bluuebunny/crossref_metadata_2025 huggingface dataset:
Financial Development and CO2 Emissions in Post-Transition European Union Countries
Authors: Bayar Yilmaz , Diaconu (Maxim) Laura , Maxim Andrei
Published: April 2020

Carbon dioxide emissions are on the rise, posing a serious global issue. Therefore, it is important that policymakers identify the exact causes of these emissions. This paper investigates the influence of financial development, primary energy consumption, and economic growth on CO2 emissions in 11 post-transition European economies. The assessment was made for the 1995–2017 period using panel cointegration and causality analyses. The causality analyses did not reveal significant connection between financial sector development and CO2 emissions, but rather a two-way causality between primary energy consumption and economic growth, on one hand, and CO2 emissions on the other. Meanwhile, long-run analysis disclosed that financial sector development and primary energy consumption positively affected CO2 emissions. Our results seek to grab the attention of policy makers, who could work towards creating country-specific strategies that balance the relationship between financial development and CO2 emissions. These long-term policies could ensure both development of the financial sector and environmental protection.
Are There Local Versions of Sustainability? Food Networks in the Semi-Periphery
Authors: Kopczyńska Ewa
Published: April 2020

The results of many studies of Central and Eastern European food networks suggest that the changes in local food systems are not a delayed repetition of their Western counterparts but have different dynamics resulting from the political and economic circumstances in the countries. To examine the specific sustainability potential of local food networks in Poland, this study compares the collectives based on novel alternative food networks and traditional networks. Drawing on the concept of actant in actor–network theory and content analysis methodology, the study identifies the specificity of these networks. The results show that traditional networks are more focused on the material core of practices, being geographically close, unified, and more specific regarding material actants of the networks. On the other hand, collectives based on Western-style alternative food networks are more widely distributed, reaching out to more abstract and distant actants.
Particles with Negative Energies in Nonrelativistic and Relativistic Cases
Authors: Grib Andrey A. , Pavlov Yuri V.
Published: April 2020

States of particles with negative energies are considered for the nonrelativistic and relativistic cases. In the nonrelativistic case it is shown that the decay close to the attracting center can lead to the situation similar to the Penrose effect for a rotating black hole when the energy of one of the fragments is larger than the energy of the initial body. This is known as the Oberth effect in the theory of the rocket movement. The realizations of the Penrose effect in the non-relativistic case in collisions near the attracting body and in the evaporation of stars from star clusters are indicated. In the relativistic case similar to the well known Penrose process in the ergosphere of the rotating black hole it is shown that the same situation as in ergosphere of the black hole occurs in rotating coordinate system in Minkowski space-time out of the static limit due to existence of negative energies. In relativistic cases differently from the nonrelativistic ones, the mass of the fragment can be larger than the mass of the decaying body. Negative energies for particles are possible in the relativistic case in cosmology of the expanding space when the coordinate system is used with a nondiagonal term in metrical tensor of the space-time. Friedmann metrics for three cases: open, close and quasieuclidian, are analyzed. The De Sitter space-time is shortly discussed.
Bottom-Up Assessment of Climate Risk and the Robustness of Proposed Flood Management Strategies in the American River, CA
Authors: DiFrancesco Kara , Gitelman Alix , Purkey David
Published: April 2020

The hydrologic nonstationarity and uncertainty associated with climate change requires new decision-making methods to incorporate climate change impacts into flood frequency and flood risk analyses. To aid decision-making under climate change, we developed a bottom-up approach for assessing the performance of flood management systems under climate uncertainty and nonstationarity. The developed bottom-up approach was applied to the American River, CA, USA flood management system by first identifying the sensitivity and vulnerability of the system to different climates. To do this, we developed a climate response surface by calculating and plotting Expected Annual Damages (EAD, $/year) under different flood regimes. Next, we determined a range of plausible future climate change and flood frequency scenarios by applying Bayesian statistical methods to projected future flows derived from a Variable Infiltration Capacity (VIC) model forced with Global Circulation Model (GCM) output. We measured system robustness as the portion of plausible future scenarios under which the current flood system could meet its performance goal. Using this approach, we then evaluated the robustness of four proposed management strategies in the 2012 Central Valley Flood Protection Plan in terms of both flood risk and cost-effectiveness, to assess the performance of the strategies in the face of climate risks. Results indicated that the high sensitivity of the expected damages to changes in flood regimes makes the system extremely vulnerable to a large portion of the plausible range of future flood conditions. The management strategy that includes a combination of nature-based flood management actions along with engineered structures yields the greatest potential to increase system robustness in terms of maintaining EAD below an acceptable risk threshold. However, this strategy still leaves the system vulnerable to a wide range of plausible future conditions. As flood frequency regimes increase in intensity from the current conditions, the cost-effectiveness of the management strategies increases, to a point, before decreasing. This bottom up analysis demonstrated a viable decision-making approach for water managers in the face of uncertain and changing future conditions. Neglecting to use such an approach and omitting climate considerations from water resource planning could lead to strategies that do not perform as expected or which actually lead to mal-adaptations, increasing vulnerability to climate change.
Numerical Simulation of Unstable Preferential Flow during Water Infiltration into Heterogeneous Dry Soil
Authors: Cueto-Felgueroso Luis , Suarez-Navarro María José , Fu Xiaojing , Juanes Ruben
Published: April 2020

