bluuebunny/crossref_metadata_2025 huggingface dataset:
Natural and Anthropogenic Controls of Groundwater Quality in Sri Lanka: Implications for Chronic Kidney Disease of Unknown Etiology (CKDu)
Authors: Xu Sen , Li Si-Liang , Yue Fujun , Udeshani Charitha , Chandrajith Rohana
Published: October 2021

Poor groundwater quality in household wells is hypothesized as being a potential contributor to chronic kidney disease of unknown etiology (CKDu) in Sri Lanka. However, the influencing factors of groundwater quality in Sri Lanka are rarely investigated at a national scale. Here, the spatial characteristics of groundwater geochemistry in Sri Lanka were described. The relationships of groundwater quality parameters with environmental factors, including lithology, land use, and climatic conditions, were further examined to identify the natural and anthropogenic controlling factors of groundwater quality in Sri Lanka. The results showed that groundwater geochemistry in Sri Lanka exhibited significant spatial heterogeneity. The high concentrations of NO3− were found in the districts that have a higher percentage of agricultural lands, especially in the regions in the coastal zone. Higher hardness and fluoride in groundwater were mainly observed in the dry zone. The concentrations of trace elements such as Cd, Pb, Cu, and Cr of all the samples were lower than the World Health Organization guideline values, while some the samples had higher As and Al concentrations above the guideline values. Principal component analysis identified four components that explained 73.2% of the total data variance, and the first component with high loadings of NO3−, hardness, As, and Cr suggested the effects of agricultural activities, while other components were primarily attributed to natural sources and processes. Further analyses found that water hardness, fluoride and As concentration had positive correlations with precipitation and negative correlations with air temperature. The concentration of NO3− and water hardness were positively correlated with agricultural lands, while As concentration was positively correlated with unconsolidated sediments. The environmental factors can account for 58% of the spatial variation in the overall groundwater geochemistry indicated by the results of redundancy analysis. The groundwater quality data in this study cannot identify whether groundwater quality is related to the occurrence of CKDu. However, these findings identify the coupled controls of lithology, land use, and climate on groundwater quality in Sri Lanka. Future research should be effectively designed to clarify the synergistic effect of different chemical constituents on CKDu.
An Efficient No-Shutdown Pipe-Fixing Freezing Design for Water Management System in Hospitals during COVID-19: A Case Study
Authors: Liu Fei-Lung , Fan Shu-Kai S. , Ndi Ebede , Tu Jih-Fu
Published: October 2021

Ensuring the uninterrupted flow of the complex piped water distribution networks to combat the COVID-19 pandemic in Taiwan’s hospitals has become a priority. The process involved in the no-shutdown pipe fixing freezing method depends on the water supply system design and the conditions of the environment. Before carrying out repair works onsite, two experiments were undertaken to estimate the liquid nitrogen supply rate and make sure of its adequacy in relation to the fixing system’s heat transfer performance. Using an iron exhaust pipe and galvanized steel inlet pipe with jacket for a 50-mm-diameter water pipe, temperature variations and timelapse were recorded and analyzed. The results showed that the frost length on the water pipe surface at either side of the jacket was 1.2–1.8 times of the pipe diameter. The ice length (~45 cm) was longer than the jacket (~34 cm), and the water pressure at the jacket inlet side was 1 kg/cm2 greater than at the exit. Injecting the right amount of liquid nitrogen into the inlet and at a proper speed between 0.7 and 0.8 kg/min will ensure a safe and smooth completion of the ice plug formation process. The design and processes have been used successfully in hospital water supply system fixing works.
Structural Characteristics of Aerobic Granular Sludge and Factors That Influence Its Stability: A Mini Review
Authors: Hou Yizhi , Gan Chunjuan , Chen Renyu , Chen Ying , Yuan Shaochun , Chen Yao
Published: October 2021

Current extensive research on aerobic granular sludge (AGS) largely focuses on improving its microbial biodiversity, settlement behavior, nitrogen and phosphorus removal efficiency, and shock load resistance. Great challenges that have to be faced are the bottleneck of slow-speed granulation and easy disintegration after granulation, which are key to the extended application of AGS technology. In the present review, the typical morphological structures of AGS are firstly summarized as well as the granulation model hypotheses, and then, we analyze the dominant microflora and their spatial distribution features. The influencing factors on particle structure stability are discussed thereafter on a macro and micro scale. Prospects and future research trends are also discussed based on the current study results for AGS technology.
Expert-Based Assessment and Mapping of Ecosystem Services Potential in the Nemunas Delta and Curonian Lagoon Region, Lithuania
Authors: Kaziukonytė Karolina , Lesutienė Jūratė , Gasiūnaitė Zita Rasuolė , Morkūnė Rasa , Elyaagoubi Soukaina , Razinkovas-Baziukas Artūras
Published: October 2021

