forests. Full article
(This article belongs to the Special Issue BMP Development, Implementation, and Performance)
Show Figures

Figure 1

Open AccessArticle
Uncertainty Analysis in the Evaluation of Extreme Rainfall Trends and Its Implications on Urban Drainage System Design
Water 2015, 7(12), 6931-6945; https://doi.org/10.3390/w7126667 - 05 Dec 2015
Cited by 25 | Viewed by 3195
Abstract
Future projections provided by climate models suggest that the occurrence of extreme rainfall events will increase and this is evidence that the climate is changing. Because the design of urban drainage systems is based on the statistical analysis of past events, variations in [...] Read more.
Future projections provided by climate models suggest that the occurrence of extreme rainfall events will increase and this is evidence that the climate is changing. Because the design of urban drainage systems is based on the statistical analysis of past events, variations in the intensity and frequency of extreme rainfall represent a critical issue for the estimation of rainfall. For this reason, the design criteria of drainage systems should take into account the trends in the past and the future climate changes projections. To this end, a Bayesian procedure was proposed to update the parameters of depth–duration–frequency (DDF) curves to assess the uncertainty related to the estimation of these values, once the evidence of annual maximum rainfall trends was verified. Namely, in the present study, the historical extreme rainfall series with durations of 1, 3, 6, 12 and 24 h for the period of 1950–2008, recorded by the rain gauges located near the Paceco urban area (southern Italy), were analyzed to detect statistically significant trends using the non‐parametric Mann‐Kendall test. Based on the rainfall trends, the parameters of the DDF curves for a five‐year return period were updated to define some climate scenarios. Finally, the implications of the uncertainty related to the DDF parameters estimation on the design of a real urban drainage system was assessed to provide an evaluation of its performance under the assumption of climate change. Results showed that the future increase of annual maximum precipitation in the area of study would affect the analyzed drainage system, which could face more frequent episodes of surcharge. Full article
(This article belongs to the Special Issue Uncertainty Analysis and Modeling in Hydrological Forecasting)
Show Figures

Graphical abstract

Open AccessArticle
Modeling Typhoon‐Induced Alterations on River Sediment Transport and Turbidity Based on Dynamic Landslide Inventories: Gaoping River Basin, Taiwan
Water 2015, 7(12), 6910-6930; https://doi.org/10.3390/w7126666 - 05 Dec 2015
Cited by 5 | Viewed by 3246
Abstract
This study examines the impacts of storm‐triggered landslides on downstream sediment and turbidity responses in the Gaoping River Basin, Taiwan using the Soil and Water Assessment Tool (SWAT). Attention is given to analyzing the increased and altered baseline of suspended sediment load and [...] Read more.
This study examines the impacts of storm‐triggered landslides on downstream sediment and turbidity responses in the Gaoping River Basin, Taiwan using the Soil and Water Assessment Tool (SWAT). Attention is given to analyzing the increased and altered baseline of suspended sediment load and turbidity after the disturbances caused by the rainfall and landslides associated with Typhoon Morakot in 2009. SWAT parameters were calibrated by the observed hydrometric data from 1999 to 2003 using the log‐scale root‐mean‐square error (log‐RMSE) and Nash‐Sutcliffe Model Efficiency. Both parameter sets were applied for the simulation of suspended sediment yield and turbidity with annual updated landslide inventories for the period 2004–2012. The landslide updating mirrors the physical land‐cover changes and has slightly improved the model performance, yet landslides alone cannot explain the difference between Morakot‐induced and SWAT‐simulated sediment discharge. The set of parameters calibrated by log‐RMSE can better approximate the increased baseline and typhoon induced alterations. The results show alterations in sediment erosion and transport: (1) drastically increased the turbidity baseline and occurrence of high‐turbidity; (2) altered coefficient and exponent values of the sediment rating curve; and (3) altered relationship between rainfall and induced turbidity during major rainfall events. The research in this study provides an improved modeling approach to typhoon‐induced alterations on river sediment loads and turbidity. Full article
(This article belongs to the Special Issue Geospatial Modeling of River Systems)
Show Figures