Water infiltration and unsaturated flow through heterogeneous soil control the distribution of soil moisture in the vadose zone and the dynamics of groundwater recharge, providing the link between climate, biogeochemical soil processes and vegetation dynamics. Infiltration into dry soil is hydrodynamically unstable, leading to preferential flow through narrow wet regions (fingers). In this paper we use numerical simulation to study the interplay between fingering instabilities and soil heterogeneity during water infiltration. We consider soil with heterogeneous intrinsic permeability. Permeabilities are random, with point Gaussian statistics, and vary smoothly in space due to spatial correlation. The key research question is whether the presence of moderate or strong heterogeneity overwhelms the fingering instability, recovering the simple stable displacement patterns predicted by most simplified model of infiltration currently used in hydrological models from the Darcy to the basin scales. We perform detailed simulations of constant-rate infiltration into soils with isotropic and anisotropic intrinsic permeability fields. Our results demonstrate that soil heterogeneity does not suppress fingering instabilities, but it rather enhances its effect of preferential flow and channeling. Fingering patterns strongly depend on soil structure, in particular the correlation length and anisotropy of the permeability field. While the finger size and flow dynamics are only slightly controlled by correlation length in isotropic fields, layering leads to significant finger meandering and bulging, changing arrival times and wetting efficiencies. Fingering and soil heterogeneity need to be considered when upscaling the constitutive relationships of multiphase flow in porous media (relative permeability and water retention curve) from the finger to field and basin scales. While relative permeabilities remain unchanged upon upscaling for stable displacements, the inefficient wetting due to fingering leads to relative permeabilities at the field scale that are significantly different from those at the Darcy scale. These effective relative permeability functions also depend, although less strongly, on heterogeneity and soil structure.
An Assessment of the Influence of Uncertainty in Temporally Evolving Streamflow Forecasts on Riverine Inundation Modeling
Authors: Feng Youcan , Judi David R. , Rakowski Cynthia L.
Published: April 2020

Continental-scale river forecasting platforms forecast streamflow at reaches that can be used as boundary conditions to drive a local-scale flood inundation model. Uncertainty accumulated during this process stems not only from any part of the forecasting chain but can also be caused by the daily variations in weather forcing that keeps evolving as the event advances. This work aims to examine the influence of the evolving forecast streamflow on predicting the maximum inundation for extreme floods. A diagnostic case study was made on the basis of a hindcast of Hurricane Matthew striking the eastern U.S. in 2016. The U.S. National Water Model was one-way coupled to a hydrodynamic inundation model through a developed automated workflow. Although the river forcing has significantly mismatched hydrographs versus observations, the simulated peak water surface elevations and maximum extents were validated to be comparable with the observations, which indicates that the inundation model may not be sensitive to the inherited uncertainty from the weather forcing. Moreover, the uncertainty of the forecast streamflow time series caused only one order of magnitude fewer variations in inundation prediction; this dampening effect may become clearer for extreme events with large areas inundated. In addition, the forecast total volume of stream discharge appears to be an important metric for assessing the performance of river forcing for inundation mapping, as a linear correlation between the total volume and the accuracy of the predicted peak water surface elevation and maximum extent was found, with the coefficients of determination all above 0.8. Extra best-practice experience of running similar operational tasks demonstrated the tradeoff between the cost and accuracy gain.
New Approaches to Monitor Inequalities in Access to Water and Sanitation: The SDGs in Latin America and the Caribbean
Authors: Queiroz Vitor Carvalho , Carvalho Rodrigo Coelho de , Heller Léo
Published: April 2020

In the 2030 Agenda for Sustainable Development, Targets 6.1 and 6.2 show, in their formulation, some alignment with the normative content of the human rights to water and sanitation (HRWS). However, the principle of equality and non-discrimination, which applies to all human rights, was not clearly incorporated into the indicators adopted to assess and monitor these targets. This paper contributes to bridging this gap by proposing two methodological strategies to address inequalities in analyses of access to water and sanitation services. The first consists in adjusting the indicators of access to these services according to inequality. The second proposes an assessment of intersecting forms of inequality. An application of these methods in Latin America and the Caribbean highlights significant regional heterogeneity and elevated inequality in access to services in the countries of this region. The methods demonstrate their potential in contributing to assessment and monitoring of the SDGs, but outdated or lacking data are obstacles to more in-depth analyses.
The Recovery of Phosphorus from Acidic Ultra-High Phosphorous Wastewater by the Struvite Crystallization
Authors: Li Qiang , Wang Song , Wang Lifang , Zhang Li , Wan Xiaohui , Sun Zhiguo
Published: April 2020