The Curonian Lagoon (SE Baltic Sea) and the coastal wetland system play a vital role in maintaining the overall cultural, economic and ecological health of the region. However, its value is still largely underestimated and there is a lack of integrated ecosystem management based on multiple ecosystem services assessment. In this study, 34 ecosystem services (ES) were identified, assessed and mapped following the Common International Classification of Ecosystem Services (CICES). Using expert opinion, 35 land cover classes were scored for their ES potential, these being 15 CORINE land cover classes (CLC) and 20 Natura 2000 areas of conservation (habitat types, i.e., Sites of Community Importance). The total ES potential was calculated by averaging the opinions of experts, using self-confidence scoring as weights, and the ES relative importance index was derived from a questionnaire. As a result, three maps corresponding to each ES potential category (provisioning, regulation and maintenance and cultural) were calculated and further used for hot- and coldspot analyses. Regulation and maintenance and cultural ES were highly interrelated and had the highest potential in the studied area. Forested areas had the highest total ES potential and contributed significantly to the land cover of the ES hotspots.
Three-Dimensional Numerical Investigation on the Seepage Field and Stability of Soil Slope Subjected to Snowmelt Infiltration
Authors: Cong Shengyi , Tang Liang , Ling Xianzhang , Xing Wenqiang , Geng Lin , Li Xinyu , Li Guoyu , Li Hui
Published: October 2021

Cutting slope failures occur frequently along the high-speed railways in Northeast China during the construction due to snowmelt infiltration. This study addresses this issue by applying a three-dimensional numerical model. The influence of the depth of accumulated snow (ds), daily temperature variation (ΔT), and freeze-thaw (F-T) cycles on the seepage field and stability of cutting slopes is discussed. The results demonstrate that water seepage due to snowmelt infiltration primarily extends through the ground surface by about 10 m. The deep-seated instability is likely to occur under a prolonged and highly accumulated infiltration, while shallow failure is associated with intense, short-duration snowmelt infiltration. The maximum degree of saturation (Sr) and pore-water pressure (PWP) values are observed at the slope toe. Increasing ds and ΔT increase the Sr and PWP due to snowmelt infiltration and thereby decreases cutting slope stability. Compared to the ds and ΔT, the F-T cycle is more likely to cause slope failure. In addition, the F-T cycle also induces the reduction of soil strength and the crack propagation. Overall, the conducted study provided useful help toward the process of safer design for cutting slope along the high-speed railway in seasonally cold regions.
The Simultaneous Analysis of Droplets’ Impacts and Heat Transfer during Water Spray Cooling Using a Transparent Heater
Authors: Serdyukov Vladimir , Miskiv Nikolay , Surtaev Anton
Published: October 2021

This paper demonstrates the advantages and prospects of transparent design of the heating surface for the simultaneous study of the hydrodynamic and thermal characteristics of spray cooling. It was shown that the high-speed recording from the reverse side of such heater allows to identify individual droplets before their impact on the forming liquid film, which makes it possible to measure their sizes with high spatial resolution. In addition, such format enables one to estimate the number of droplets falling onto the impact surface and to study the features of the interface evolution during the droplets’ impacts. In particular, the experiments showed various possible scenarios for this interaction, such as the formation of small-scale capillary waves during impacts of small droplets, as well as the appearance of “craters” and splashing crowns in the case of large ones. Moreover, the unsteady temperature field during spray cooling in regimes without boiling was investigated using high-speed infrared thermography. Based on the obtained data, the intensity of heat transfer during spray cooling for various liquid flow rates and heat fluxes was analyzed. It was shown that, for the studied regimes, the heat transfer coefficient weakly depends on the heat flux density and is primarily determined by the flow rate. In addition, the comparison of the processes of spray cooling and nucleate boiling was made, and an analogy was shown in the mechanisms that determine their intensity of heat transfer.
Release of Antibiotic-Resistance Genes from Hospitals and a Wastewater Treatment Plant in the Kathmandu Valley, Nepal
Authors: Thakali Ocean , Malla Bikash , Tandukar Sarmila , Sthapit Niva , Raya Sunayana , Furukawa Takashi , Sei Kazunari , Sherchand Jeevan B. , Haramoto Eiji
Published: October 2021

