bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding Potential Cyber-Armies in Elections: A Study of Taiwan
Authors: Wang Ming-Hung , Nguyen Nhut-Lam , Dai Shih-chan , Chi Po-Wen , Dow Chyi-Ren
Published: March 2020

Currently, online social networks are essential platforms for political organizations to monitor public opinion, disseminate information, argue with the opposition, and even achieve spin control. However, once such purposeful/aggressive articles flood social sites, it would be more difficult for users to distinguish which messages to read or to trust. In this paper, we aim to address this issue by identifying potential “cyber-armies/professional users” during election campaigns on social platforms. We focus on human-operated accounts who try to influence public discussions, for instance, by publishing hundreds/thousands of comments to show their support or rejection of particular candidates. To achieve our objectives, we collected activity data over six months from a prominent Taiwan-based social forum before the 2018 national election and applied a series of statistical analyses to screen out potential targets. From the results, we successfully identified several accounts according to distinctive characteristics that corresponded to professional users. According to the findings, users and platforms could realize potential information manipulation and increase the transparency of the online society.
Job Performance Model Based on Employees’ Dynamic Capabilities (EDC)
Authors: Bieńkowska Agnieszka , Tworek Katarzyna
Published: March 2020

This article concerns the newly developed construct—EDC (Employees’ Dynamic Capabilities)—and the mechanism of its influence on the job performance of contemporary employees aiming to contribute to the sustainable development of organizations. EDC seems to be especially important in a modern, dynamically changing work environment, in which obtaining sustainability is not possible without dynamic capabilities, and EDC should be included as the element of organizational dynamic capabilities. The paper aims to define and characterize EDC and then develop a mediation model of EDC influence on job performance, introducing the person–job fit, work motivation, job satisfaction, work engagement and organizational commitment as potential mediators related to sustainable development. The model is empirically verified based on the sample of 550 employees from Poland and USA (research carried out in December 2018) using factors analysis for verification of EDC as a new construct and then regression analysis with mediators for the verification of the proposed model. The results confirmed the role of person–job fit, work motivation, job satisfaction and work engagement as mediators of the analyzed relation, underlining the mechanism of the EDC influence on job performance. The empirical research confirms that EDC influences job performance in a way that is crucial for achieving sustainable development of organizations.
Thermal Comfort Improvement for Atrium Building with Double-Skin Skylight in the Mediterranean Climate
Authors: Sokkar Refaa , Alibaba Halil Z.
Published: March 2020

Atria are added to buildings for their aesthetical, environmental, and economic benefits; the appropriate atrium design can enhance an atrium’s thermal performance and the adjacent spaces’ temperatures. However, inappropriate design decisions cause thermal discomfort and consequently, higher energy consumption. Since the Mediterranean climate has diverse climatic conditions around the year, a central atrium with a top-lit skylight is recommended, but during the summer period it can cause overheating, and the insertion of shading elements shrinks the lighting performance: thus, the atrium skylight design is supposed to improve thermal comfort without affecting the lighting level. This study investigated the improvement of thermal performance in the atrium building by the implementation of a double-skin skylight (DSS) to enhance the atrium thermal performance without shading. The research conducted computer simulations with Environmental Design Solutions (EDSL) Tas software sequentially. The study prepared various design strategies, and different proposals were tested and compared in terms of indoor temperatures, with reference to American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE-55). The implementation of DSS achieved an average of 77% comfort in working hours around the year with different opening percentages according to the outdoor conditions. Moreover, results show that changing the DSS glazing materials did not affect the thermal performance of the atrium.
Grass–Legume Forage Systems Effect on Phosphorus Removal from a Grassland Historically Irrigated with Reclaimed Wastewater
Authors: Mclennon Everald , Solomon Juan K. Q. , Davison Jason
Published: March 2020

The utilization of reclaimed wastewater is a suitable and sustainable approach to agriculture production in water-scarce regions. However, even though the wastewater is treated to reduce nutrient concentration such as phosphorus, the 10,600 to 14,006 m3 of water applied ha−1 year−1 on grass and alfalfa hay crops in Nevada can lead to soil phosphorus buildup over an extended period. This study evaluated the effectiveness of forage systems (FS) of monoculture grass, monoculture legume, and their mixtures on herbage accumulation, tissue phosphorus concentration, and quantity of phosphorus removed from a grassland under wastewater irrigation. The study was carried out at the Main Station Field laboratory in Reno, Nevada, USA. A total of 23 FS using tall fescue (Schedonorus arundinaceus (Schreb.) Dumort), alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.) and white clover (Trifolium repens L.) in monocultures or grass–legume mixtures (25:75, 50:50, and 75:25) based on seeding rate were used. The response variables were herbage accumulation (HA), tissue phosphorus concentration, and phosphorus removal. Forage systems means were considered different P ≤ 0.05. Herbage accumulation, tissue phosphorus concentration, and phosphorus removal differed among FS and year. Herbage accumulation was similar for the grass monocultures (10.5 Mg ha−1; SE = 1.1) and the majority of the grass–legume mixtures (9.0 Mg ha−1; SE = 1.1) but both systems had greater HA than legumes monoculture (4.3 Mg ha−1; SE = 1.1). The legume monocultures of alfalfa and white clover had the greatest phosphorus concentrations (10.9 g kg−1 dry matter; SE = 0.44) among all FS. Total phosphorus removed was least among legume monocultures (34.0 kg P ha−1; SE = 6.2) in this study and generally similar for grass monocultures (67.4 kg P ha−1; SE = 6.2) and grass–legume mixtures of 75:25 (61.7 kg P ha−1; SE = 6.2). Based on the response variables, agronomic, and environmental considerations a grass–legume mixture that includes 75:25 or even a 50:50 seeding rate ratio will be suitable options for phosphorus removal from phosphorus enriched grasslands in semiarid ecosystems that utilized wastewater for irrigation.
A Bimodal Discrete Shifted Poisson Distribution. A Case Study of Tourists’ Length of Stay
Authors: Gómez-Déniz Emilio , Pérez-Rodríguez Jorge Vicente , Reyes Jimmy , Gómez Héctor W.
Published: March 2020