Phosphorus recovery from industrial wastewater has attracted considerable interest. In this study, struvite crystallization method has been used for treatment of high phosphorus wastewater. The new combination agents of Mg5(CO3)4(OH)2·4H2O and NH4Cl were used as the precipitant. The effects of initial pH, n(Mg):n(P), n(N):n(P), and reaction time on the removal of total phosphorus (TP) in wastewater were investigated. The results showed that under the condition of initial pH = 4, Mg:N:P = 1.2:1.1:1, reaction time for 30 min, and static storage for 20 min, the residual amount of TP in wastewater was 2.98 mg /L, and the removal rate of TP reached 99.99%. The mass fraction of P2O5 in the generated sediment reached 25.22%, equivalent to high grade phosphate ore and slow-release fertilizer, so as to realize the recycling and utilization of phosphorus in ultra-high phosphorous wastewater. This work will have practical application potential in treatment of high phosphorus wastewater and environmental management.
Suspended Sediment Transport Responses to Increasing Human Activities in a High-Altitude River: A Case Study in a Typical Sub-Catchment of the Yarlung Tsangpo River
Authors: Huang Zhe , Lin Binliang , Sun Jian , Luozhu Nima , Da Ping , Dawa Jinmei
Published: April 2020

The Yarlung Tsangpo River is one of the highest major rivers in the world. The river is known for its pristine landscape. However, in recent years, increasing human activities, such as inhabitation, afforestation, and infrastructure projects, have significantly disturbed this fluvial system, while their impacts are not fully known. In this study, the water and sediment transport processes in the Nugesha–Yangcun (N–Y) reach of the Yarlung Tsangpo River, as well as the impact of human activity, are investigated. The N–Y sub-catchment consists of two parts, i.e., the Lhasa River catchment and the mainstream catchment. Riverine discharge, suspended sediment concentration (SSC), and precipitation data are acquired, and a detailed investigation is conducted. The water yield has not changed considerably in recent years, while the sediment yield has exhibited a sharp decline, from ~5 Mt to ~1 Mt. The sediment decrease is mainly caused by the reduced sediment source, which is considered highly related to afforestation. In addition, the dominant sediment contributor has changed from the mainstream catchment to the tributary catchment (while the sediment yield in the mainstream catchment has decreased to almost zero). An anomalously enhanced SSC occurred in the Lhasa River in two consecutive years from 2015, with the SSC value increasing sharply from 0.2 kg/m3 to 0.8 kg/m3, and maintaining a high level for approximately three months. This phenomenon is considered to be related to infrastructure projects in the same period, with the SSC recovered after road construction ended. The increasing human activities have had significant impacts on the sediment regimes in the Yarlung Tsangpo River; hence, more attention should be paid to river basin management.
Three-Dimensional Flow Characteristics in Slit-Type Permeable Spur Dike Fields: Efficacy in Riverbank Protection
Authors: Shampa  , Hasegawa Yuji , Nakagawa Hajime , Takebayashi Hiroshi , Kawaike Kenji
Published: April 2020

This paper focuses on finding efficient solutions for the design of a highly permeable pile spur (or slit type) dike field used in morphologically dynamic alluvial rivers. To test the suitability of different arrangements of this type of permeable pile spur dike field, laboratory experiments were conducted, and a three-dimensional multiphase numerical model was developed and applied, based on the experimental conditions. Three different angles to the approach flow and two types of individual pile position arrangements were tested. The results show that by using a series of slit-type spurs, the approach velocity of the flow can be considerably reduced within the spur dike zone. Using different sets of angles and installation positions, this type of permeable spur dike can be used more efficiently than traditional dikes. Notably, this type of spur dike can reduce the longitudinal velocity, turbulence intensity, and bed shear stress in the near-bank area. Additionally, the deflection of the permeable spur produces more transverse flow to the opposite bank. Arranging the piles in staggered grid positions among different spurs in a spur dike field improves functionality in terms of creating a quasi-uniform turbulence zone while simultaneously reducing the bed shear stress. Finally, the efficacy of the slit-type permeable spur dike field as a solution to the riverbank erosion problem is numerically tested in a reach of a braided river, the Brahmaputra–Jamuna River, and a comparison is made with a conventional spur dike field. The results indicate that the proposed structure ensures the smooth passing of flow compared with that for the conventional impermeable spur structure by producing a lower level of scouring (low bed shear stress) and flow intensification.
Predicting Event-Based Sediment and Heavy Metal Loads in Untreated Urban Runoff from Impermeable Surfaces
Authors: Charters Frances J. , Cochrane Thomas A. , O’Sullivan Aisling D.
Published: April 2020