Graphical abstract

Open AccessArticle
Assessment on Hydrologic Response by Climate Change in the Chao Phraya River Basin, Thailand
Water 2015, 7(12), 6892-6909; https://doi.org/10.3390/w7126665 - 04 Dec 2015
Cited by 23 | Viewed by 4599
Abstract
The Chao Phraya River in Thailand has been greatly affected by climate change and the occurrence of extreme flood events, hindering its economic development. This study assessed the hydrological responses of the Chao Phraya River basin under several climate sensitivity and greenhouse gas [...] Read more.
The Chao Phraya River in Thailand has been greatly affected by climate change and the occurrence of extreme flood events, hindering its economic development. This study assessed the hydrological responses of the Chao Phraya River basin under several climate sensitivity and greenhouse gas emission scenarios. The Soil and Water Assessment Tool (SWAT) model was applied to simulate the streamflow using meteorological and observed data over a nine-year period from 2003 to 2011. The SWAT model produced an acceptable performance for calibration and validation, yielding Nash-Sutcliffe efficiency (NSE) values greater than 0.5. Precipitation scenarios yielded streamflow variations that corresponded to the change of rainfall intensity and amount of rainfall, while scenarios with increased air temperatures predicted future water shortages. High CO2 concentration scenarios incorporated plant responses that led to a dramatic increase in streamflow. The greenhouse gas emission scenarios increased the streamflow variations to 6.8%, 41.9%, and 38.4% from the reference period (2003–2011). This study also provided a framework upon which the peak flow can be managed to control the nonpoint sources during wet season. We hope that the future climate scenarios presented in this study could provide predictive information for the river basin. Full article
(This article belongs to the Special Issue Water Resource Variability and Climate Change)
Show Figures

Figure 1

Open AccessArticle
An Amplification Model for the Regional Estimation of Extreme Rainfall within Orographic Areas in Campania Region (Italy)
Water 2015, 7(12), 6877-6891; https://doi.org/10.3390/w7126664 - 04 Dec 2015
Cited by 10 | Viewed by 2480
Abstract
Orography strongly interacts with the atmospheric circulation, especially during frontal events, generating an enhanced spatial variability of the rainfall field. Regional models of extreme rainfall have to deal with these circumstances in order to provide good spatial estimation of the regionalized variable. We [...] Read more.
Orography strongly interacts with the atmospheric circulation, especially during frontal events, generating an enhanced spatial variability of the rainfall field. Regional models of extreme rainfall have to deal with these circumstances in order to provide good spatial estimation of the regionalized variable. We present a model for the regional estimation of the mean of the probability distribution of the annual daily rainfall maxima in a region (Campania, Southern Italy) with complex orography. In a recent work, we found that areas with enhanced variability of extreme rainfall, in the same region, correspond to a particular set of orographic objects, which had been classified through an automatic, GIS-based geomorphological procedure. Here, we propose an approach that considers the same orographic objects as building blocks for a regional model that is able to capture the amplification of extreme rainfall caused by orography. The regional model is then the product of a basic stationary random spatial process and an amplification factor, whose values are related to the topographic features of the orographic objects. This approach represents a step towards the improvement of the predictive ability of regional models of extreme rainfall within orographically complex areas. Full article
Show Figures