Although the Poisson distribution is appropriate for modelling equi-dispersed distributions, it reflects bimodality less well. In this paper, we propose a distribution which is more suitable for the latter purpose. It can be fitted to both positively and negatively skewed data and appears to represent overdispersion phenomena correctly in count data models obtained using a Poisson distribution. Furthermore, the distribution can be normalised in terms of its mean value, and therefore covariates can be included. Our empirical results are based on tourists’ length of stay in the Canary Islands (Spain), a popular holiday destination. The study analyses data supplied by the Canary Islands Tourist Expenditure Survey. Our findings show that the model presented is valid and that the fit obtained is reasonably good.
Post Quantum Integral Inequalities of Hermite-Hadamard-Type Associated with Co-Ordinated Higher-Order Generalized Strongly Pre-Invex and Quasi-Pre-Invex Mappings
Authors: Kalsoom Humaira , Rashid Saima , Idrees Muhammad , Safdar Farhat , Akram Saima , Baleanu Dumitru , Chu Yu-Ming
Published: March 2020

By using the contemporary theory of inequalities, this study is devoted to proposing a number of refinements inequalities for the Hermite-Hadamard’s type inequality and conclude explicit bounds for two new definitions of ( p 1 p 2 , q 1 q 2 ) -differentiable function and ( p 1 p 2 , q 1 q 2 ) -integral for two variables mappings over finite rectangles by using pre-invex set. We have derived a new auxiliary result for ( p 1 p 2 , q 1 q 2 ) -integral. Meanwhile, by using the symmetry of an auxiliary result, it is shown that novel variants of the the Hermite-Hadamard type for ( p 1 p 2 , q 1 q 2 ) -differentiable utilizing new definitions of generalized higher-order strongly pre-invex and quasi-pre-invex mappings. It is to be acknowledged that this research study would develop new possibilities in pre-invex theory, quantum mechanics and special relativity frameworks of varying nature for thorough investigation.
Special Issue “Kinetic Theory and Swarming Tools to Modeling Complex Systems—Symmetry problems in the Science of Living Systems”—Editorial and Research Perspectives
Authors: Bellomo Nicola , Knopoff Damián A. , Terna Pietro
Published: March 2020

This editorial paper presents a special issue devoted to the development of mathematical tools from kinetic and swarms theory to the modeling and simulations of the dynamics of living systems constituted by very many interacting living entities. Applications refer to several fields: collective learning, behavioral economy, multicellular systems, vehicular traffic, and human crowds. A forward look to research perspectives is focused on the conceptual links between swarms methods and the kinetic theory approach.
Efficacy of Divinylbenzenic Resin in Removing Indoxyl Sulfate and P-cresol Sulfate in Hemodialysis Patients: Results from an In Vitro Study and an In Vivo Pilot Trial (xuanro4-Nature 3.2)
Authors: Rocchetti Maria Teresa , Cosola Carmela , di Bari Ighli , Magnani Stefania , Galleggiante Vanessa , Scandiffio Letizia , Dalfino Giuseppe , Netti Giuseppe Stefano , Atti Mauro , Corciulo Roberto , Gesualdo Loreto
Published: March 2020

High serum levels of microbiota-derived uremic toxins, indoxyl sulfate (IS) and p-cresyl sulfate (PCS), are associated with chronic kidney disease (CKD) progression and cardiovascular complications. IS and PCS cannot be efficiently removed by conventional hemodialysis (HD), due to their high binding affinity for albumin. This study evaluates the efficacy of a divinylbenzene-polyvinylpyrrolidone (DVB-PVP) cartridge and a synbiotic to reduce uremic toxins in HD patients. First, the in vitro efficacy of DVB-PVP in adsorbing IS and PCS was evaluated. Second, a randomized, placebo-controlled pilot study in HD patients was carried out to establish whether the administration of a synbiotic, either individually and in association with DVB-PVP-HD, could reduce the production of uremic toxins. In vitro data showed that DVB-PVP resin removed a mean of 56% PCS and around 54% IS, after 6 h of perfusion. While, in the in vivo study, the DVB-PVP cartridge showed its adsorbing efficacy only for IS plasma levels. The combination of synbiotic treatment with DVB-PVP HD decreased IS and PCS both at pre- and post-dialysis levels. In conclusion, this study provides the first line of evidence on the synergistic action of gut microbiota modulation and an innovative absorption-based approach in HD patients, aimed at reducing plasma levels of IS and PCS.
Occurrence of Fungi and Fungal Toxins in Fish Feed during Storage
Authors: Pietsch Constanze , Müller Georg , Mourabit Sulayman , Carnal Simon , Bandara Kasun
Published: March 2020

