bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Resource Systems Analysis for Water Scarcity Management: The Thames Water Case Study
Authors: Morley Mark , Savić Dragan
Published: June 2020

Optimisation tools are a practical solution to problems involving the complex and interdependent constituents of water resource systems and offer the opportunity to engage with practitioners as an integral part of the optimisation process. A multiobjective genetic algorithm is employed in conjunction with a detailed water resource model to optimise the “Lower Thames Control Diagram”, a set of control curves subject to a large number of constraints. The Diagram is used to regulate abstraction of water for the public drinking water supply for London, UK, and to maintain downstream environmental and navigational flows. The optimisation is undertaken with the aim of increasing the amount of water that can be supplied (deployable output) through solely operational changes. A significant improvement of 33 Ml/day (1% or £59.4 million of equivalent investment in alternative resources) of deployable output was achieved through the optimisation, improving the performance of the system whilst maintaining the level of service constraints without negatively impacting on the amount of water released downstream. A further 0.2% (£11.9 million equivalent) was found to be realisable through an additional low-cost intervention. A more realistic comparison of solutions indicated even larger savings for the utility, as the baseline solution did not satisfy the basic problem constraints. The optimised configuration of the Lower Thames Control Diagram was adopted by the water utility and the environmental regulators and is currently in use.
Numerical and Experimental Study of Classical Hydraulic Jump
Authors: Retsinis Eugene , Papanicolaou Panayiotis
Published: June 2020

The present work is an effort to simulate numerically a classical hydraulic jump in a horizontal open channel with a rectangular cross-section, as far as the jump location and free surface elevation is concerned, and compare the results to experiments with Froude numbers in the range 2.44 to 5.38. The governing equations describing the unsteady one-dimensional rapidly varied flow have been solved with the assumption of non-hydrostatic pressure distribution. Two finite difference schemes were used for the discretization of the mass and momentum conservation equations, along with the appropriate initial and boundary conditions. The method of specified intervals has been employed for the calculation of the velocity at the downstream boundary node. Artificial viscosity was required for damping the oscillations near the steep gradients of the jump. An iterative algorithm was used to minimize the difference of flow depth between two successive iterations that must be less than a threshold value, for achieving steady state solution. The time interval varied in each iteration as a function of the Courant number for stability reasons. Comparison of the numerical results with experiments showed the validity of the computations. The numerical codes have been implemented in house using a Matlab® environment.
A Proposed Simultaneous Calculation Method for Flood by River Water, Inland Flood, and Storm Surge at Tidal Rivers of Metropolitan Cities: A Case Study of Katabira River in Japan
Authors: Koyama Naoki , Yamada Tadashi
Published: June 2020

All metropolitan cities in Japan are located in low-lying areas that surround ports. Accordingly, significant floods that occur in these cities will trigger the simultaneous occurrence of flooding by river water and inland flooding. However, existing studies have focused on the impact of flooding by river water, inland flooding, and high tide in tidal rivers, and disaster mitigation measures focused on detailed flooding processes in such flooding areas have not been conducted thus far. This study focused on a tidal river, i.e., Katabira River of Yokohama city, one of Japan’s metropolitan cities, to construct a simultaneous occurrence model of flooding by river water and inland flooding, including the impact of a high tide. Numerical analysis was conducted using this model, and the results show that the flooded area significantly changed from 0.004 to 0.149 km2 according to the tide level of the estuary. Moreover, by simultaneously solving the calculation of flooding by river water and inland flooding, we found that there was a difference of 50 min between the occurrences of these floods. Therefore, we found that there is a possibility that, if evacuation is not conducted at the time of occurrence of inland flooding, evacuation during subsequent river-water flooding may not be possible. Based on these results, our proposed method was found to be useful for tidal rivers of metropolitan cities.
The Importance of Biological and Ecological Properties of Phragmites Australis (Cav.) Trin. Ex Steud., in Phytoremendiation of Aquatic Ecosystems—The Review
Authors: Milke Justyna , Gałczyńska Małgorzata , Wróbel Jacek
Published: June 2020

Phragmites australis (common reed) is one of the most extensively distributed species of emergent plant worldwide. The adaptive features of this plant show its competitive character. Owing to high intraspecific diversity of common reed, as well as its phenotypic plasticity, the plant shows a broad ecological amplitude. Moreover, the plant exhibits a high capacity for acclimatization to environmental conditions which are considered adverse. This plant has been used for many years in phytoremediation to purify various types of wastewater. Phragmites australis has a high ability to accumulate various nutrients, heavy metals, and micropollutants, and in this respect, it is superior to other aquatic plants. This review examines the existing literature on the biological and ecological properties of common reed, the use of common reed in wastewater treatment for removing pollutants and tolerance for metals, and in hydrophyte treatment systems. It seems vital to conduct further research on the physiology and biochemistry of the common reed, with the aim of increasing the plant’s efficiency for pollutants removal.
Design Aspects, Energy Consumption Evaluation, and Offset for Drinking Water Treatment Operation
Authors: Bukhary Saria , Batista Jacimaria , Ahmad Sajjad
Published: June 2020