Figure 1

Open AccessArticle
Agricultural Best Management Practice Abundance and Location does not Influence Stream Ecosystem Function or Water Quality in the Summer Season
Water 2015, 7(12), 6861-6876; https://doi.org/10.3390/w7126661 - 04 Dec 2015
Cited by 10 | Viewed by 2571
Abstract
Best management practices (BMPs) are tools commonly used to mitigate negative impacts of agriculture on water quality; however, the relationship between BMPs and aquatic ecological function is unknown. Our research goal was to determine the association between both stream ecosystem metabolism and water [...] Read more.
Best management practices (BMPs) are tools commonly used to mitigate negative impacts of agriculture on water quality; however, the relationship between BMPs and aquatic ecological function is unknown. Our research goal was to determine the association between both stream ecosystem metabolism and water quality, and the abundance and location of four different BMPs in agricultural catchments. Dissolved oxygen was measured over a two-week period in mid-June and used to estimate ecosystem metabolism of 13 headwater streams representing a gradient of BMP implementation in Southern Ontario, Canada. Stepwise regression analyses were used to associate stream metabolism and water quality with metrics describing the abundance and location of BMPs within each catchment. Studied streams exhibited rates of metabolism comparable to catchments from other agricultural regions. However, metrics of BMP implementation were not associated with either stream metabolism or water quality. Our results suggest that BMPs in the studied agricultural catchments are not improving water quality or mitigating water quality impacts on stream metabolism during the summer season. We propose that seasonality of catchment hydrology and time lag effects associated with past agricultural land use may be masking the mitigation benefits of BMPs on stream ecosystem conditions during the summer season. Full article
(This article belongs to the Special Issue BMP Development, Implementation, and Performance)
Show Figures

Figure 1

Open AccessArticle
Comparative Studies of Different Imputation Methods for Recovering Streamflow Observation
Water 2015, 7(12), 6847-6860; https://doi.org/10.3390/w7126663 - 04 Dec 2015
Cited by 18 | Viewed by 2966
Abstract
Faulty field sensors cause unreliability in the observed data that needed to calibrate and assess hydrology models. However, it is illogical to ignore abnormal or missing values if there are limited data available. This study addressed this problem by applying data imputation to [...] Read more.
Faulty field sensors cause unreliability in the observed data that needed to calibrate and assess hydrology models. However, it is illogical to ignore abnormal or missing values if there are limited data available. This study addressed this problem by applying data imputation to replace incorrect values and recover missing streamflow information in the dataset of the Samho gauging station at Taehwa River (TR), Korea from 2004 to 2006. Soil and Water Assessment Tool (SWAT) and two machine learning techniques, Artificial Neural Network (ANN) and Self Organizing Map (SOM), were employed to estimate streamflow using reasonable flow datasets of Samho station from 2004 to 2009. The machine learning models were generally better at capturing high flows, while SWAT was better at simulating low flows. Full article
Show Figures

Figure 1

Open AccessArticle
Developing an Effective Model for Predicting Spatially and Temporally Continuous Stream Temperatures from Remotely Sensed Land Surface Temperatures
Water 2015, 7(12), 6827-6846; https://doi.org/10.3390/w7126660 - 04 Dec 2015
Cited by 19 | Viewed by 3405
Abstract
Although water temperature is important to stream biota, it is difficult to collect in a spatially and temporally continuous fashion. We used remotely-sensed Land Surface Temperature (LST) data to estimate mean daily stream temperature for every confluence-to-confluence reach in the John Day River, [...] Read more.
Although water temperature is important to stream biota, it is difficult to collect in a spatially and temporally continuous fashion. We used remotely-sensed Land Surface Temperature (LST) data to estimate mean daily stream temperature for every confluence-to-confluence reach in the John Day River, OR, USA for a ten year period. Models were built at three spatial scales: site-specific, subwatershed, and basin-wide. Model quality was assessed using jackknife and cross-validation. Model metrics for linear regressions of the predicted vs. observed data across all sites and years: site-specific r2 = 0.95, Root Mean Squared Error (RMSE) = 1.25 °C; subwatershed r2 = 0.88, RMSE = 2.02 °C; and basin-wide r2 = 0.87, RMSE = 2.12 °C. Similar analyses were conducted using 2012 eight-day composite LST and eight-day mean stream temperature in five watersheds in the interior Columbia River basin. Mean model metrics across all basins: r2 = 0.91, RMSE = 1.29 °C. Sensitivity analyses indicated accurate basin-wide models can be parameterized using data from as few as four temperature logger sites. This approach generates robust estimates of stream temperature through time for broad spatial regions for which there is only spatially and temporally patchy observational data, and may be useful for managers and researchers interested in stream biota. Full article
Show Figures