Hospitals and wastewater treatment plants (WWTPs) are high-risk point sources of antibiotic-resistance genes (ARGs) and antibiotic-resistant bacteria. This study investigates the occurrence of clinically relevant ARGs (sul1, tet(B), blaCTX-M, blaNDM-1, qnrS) and a class one integron (intI1) gene in urban rivers, hospitals, and municipal wastewater in the Kathmandu Valley, Nepal. Twenty-five water samples were collected from three rivers, six hospitals, and a wastewater treatment plant to determine the concentrations of ARGs and intI1 using quantitative polymerase chain reactions. From the results, all tested ARGs were detected in the river water; also, concentrations of ARGs in WWTP and hospital effluents varied from 6.2 to 12.5 log10 copies/L, highlighting the role of a WWTP and hospitals in the dissemination of ARGs. Except for blaNDM-1, significant positive correlations were found between intI1 and other individual ARGs (r = 0.71–0.96, p < 0.05), indicating the probable implications of intI1 in the transfer of ARGs. Furthermore, this study supports the statement that the blaNDM-1 gene is most likely to be spread in the environment through untreated hospital wastewater. Due to the interaction of surface water and groundwater, future research should focus on ARGs and factors associated with the increase/decrease in their concentration levels in drinking water sources of the Kathmandu Valley.
Effective Management of Scarce Water Resources: From Antiquity to Today and into the Future
Authors: Šulyová Dominika , Vodák Josef , Kubina Milan
Published: October 2021

Water is a critically important element of human life. The best practice of effective water management comes from ancient civilizations that, despite their technologies and practices, were unable to prevent collapse from water scarcity. In the 21st century, in an era of climate change, pollution or population explosion, cities are looking for innovative ways to effectively manage scarce resources for future generations. Which elements should cities of the future follow to avoid water collapse? The following article aims to identify the key elements of effective management and to represent them graphically in the form of a recommended model, which will be verified in the future in Slovakia. The article uses case analysis of best past and current practices, comparison and summarization to identify the elements, creativity, and logic in the development of the model, including induction and deduction. The article serves as a basis for fellow researchers (analyses carried out) and strategic urban management (effective urban water management). The main finding of the article is that ecological change puts pressure on social elements and therefore it is necessary to focus on the area of strategic management. Cities should not only know how to manage resource abundance or short-term scarcity, but also long-term scarcity. They should use elements of trust, awareness and continuous improvement through modern monitoring technologies (UAVs, sensors) and prediction (machine learning). This is the only way to generate water sustainability in the urban concept of the future.
Deep Learning Based Filtering Algorithm for Noise Removal in Underwater Images
Authors: Cherian Aswathy K. , Poovammal Eswaran , Philip Ninan Sajeeth , Ramana Kadiyala , Singh Saurabh , Ra In-Ho
Published: October 2021

Under-water sensing and image processing play major roles in oceanic scientific studies. One of the related challenges is that the absorption and scattering of light in underwater settings degrades the quality of the imaging. The major drawbacks of underwater imaging are color distortion, low contrast, and loss of detail (especially edge information). The paper proposes a method to address these issues by de-noising and increasing the resolution of the image using a model network trained on similar data. The network extracts frames from a video and filters them with a trigonometric–Gaussian filter to eliminate the noise in the image. It then applies contrast limited adaptive histogram equalization (CLAHE) to improvise the image contrast, and finally enhances the image resolution. Experimental results show that the proposed method could effectively produce enhanced images from degraded underwater images.
Barriers to Water Access in Rural Communities: Examining the Factors Influencing Water Source Choice
Authors: Aikowe Jocelyn Ojochide , Mazancová Jana
Published: October 2021