Drinking water treatment, wastewater treatment, and water distribution are energy-intensive processes. The goal of this study was to design the unit processes of an existing drinking water treatment plant (DWTP), evaluate the associated energy consumption, and then offset it using solar photovoltaics (PVs) to reduce carbon emissions. The selected DWTP, situated in the southwestern United States, utilizes coagulation, flocculation, sedimentation, filtration, and chlorination to treat 3.94 m3 of local river water per second. Based on the energy consumption determined for each unit process (validated using the plant’s data) and the plant’s available landholding, the DWTP was sized for solar PV (as a modeling study) using the system advisor model. Total operational energy consumption was estimated to be 56.3 MWh day−1 for the DWTP including water distribution pumps, whereas energy consumption for the DWTP excluding water distribution pumps was 2661 kWh day−1. The results showed that the largest consumers of energy—after the water distribution pumps (158.1 Wh m−3)—were the processes of coagulation (1.95 Wh m−3) and flocculation (1.93 Wh m−3). A 500 kW PV system was found to be sufficient to offset the energy consumption of the water treatment only operations, for a net present value of $0.24 million. The net reduction in carbon emissions due to the PV-based design was found to be 450 and 240 metric tons CO2-eq year−1 with and without battery storage, respectively. This methodology can be applied to other existing DWTPs for design and assessment of energy consumption and use of renewables.
Response of Preferential Soil Flow to Different Infiltration Rates and Vegetation Types in the Karst Region of Southwest China
Authors: Kan Xiaoqing , Cheng Jinhua , Hou Fang
Published: June 2020

The widespread preferential flow phenomenon has an important impact on the water resource allocation of vegetation restoration in karst regions. In this study, four kinds of water infiltration experiments were conducted on six kinds of vegetation types (Pinus yunnanensis Franch. var. tenuifolia plantation forestlands, Eucalyptus robusta Smith plantation forestlands, Platycladus orientalis (L.) Francoptmxjjkmsc plantation forestlands, secondary forestlands, scrublands, and natural grasslands) separately to evaluate the effect of vegetation restoration on preferential flow in karst regions. The distribution of soil water infiltration was visualized via Brilliant Blue staining (290 images of soil vertical section staining) and data were processed via structural equation model (SEM). Results showed that 15–35 mm water accumulation was beneficial to the visualization of preferential flow. The experimental statement of a higher matrix flow in grassland than in plantations made it possible to draw conclusions of economic importance. Therefore, undergrowth of vegetation coverage in plantation forestlands should be increased. Experimentally analyzing the water-vegetation-soil interaction, shows an increase in vegetation coverage inhibits the development of matrix flow, an increase in soil erodibility may inhibit the development of preferential flow, and an increase in soil clay content may promote the deepening of matrix flow depth. The artificial forest can improve the soil structure and can effectively restore the degree of soil fragmentation; vegetation can be restored reasonably to prevent desertification in karst regions. Therefore, identifying and analyzing the structure characteristics of the soil macropore network under the conditions of natural vegetation communities and artificial vegetation communities in karst-geologic settings is an urgent study, which can provide a reference for improving the restoration measures of artificial forests and sustainable forestry development in karst desertification areas.
Numerical Solution of the Two-Dimensional Richards Equation Using Alternate Splitting Methods for Dimensional Decomposition
Authors: Gąsiorowski Dariusz , Kolerski Tomasz
Published: June 2020

Research on seepage flow in the vadose zone has largely been driven by engineering and environmental problems affecting many fields of geotechnics, hydrology, and agricultural science. Mathematical modeling of the subsurface flow under unsaturated conditions is an essential part of water resource management and planning. In order to determine such subsurface flow, the two-dimensional (2D) Richards equation can be used. However, the computation process is often hampered by a high spatial resolution and long simulation period as well as the non-linearity of the equation. A new highly efficient and accurate method for solving the 2D Richards equation has been proposed in the paper. The developed algorithm is based on dimensional splitting, the result of which means that 1D equations can be solved more efficiently than as is the case with unsplit 2D algorithms. Moreover, such a splitting approach allows any algorithm to be used for space as well as time approximation, which in turn increases the accuracy of the numerical solution. The robustness and advantages of the proposed algorithms have been proven by two numerical tests representing typical engineering problems and performed for typical properties of soil.
A Dynamic Comparison Sustainability Study of Standard Wastewater Treatment System in the Straw Pulp Papermaking Process and Printing & Dyeing Papermaking Process Based on the Hybrid Neural Network and Emergy Framework
Authors: Zhang Junxue , Ma Lin , Yan Yanyan
Published: June 2020