Periods of unfavorable storing conditions can lead to changes in the quality of fish feeds, as well as the development of relevant mycotoxins. In the present study, a commercial fish feed was stored under defined conditions for four weeks. The main findings indicate that even storing fish feeds under unsuitable conditions for a short duration leads to a deterioration in quality. Mycotoxin and fungal contamination were subsequently analyzed. These investigations confirmed that different storage conditions can influence the presence of fungi and mycotoxins on fish feed. Notably, ochratoxin A (OTA) was found in samples after warm (25 °C) and humid (>60% relative humidity) treatment. This confirms the importance of this compound as a typical contaminant of fish feed and reveals how fast this mycotoxin can be formed in fish feed during storage.
An Acetylcholinesterase Inhibition-Based Biosensor for Aflatoxin B1 Detection Using Sodium Alginate as an Immobilization Matrix
Authors: Chrouda Amani , Zinoubi Khouala , Soltane Raya , Alzahrani Noof , Osman Gamal , Al-Ghamdi Youssef O. , Qari Sameer , Al Mahri Albandary , Algethami Faisal K. , Majdoub Hatem , Jaffrezic Renault Nicole
Published: March 2020

In this study, we investigated a novel aflatoxin biosensor based on acetylcholinesterase (AChE) inhibition by aflatoxin B1 (AFB1) and developed electrochemical biosensors based on a sodium alginate biopolymer as a new matrix for acetylcholinesterase immobilization. Electrochemical impedance spectroscopy was performed as a convenient transduction method to evaluate the AChE activity through the oxidation of the metabolic product, thiocholine. Satisfactory analytical performances in terms of high sensitivity, good repeatability, and long-term storage stability were obtained with a linear dynamic range from 0.1 to 100 ng/mL and a low detection limit of 0.1 ng/mL, which is below the recommended level of AFB1 (2 µg/L). The suitability of the proposed method was evaluated using the samples of rice supplemented with AFB1 (0.5 ng/mL). The selectivity of the AChE-biosensor for aflatoxins relative to other sets of toxic substances (OTA, AFM 1) was also investigated.
Analysis of Covalently Bound Microcystins in Sediments and Clam Tissue in the Sacramento–San Joaquin River Delta, California, USA
Authors: Bolotaolo Melissa , Kurobe Tomofumi , Puschner Birgit , Hammock Bruce G , Hengel Matt J. , Lesmeister Sarah , Teh Swee J.
Published: March 2020

Harmful cyanobacterial blooms compromise human and environmental health, mainly due to the cyanotoxins they often produce. Microcystins (MCs) are the most commonly measured group of cyanotoxins and are hepatotoxic, neurotoxic, and cytotoxic. Due to MCs ability to covalently bind to proteins, quantification in complex matrices is difficult. To analyze bound and unbound MCs, analytical methods were optimized for analysis in sediment and clam tissues. A clean up step was incorporated to remove lipids, improving percent yield. This method was then applied to sediment and clam samples collected from the Sacramento–San Joaquin River Delta (Delta) in the spring and fall of 2017. Water samples were also tested for intracellular and extracellular MCs. These analyses were used to quantify the partitioning of MCs among sediment, clams, and water, and to examine whether MCs persist during non-summer months. Toxin analysis revealed that multiple sediment samples collected in the Delta were positive for MCs, with a majority of the positive samples from sites in the San Joaquin River, even while water samples from the same location were below detection limit. These data highlight the importance of analyzing MCs in complex matrices to accurately evaluate environmental risk.
Correction: Tabassum Abbasi et al., Modelling Methane and Nitrous Oxide Emissions from Rice Paddy Wetlands in India Using Artificial Neural Networks (ANNs). Water 2019, 11, 2169
Authors: Abbasi Tabassum , Abbasi Tasneem , Luithui Chirchom , Abbasi S. A.
Published: March 2020

The authors wish to make the following corrections to this paper [...]
Incorporating Rainwater Harvesting Systems in Iran’s Potable Water-Saving Scheme by Using a GIS-Simulation Based Decision Support System
Authors: Chiu Yie-Ru , Aghaloo Kamaleddin , Mohammadi Babak
Published: March 2020

Rainwater harvesting systems (RWHSs) have been accepted as a simple and effective approach to ease the worsening of urban water stress. However, in arid and semiarid regions, a comprehensive method for promoting domestic RWHSs in a large-scale water-saving scheme that incorporates water consumption reducing equipment (WCRE) and gray water reuse (GWR), has not been well developed. For this, based on the case study of Guilan Province, Iran, this study addressed the temporal-spatial complex of rainfall and proposed a GIS-simulation-based decision support system (DSS). Herein, two scenarios, i.e., the typical RWHS and the modified RWHS for arid areas, were tested; and the associated economic analysis was performed and compared with WCRE and GWR. Moreover, for larger-scale implementation, the multiple criteria decision making (MCDM) technique was further applied to address the social-environmental complexity of these water-saving methods. Guilan Province has thereby been classified into three priority levels, providing a straightforward understanding of how to promote the large-scale water-saving scheme. Compared with the traditional generalized method, sensitivity analysis verified that this DSS enhanced the information value. Hence, the DSS that provides more holistic and comprehensive support has been identified as a useful tool to ease the threat of urban water stress.
History of Hygiene Focusing on the Crucial Role of Water in the Hellenic Asclepieia (i.e., Ancient Hospitals)
Authors: Angelakis Andreas N. , Antoniou Georgios P. , Yapijakis Christos , Tchobanoglous George
Published: March 2020