Understanding the amount of pollutants contributed by impermeable urban surfaces during rain events is necessary for developing effective stormwater management. A process-based pollutant load model, named Modelled Estimates of Discharges for Urban Stormwater Assessments (MEDUSA), was further developed (MEDUSA2.0; Christchurch, New Zealand) to include simulations of dissolved metal loadings and improve total suspended solids (TSS) loading estimations. The model uses antecedent dry days, rainfall pH, average event intensity and duration to predict sediment and heavy metal loads generated by individual surfaces. The MEDUSA2.0 improvements provided a moderate to strong degree of fit to observed sediment, copper, and zinc loads for each modelled road and roof surface type. The individual surface-scale modelling performed by MEDUSA2.0 allows for identification of specific source areas of high pollution for targeted surface management within urban catchments.
Mining Activities and the Chemical Composition of R. Modonkul, Transbaikalia
Authors: Khazheeva Zinaida Ivanovna , Plyusnin Aleksey Maksimovich , Smirnova Olga Konstantinovna , Peryazeva Elena Georgievna , Zhambalova Dashima Ivanovna , Doroshkevich Svetlana Gennadievna , Dabaeva Viktoriya Valerievna
Published: April 2020

The Dzhidinsky orefield is located in the Zakamensky district of Buryatia. It is characterized by a high concentration of mineralization in a small area. The ores of the Dzhidinsky economic deposits are complex. This ore field includes Pervomaiskoye Mo, Kholtosonskoe W, and Inkurskoe W deposits. The catchment basin of the river Modonkul is located in the Dzhidinsky orefield. Mineral resource industry waste is a real threat to the city Zakamensk. Currently, the waste of deposits is located at the floodplain terrace and the watershed of the river Modonkul. In this work, the impact of the drainage mine and tributary Inkur on the formation chemical composition of the river Modonkul is studied. The 80 samples of water and suspended matter were taken from a surface of 0–0.5 m on seven sites. Physical and chemical parameters were measured at the sampling sites, and chemical composition was analyzed in the laboratory. In the natural background of the river, the major cations are, in decreasing order, Ca2+ > Mg2+ > Na+ + K+, and major anions are, also in decreasing order, HCO3− > SO42− > Cl−. Along the river, the chemical type of water changes from bicarbonate to sulfate across the sulfate-bicarbonate or bicarbonate-sulfate class and from calcium-magnesium across sodium-calcium-magnesium reverse calcium-magnesium group. Total dissolved solids (TDS) increase by a factor of 4.0–4.7 between the upper and mouth of the river. The dissolved and suspended loads were studied in the mixing zone of acid mine and river water. The different hydrochemistry characteristics may result from Fe, Al, and Mn hydroxide precipitation. The pH values and dissolved oxygen cycles could change the uptake of heavy metals on suspended iron and manganese oxides, and the mechanism of removing it in water. River particulates have the potential of regulating heavy metal inputs to aquatic systems from pollution. The ore elements or the heavy metals are removed from the water in two ways: by the runoff of Modonkul and the sedimentation of suspended material at the bottom. The inflow of mine water into the Modonkul river leads to the rare earth elements (REEs) composition with negative cerium and positive europium anomalies.
Sedimentation and Transport of Different Soil Colloids: Effects of Goethite and Humic Acid
Authors: Chen Yali , Ma Jie , Wu Xiaojuan , Weng Liping , Li Yongtao
Published: April 2020

Soil colloids significantly facilitate the transport of contaminants; however, little is known about the effects of highly reactive iron oxide and the most representative organic matter on the transport of soil colloids with different physicochemical properties. This study investigated the effects of goethite (GT) and humic acid (HA) on the sedimentation and transport of soil colloids using settling and column experiments. The stability of soil colloids was found to be related to their properties and decreased in the following order: black soil colloids (BSc) > yellow soil colloids (YSc) > fluvo-aquic soil colloids (FSc). Organic matter increased the stability of BSc, and ionic strength (Ca2+) promoted the deposition of FSc. Colloids in individual and GT colloids (GTc) coexistence systems tended to stabilize at high pH and showed a pH-dependence whereby the stability decreased with decreasing pH. The interaction of GTc and kaolinite led to a dramatic sedimentation of YSc at pH 4.0. HA enhanced the stability of soil colloids, especially at pH 4.0, and obscured the pH-dependent sedimentation of soil colloids. The transport ability of soil colloids was the same as their stability. The addition of GT retarded the transport of soil colloids, which was quite obvious at pH 7.0. This retardation effect was attributed to the transformation of the surface charge of sand from negative to positive, which increased the electrical double-layer attraction. Although sand coated with GT–HA provided more favorable conditions for the transport of soil colloids in comparison to pure sand, the corresponding transport was relatively slow. This suggests that the filtration effect, heterogeneity, and increased surface roughness may still influence the transport of soil colloids.
Mapping of Groundwater Spring Potential in Karst Aquifer System Using Novel Ensemble Bivariate and Multivariate Models
Authors: Nhu Viet-Ha , Rahmati Omid , Falah Fatemeh , Shojaei Saeed , Al-Ansari Nadhir , Shahabi Himan , Shirzadi Ataollah , Górski Krzysztof , Nguyen Hoang , Ahmad Baharin
Published: April 2020