Sustainability study of the standard wastewater treatment system is the pivotal procedure in the water protection field. In order to better study the sustainability of sewage treatment systems, wastewater treatment system of straw pulp papermaking (WTSPP) and wastewater treatment system of printing and dyeing and papermaking (WTPDP) have been selected to assess the sustainable level in China. Based on the hybrid neural network and emergy framework, WTSPP and WTPDP were considered and analyzed in this paper. Therein, three types of indicators were used to evaluate these two systems, including basic structure emergy indicators (BEI), functional emergy indicators (FEI), and eco-efficiency emergy indicators (EEI). Through the basic neural network model and detailed neural network model design, the iteration paths and algorithm operation diagram of WTSPP and WTPDP were designed and realized in this article. Primary contents include: (1) For WTSPP and WTPDP, nonrenewable resources emergy are both the primary contributor and account for roughly 62.5% and 53.7%, respectively. (2) As the important indicator group, the environmental loading ratio (ELR) is 176 in the WTSPP and 323 in the WTPDP, respectively. Emergy sustainability indicators (ESIs) in the WTSPP and WTPDP, are 0.015 and 0.014, respectively. (3) Depending on fluctuation degrees, WTSPP is better than WTPDP. The maximum fluctuation ranges of WTSPP and WTPDP are (3%, −27%) and (28%, 61%), respectively. (4) All neural network analysis results manifest that the emergy sustainability indicators (ESIs) of WTSPP and WTPDP are [0.0151, 0.011] and [0.0179, 0.0055] in view of a long-term predictive view, respectively.
Spatial Differentiation of the Maximum River Runoff Synchronicity in the Warta River Catchment, Poland
Authors: Perz Adam , Sobkowiak Leszek , Wrzesiński Dariusz
Published: June 2020

Based on daily flows recorded in the period 1971–2010, the synchronous occurrence of the annual (AMAXq), winter (WMAXq), and summer (SMAXq) maximum specific runoffs in 39 sub-catchments of the Warta River catchment (WRC) in Poland was analyzed. First, trends in the flows were detected using the non-parametric Mann–Kendall (M-K) test. Then, the degree of the synchronous and asynchronous occurrences of the maximum specific runoffs (MAXq) in respective sub-catchments in relation to the Gorzów Wielkopolski gauge closing the WRC was calculated. Finally, the reasons for the detected spatial and temporal differences were discussed. The study revealed a noticeable variability of the analyzed parameters. The highest synchronicity of AMAXq and WMAXq in relation to the closing Gorzów Wielkopolski gauge was revealed in the man-made Kościański and Mosiński canals and in the sub-catchments of the Noteć, Wełna, and lower Prosna rivers. While compared to AMAXq and WMAXq, the summer maxima showed relatively lower degrees of synchronicity, an increase in the synchronous occurrence of SMAXq in the southern part of WRC, and a decrease in its central part were identified. It was concluded that the stronger synchronicity of WMAXq resulted from the nival regime of the investigated rivers. Consequently, the annual maxima were most often associated with the winter half-year. The detected differences of synchronicity of the annual and seasonal runoffs are conditioned by climate, more specifically by the course of winter and resulting from it snow cover thickness, and also the amount and intensity of rainfall in summer.
Soil Hydraulic Properties of Plinthosol in the Middle Yangtze River Basin, Southern China
Authors: Wang Yongwu , Wu Tieniu , Huang Jianwu , Tian Pei , Zhang Hailin , Yang Tiantian
Published: June 2020

Soil hydraulic properties are ecologically important in arranging vegetation types at various spatial and temporal scales. However, there is still a lack of detailed understanding of the basic parameters of plinthosol in the Middle Yangtze River basin. This paper focuses on the soil hydraulic properties of three plinthosol profiles at Yueyang (YE), Wuhan (WH), and Jiujiang (JU) and tries to reveal the origin of plinthosol and the relationship among the soil hydraulic parameters. Discriminant analysis indicated that the plinthosol in the JU profile was of aeolian origin, while that in the WH and YE profiles was of alluvial origin; soil hydraulic properties varied greatly among these profiles. The proportion of macro-aggregates (>0.25 mm, weight%) in the JU profile (88.28%) was significantly higher than that in the WH (73.63%) and YE (57.77%) profiles; the water holding capacity and saturated hydraulic conductivity of JU plinthosol was also higher than that of WH and YE plinthosol; the fact that Dr and Di of the JU profile are lower than those of the YE and WH profiles illustrates the stability of JU plinthosol is better than that of YE and WH plinthosol, which is consistent with the fractal dimension of aggregates. The disintegration curves of white vein and red matrix demonstrated a large discrepancy in the JU profile, but these curves showed a similar trend in the WH and YE profiles. The differences in hydraulic properties might be ascribed to the origin of plinthosol, and the results of the fractal dimension also confirmed this conclusion. This study might provide a better understanding of the soil physical properties of plinthosol and shed light on the soil and water conservation measures in the Middle Yangtze River basin.
Can Lumped Characteristics of a Contributing Area Provide Risk Definition of Sediment Flux?
Authors: Jáchymová Barbora , Krása Josef , Dostál Tomáš , Bauer Miroslav
Published: June 2020