Prehistoric Hellenic civilizations like many other civilizations believed in gods and thought they had influence on the everyday life of the people. During the Bronze Ages the explanations of illness and health problems were based on mythological, divine, or religious (i.e., theocratic) reasoning or explanations. However, during the Classical and the Hellenistic periods, the Greeks clearly differentiated their thinking from all other civilizations by inventing philosophy and empirical science. Drains/sewers, baths and toilets and other sanitary installations reflect the high cultural and technological level of the period; they are also associated with hygienic and medical studies and practical applications. At that time, medicine was mainly based on clinical observations and scientific investigations. Prior to that time, in the Bronze Age, medicine was entirely confined to religious rituals and beliefs. In ancient Greece, medicine was practiced in Asclepieia (or Asklepieia), which were healing sanctuaries which also functioned as medical schools and hospitals. In the Classical Greece period, more than 400 Asclepieia were operating offering their medical services. The basic elements of each Asclepieia included a clean source of water and related infrastructure. At that time Hippocrates, the father of medicine, and his successors wrote a large number of medical texts in which the crucial role of water and sanitation is documented. They also identified numerous medical terms, many of which remain in use today. The Hippocratic treatises also contributed to the scientific evolution which occurred in later centuries, because they sought to explain the causes of observed natural phenomena in a deterministic way rather than on theocratic explanations in use at the time. In this paper, the evolution of hygiene, focusing on water use in ancient Greece is examined.
Projections of Future Climate Change in the Vu Gia Thu Bon River Basin, Vietnam by Using Statistical DownScaling Model (SDSM)
Authors: Phuong Dang Nguyen Dong , Duong Trung Q. , Liem Nguyen Duy , Tram Vo Ngoc Quynh , Cuong Dang Kien , Loi Nguyen Kim
Published: March 2020

Future projections of anthropogenic climate change play a pivotal role in devising viable countermeasures to address climate-related risks. This study strove to construct future daily rainfall and maximum and minimum temperature scenarios in Vu Gia Thu Bon river basin by employing the Statistical DownScaling Model (SDSM). The model performance was evaluated by utilizing a Taylor diagram with dimensioned and dimensionless statistics. During validation, all model-performance measures show good ability in simulating extreme temperatures and reasonable ability for rainfall. Subsequently, a set of predictors derived from HadCM3 and CanESM2 was selected to generate ensembles of each climatic variables up to the end of 21st century. The generated outcomes exhibit a consistent increase in both extreme temperatures under all emission scenarios. The greatest changes in maximum and minimum temperature were predicted to increase by 2.67–3.9 °C and 1.24–1.96 °C between the 2080s and reference period for the worst-case scenarios. Conversely, there are several discrepancies in the projections of rainfall under different emission scenarios as well as among considered stations. The predicted outcomes indicate a significant decrease in rainfall by approximately 11.57%–17.68% at most stations by 2099. Moreover, all ensemble means were subjected to the overall and partial trend analysis by applying the Innovative-Şen trend analysis method. The results exhibit similar trend patterns, thereby indicating high stability and applicability of the SDSM. Generally, it is expected that these findings will contribute numerous valuable foundations to establish a framework for the assessment of climate change impacts at the river basin scale.
Trends in Ozonation Disinfection By-Products—Occurrence, Analysis and Toxicity of Carboxylic Acids
Authors: Pulicharla Rama , Proulx François , Behmel Sonja , Sérodes Jean-B. , Rodriguez Manuel J.
Published: March 2020

Ozonation is becoming a common disinfection method for drinking water treatment. This has prompted the investigation of ozonation disinfection by-products (ODBPs) in drinking water. Ozonation generates a diverse range of carbonyl disinfection by-products, including carboxylic acids, aldehydes, ketones and aldo-ketoacids. Among these ODBPs, carboxylic acid by-products (CABPs) are observed in higher concentrations compared to other carbonyl by-products. However, relatively little research has been conducted on CABPs, including their precursors, formation and occurrence, methods of detection and toxicity. This review outlines the occurrence and variability of CABPs in a number of water sources treated and disinfected with ozonation. It considers the effect of ozonation parameters, including ozone dose, temperature and time of ozonation on the formation of CABPs. The review also discusses the various analytical approaches for CABP quantification, as well as their possible toxicity in drinking water.
Response of Zooplankton Indices to Anthropogenic Pressure in the Catchment of Field Ponds
Authors: Kuczyńska-Kippen Natalia
Published: March 2020