In Nigeria, the rural population comprises 49% of the total population and has been reported to bear the brunt of ongoing water access challenges. For communities to have access to clean and safe water, an adequate water source should be ensured. In dissevering the definition of water access, this research identifies that distance to a water source, time spent to collect water, water availability, and water quality are determinants of water source choice. A survey with 404 randomly selected respondents was conducted in three local government areas in Kogi state alongside interviews with key participants (n = 12). The data collected were analysed using a Chi-square test to determine any significant relationship between water source choice and the predictor variables (age, education, occupation, religion, ethnic group, household size, income, and distance). Furthermore, multinomial logistic regression was adopted to investigate the relationship and effect between these variables. Findings indicated that the predictor factors such as age, level of education, ethnic group, and participants’ occupation have a statistically significant relationship with using a particular water source. Finally, more insights for policymakers are provided to bridge the gap surrounding water access in developing countries while focusing on an adequate water source.
Insights into the Simultaneous Sorption of Ciprofloxacin and Heavy Metals Using Functionalized Biochar
Authors: Cuprys Agnieszka , Maletskyi Zakhar , Rouissi Tarek , Ratnaweera Harsha , Brar Satinder Kaur , Knystautas Emile , Drogui Patrick
Published: October 2021

Biochar and chitosan are considered as green and cost-effective adsorbents for water purification; the combination of these two materials may lead to an improved adsorption capacity of the generated adsorbents. Most sorption studies have been focused on the ability to adsorb one contaminant or the same type of contaminants. Thus, this study aimed to produce chitosan-biochar beads (CH-BB) and test their efficiency in the simultaneous removal of a metal-complexing antibiotic, ciprofloxacin (CIP), and three metal(loid)s (As, Cd and Pb). Modification of raw pig manure biochar resulted in an increase in its adsorption capacity, except for Pb. The highest increment was observed for As (almost 6-fold) and the lowest was observed for CIP (1.1-fold). The adsorbent was able to simultaneously remove all targeted contaminants, individually and in the mixture. The adsorption capacity of CH-BB followed the order: Pb > Cd > >As > CIP. When Pb and As were present in the same mixture, their removal efficiency increased from 0.13 ± 0.01 to 0.26 ± 0.05 mg/g for As and from 0.75 ± 0.08 to 0.85 ± 0.02 mg/g for Pb due to their co-precipitation. The CIP–metal complexation probably resulted in a reduced adsorption ability for inorganics due to the decreased concentration of free ions. The presence of metals and metalloids led to alterations in CIP’s mobility.
Living with Urban Flooding: A Continuous Learning Process for Local Municipalities and Lessons Learnt from the 2021 Events in Germany
Authors: Bosseler Bert , Salomon Mirko , Schlüter Marco , Rubinato Matteo
Published: October 2021

In 2021, heavy precipitation events in Germany have confirmed once again that pluvial flooding can cause catastrophic damage in large, medium, and small cities. However, despite several hazard-oriented strategies already in place, to date there is still a lack of integrated approaches to actually preventing negative consequences induced by heavy rainfall events. Furthermore, municipalities across the world are still learning from recent episodes and there is a general need to explore new techniques and guidelines that could help to reduce vulnerability, and enhance the resilience, adaptive capacity, and sustainability of urban environments, considering the already predicted future challenges associated with climate variability. To address this gap, this paper presents the outcomes of the research project “Heavy Rainfall Checklist for Sewer Operation” which was conducted by IKT Institute for Underground Infrastructure, to involve all the stakeholders affected by pluvial flooding within cities, and implement a series of documents that can be adopted by municipalities across the world to support organizations and their operational staff in preventing problems caused by heavy rainfall incidents. More in detail, three different rainfall scenarios have been deeply analysed, and for each of them a list of specific tasks and suggestions has been provided for aiding decision-making.
Tool for Quantitative Risk Analysis of Urban Flooding
Authors: Kvitsjøen Julia , Karlsson Dick , Teigene Trym , Finsland Webjørn
Published: October 2021

One of the effects of climate change is an increasing frequency of heavy rainfall events, which in turn leads to increased flooding damage in urban areas. The purpose of this study was to develop a tool for dynamic risk evaluation that can be used to fulfil several of the goals in the European Flood Risk Management Directive. Flood risk analysis was performed as a spatial GIS analysis with the FME software. The primary data source for the analysis was a 1D/2D model calculation, wherein 1D models described the pipeline network and the watercourses and a 2D model described surface runoff. An ArcGIS online platform was developed to visualize the results in a format understandable for decision makers. The method and tool were tested for the Norwegian capital of Oslo. The tool developed in the study enabled the efficient analysis of consequences for various precipitation scenarios. Results could be used to identify the areas most vulnerable to flooding and prioritize areas in which measures need to be implemented. The study showed that for urban areas in steep terrain, it is essential to include water velocity and depth-integrated velocity in risk analysis in addition to water depths and pipe network capacity.
Implications of Hysteresis on the Horizontal Soil Water Redistribution after Infiltration
Authors: Kargas George , Soulis Konstantinos X. , Kerkides Petros
Published: October 2021