Accelerated soil erosion by water has many offsite impacts on the municipal infrastructure. This paper discusses how to easily detect potential risk points around municipalities by simple spatial analysis using GIS. In the Czech Republic, the WaTEM/SEDEM model is verified and used in large scale studies to assess sediment transports. Instead of computing actual sediment transports in river systems, WaTEM/SEDEM has been innovatively used in high spatial detail to define indices of sediment flux from small contributing areas. Such an approach has allowed for the modeling of sediment fluxes in contributing areas with above 127,484 risk points, covering the entire Czech Republic territory. Risk points are defined as outlets of contributing areas larger than 1 ha, wherein the surface runoff goes into residential areas or vulnerable bodies of water. Sediment flux indices were calibrated by conducting terrain surveys in 4 large watersheds and splitting the risk points into 5 groups defined by the intensity of sediment transport threat. The best sediment flux index resulted from the correlation between the modeled total sediment input in a 100 m buffer zone of the risk point and the field survey data (R2 from 0.57 to 0.91 for the calibration watersheds). Correlation analysis and principal component analysis (PCA) of the modeled indices and their relation to 11 lumped characteristics of the contributing areas were computed (average K-factor; average R-factor; average slope; area of arable land; area of forest; area of grassland; total watershed area; average planar curvature; average profile curvature; specific width; stream power index). The comparison showed that for risk definition the most important is a combination of morphometric characteristics (specific width and stream power index), followed by watershed area, proportion of grassland, soil erodibility, and rain erosivity (described by PC2).
Numerical Analysis of Drag Force Acting on 2D Cylinder Immersed in Accelerated Flow
Authors: Son Hyun A. , Lee Sungsu , Lee Jooyong
Published: June 2020

In this study, the drag exerted by an accelerating fluid on a stationary 2D circular cylinder is numerically investigated using Fluent 19.2 based on the finite-volume method. The SST k–ω model is chosen as the turbulence model because of its superiority in treating the viscous near-wall region. The results are compared to literature, and the numerical methods are validated. The acceleration of the inflow is analyzed for the range of 0.0981–9.81 m/s2, and the drag for each acceleration is compared. Additionally, the effect of the initial velocity on the drag acting on the circular cylinder is investigated at two initial velocities. As a result, a supercritical region, typically found under steady state conditions, is observed. Furthermore, vortex shedding is observed at a high initial velocity. This flow characteristic is explained via comparison with respect to the recirculation length and separation angle.
Analyzing Particle-Associated Pollutant Transport to Identify In-Stream Sediment Processes during a High Flow Event
Authors: Glaser Clarissa , Zarfl Christiane , Rügner Hermann , Lewis Amelia , Schwientek Marc
Published: June 2020

Urban areas are a leading source of polycyclic aromatic hydrocarbons (PAHs) that result from combustion processes and are emitted into rivers, especially during rain events and with particle wash-off from urban surfaces. In-stream transport of suspended particles and attached PAHs is linked strongly to sediment turnover processes. This study aimed to identify particle exchange processes that contribute to the transport of suspended particles during flood events. An urban high-flow signal was tracked in high temporal resolution at two sampling sites in the Ammer River (South-western Germany). Samples were analyzed for turbidity, total suspended solids concentrations (TSS), particle-size distribution, organic carbon, and PAH. Maximum discharge and the highest TSS occurred nearly simultaneously at the upstream sampling site, whereas a temporally shifted course was observed for downstream. The total load of particles was similar, yet a decrease of PAH mass (~28%) and an increase of the particulate organic carbon (POC) content (~3.5%-points) occurred. Coarser particles (≥26 µm) dominated at the beginning of the event at both sampling sites. The signal of remobilized riverbed sediment increases downstream and leads to well-established, robust linear correlations between TSS and PAHs. This study highlights that riverbed sediment acts as intermediate storage for contaminated particles from upstream sources that shape, together with the fresh urban input, the “particle signature” of suspensions moving through catchments during high discharge conditions.
Isotopic ‘Altitude’ and ‘Continental’ Effects in Modern Precipitation across the Adriatic–Pannonian Region
Authors: Kern Zoltán , Hatvani István , Czuppon György , Fórizs István , Erdélyi Dániel , Kanduč Tjaša , Palcsu László , Vreča Polona
Published: June 2020