Graphical abstract

Open AccessArticle
On Approaches to Analyze the Sensitivity of Simulated Hydrologic Fluxes to Model Parameters in the Community Land Model
Water 2015, 7(12), 6810-6826; https://doi.org/10.3390/w7126662 - 04 Dec 2015
Cited by 6 | Viewed by 2467
Abstract
Effective sensitivity analysis approaches are needed to identify important parameters or factors and their uncertainties in complex Earth system models composed of multi-phase multi-component phenomena and multiple biogeophysical-biogeochemical processes. In this study, the impacts of 10 hydrologic parameters in the Community Land Model [...] Read more.
Effective sensitivity analysis approaches are needed to identify important parameters or factors and their uncertainties in complex Earth system models composed of multi-phase multi-component phenomena and multiple biogeophysical-biogeochemical processes. In this study, the impacts of 10 hydrologic parameters in the Community Land Model on simulations of runoff and latent heat flux are evaluated using data from a watershed. Different metrics, including residual statistics, the Nash–Sutcliffe coefficient, and log mean square error, are used as alternative measures of the deviations between the simulated and field observed values. Four sensitivity analysis (SA) approaches, including analysis of variance based on the generalized linear model, generalized cross validation based on the multivariate adaptive regression splines model, standardized regression coefficients based on a linear regression model, and analysis of variance based on support vector machine, are investigated. Results suggest that these approaches show consistent measurement of the impacts of major hydrologic parameters on response variables, but with differences in the relative contributions, particularly for the secondary parameters. The convergence behaviors of the SA with respect to the number of sampling points are also examined with different combinations of input parameter sets and output response variables and their alternative metrics. This study helps identify the optimal SA approach, provides guidance for the calibration of the Community Land Model parameters to improve the model simulations of land surface fluxes, and approximates the magnitudes to be adjusted in the parameter values during parametric model optimization. Full article
(This article belongs to the Special Issue Uncertainty Analysis and Modeling in Hydrological Forecasting)
Show Figures

Graphical abstract

Open AccessFeature PaperArticle
Uncertainty Analysis of Multi-Model Flood Forecasts
Water 2015, 7(12), 6788-6809; https://doi.org/10.3390/w7126654 - 01 Dec 2015
Cited by 5 | Viewed by 2648
Abstract
This paper demonstrates, by means of a systematic uncertainty analysis, that the use of outputs from more than one model can significantly improve conditional forecasts of discharges or water stages, provided the models are structurally different. Discharge forecasts from two models and the [...] Read more.
This paper demonstrates, by means of a systematic uncertainty analysis, that the use of outputs from more than one model can significantly improve conditional forecasts of discharges or water stages, provided the models are structurally different. Discharge forecasts from two models and the actual forecasted discharge are assumed to form a three-dimensional joint probability density distribution (jpdf), calibrated on long time series of data. The jpdf is decomposed into conditional probability density distributions (cpdf) by means of Bayes formula, as suggested and explored by Krzysztofowicz in a series of papers. In this paper his approach is simplified to optimize conditional forecasts for any set of two forecast models. Its application is demonstrated by means of models developed in a study of flood forecasting for station Stung Treng on the middle reach of the Mekong River in South-East Asia. Four different forecast models were used and pairwise combined: forecast with no model, with persistence model, with a regression model, and with a rainfall-runoff model. Working with cpdfs requires determination of dependency among variables, for which linear regressions are required, as was done by Krzysztofowicz. His Bayesian approach based on transforming observed probability distributions of discharges and forecasts into normal distributions is also explored. Results obtained with his method for normal prior and likelihood distributions are identical to results from direct multiple regressions. Furthermore, it is shown that in the present case forecast accuracy is only marginally improved, if Weibull distributed basic data were converted into normally distributed variables. Full article
(This article belongs to the Special Issue Uncertainty Analysis and Modeling in Hydrological Forecasting)
Show Figures