Although soil water redistribution is critical for a number of problems, a rather limited study of this process has been reported up to now and especially as regards the implications of hysteresis on horizontal soil water redistribution after infiltration. To this end, a thorough theoretical and numerical investigation of the redistributed soil water content profiles formed after the cessation of a horizontal infiltration is presented. A number of different initial soil water contents before the initiation of the horizontal infiltration and different infiltration depths were analyzed using the HYDRUS-1D software package considering the appropriate hysteretic wetting and drying curves. The effect of neglecting hysteresis was also investigated for the same conditions. The main wetting and drying boundary curves of the studied porous medium and the hydraulic conductivity at saturation were experimentally determined. The theoretical and numerical analysis indicated that the form of the redistributed soil water content profiles in the presence of hysteresis was similar to the original infiltration profile independently of whether the initial soil water content was taken on the boundary wetting or drying curve and independently of the porous medium type. Specifically, in a relatively short time after the initiation of the redistribution process, the magnitude of the soil matrix head gradient tended to zero due to hysteresis, and this resulted in an insignificant soil water movement, although the soil water content and the hydraulic conductivity values were still high. In addition, the redistribution proceeded at a faster rate than the smallest depth of infiltration water prior to the redistribution, and it was faster during the early stages of the redistribution. Accordingly, hysteresis is important for the simulation of horizontal soil water redistribution as it is, for example, in the case of localized irrigation systems’ design and management.
Vulnerability Assessment as a Basis for Sanitary Zone Delineation of Karst Groundwater Sources—Blederija Spring Case Study
Authors: Živanović Vladimir , Atanacković Nebojša , Stojadinović Saša
Published: October 2021

The application of groundwater vulnerability methods has great importance for the sanitary protection zones delineation of karstic sources. Source vulnerability assessment of karst groundwater has mainly relied on the European approach (European Cooperation in Science and Technology—COST action 620), which includes analysis of the K factor, which refers to water flow through the saturated zone of the karst system. In the paper, two approaches to groundwater vulnerability assessment have been applied, COP + K and TDM (Time-Dependent Model) methods, to produce the most suitable source vulnerability map that can be transformed into sanitary protection zones maps. Both methods were tested on the case example of Blederija karst spring in Eastern Serbia. This spring represents a classical karst spring with allogenic and autogenic recharge. Dual aquifer recharge points out the necessity for the inclusion of the vulnerability assessment method created especially for the assessment of karst groundwater. Obtained vulnerability maps show similar results, particularly in the spring and the ponor areas, and these zones are most important for future protection. The COP + K method brings out three vulnerability classes that can be directly transformed into three sanitary protection zones. Contrary to the previous one, the TDM method uses water travel time as a vulnerability degree. The results show that the final map can be easily used to define sanitary zones considering different national legislation.
Passive Microwave Remote Sensing Soil Moisture Data in Agricultural Drought Monitoring: Application in Northeastern China
Authors: Cheng Tao , Hong Siyang , Huang Bensheng , Qiu Jing , Zhao Bikui , Tan Chao
Published: October 2021

Drought is the costliest disaster around the world and in China as well. Northeastern China is one of China’s most important major grain producing areas. Frequent droughts have harmed the agriculture of this region and further threatened national food security. Therefore, the timely and effective monitoring of drought is extremely important. In this study, the passive microwave remote sensing soil moisture data, i.e., the SMOS soil moisture (SMOS-SM) product, was compared to several in situ meteorological indices through Pearson correlation analysis to assess the performance of SMOS-SM in monitoring drought in northeastern China. Then, maps based on SMOS-SM and in situ indices were created for July from 2010 to 2015 to identify the spatial pattern of drought distributions. Our results showed that the SMOS-SM product had relatively high correlation with in situ indices, especially SPI and SPEI values of a nine-month scale for the growing season. The drought patterns shown on maps generated from SPI-9, SPEI-9 and sc-PDSI were also successfully captured using the SMOS-SM product. We found that the SMOS-SM product effectively monitored drought patterns in northeastern China, and this capacity would be enhanced when field capacity information became available.
Phytoplankton Dynamics and Water Quality in the Venice Lagoon
Authors: Bernardi Aubry Fabrizio , Acri Francesco , Finotto Stefania , Pugnetti Alessandra
Published: October 2021