It is generally observed that precipitation is gradually depleted in 18O and 2H isotopes as elevation increases (‘altitude’ effect) or when moving inland from seacoasts (‘continental’ effect); the regionally accurate estimation of these large-scale effects is important in isotope hydrological or paleoclimatological applications. Nevertheless, seasonal and spatial differences should be considered. Stable isotope composition of monthly precipitation fallen between January 2016 and December 2018 was studied for selected stations situated along an elevation transect and a continental transect in order to assess the isotopic ‘altitude’ and ‘continental’ effects in modern precipitation across the Adriatic–Pannonian region. Isotopic characteristics argue that the main driver of the apparent vertical depletion of precipitation in heavy stable isotopes is different in summer (raindrop evaporation) and winter (condensation), although, there is no significant difference in the resulting ‘altitude’ effect. Specifically, an ‘altitude’ effect of −1.2‰/km for δ18O and −7.9‰/km for δ2H can be used in modern precipitation across the Adriatic–Pannonian region. Isotopic characteristics of monthly precipitation showed seasonally different patterns and suggest different isotope hydrometeorological regimes along the continental transect. While no significant decrease was found in δ18O data moving inland from the Adriatic from May to August of the year, a clear decreasing trend was found in precipitation fallen during the colder season of the year (October to March) up to a break at ~400 km inland from the Adriatic coast. The estimated mean isotopic ‘continental’ effect for the colder season precipitation is −2.4‰/100 km in δ18O and −20‰/100 km in δ2H. A prevailing influence of the Mediterranean moisture in the colder season is detected up to this breakpoint, while the break in the δ18O data probably reflects the mixture of moisture sources with different isotopic characteristics. A sharp drop in the d-excess (>3‰) at the break in precipitation δ18O trend likely indicates a sudden switch from the Mediterranean moisture domain to additional (mainly Atlantic) influence, while a gradual change in the d-excess values might suggest a gradual increase of the non-Mediterranean moisture contribution along the transect.
Pollution Characteristics and Ecological Risk Assessment of Heavy Metals in Sediments of the Three Gorges Reservoir
Authors: Shui Lujie , Pan Xiaojie , Chen Xiaojuan , Chang Fengyi , Wan Duanji , Liu Defu , Hu Mingming , Li Shanze , Wang Yuchun
Published: June 2020

In order to understand the spatial distribution and ecological risk of heavy metal pollution in the sediments of the Three Gorges Reservoir, surface sediment samples in six typical tributaries and estuaries were analyzed. The heavy metal content in sediment was detected by ICP-MS (PE Elan DRC Ⅱ, PerkinElmer, Waltham, MA, USA) after digestion by mixed acid. The data were evaluated and analyzed using multiple methods, including the potential ecological risk index, the geoaccumulation index (Igeo), and cluster analysis. The results show that the tributary surface sediments were polluted by heavy metals to a certain extent. Cu, Zn, Pb, and Cr have been enriched in sediments in recent years. The results of Igeo show that the pollution degree is as follows: Pb > Cu > Zn > Cr > Cd > Ni > As > Hg. According to the potential ecological risk index, the grades of Yunyang, Xiaojiang, and Xinjin are all medium risk, and Cd has the highest contribution rate. Combined with field investigation data, cluster analysis, and correlation analysis, we conclude that Cu, Zn, and Cr are likely to come from agricultural chemical fertilizers and industrial sewage, while Pb mainly comes from the discharge of ship fuel.
Integrated Monitoring with Moss-Bag and Mussel Transplants in Reservoirs
Authors: Gecheva Gana , Yancheva Vesela , Velcheva Iliana , Georgieva Elenka , Stoyanova Stela , Arnaudova Desislava , Stefanova Violeta , Georgieva Deyana , Genina Vesela , Todorova Borislava , Mollov Ivelin
Published: June 2020

For the first time, transplants with moss-bags and mussels together were applied to study the water quality in standing water bodies. The tested species: Fontinalis antipyretica Hedw. and Sinanodonta woodiana (Lea, 1834) were collected from unpolluted sites and analyzed to obtain background levels. Then, the moss and mussels were left in cages for a period of 30 days in three reservoirs where both are not present naturally. Two of the reservoirs suffer from old industrial contamination and one is affected by untreated wastes. Twenty-four compounds were studied, among them trace elements Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn and organic priority substances: six polybrominated diphenyl ethers (PBDEs) congeners and short-chain chlorinated paraffins (SCCPs). The trace element accumulation was significant after the exposition period in all studied stations. PBDEs and SCCPs were also accumulated up to two times more in the moss tissues. PBDEs in the mussels exceeded the environmental quality standard (EQS). The applied combined transplants, and especially the moss-bags, revealed severe contamination with heavy metals not detected by the water samples. The moss and the mussel followed a different model of trace element and PBDEs accumulation. The SCCPs levels were alarmingly high in all plant samples. The study confirmed PBDEs and SCCPs as bioaccumulative compounds and suggested that an EQS for SCCPs in biota needs to be established.
Watershed Hydrological Response to Combined Land Use/Land Cover and Climate Change in Highland Ethiopia: Finchaa Catchment
Authors: Dibaba Wakjira Takala , Demissie Tamene Adugna , Miegel Konrad
Published: June 2020