Groundwater is an important natural resource in arid and semi-arid environments, where discharge from karst springs is utilized as the principal water supply for human use. The occurrence of karst springs over large areas is often poorly documented, and interpolation strategies are often utilized to map the distribution and discharge potential of springs. This study develops a novel method to delineate karst spring zones on the basis of various hydrogeological factors. A case study of the Bojnourd Region, Iran, where spring discharge measurements are available for 359 sites, is used to demonstrate application of the new approach. Spatial mapping is achieved using ensemble modelling, which is based on certainty factors (CF) and logistic regression (LR). Maps of the CF and LR components of groundwater potential were generated individually, and then, combined to prepare an ensemble map of the study area. The accuracy (A) of the ensemble map was then assessed using area under the receiver operating characteristic curve. Results of this analysis show that LR (A = 78%) outperformed CF (A = 67%) in terms of the comparison between model predictions and known occurrences of karst springs (i.e., calibration data). However, combining the CF and LR results through ensemble modelling produced superior accuracy (A = 85%) in terms of spring potential mapping. By combining CF and LR statistical models through ensemble modelling, weaknesses in CF and LR methods are offset, and therefore, we recommend this ensemble approach for similar karst mapping projects. The methodology developed here offers an efficient method for assessing spring discharge and karst spring potentials over regional scales.
Application of Bottom Ash as Filter Media for Construction Site Runoff Control
Authors: Bang Ki Woong , Joo Jin Chul , Kim Jin Ho , Kang Eunbi , Choi Jongsoo , Lee Jung Min , Kim Yonghyok
Published: April 2020

The potential application of bottom ash (BA) for construction site runoff control as an alternative filter media with high removal efficiency of total suspended solids (TSS) and longer operation period were evaluated. Both lab-scale single-layer and pilot-scale multi-layer filtration experiments were performed using BA filter media with different particle sizes and various volumetric flow rates. Due to the mesoporous, irregular, and spherical shape of gravel-size BA filter media used in this study, relatively low surface area, negligible pore volume, and greater pore size were observed. Both TSS removal efficiencies and clogging of BA filter media were a complex function of particle size of BA filter media and loading rate of TSS. Incoming TSS particles did not significantly penetrate beyond 46-cm BA filter media depth, accumulating on the upper layers and gradually forming a clogging layer to critical thickness, and finally the clogging filtration mechanism dominated the overall removal efficiency of TSS. Accumulation of TSS on BA filter media can be explained by the lumped sigmoidal empirical model, and an exponential decline in accumulation of TSS with depth results in minimal accumulation beneath the clogging layer. As practical implications, BA filter media depth of less than 46 cm is recommended with dual- or multi-media filters using mixtures of gravel-size BA and silt-size fine media, and a combination of detention basins can reduce frequent periodic de-clogging operation and management.
Investigate the Applicability of CMADS and CFSR Reanalysis in Northeast China
Authors: Zhang Limin , Meng Xianyong , Wang Hao , Yang Mingxiang , Cai Siyu
Published: April 2020

Reanalysis datasets can provide alternative and complementary meteorological data sources for hydrological studies or other scientific studies in regions with few gauge stations. This study evaluated the accuracy of two reanalysis datasets, the China Meteorological Assimilation Driving Datasets for the Soil and Water Assessment Tool (SWAT) model (CMADS) and Climate Forecast System Reanalysis (CFSR), against gauge observations (OBS) by using interpolation software and statistical indicators in Northeast China (NEC), as well as their annual average spatial and monthly average distributions. The reliability and applicability of the two reanalysis datasets were assessed as inputs in a hydrological model (SWAT) for runoff simulation in the Hunhe River Basin. Statistical results reveal that CMADS performed better than CFSR for precipitation and temperature in NEC with the indicators closer to optimal values (the ratio of standard deviations of precipitation and maximum/minimum temperature from CMADS were 0.92, 1.01, and 0.995, respectively, while that from CFSR were 0.79, 1.07, and 0.897, respectively). Hydrological modelling results showed that CMADS + SWAT and OBS + SWAT performed far better than CFSR + SWAT on runoff simulations. The Nash‒Sutcliffe efficiency (NSE) of CMADS + SWAT and OBS + SWAT ranged from 0.54 to 0.95, while that of CFSR + SWAT ranged from −0.07 to 0.85, exhibiting poor performance. The CMADS reanalysis dataset is more accurate than CFSR in NEC and is a suitable input for hydrological simulations.
Comparative Hydrodynamic Analysis by Using Two−Dimensional Models and Application to a New Bridge
Authors: Mateo-Lázaro Jesús , Castillo-Mateo Jorge , García-Gil Alejandro , Sánchez-Navarro José Ángel , Fuertes-Rodríguez Víctor , Edo-Romero Vanesa
Published: April 2020