As methods for assessing the environmental conditions in ponds are still not well developed, I studied zooplankton to identify a response of community indices to abiotic, biotic, and habitat type in two types of ponds differing in the level of human stress. Ponds of low human alterations (LowHI) harbored generally richer communities and a higher share littoral zooplankton, whose occurrence was associated with higher water transparency and complex macrophyte habitat, particularly the presence of hornworts and charoids. In high human-impact ponds (HighHI) planktonic communities prevailed. Their distribution was mainly related to the open water area and fish presence. Anthropogenic disturbance was also reflected in the frequency of rare species, which were associated with LowHI ponds. Higher diversity of zooplankton increased the chance for rare species to occur. Despite the fact that the majority of rare species are littoral-associated, they had no prevalence towards a certain ecological type of plants, which suggests that any kind of plant cover, even macrophytes typical for eutrophic waters (e.g., Ceratophyllum demersum) will create a valuable habitat for conservation purposes. Thus, it is postulated that a complex and dense cover of submerged macrophytes ought to be maintained in order to improve the ecological value of small water bodies.
A Definition of Aquaculture Intensity Based on Production Functions—The Aquaculture Production Intensity Scale (APIS)
Authors: Oddsson Guðmundur Valur
Published: March 2020

Aquaculture intensity has been used for years as a means to gauge how much production a site makes using three terms: extensive, semi-intensive and intensive aquaculture production systems. The industry has a relatively coordinated understanding of these terms, but an explicit general definition does not seem to exist. This paper aims to use three kinds of production function groups; the input, treatment and output functions to describe and define the terms extensive, semi-intensive and intensive explicitly. This is done with extensive literature review to find the meaning of the terms. The terms are then mapped onto the three production function groups. The resulting framework accomplishes two things. Firstly, it defines extensive, semi-intensive and intensive aquaculture in terms of production functions. Secondly, it creates an eight level scale, the aquaculture production intensity scale (APIS), that provides three levels of extensive systems, two level of semi-intensive systems and three level of intensive systems. APIS allows mapping of all uses of the terms in current literature to an APIS score, though some results might differ from current usage.
Earthquake-Induced Spring Discharge Modifications: The Pescara di Arquata Spring Reaction to the August–October 2016 Central Italy Earthquakes
Authors: Valigi Daniela , Fronzi Davide , Cambi Costanza , Beddini Giulio , Cardellini Carlo , Checcucci Roberto , Mastrorillo Lucia , Mirabella Francesco , Tazioli Alberto
Published: March 2020

Co-seismic changes in groundwater regime are often observed after moderate to strong earthquakes. The 24 August 2016 Mw 6.0 extensional Amatrice earthquake, which was the first event of a long-lasting seismic sequence, including the 30 October 2016 Mw 6.5 Norcia event, triggered a significant discharge alteration to the Pescara di Arquata spring, located in the Umbria-Marche Apennines (Northern Apennines, Central Italy) and exploited for drinking purposes. During the first five months after the first mainshock, an extra flow of about 30% was recorded, while both water chemistry and temperature did not show significant changes. Thereafter, the spring discharge decreased significantly, and at the end of 2019 it was still lower than normal. The Standardized Precipitation Index (SPI) indicates that these low mean monthly discharge values are not related to particularly dry conditions. The increase in post-seismic depletion coefficients indicates that the aquifer empties faster than it did during the inter-seismic period. The observed transient increase and subsequent decrease of discharge are consistent with a transient, earthquake-related increase in hydraulic conductivity.
Emerging Issues and Methodologies for Resilient and Robust Water Distribution Systems
Authors: Jung Donghwi , Kim Joong Hoon
Published: March 2020

This editorial summarizes the 11 papers published in the Special Issue entitled “Resilient and Robust Water Distribution Systems: State-of-the-Art and Research Challenges” which were classified into five themes related to water distribution systems (WDSs): (1) state-of-the-art review on WDS resilience and robustness (ROB), (2) WDS performance quantification and recovery under earthquakes, (3) criticality analysis and visualization, (4) novel design methodologies, and (5) hydraulic parameter monitoring for WDS rapidity improvement. Following the provision of the number of views and citations of each paper in a brief manner, a paper in category (1) that reviewed recent studies on WDS robustness is summarized. Category (2) covers three papers on improving the WDS capacity to fulfil customers’ demands in the case of an earthquake, a representative catastrophic failure event, while category (3) includes papers on visualization methods to represent the system’s criticality. The studies included in themes (4) and (5) proposed novel design methods and monitoring approaches for improving WDS resilience, respectively. Contributions from each study are described in the context of WDS resilience. We hope that this Special Issue can (1) serve as a reference point from which readers review progress, recent trends, and emerging issues, and (2) shed light on the appropriate future directions of WDS resilience studies.
Deciphering Morphological Changes in a Sinuous River System by Higher-Order Velocity Moments
Authors: Taye Jyotismita , Barman Jyotirmoy , Kumar Bimlesh , Oliveto Giuseppe
Published: March 2020