Land use/land cover (LULC) and climate change affect the availability of water resources by altering the magnitude of surface runoff, aquifer recharge, and river flows. The evaluation helps to identify the level of water resources exposure to the changes that could help to plan for potential adaptive capacity. In this research, Cellular Automata (CA)-Markov in IDRISI software was used to predict the future LULC scenarios and the ensemble mean of four regional climate models (RCMs) in the coordinated regional climate downscaling experiment (CORDEX)-Africa was used for the future climate scenarios. Distribution mapping was used to bias correct the RCMs outputs, with respect to the observed precipitation and temperature. Then, the Soil and Water Assessment Tool (SWAT) model was used to evaluate the watershed hydrological responses of the catchment under separate, and combined, LULC and climate change. The result shows the ensemble mean of the four RCMs reported precipitation decline and increase in future temperature under both representative concentration pathways (RCP4.5 and RCP8.5). The increases in both maximum and minimum temperatures are higher for higher emission scenarios showing that RCP8.5 projection is warmer than RCP4.5. The changes in LULC brings an increase in surface runoff and water yield and a decline in groundwater, while the projected climate change shows a decrease in surface runoff, groundwater and water yield. The combined study of LULC and climate change shows that the effect of the combined scenario is similar to that of climate change only scenario. The overall decline of annual flow is due to the decline in the seasonal flows under combined scenarios. This could bring the reduced availability of water for crop production, which will be a chronic issue of subsistence agriculture. The possibility of surface water and groundwater reduction could also affect the availability of water resources in the catchment and further aggravate water stress in the downstream. The highly rising demands of water, owing to socio-economic progress, population growth and high demand for irrigation water downstream, in addition to the variability temperature and evaporation demands, amplify prolonged water scarcity. Consequently, strong land-use planning and climate-resilient water management policies will be indispensable to manage the risks.
Applicability and Hydrologic Substitutability of TMPA Satellite Precipitation Product in the Feilaixia Catchment, China
Authors: Chen Xiaoli , Huang Guoru
Published: June 2020

The assessment of various precipitation products’ performances in extreme climatic conditions has become a topic of interest. However, little attention has been paid to the hydrological substitutability of these products. The objective of this study is to explore the performance of the Tropical Rainfall Measuring Mission Multi-Satellite Precipitation Analysis (TMPA) product in the Feilaixia catchment, China. To assess its applicability in extreme consecutive climates, several statistical indices are adopted to evaluate the TMPA performance both qualitatively and quantitatively. The Cox–Stuart test is used to investigate extreme climate trends. The Soil and Water Assessment Tool (SWAT) model is used to test the TMPA hydrological substitutability via three scenarios of runoff simulation. The results demonstrate that the overall TMPA performance is acceptable, except at high-latitudes and locations where the terrain changes greatly. Moreover, the accuracy of the SWAT model is high both in the semi-substitution and full-substitution scenarios. Based on the results, the TMPA product is a useful substitute for the gauged precipitation in obtaining acceptable hydrologic process information in areas where gauged sites are sparse or non-existent. The TMPA product is satisfactory in predicting the runoff process. Overall, it must be used with caution, especially at high latitudes and altitudes.
Experimental and Numerical Assessment of Water Leakages in a PVC-A Pipe
Authors: Ferraiuolo Roberta , De Paola Francesco , Fiorillo Diana , Caroppi Gerardo , Pugliese Francesco
Published: June 2020

Nowadays, in the definition of effective approaches for the sustainable management of water pressurized systems, the assessment of water leakages in water supply and distribution systems represents a key aspect. Indeed, the large water volumes dispersed yearly provoke relevant environmental, technical and socio-economic costs. Worldwide, many water systems show alarming levels of water losses, due to both the poor sealing of joints and the presence of cracks, enhanced by a high pressure level greater than that strictly required for assuring a proper service level to users. With the aim of analysing the correlation between pressure and leakages, in this work the results of an experimental and a numerical Computational Fluid Dynamics (CFD) investigation are provided and discussed. With reference to a drilled PVC-A (Polyvinyl Chloride-Alloy) pipe, a new-generation plastic material for water systems use, an experimental investigation was first carried out at the Laboratory of Hydraulics of the University of Naples Federico II, aimed at assessing the leakage-pressure relation for transversal rectangular orifices. A CFD model was then implemented and calibrated with experimental results, to different geometric configurations of the orifice, with the aim of assessing the dependence of the orifice geometry and orientation on the calibration of leakage law parameters.
Spatial Dependence Modeling of Flood Risk Using Max-Stable Processes: The Example of Austria
Authors: Albrecher Hansjörg , Kortschak Dominik , Prettenthaler Franz
Published: June 2020