This document develops a methodology that evaluates the impact on the environment of the rivers produced by the creation of civil infrastructures. The methodology is based on the two-dimensional hydrodynamic calculation by using shallow water equations both in the conditions prior to the creation of the infrastructure, and in the new conditions after the infrastructure is created. Subsequently, several characteristics, such as water depth and velocity, among others, are compared between the initial and final conditions, and a two-dimensional zoning of the changes observed is obtained. The methodology herein presented is useful to verify the impact that the implantation of different infrastructures around the river currents could produce. In addition, it is also relevant for carrying out a study taking into account different infrastructure options related to river currents, as well as for selecting the most suitable one. By using the methodology presented, changes on the regime of the currents caused by the infrastructures can be deduced, including a qualitative and quantitative zoning of the changes, with a special emphasis on some characteristics, such as depth and velocity. The methodology is applied in a case study for the creation of a road bridge over the Jalon River in Spain.
Analysis of Agricultural Drought Using Remotely Sensed Evapotranspiration in a Data-Scarce Catchment
Authors: Wambura Frank Joseph , Dietrich Ottfried
Published: April 2020

Understanding spatial drought characteristics is vital for planning adaptation and mitigation measures in river catchments. In many parts of the world, spatial drought information is not available due to lack of adequate evenly distributed data for spatial drought analyses. This study elucidates a spatial drought analysis in a data-scarce tropical catchment using remote sensing actual evapotranspiration (ET) and potential evapotranspiration (PET) data. Firstly, the time series of 690 images of remotely sensed ET and PET between the years 2000 and 2014 were spatially analyzed using the evapotranspiration deficit index (ETDI) approach to obtain ETDIs in the Kilombero River catchment (Tanzania). Then, spatio-temporal patterns of ETDIs were used to characterize drought frequency, total drought durations, total drought severity, and drought intensity. The frequency, durations, severity, and intensity of drought increased from the year 2000 towards 2014, causing substantial drought changes in the catchment. However, drought intensity revealed that those changes were mainly from no drought and mild drought to moderate drought. Between the years 2000 and 2014, no-drought areas and mild drought areas declined from 10% to 0% and from 42% to 19%, respectively, whereas moderate drought areas increased from 47% to 81% of the catchment size. Those changes of drought conditions were partly attributed to anthropogenic land cover change, especially in the southwest grasslands, and were partly attributed to meteorological factors in other parts of the catchment. This information is crucial for further land cover change and climate change investigations, as well as planning water and land resources in the Kilombero River catchment. Moreover, the study also demonstrates the potential of using publicly available remote sensing ET products and the ETDI approach for spatially characterizing drought in ungauged regions.
An Improved Model for the Evaluation of Groundwater Recharge Based on the Concept of Conservative Use Potential: A Study in the River Pandeiros Watershed, Minas Gerais, Brazil
Authors: Alvares Tenenwurcel Marcelo , Soares de Moura Maíse , Monteiro da Costa Adriana , Karen Mota Paula , Moreira Viana João Hebert , Fernandes Luís Filipe Sanches , Leal Pacheco Fernando António
Published: April 2020

Water resources have been increasingly impacted due to the growth of water demand associated with environmental degradation. In this context, the mapping of groundwater recharge potential has become attractive to water managers as it can be used to direct public policies and conserve this natural asset. The present study modifies (improves) a spatially explicit model to determine groundwater recharge potential at the catchment scale, testing it in the Pandeiros River basin located in the state of Minas Gerais, Brazil. The model is generally based on the water balance approach and the input variables were compiled from institutional sources and processed in a Geographic Information System. The novelty brought by the aforementioned modification relates to the coupling of physical variables (conventional way) and land management practices (introduced here) in the estimation of a percolation factor. The role of land management practices for percolation was assessed by the so-called Conservative Use Potential (PUC) method, which classifies the areas of a river basin in terms of their potential for sustainable use. The results were validated by an independent method, namely the recession curve method based on the interpretation of hydrographs. In general, the groundwater recharge potential is favored in flat to gently undulating areas and forested regions, as well as where the landscape is characterized by well-structured soils, good drainage conditions and large hydraulic conductivity. The map of groundwater recharge potential produced in this study can be used by planners and decision makers in the Pandeiros River basin as a tool to achieve sustainable use of groundwater resources and the protection of recharge areas.
Temporal Variations of Spring Water in Karst Areas: A Case Study of Jinan Spring Area, Northern China
Authors: Gao Zongjun , Liu Jiutan , Xu Xingyong , Wang Qingbing , Wang Min , Feng Jianguo , Fu Tengfei
Published: April 2020