Figure 1

Open AccessArticle
Stressors and Strategies for Managing Urban Water Scarcity: Perspectives from the Field
Water 2015, 7(12), 6775-6787; https://doi.org/10.3390/w7126659 - 01 Dec 2015
Cited by 6 | Viewed by 3407
Abstract
Largely because water resource planning in the U.S. has been separated from land-use planning, opportunities for explicitly linking planning policies to water availability remain unexamined. The pressing need for better coordination between land-use planning and water management is amplified by changes in the [...] Read more.
Largely because water resource planning in the U.S. has been separated from land-use planning, opportunities for explicitly linking planning policies to water availability remain unexamined. The pressing need for better coordination between land-use planning and water management is amplified by changes in the global climate, which will place even greater importance on managing water supplies and demands than in the past. By surveying land and water managers in two urbanizing regions of the western United States—Portland, Oregon and Phoenix Arizona—we assessed the extent to which their perspectives regarding municipal water resource management align or differ. We specifically focus on characterizing how they perceive water scarcity problems (i.e., stressors) and solutions (i.e., strategies). Overall, the results show a general agreement across both regions and professions that long-term drought, population growth, and outdoor water use are the most important stressors to urban water systems. The results of the survey indicated more agreement across cities than across professions with regard to effective strategies, reinforcing the idea that land-use planners and water managers remain divided in their conception of the solutions to urban water management. To conclude, we recommend potential pathways for coordinating the fields of land and water management for urban sustainability. Full article
(This article belongs to the Special Issue Water Resource Variability and Climate Change)
Show Figures

Figure 1

Open AccessConcept Paper
Technologies for Decentralized Fluoride Removal: Testing Metallic Iron-based Filters
Water 2015, 7(12), 6750-6774; https://doi.org/10.3390/w7126657 - 30 Nov 2015
Cited by 32 | Viewed by 4185
Abstract
Since the realization in the 1930s that elevated fluoride concentrations in drinking water can have detrimental effects on human health, new methods have been progressively developed in order to reduce fluoride to acceptable levels. In the developing world the necessity for filtration media [...] Read more.
Since the realization in the 1930s that elevated fluoride concentrations in drinking water can have detrimental effects on human health, new methods have been progressively developed in order to reduce fluoride to acceptable levels. In the developing world the necessity for filtration media that are both low-cost and sourced from locally available materials has resulted in the widespread use of bone char. Since the early 1990s metallic iron (Fe0) has received widespread use as both an adsorbent and a reducing agent for the removal of a wide range of contaminant species from water. The ion-selectivity of Fe0 is dictated by the positively charged surface of iron (hydr)oxides at circumneutral pH. This suggests that Fe0 could potentially be applied as suitable filter media for the negatively charged fluoride ion. This communication seeks to demonstrate from a theoretical basis and using empirical data from the literature the suitability of Fe0 filters for fluoride removal. The work concludes that Fe0-bearing materials, such as steel wool, hold good promise as low-cost, readily available and highly effective decentralized fluoride treatment materials. Full article
Show Figures