We analyzed the phytoplankton abundance and community structure monthly over a 20-year period (1998–2017) at five stations in the Venice lagoon (VL), one of the sites belonging to the Long-Term Ecological Research network of Italy (LTER-Italy). We focused on phytoplankton seasonal patterns, inter-annual variability and long-term trends in relation to water quality. Diatoms numerically dominated (ca. 60% on average), followed by nanoflagellates (37%), while coccolithophorids and dinoflagellates contributed less than 2%. We observed distinct seasonal and inter-annual changes in the abundance and floristic composition of the phytoplankton groups, whilst no clear long-term trend was statistically significant. We also assessed the water quality changes, applying to our dataset the multimetric phytoplankton index (MPI), recently officially adopted by Italy to accomplish the water framework directive (WFD) requirements. The index evidenced a temporal improvement of the water quality from “moderate” to “good” and allowed us to confirm its reliability to address the changes in the water quality, not only spatially—as previously known—but also for following the yearly time trends. Overall, our results highlight the importance of long-term observations, for understanding the variability in the phytoplankton communities of the lagoon as well as the relevance of their use to test and apply synthetic descriptors of water quality, in compliance with the environmental directives.
Modelling the Impact of Vegetation Change on Hydrological Processes in Bayin River Basin, Northwest China
Authors: Jin Xin , Jin Yanxiang , Mao Xufeng , Zhai Jingya , Fu Di
Published: October 2021

Vegetation change in arid areas may lead to the redistribution of regional water resources, which can intensify the competition between ecosystems and humans for water resources. This study aimed to accurately model the impact of vegetation change on hydrological processes in an arid endorheic river watershed undergoing revegetation, namely, the middle and lower reaches of the Bayin River basin, China. A LU-SWAT-MODFLOW model was developed by integrating dynamic hydrological response units with a coupled SWAT-MODFLOW model, which can reflect actual land cover changes in the basin. The LU-SWAT-MODFLOW model outperformed the original SWAT-MODFLOW model in simulating the impact of human activity as well as the leaf area index, evapotranspiration, and groundwater table depth. After regional revegetation, evapotranspiration and groundwater recharge in different sub-basins increased significantly. In addition, the direction and amount of surface-water–groundwater exchange changed considerably in areas where revegetation involved converting low-coverage grassland and bare land to forestland.
Systematic Review of Flood and Drought Literature Based on Science Mapping and Content Analysis
Authors: Fasihi Siavash , Lim Wen Zyn , Wu Wenyan , Proverbs David
Published: October 2021

The severity and frequency of flood and drought events have increased in recent decades. These climate change-induced and anthropogenic stressors on water resources represent the leading water-related hazards to communities. Further, the increasing exposure of the population and infrastructure to such events has heightened the risks. Assessing the impact scope of these events in different subfields towards comprehensively evaluating the risks requires an unbiased systematic approach. This paper combines content analysis and science mapping to investigate the existing multidisciplinary body of knowledge on analyzing flood and drought together. Searching the literature using selected search terms yielded a sample of 119 publications. Initially, various contents, such as the authors’ keywords, applied methods and indices, and study scale, were extracted from these articles. These contents were then incorporated into the science mapping technique to form communicative networks. Analyzing these publications revealed 13 major research themes, with a sustained focus on hydrological issues. However, a more diverse range of themes was recently revealed, including economy, sociology, insurance, and policymaking. Producing such computational and visual networks explained informative insights that can help further develop both existing and new frameworks to support the management, design and policymaking sectors in responding to both flood and drought events.
Relationship between Earthquake-Induced Hydrologic Changes and Faults
Authors: Ma Yuchuan , Wang Guangcai , Yan Rui , Wang Bo , Yu Huaizhong , Yu Chen , Yue Chong , Wang Yali
Published: October 2021