Jinan is known as “Spring City,” because of its famous 72 artesian springs. Spring water plays an important role in the social and economic development of Jinan. However, the accelerating process of urbanization and more intensive human activities have significantly affected the Jinan springs. Based on the data from four spring groups (2015–2018), the hydrochemical characteristics of spring water were analyzed and 14 parameters were selected to evaluate the quality of spring water. In addition, the main ions variation characteristics of spring water in Jinan from 1958 to 2018 were analyzed, based on the previous studies. Subsequently, the spring flow dynamics of the Jinan spring area from 1958 to 2012 were also discussed. Overall, the water quality of the four spring groups is good. The chemical composition of the spring water is mainly controlled by the dissolution of calcite, followed by dolomite, and de-dolomitization. However, spring water is affected by human activities, and the hydrochemical type tends to evolve from HCO3-Ca to HCO3·SO4-Ca or HCO3-Ca·Mg. From 1958 to 2013, the main ions in spring water increased, while a relatively steady and certain fluctuation trend was observed from 2015 to 2018. Since 1958, the spring water flow in Jinan has experienced four stages, from decline to recovery. The exploitation of karst groundwater, change of land use type, and decrease of atmospheric precipitation are the three most important factors, affecting spring discharge dynamics. The slowdown of the increase of the main ion concentration in Jinan spring water and the resumption of spring water flowing indicate that remarkable achievements have been made to protect spring water, but there is still a long way to go to fully protect Jinan spring water.
Model Analysis and System Parameters Investigation for Transient Wave in a Pump–Pipe–Valve System
Authors: Liu Zubin , Pan Dingyi , Qu Fengzhong , Hu Jianxin
Published: April 2020

The frequency responses of the transient wave propagating in a pump–pipe–valve system are studied with the system transfer matrix analysis (STMA) method. Being different to that in the reservoir–pipe–valve system, the transient wave is used as a long-distance communication technology in the pump–pipe–valve system, and very few works have been done on the model analysis and strategies to control the behavior of the oscillation signal of the pipe pressure. The theoretic solutions are studied with three internal friction models: frictionless, steady friction, and unsteady friction. The dimensionless parameter of the valve signal intensity (VSI) is proposed, and it is found to be a key factor affecting the quality of the wave propagation in the pipe. A larger pressure oscillation at the upstream side results when the VSI is smaller than one, whereas a more uniform amplitude for the resonances and anti-resonances is obtained when VSI approaches one. Some feasible suggestions are provided to obtain high quality wave signals.
Assessing the Cadmium Effects on the Benthic Foraminifer Ammonia cf. parkinsoniana: An Acute Toxicity Test
Authors: Losada Ros María Teresa , Al-Enezi Eqbal , Cesarini Erica , Canonico Barbara , Bucci Carla , Alves Martins Maria Virgínia , Papa Stefano , Frontalini Fabrizio
Published: April 2020

Heavy metals are one of the most hazardous pollutants in marine environments because of their bioaccumulation and biomagnification capabilities. Among them, cadmium (Cd) has been considered as one of the most dangerous for marine organisms. Here we incubated Ammonia cf. parkinsoniana specimens, a benthic foraminiferal taxon used in previous experiments, for up to 48 h in natural seawater with different concentrations of Cd to unravel the physiological change. We document a reduced pseudopodial activity of the Cd-treated specimens at concentrations >10–100 ppb in comparison with the control specimens. Moreover, confocal images of Cd-treated specimens using Nile Red as a fluorescent probe reveal an enhanced intracellular neutral lipid accumulation in the form of lipid droplets at 6 h and 12 h. This bioassay experiment allows for the direct evaluation of Cd-dose to A. cf. parkinsoniana-response relationships under laboratory controlled conditions and provides complementary information to field observations as well as to water quality guidelines and thresholds.
Influence of Farming Intensity and Climate on Lowland Stream Nitrogen
Authors: Goyenola Guillermo , Graeber Daniel , Meerhoff Mariana , Jeppesen Erik , Teixeira-de Mello Franco , Vidal Nicolás , Fosalba Claudia , Ovesen Niels Bering , Gelbrecht Joerg , Mazzeo Néstor , Kronvang Brian
Published: April 2020

Nitrogen lost from agriculture has altered the geochemistry of the biosphere, with pronounced impacts on aquatic ecosystems. We aim to elucidate the patterns and driving factors behind the N fluxes in lowland stream ecosystems differing about land-use and climatic-hydrological conditions. The climate-hydrology areas represented humid cold temperate/stable discharge conditions, and humid subtropical climate/flashy conditions. Three complementary monitoring sampling characteristics were selected, including a total of 43 streams under contrasting farming intensities. Farming intensity determined total dissolved N (TDN), nitrate concentrations, and total N concentration and loss to streams, despite differences in soil and climatic-hydrological conditions between and within regions. However, ammonium (NH4+) and dissolved organic N concentrations did not show significant responses to the farming intensity or climatic/hydrological conditions. A high dissolved inorganic N to TDN ratio was associated with the temperate climate and high base flow conditions, but not with farming intensity. In the absence of a significant increase in farming N use efficiency (or the introduction of other palliative measures), the expected farming intensification would result in a stronger increase in NO3−, TDN, and TN concentrations as well as in rising flow-weighted concentrations and loss in temperate and subtropical streams, which will further exacerbate eutrophication.
Research methods and techniques in new management trends: research results
Authors: Dźwigoł Henryk
Published: April 2020