Figure 1

Open AccessArticle
Major Hydraulic Projects, Coalitions and Conflict. Seville’s Harbour and the Dredging of the Guadalquivir (Spain)
Water 2015, 7(12), 6736-6749; https://doi.org/10.3390/w7126658 - 30 Nov 2015
Cited by 9 | Viewed by 2472
Abstract
Major hydraulic projects have a long tradition in Spain and must be contextualised within the framework of the so-called “hydraulic paradigm”, according to which demand must be met with a sustained increase in supply. These large projects, which include but are not limited [...] Read more.
Major hydraulic projects have a long tradition in Spain and must be contextualised within the framework of the so-called “hydraulic paradigm”, according to which demand must be met with a sustained increase in supply. These large projects, which include but are not limited to the construction of large reservoirs, share a series of characteristics: their implementation relies on state economic and ideological support, their socioeconomic impact tends to be overestimated, their cost tends to be underestimated, they are presented as politically neutral, and they are the source of socio-environmental conflict. In order to gain a better understanding of this, we analyse the conflict generated by the dredging of the Guadalquivir River (Proyecto de Mejora de Accesos Marítimos al Puerto de Sevilla—MAM), a project aimed at improving navigability and access to the harbour of Seville (Spain). This project has highlighted the tensions underlying decision-making processes which pitch hegemonic policy makers against the rest of the stakeholders, as well as the lack of integrative and adaptive perspectives, institutional transparency and effective participation of all stakeholders in hydraulic policies. Full article
Show Figures

Figure 1

Open AccessArticle
Application of the Entropy Method to Select Calibration Sites for Hydrological Modeling
Water 2015, 7(12), 6719-6735; https://doi.org/10.3390/w7126652 - 26 Nov 2015
Cited by 6 | Viewed by 2480
Abstract
Selecting an optimum number of calibration sites for hydrological modeling is challenging. Modelers often spend a lot of time and effort on trial and error because there is no guide. We propose a novel entropy method to automate the selection of the optimum [...] Read more.
Selecting an optimum number of calibration sites for hydrological modeling is challenging. Modelers often spend a lot of time and effort on trial and error because there is no guide. We propose a novel entropy method to automate the selection of the optimum combination of calibration sites. To illustrate, the proposed entropy method is applied using discharge data from one river basin in Korea. First, different combinations of discharge-gauging sites were grouped based on the maximum information estimated by the entropy method. Then, a hydrological model was set up for the study basin and was calibrated by estimating optimal parameters using a genetic algorithm at the discharge-gauging sites. The calibration result confirmed that the model’s performance was best when it was calibrated using the site number and combination suggested by the entropy method. In addition, the entropy method was useful in reducing the time and effort of model calibration. Therefore, we suggest and confirm the applicability of the entropy method in selecting calibration sites for hydrological modeling. Full article
(This article belongs to the Special Issue Use of Meta-Heuristic Techniques in Rainfall-Runoff Modelling)
Show Figures

Figure 1

Open AccessArticle
Distribution of Epilithic Diatoms in Estuaries of the Korean Peninsula in Relation to Environmental Variables
Water 2015, 7(12), 6702-6718; https://doi.org/10.3390/w7126656 - 26 Nov 2015
Cited by 8 | Viewed by 2687
Abstract
This study explores the relationships between environmental factors and the distribution of epilithic diatoms in 161 estuaries of three coastal areas on the Korean peninsula. We investigated epilithic diatoms, water quality, and land use in the vicinities of the estuaries during the months [...] Read more.
This study explores the relationships between environmental factors and the distribution of epilithic diatoms in 161 estuaries of three coastal areas on the Korean peninsula. We investigated epilithic diatoms, water quality, and land use in the vicinities of the estuaries during the months of May 2012, 2013 and 2014, because Korea is relatively free from the influences of rainfall at that time of year. We recorded 327 diatom taxa from the study sites, and the assemblage was dominated by members of the Naviculaceae. Bacillariaceae accounted for the largest proportion of diatoms, and Nitzschia inconspicua (18%) and N. frustulum (9.6%) were the most dominant species. A cluster analysis based on epilithic diatom abundance suggested that the epilithic diatom communities of Korean estuaries can be classified into four large groups (G) according to geography, as follows: Ia—the East Sea watershed, Ib—the eastern watershed of the South Sea, IIa—the West Sea watershed, and IIb—the western watershed of the South Sea. The former two groups, Ia and Ib, showed higher proportions of forest land cover and use, higher species occurrence, lower salinity, lower turbidity, and lower concentrations of nutrients than the latter two groups, while the latter groups, IIa and IIb, had higher proportions of agricultural land cover and use, higher electrical conductivity, higher turbidity, higher concentrations of nutrients, and lower species occurrence. The environmental factors underlying the distribution of epilithic diatoms, representative of each region, are as follows: dissolved oxygen and forest land cover and use for Reimeria sinuate and Rhoicosphenia abbreviate of the East Sea (ES), salinity and turbidity for Tabularia fasciculate of the West Sea (WS), and biochemical oxygen demand (BOD) and nutrients for Cyclotella meneghiniana of the WS. On the other hand, the most influential environmental factors affecting the occurrence of indicator species showing the highest indicator values (>60%) of each group were electrical conductivity for Navicula saprophila and Reimeria sinuate of Ia, and turbidity for Encyonema minutum of IIa. Collectively, the distribution of epilithic diatom communities inhabiting Korean estuaries are determined by geographical factors and water quality, which are in turn influenced by land cover and use, and which differ from east to west. Full article
Show Figures