Hydraulic properties of fault zones are important to understanding the pore pressure development and fault stability. In this work, we examined the relationship between water level changes caused by the 2008 Wenchuan Mw 7.9 earthquake and faults using four wells with the same lithology around the Three Gorges Dam, China. Two of the wells penetrating the fault damage zones recorded sustained water level changes, while the other two wells that are not penetrating any fault damage zones recorded transient water level changes. The phase shift and tidal factor calculated from water level, a proxy of permeability and storage coefficient, revealed that both the permeability and storage coefficient changed in the two wells penetrating the fault damage zones, while the other two wells not penetrating the fault damage zone did not show any change in permeability and storage coefficient. Thus, we tentatively suggest that faults may play an important controlling role on earthquake-induced hydrologic changes because the detrital or clogging components in the fractures may be more easily removed by seismic waves.
Tracers and Timescales: Tools for Distilling and Simplifying Complex Fluid Mechanical Problems
Authors: Lucas Lisa V. , Deleersnijder Eric
Published: October 2021

The last several decades have seen significant advances in fluid–mechanical, water-quality, and ecological observation systems, as well as in related scientific computing capabilities [...]
A Simplified Model for Predicting the Effectiveness of Bioswale’s Control on Stormwater Runoff from Roadways
Authors: Zhou Jianpeng , Bloorchian Azadeh Akhavan , Nassiri Sina , Osouli Abdolreza
Published: October 2021

Bioswales are commonly constructed along roadways to control stormwater runoff. Many factors can affect the performance of a bioswale such as the size of the bioswale and its associated drainage area, rainfall characteristics, site conditions, soil properties, and deterioration of the bioswale’s condition over usage. Transportation agencies and engineering communities need a reliable and convenient method for predicting the effectiveness of bioswale. Although available software tools can be used to model and analyze design options, input values for a large number of variables and highly skilled modelers are required to handle these sophisticated modeling tools. The objective of this study was to develop a simplified and easy-to-use mathematical model for predicting the effectiveness of bioswales through empirical predictions of stormwater runoff as a function of four key parameters: area ratio (bioswale surface area to its drainage service area), rainfall depth, rainfall intensity, and sediment accumulation (build-up) on bioswale’s surface area. A PCSWMM model was developed to simulate the physical conditions of a field-scale bioswale. This PCSWMM tool was also used to simulate an idealized (conceptual) catchment model that represents common highway geometries and characteristics. A total of 72 scenarios were simulated on various combinations of the four studied parameters: area ratio (9%, 13%); rainfall depth (2.54, 5.08, 7.62, 10.16 cm); rainfall intensity (2.54, 5.08, 10.16 cm/h); and sediment accumulation (0, 0.25, 1.78 cm). Half of the total scenarios (i.e., 36 scenarios) were used to develop a new simplified mathematical model, and the other 36 scenarios were used to calibrate and validate this newly developed model. The analysis revealed a reasonable correlation (R2 = 0.967) between modelled predictions and PCSWMM-simulated results, indicating the newly developed mathematical model can serve as an adequate alternative for simulating bioswales’ performance for stormwater runoff control.
Impacts of Massive Sediment Input on the Channel Geometry Adjustment of Alluvial Rivers: Revisiting the North Fork Toutle River Case
Authors: Wang Xiaofan , Ma Xudong , Liu Xingnian
Published: October 2021

In this study, the impacts of massive sediment input on channel geometry adjustment were analyzed across decades based on the downstream hydraulic geometry. Massive amounts of field data and evolution models showed that the alternation of degradation and aggradation in short-to-medium-term channel adjustment is common in evolving rivers. This phenomenon has always been challenging in research; most existing studies have focused on unidirectional adjustment in short-term channel adjustment. A few studies have considered the alternation of degradation and aggradation in short-to-medium-term channel adjustment, presuming that this phenomenon is caused by water and sediment changes. However, we found that the alternations also occurred under stable water and sediment transport in the North Fork Toutle River, southwestern Washington, USA. This adjustment across decades was analyzed by downstream hydraulic geometry in this study. It was concluded that the river consumes surplus energy to reach the optimal cross section through this short-to-medium-term adjustment under stable water and sediment transport. The objective of channel adjustment is minimal energy loss.
Hydrogeochemical Processes and Natural Background Levels of Chromium in an Ultramafic Environment. The Case Study of Vermio Mountain, Western Macedonia, Greece
Authors: Vasileiou Eleni , Papazotos Panagiotis , Dimitrakopoulos Dimitrios , Perraki Maria
Published: October 2021