Findings from domestic and foreign literature analyses on the research methods and techniques applied in the management sciences confirmed the necessity to elaborate a certain procedure of selecting proper research methods, with consideration given to new management trends. With reference to the foregoing, the article presented qualitative studies (interviews, experts’ opinions) and quantitative ones (surveys) in order to diagnose the problem in a proper way by providing answers to five research hypotheses. As a result of the research effort, the anticipated goal of the article was achieved, i.e. the readers were presented with an elaborated procedure (Dźwigoł, 2018) of selecting the methods and techniques for the sake of the management-related research process, and with essential components of the research process used for designing the procedure in question. Since the research hypotheses were positively assessed, the author was able to present recommendations as to putting the procedures into practice, which were supported by a dedicated online tool. What is more, the achieved goal allowed not only to determine the application rate of the particular methods and techniques, or their combined versions, but also to identify certain rules as to recognising the research process in the present context and in terms of other variables, since the latter may influence whether the selected methods and techniques, related to the research subject in the context of management sciences, are essential. All foregoing steps were aimed at enhancing the reliability, quality and level of the research studies being carried out. Furthermore, it was recommended to perform further research studies aimed at verifying the adopted model and procedure of selecting research methods and techniques in the management sciences, especially in the practical context.
MECHANICS OF THE SUSPENDED LAYER WITH POLYDISPERSE PARTICLES IN CONTINUOUS AIR MIXERS
Authors: Kachaev A. , Orehova T. , Okushko V. , Shestakov Yu.
Published: April 2020

The quality of mixing of dry building mixes largely depends on the specialized equipment that is used in this process. For the best mixing of dry building mixes, continuous pneumatic mixers are used. Continuous air mixers are the most effective equipment for producing dry building mixes with a higher degree of uniformity. This indicator allows to achieve a better final product. Currently, there are a large number of continuous air mixers that are actively being modernized both in our country and abroad. The article presents a technique that describes the mechanics of a suspended layer with polydisperse particles in the working volume of the displacement palette of a continuous air mixer. The method is based on research conducted by the authors of the article, taking into account experimental data obtained by other scientists. This paper summarizes an approach to numerical modeling of a suspended layer with particles of different dispersion (for example, for dry building mixes) and density. The dependences of the layer boundary, its porosity, and speed parameters on the particle diameters, geometric parameters of the mixing chamber, and other technological values that affect the suspended layer inside the chamber are established. The article presents an algorithm for calculating the mechanics of the weighted layer, which proved itself in numerical modeling of the layer with high accuracy of calculations, which is later confirmed by the necessary amount of experimental data.
PERSEKUTUAN MURID-MURID KRISTUS: HIDUP YANG BERKEMBANG MENUJU KESEMPURNAAN
Authors: Widiatna Alexius Dwi
Published: April 2020

Being a disciple of Christ is a gift of a special Christian vocation. A true disciple of Christ is required to follow Jesus bravely denying himself, taking up his cross every day, and following Jesus. A disciple of Christ is a human being’s community, who is called to always be united with Jesus and love others. In his life, a disciple of Christ is required to imitate and follow in the footsteps of Christ toward the perfection of life like Jesus who reached the perfection of His life by dying on the cross. A disciple becomes perfect when he unites himself with Christ totally, follows Christ wherever he walks, follows each of his steps, and always constantly learns from him under the guidance of the Holy Spirit.
Excessive Daytime Sleepiness and Safety Performance: Comparing Proactive and Reactive Approaches
Authors: Gharibi Vahid , Mokarami Hamidreza , Cousins Rosanna , Jahangiri Mehdi , Eskandari Davood
Published: April 2020

Background: Sleep disorders and excessive daytime sleepiness negatively affect employees' safety performance. Objective: To investigate the relationship between excessive daytime sleepiness with obstructive sleep apnea and safety performance at an oil construction company in Iran. Methods: 661 employees consented to participate in this study. Excessive daytime sleepiness was measured with the STOP-BANG questionnaire and Epworth Sleepiness Scale (ESS). To determine how sleepiness would affect the studied occupational incidents, accidents causing injury and near misses, both reactive data and proactive safety performance indices were measured. Demographic and predictor variables were analyzed with hierarchical multiple linear regression. Results: Employees who met the criteria of excessive daytime sleepiness and obstructive sleep apnea had significantly poorer safety performance indicators. STOP-BANG and ESS were significant predictors of safety compliance (β 0.228 and 0.370, respectively), safety participation (β 0.210 and 0.144, respectively), and overall safety behavior (β 0.332 and 0.213, respectively). Further, occupational incidents were 2.5 times higher in workers with indicators of excessive daytime sleepiness and 2 times higher in those with obstructive sleep apnea compared with those without. Conclusion: These findings confirmed that excessive daytime sleepiness is a serious safety hazard, and that both reactive and proactive measures are important to understand the relative contribution of predictor variables.