Figure 1

Open AccessArticle
Drought Management Strategies in Spain
Water 2015, 7(12), 6689-6701; https://doi.org/10.3390/w7126655 - 26 Nov 2015
Cited by 15 | Viewed by 3090
Abstract
The ongoing debate on water policies in Spain is characterised by a traditional paradigm, dominated by the intervention on hydrological systems through the construction and management of infrastructure, which is progressively being abandoned but is currently still strong while the emergence of new [...] Read more.
The ongoing debate on water policies in Spain is characterised by a traditional paradigm, dominated by the intervention on hydrological systems through the construction and management of infrastructure, which is progressively being abandoned but is currently still strong while the emergence of new management approaches. Climate change and the Water Framework Directive (WFD) are, in addition, the background to increasing challenges to traditional perspectives on drought, and important steps have been taken towards their replacement. This work analyzes the evolution of the normative structure and management models to identify recent shifts. The analysis is based on a fundamental conceptual change that places drought in the framework of risk, rather than that of crisis. I argue for the need to advance new prevention policies that can finally overcome productivist inertia and undertake essential tasks such as reallocating water flows, revising and controlling the water-concession system, and reinforcing and guaranteeing public participation. Full article
Show Figures

Figure 1

Open AccessArticle
Estimating Evapotranspiration from an Improved Two-Source Energy Balance Model Using ASTER Satellite Imagery
Water 2015, 7(12), 6673-6688; https://doi.org/10.3390/w7126653 - 26 Nov 2015
Cited by 15 | Viewed by 3266 | Correction
Abstract
Reliably estimating the turbulent fluxes of latent and sensible heat at the Earth’s surface by remote sensing is important for research on the terrestrial hydrological cycle. This paper presents a practical approach for mapping surface energy fluxes using Advanced Spaceborne Thermal Emission and [...] Read more.
Reliably estimating the turbulent fluxes of latent and sensible heat at the Earth’s surface by remote sensing is important for research on the terrestrial hydrological cycle. This paper presents a practical approach for mapping surface energy fluxes using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images from an improved two-source energy balance (TSEB) model. The original TSEB approach may overestimate latent heat flux under vegetative stress conditions, as has also been reported in recent research. We replaced the Priestley-Taylor equation used in the original TSEB model with one that uses plant moisture and temperature constraints based on the PT-JPL model to obtain a more accurate canopy latent heat flux for model solving. The collected ASTER data and field observations employed in this study are over corn fields in arid regions of the Heihe Watershed Allied Telemetry Experimental Research (HiWATER) area, China. The results were validated by measurements from eddy covariance (EC) systems, and the surface energy flux estimates of the improved TSEB model are similar to the ground truth. A comparison of the results from the original and improved TSEB models indicates that the improved method more accurately estimates the sensible and latent heat fluxes, generating more precise daily evapotranspiration (ET) estimate under vegetative stress conditions. Full article
Show Figures

Figure 1

Previous Issue
Next Issue
Back to TopTop