Bank erosion in a sinuous alluvial channel is a continuous phenomenon resulting in bank instability and migration of sediment. In this study, flume experiments were conducted in a sinuous channel to investigate its morphological changes and hydrodynamics. High-order velocity fluctuation moments are analyzed at outer and inner banks to explain the morphological variation in a sinuous river channel. The variance of streamwise velocity fluctuations on both banks of the sinuous channel follows a logarithmic law from a particular depth. In the outer bend region, the magnitude of velocity fluctuation moment is significant, indicating erosion. The trend of velocity fluctuation at higher even-order moments is similar to the variance of streamwise velocity fluctuations where the outer bend magnitude is greater than the inner bend. The premultiplied probability density functions (PDFs) and the flatness factor show greater magnitude in the outer bend of the channel as compared to the inner bend.
Evaluating the Water Holding Capacity of Multilayer Soil Profiles Using Hydrus-1D and Multi-Criteria Decision Analysis
Authors: Wang Xin , Zhao Yanling , Liu Huifang , Xiao Wu , Chen Shuzhao
Published: March 2020

In semi-arid climate regions of China, vegetation restoration on open pit mining lands is limited by soil moisture. However, multi-layered soil profiles can impede water infiltration into deeper underground, leaving more water stored in the root zone. Here, three types of soils with contrasting texture, sandy loam (SL), sand (S), and silt loam (SiL), were used to construct four multilayer profiles: SL-SiL, SL-S, SL-S-SiL, and SL-SiL-S. Silt loam was taken from the humus layer, which is more conducive to plant growth than other layers, and it was allocated to the first layer in the four profiles, while sand and silt loam underlay the silt loam layer. Column experiments and Hydrus-1D simulation of the vertical infiltration and drainage process were performed: (1) The simulated results showed that when the sand layer underlay the sandy loam layer (SL-SiL and SL-S-SiL), the sandy loam layer could hold more water than the silt loam layer underlaying the sandy loam layer (SL-SiL and SL-SiL-S). The water content of the sandy loam layer in SL-SiL (95 cm) and SL-S-SiL (95 cm) was 28.3% higher than SL-SiL (74 cm) and 10.5% higher than SL-SiL-S (86 cm). (2) Both the measured and simulated cumulative infiltration and wetting front penetration time were positively related to the thickness of the silt loam layer and negatively related to the thickness of the sand layer. (3) The simulated infiltration rate, accumulation infiltration, and wetting front of the first layer were unaffected by the texture of the underlying layer. According to multi-criteria decision analysis, SL-S-SiL had the best water holding capacity and was suggested for land reclamation in the open pit mine in our research.
Statistical Analysis and Thermodynamic Equilibrium Modelling for Chemical Composition of Groundwater and Spring Water at Jeju Island, South Korea
Authors: Lee Byeong Dae , Jeong Chan Ho , Lee Yong Cheon , Lee Yu Jin , Yang Jae Ha , Choo Chang Oh , Jang Hyeon Woo , Oh Yong Hwa , Hong Jin Woo
Published: March 2020

The purpose of this study is to delineate the main contributions controlling the chemical composition of groundwater and spring water samples at Jeju Island, South Korea. Groundwater and spring water can be grouped as three chemical types: Fresh water (Ca, Na-HCO3), sea water mixing (Na-Cl, SO4) and contamination (Ca-NO3, Cl). By factor analysis, three factors can explain about 87% of chemical variances: Factor 1 (Na+ and Cl−), factor 2 (NO3−), and factors 3 (HCO3−), which are regarded as indicative ions of sea water mixing, contamination and mineral-water interaction, respectively. Sea water intrusion in the southeastern area of Jeju Island is due to downward distribution of Seogwipo Formation, which plays a role as an aquiclude preventing sea water intrusion in other areas, under sea level at the southeastern coastal area. Nitrate contamination is likely to be affected by pollution sources, i.e., agricultural activities, horse farms and municipal sewage. Thermodynamic saturation index indicates that most of waters are undersaturated with respect to major minerals, which may result from insufficient reaction time within a permeable aquifer. The unsaturation state corresponds to low load scores of Ca, Mg, Na, K, and SiO2 in factor 3, which means a low contribution of mineral-water interaction.
Water Management for Sustainable Food Production
Authors: Kannan Narayanan , Anandhi Aavudai
Published: March 2020

The agricultural community has a challenge of increasing food production by more than 70% to meet demand from the global population increase by the mid-21st century. Sustainable food production involves the sustained availability of resources, such as water and energy, to agriculture. The key challenges to sustainable food production are population increase, increasing demands for food, climate change, and climate variability, decreasing per capita land and water resources. To discuss more details on (a) the challenges for sustainable food production and (b) mitigation options available, a special issue on “Water Management for Sustainable Food Production” was assembled. The special issue focused on issues such as irrigation using brackish water, virtual water trade, allocation of water resources, consequences of excess precipitation on crop yields, strategies to increase water productivity, rainwater harvesting, irrigation water management, deficit irrigation, and fertilization, environmental and socio-economic impacts, and irrigation water quality. Articles covered several water-related issues across the U.S., Asia, Middle-East, Africa, and Pakistan for sustainable food production. The articles in the special issue highlight the substantial impacts on agricultural production, water availability, and water quality in the face of increasing demands for food and energy.
Homogeneity in Patterns of Climate Extremes Between Two Cities—A Potential for Flood Planning in Relation to Climate Change
Authors: Abbas Farhat , Farooque Aitazaz A. , Afzaal Hassan
Published: March 2020