We propose a new approach to model the dependence structure for aggregating the risk of flood damages from a local level to larger areas, which is based on the structure of the river network of a country and can be calibrated with publicly available data of river discharges. Building upon a suitable adaptation of max-stable processes for a flood-relevant geometry as recently introduced in the literature, this enables the assessment of flood risk without the need for a hydrological model, and can easily be adapted for different countries. We illustrate its use for the particular case of Austria. We first develop marginal flood models for individual municipalities by intertwining available HORA risk maps with the actual location of buildings. As a second alternative for the marginal modeling, we advocate an approach based on suitably normalized historical damage data of municipalities together with techniques from extreme value statistics. We implement and compare the two alternatives and apply the calibrated dependence structure to each of them, leading to estimates for average flood damage as well as its extreme quantiles on the municipality, state, and country level. This also allows us to quantify the diversification potential for flood risk on each of these levels, a topic of considerable importance in view of the natural and strong spatial dependence of this particular natural peril.
Assessment of Different Contaminants in Freshwater: Origin, Fate and Ecological Impact
Authors: Di Lorenzo Tiziana , Hose Grant C. , Galassi Diana M.P.
Published: June 2020

Freshwater ecosystems cover over 15% of the world’s surface and provide ecosystem services that are pivotal in sustaining human society. However, fast-growing anthropogenic activities have deleterious impacts on these ecosystems. In this Special Issue, we collect ten studies encompassing five different factors of freshwater contamination: landfill leaks, nutrients, heavy metals, emerging organic contaminants and marble slurry. Using different approaches, the studies detailed the direct and indirect effects that these contaminants have on a range of freshwater organisms, from bacteria to vertebrates. Although the papers covered here focused on specific case studies, they exemplify common issues that are expanding in groundwaters, hyporheic zones, streams, lakes and ponds around the world. All the aspects of these issues are in dire need of being continuously discussed among scientists, end-users and policy-makers. To this end, the Special Issue presents a new free software suite for the analysis of the ecological risk and conservation priority of freshwater ecosystems. The software can support local authorities in the preparation of management plans for freshwater basins pursuant to the Water Directives in Europe.
Microcystis Bloom in an Urban Lake after River Water Diversion—A Case Study
Authors: Chen Xiaoyan , Bai Dong , Song Chunlei , Zhou Yiyong , Cao Xiuyun
Published: June 2020

To improve the water quality of Lake Yuehu, a water diversion from the Han River was conducted in July 2008. However, an unexpected Microcystis bloom occurred in the lake after water introduction. Water and sediment samples were collected from Lake Yuehu and the variation of chemical and biochemical parameters, as well as the phytoplankton community, were analyzed during the water diversion to assess its effect and to clarify the mechanism leading to the Microcystis bloom. The nitrogen (N) concentration was increased and phosphorus (P) concentration decreased in Lake Yuehu after receiving water from the Han River, which had a high loading of N and a low loading of P. These conditions may benefit the growth and dominance of non-N2 fixing Microcystis, as it may not have suffered from P limitation during our study because it did not produce extracellular phosphatase, which worked as an indicator of P deficiency, as evidenced by the in situ enzyme-labelled fluorescence. Notably, the sediment Fe (OOH)~P content significantly decreased in Lake Yuehu; this pulsed release of P from the sediment might have sustained the Microcystis bloom. Based on our results, algal blooms may occur as a consequence of conducting water diversion projects to improve water quality.
Floating Ice Transport Conditions at the Cross-Sections Between Pier Columns in Open Ice-Water Two-Phase Flow Canals
Authors: Mu Xiangpeng , Bao Juan , Chen Yunfei
Published: June 2020

Floating ice is easy to jam at the cross-sections contracted by bridge pier, gate pier, etc., in ice-water two-phase flow canals. To solve the problem, the critical hydraulic conditions of floating ice transport at the cross-sections between pier columns were explored in this study. Based on the generalized physical model of the cross-sections between pier columns of water transfer canals, the movement and transport characteristics of floating ice in front of the pier columns were studied under different hydraulic conditions and ice conditions, and the critical hydraulic conditions necessary for floating ice to pass through the cross-sections between pier columns were analyzed. Moreover, dimensional analysis and regression analysis were carried out in order to establish an empirical equation for calculating the critical water flow Fr (Froude number) for the floating ice to be transported through the cross-sections between pier columns, thus providing a basis for the ice jam risk assessment and hydraulic regulation of ice-water two-phase flow canals, as well as control of the emergent ice drainage of canals during freezing periods.
The Trend in the Risk of Flash Flood Hazards with Regional Development in the Guanshan River Basin, China
Authors: Chen Ningyue , Zhang Yanjun , Wu Jinjin , Dong Wenxun , Zou Yixuan , Xu Xin
Published: June 2020

The economic development of China’s mountainous areas has been rapid, but the impact of flash floods is often ignored during regional development planning. Therefore, a method needed to be developed to simulate flash flood disasters and analyze the trends in flash flood disasters with regional development. Taking Guanshan River Basin as the research area, we combined the digital elevation model (DEM) with the inflow hydrograph, using the topography-based hydrological model (TOPMODEL). Verified by historical flash flood disasters, the watershed model was built based on the finite volume conservation flood routing model (FLO-2D). Then, we simulated the hazard distribution of flash flood disasters, developed a risk status assessment factor (RSAF) for flash flood disasters and calculated the increased ratio from 2003 to 2018. The results show that in 2003, the total hazard area of flash flood disasters affecting human settlements was 61,121 m2, which increased to 118,404 m2 in 2018. Since 2003, with the development of the regional economy, more residents moved to risk and extreme risk zones; thus, the risk of flash flood disasters also increased. Due to the significant damage caused by the flash flood on 5 August 2012, some of the local residents moved away from the high risk and extreme risk zones, indicating that the risk trend of flash flood hazard was consistent with the regional development of Guanshan River. We provide suggestions for regional economic development planning; the risk assessment for flash flood disasters must be considered to ensure the stable development of the regional economy, and using the RSAF would be efficient.
Applied Strategy to Characterize the Energy Improvement Using PATs in a Water Supply System
Authors: Camilo Rosado Luis , López-Jiménez P. , Sánchez-Romero Francisco-Javier , Conejos Fuertes Pilar , Pérez-Sánchez Modesto
Published: June 2020

Sustainable development has been an idea raised in recent years. The results are related to the improvement and the use of new technologies to maximize efficiency in water management. However, energy consumption has been increasing as a consequence of new management and uses of water. Especially in pressurized water distribution systems, the use of pressure reduction valves (PRVs) increases the water usage efficiency but it decreases the energy consumption efficiency, since the valves dissipate energy that could be recovered. This research presents a proposal of a recovery system based on the installation of pumps used as turbines (PATs). These machines are located in different points of the high-pressure water distribution system in the Valencia Metropolitan System (Spain). An annual estimate of the theoretical recoverable energy as well as the “ideal” pump for each point were proposed. The theoretical recovered energy value was 847,301 kWh/year for a specific analyzed point. Besides, the characteristic curves of the PATs from a selected point were determined, estimating an improvement in the sustainable indexes. The calculus of these green parameters showed that the implementation of this solution caused a reduction in consumed energy of 1.50 kWh/m3.
Advances in Hydrologic Forecasts and Water Resources Management
Authors: Chang Fi-John , Guo Shenglian
Published: June 2020

The impacts of climate change on water resources management as well as the increasing severe natural disasters over the last decades have caught global attention. Reliable and accurate hydrological forecasts are essential for efficient water resources management and the mitigation of natural disasters. While the notorious nonlinear hydrological processes make accurate forecasts a very challenging task, it requires advanced techniques to build accurate forecast models and reliable management systems. One of the newest techniques for modelling complex systems is artificial intelligence (AI). AI can replicate the way humans learn and has the great capability to efficiently extract crucial information from large amounts of data to solve complex problems. The fourteen research papers published in this Special Issue contribute significantly to the uncertainty assessment of operational hydrologic forecasting under changing environmental conditions and the promotion of water resources management by using the latest advanced techniques, such as AI techniques. The fourteen contributions across four major research areas: (1) machine learning approaches to hydrologic forecasting; (2) uncertainty analysis and assessment on hydrological modelling under changing environments; (3) AI techniques for optimizing multi-objective reservoir operation; and (4) adaption strategies of extreme hydrological events for hazard mitigation. The papers published in this issue can not only advance water sciences but can also support policy makers toward more sustainable and effective water resources management.
Development of an information leaflet and diagnostic flow chart to improve the management of urinary tract infections in older adults: a qualitative study using the Theoretical Domains Framework
Authors: Jones Leah Ffion , Cooper Emily , Joseph Amelia , Allison Rosalie , Gold Natalie , Donald Ian , McNulty Cliodna
Published: June 2020

Background

Urinary tract infections (UTIs), older age, lack of access to health care, and recent antibiotic use are risk factors for Escherichia coli (E. coli) bloodstream infections.

Aim

To explore the diagnosis and management of UTIs in primary care to inform the development of an information leaflet, a diagnostic flow chart, and recommendations for other resources.

Design & setting

The study had a qualitative design and was undertaken in primary care settings and care homes.

Method

Interviews and focus groups were informed by the Theoretical Domains Framework (TDF) with 31 care home staff, three residents, six relatives, 57 GP staff, and 19 members of the public. An inductive thematic analysis was used and themes were placed in the Behaviour Change Wheel (BCW) to recommend interventions.

Results

Care home staff were pivotal for identifying suspected UTI, alerted clinicians to symptoms that influenced prescribing decisions, and reported confusion or behavioural changes as the most common diagnostic sign. Care home staff lacked knowledge about asymptomatic bacteriuria (ASB) and sepsis, and incorrectly diagnosed UTI using urine dipsticks. GP staff used urine dipsticks to rule out UTI and reported that stopping dipsticks would require a culture change, clear protocols, and education about ASB. Many prescribers believed that stopping urine dipstick use should help to reduce antibiotic use.

Conclusion

A consistent message about ASB and UTI diagnosis and management in older adults should be communicated across the care pathway. Resource development should increase capability, motivation, and opportunity to improve management of suspected UTIs. An educational leaflet for older adults and a diagnostic flow chart for clinicians have been developed, and recommendations for interventions are discussed.