Information about potential scenarios and causes of floods is important for future planning. Historical weather data of Fredericton (New Brunswick) and Charlottetown (Prince Edward Island), the two coastal cities of Atlantic Canada, were analyzed using RClimDex, Mann–Kendall test, and Sen’s slope estimates for potential scenarios and causes of floods. Flood hazard analyses were conducted using GIS (Geographical Information System) and ArcSWAT software. The watersheds of Fredericton and Charlottetown were delineated from 25 × 25 m resolution DEMs (Digital Elevation Models) of the two cities followed by percent watershed area calculations for different elevation classes for flood generation. Over the past 100 years, there was a significant decreasing trend in the high intensity precipitation in Charlottetown supported by a significant decrease in the number of heavy precipitation days. However, maximum one-day precipitation and maximum five-day precipitation significantly increased in Charlottetown and Fredericton, respectively. Charlottetown received more annual precipitation than Fredericton. In the last 30 years, there was an event exceeding 50 mm precipitation (considered as a threshold for the return period of urban floods) in Charlottetown; Fredericton experienced such events for more than 1.5 times. For twelve times, these events occurred more than once in a year in Charlottetown as compared to fourteen times in Fredericton. Despite statistically proven similarities in the occurrence of extreme events in the two cities, the visualized flood hazards, and the mapping of watershed characteristics, no devastating floods were reported for Charlottetown. This does not necessarily mean that there had never been risks of flooding in Charlottetown. These findings may help policymakers for future developments.
Net Ecosystem Production of a River Relying on Hydrology, Hydrodynamics and Water Quality Monitoring Stations
Authors: Rojano Fernando , Huber David , Ugwuanyi Ifeoma , Noundou Vadesse , Kemajou-Tchamba Andrielle , Chavarria-Palma Jesus
Published: March 2020

Flow and water quality of rivers are highly dynamic. Water quantity and quality are subjected to simultaneous physical, chemical and biological processes making it difficult to accurately assess lotic ecosystems. Our study investigated net ecosystem production (NEP) relying on high-frequency data of hydrology, hydrodynamics and water quality. The Kanawha River, West Virginia was investigated along 52.8 km to estimate NEP. Water quality data were collected along the river using three distributed multiprobe sondes that measured water temperature, dissolved oxygen, dissolved oxygen saturation, specific conductance, turbidity and ORP hourly for 71 days. Flows along the river were predicted by means of the hydrologic and hydrodynamic models in Hydrologic Simulation Program in Fortran (HSPF). It was found that urban local inflows were correlated with NEP. However, under hypoxic conditions, local inflows were correlated with specific conductance. Thus, our approach represents an effort for the systematic integration of data derived from models and field measurements with the aim of providing an improved assessment of lotic ecosystems.
Real-Time Probabilistic Flood Forecasting Using Multiple Machine Learning Methods
Authors: Nguyen Dinh Ty , Chen Shien-Tsung
Published: March 2020

Probabilistic flood forecasting, which provides uncertain information in the forecasting of floods, is practical and informative for implementing flood-mitigation countermeasures. This study adopted various machine learning methods, including support vector regression (SVR), a fuzzy inference model (FIM), and the k-nearest neighbors (k-NN) method, to establish a probabilistic forecasting model. The probabilistic forecasting method is a combination of a deterministic forecast produced using SVR and a probability distribution of forecast errors determined by the FIM and k-NN method. This study proposed an FIM with a modified defuzzification scheme to transform the FIM’s output into a probability distribution, and k-NN was employed to refine the probability distribution. The probabilistic forecasting model was applied to forecast flash floods with lead times of 1–3 hours in Yilan River, Taiwan. Validation results revealed the deterministic forecasting to be accurate, and the probabilistic forecasting was promising in view of a forecasted hydrograph and quantitative assessment concerning the confidence level.
The Cause and Statistical Analysis of the River Valley Contractions at the Xiluodu Hydropower Station, China
Authors: Li Mingwei , Zhou Zhifang , Zhuang Chao , Xin Yawen , Chen Meng , Wu Jian
Published: March 2020

The Xiluodu Dam is a concrete double-curvature arch dam with a crest elevation of 610 m and a height of 285.5 m. Since the impoundment of the Xiluodu reservoir, remarkable river valley contractions (RVCs) have been observed upstream and downstream of the reservoir, potentially threatening the safety of the dam. However, the cause of these RVCs remains unclear. Based on an analysis of hydrogeological conditions, the RVCs were determined a result of the expansion of the aquifer, within which the effective stress decreased due to an increase in the hydraulic head after reservoir impoundment. Referring to the hydrostatic seasonal time (HST) model, a groundwater hydrostatic seasonal (GHS) model is proposed for simulating and predicting the development of the RVCs. Unlike the HST model, the GHS model can provide information on aquifer hydraulic diffusivity. The calibration results illustrate that the GHS model can accurately fit the observed RVCs data. The calculation results revealed that the RVCs were mainly affected by the hydraulic head of the confined aquifer, and that seasonal effects gave rise to less than 10% of the total RVCs. Finally, the development of RVCs were predicted using the GHS model. The prediction results demonstrated that the RVCs of most monitoring lines in the Xiluodu reservoir would gradually approach a convergence condition after 6 February 2021. Until the deadline of the prediction on 1 May 2035, there is still one monitoring line that has not reached a convergence condition (whose RVCs are 157.6 mm, and where the RVC growth rate will decrease to 0.005 mm/d by that time). Considering the large amount of RVCs, we think the safety of the dam requires closer consideration.
Effect of Photooxidation on Nanofiltration Membrane Fouling During Wastewater Treatment from the Confectionery Industry
Authors: Marszałek Anna , Puszczało Ewa
Published: March 2020

The research in this article aimed to present the possibilities of wastewater treatment coming from the confectionery plant in the nanofiltration (NF) process and the use of photooxidation to mitigate membrane fouling. The process was carried out initially in a dead-end flow system, where the most favorable membrane was selected. Next, the purification efficiency and blocking intensity of this membrane in the system were compared with cross flow. The next research involved the use of a photolytic oxidation process to pretreat sugar wastewater. UV radiation was emitted by a medium pressure mercury UV lamp model TQ 150 V. The effectiveness of the process was also evaluated based on the degree of pollutant load removal. The evaluation of the efficiency of a treatment process was based on the change of wastewater quality indicators before and after the membrane process. The following parameters were controlled: color, COD (chemical oxygen demand), TOC (total organic carbon), absorbance of UV254, nitrate, phosphate, ammonium, conductivity, and pH. During the course of pressure filtration, the following properties of the membrane were determined: the dependence of the volumetric flux of the permeate on the process duration, the permeability of the membrane, as well as the contact angle of the membranes. It was found that the use of UV reduced the phenomenon of fouling of nanofiltration membranes. The value of the permeate volumetric flow after the hour of running the process increased by 17%. However, no impact of UV on the efficiency of wastewater treatment was found. However, the NF process provided the required quality of treated wastewater that can be reused in industrial applications. The NF process resulted in a total decrease in absorbance, 99% TOC removal, and 98% color removal.
Detailed Quantification of the Reduction Effect of Roof Runoff by Low Impact Development Practices
Authors: Zhang Pu , Chen Lei , Hou Xiaoshu , Wei Guoyuan , Zhang Xiaoyue , Shen Zhenyao
Published: March 2020

Low impact development (LID) has been widely applied to mitigate urban rainwater problems since the 1990s. However, the effect of LID practices has seldom been evaluated in detail. In this study, the effect of individual and combined LID practices on the reduction of roof runoff are specifically quantified considering the hydrological relationship between LID at the building scale and the campus scale at Beijing Normal University (BNU). The results show that individual and combined LID practices effectively reduce roof runoff for all types of rainfall and for rainfall with return periods from 0.5 to 50 years at the building scale. Combination scenarios maintain good performance with fewer areas of composed LID. Most values for the effect of combination scenarios are between the effects of composed LID. To achieve the highest cost efficiency, low elevation greenbelts should be the first choice, and green roofs should only be selected when low elevation greenbelts and rain barrels cannot be implemented. At the campus scale, individual and combined LID practices effectively reduce the outflow from and the overflow in the campus and combination scenarios have the best reduction performance. This study provides an important reference for urban water management and LID related decision making.
Trend in Extreme Precipitation Indices Based on Long Term In Situ Precipitation Records over Pakistan
Authors: Bhatti Asher Samuel , Wang Guojie , Ullah Waheed , Ullah Safi , Fiifi Tawia Hagan Daniel , Kwesi Nooni Isaac , Lou Dan , Ullah Irfan
Published: March 2020

Assessing the long-term precipitation changes is of utmost importance for understanding the impact of climate change. This study investigated the variability of extreme precipitation events over Pakistan on the basis of daily precipitation data from 51 weather stations from 1980-2016. The non-parametric Mann–Kendall, Sen’s slope estimator, least squares method, and two-tailed simple t-test methods were used to assess the trend in eight precipitation extreme indices. These indices were wet days (R1 ≥1 mm), heavy precipitation days (R10 ≥ 10 mm), very heavy precipitation days (R20 ≥ 20 mm), severe precipitation (R50 ≥ 50 mm), very wet days (R95p) defining daily precipitation ≥ 95 percentile, extremely wet days (R99p) defining daily precipitation ≥ 99 percentile, annual total precipitation in wet days (PRCPTOT), and mean precipitation amount on wet days as simple daily intensity index (SDII). The study is unique in terms of using high stations’ density, extended temporal coverage, advanced statistical techniques, and additional extreme indices. Furthermore, this study is the first of its kind to detect abrupt changes in the temporal trend of precipitation extremes over Pakistan. The results showed that the spatial distribution of trends in different precipitation extreme indices over the study region increased as a whole; however, the monsoon and westerlies humid regions experienced a decreasing trend of extreme precipitation indices during the study period. The results of the sequential Mann–Kendall (SqMK) test showed that all precipitation extremes exhibited abrupt dynamic changes in temporal trend during the study period; however, the most frequent mutation points with increasing tendency were observed during 2011 and onward. The results further illustrated that the linear trend of all extreme indices showed an increasing tendency from 1980- 2016. Similarly, for elevation, most of the precipitation extremes showed an inverse relationship, suggesting a decrease of precipitation along the latitudinal extent of the country. The spatiotemporal variations in precipitation extremes give a possible indication of the ongoing phenomena of climate change and variability that modified the precipitation regime of Pakistan. On the basis of the current findings, the study recommends that future studies focus on underlying physical and natural drivers of precipitation variability over the study region.