The hydrogeochemical processes and natural background levels (NBLs) of chromium in the ultramafic environment of Vermio Mountain, Western Macedonia, Greece, were studied. Seventy groundwater samples were collected from 15 natural springs between 2014–2020, and an extensive set of physical and chemical parameters were determined. The ultramafic-dominated environment of western Vermio Mt. favors elevated groundwater concentrations of dissolved magnesium (Mg2+), silicon (Si), nickel (Ni), and Cr in natural spring waters. Chromium was the principal environmental parameter that exhibited a wide range of concentrations, from 0.5 to 131.5 μg/L, systematically exceeding the permissible limit of 50 μg/L for drinking water. Statistical evaluation of hydrogeological, hydrochemical, and hydrological data highlighted the water-ultramafic rock process as the predominant contributor of Cr in groundwater. The NBL assessment for Cr and Cr(VI) was successfully applied to the typical ultramafic-dominated spring “Potistis” that satisfied all the methodology criteria. The NBLs of Cr and Cr(VI) were defined at 130 μg/L and 100 μg/L, respectively, revealing that a natural ultramafic-dominated environment exhibits the geochemical potential to contribute very high concentrations of geogenic Cr to groundwater. The holistic methodology, proposed herein, could be implemented in any catchment scale to assess geogenic and anthropogenic Cr-sources that degrade groundwater quality.
Optimal Operation Model of Drainage Works for Minimizing Waterlogging Loss in Paddy Fields
Authors: Liu Zhenyang , Xiong Yujiang , Xu Juzeng , Yang Shihong , Jiang Zewei , Liu Fangping
Published: October 2021

The risk of flood or waterlogging in irrigation districts has increased due to global climate change and intensive human activities. A Model of Optimal Operation of Drainage Works (MOODW) for flat irrigation district was established by incorporating the hydrological model of waterlogging process and waterlogging loss estimation, which was solved by an optimization method of genetic algorithm. The model of waterlogging process was built based on a modified Tank model and hydrodynamic model for the ditch-river system. The waterlogging loss is calculated under the condition of inconstant inundated depth by linear interpolation. The adaptive genetic algorithm with the global optimization function was selected to solve the model. With an extreme rainfall events in Gaoyou irrigation district as cases, results showed that operation time and numbers of pumps increased; thus, operating costs were 1.4 times higher than before, but the yield loss of rice decreased by 35.4% observably. Finally, the total waterlogging loss was reduced by 33.8% compared with the traditional operation of waterlogging work. The most significant improvement was found in units with high waterlogging vulnerability. The MOODW can provide the waterlogging information visually and assist the district manager in making a reasonable decision.
Formation of Coherent Flow Structures beyond Vegetation Patches in Channel
Authors: Kazem Masoud , Afzalimehr Hossein , Sui Jueyi
Published: October 2021

By using model vegetation (e.g., synthetic bars), vortex structures in a channel with vegetation patches have been studied. It has been reported that vortex structures, including both the vertical and horizontal vortexes, may be produced in the wake in the channel bed with a finite-width vegetation patch. In the present experimental study, both velocity and TKE have been measured (via Acoustic Doppler Velocimeter—ADV) to study the formation of vortexes behind four vegetation patches in the channel bed. These vegetation patches have different dimensions, from the channel-bed fully covered patch to small-sized patches. Model vegetation used in this research is closely similar to vegetation in natural rivers with a gravel bed. The results show that, for a channel with a small patch (Lv/Dc = 0.44 and Dv/Dc = 0.33; where Lv and Dv are the length and width of patch and Dc is the channel width, respectively), both the flow passing through the patch and side flow around the patch have a considerable effect on the formation of flow structures beyond the patch. The results of further analysis via 3D classes of the bursting events show that the von Karman vortex street splits into two parts beyond the vegetation patch as the strong part near the surface and the weak part near the bed; while the middle part of the flow is completely occupied by the vertical vortex formed at a distance of 0.8–1 Hv beyond the vegetation patch, and thus, the horizontal vortexes cannot be detected in this region. The octant analysis is conducted for the coherent shear stress analysis that confirms the results of this experimental study.
Hydro-Technologies of Mehrgarh, Baluchistan and Indus Valley Civilizations, Punjab, Pakistan (ca. 7000–1500 BC)
Authors: Khan Saifullah , Yilmaz Nese , Valipour Mohammad , Angelakis Andreas N.
Published: October 2021

Weather and climate have been participating in an imperative function in both the expansion and crumple of mankind civilizations diagonally across the globe ever since the prehistoric eras. The Neolithic Mehrgarh (ca. 7000–2500 BC) and Balochistan and Indus Valley civilizations (ca. 2500–1500 BC), in Sindh Province in Pakistan, have been the spotlight of explorations to historians, anthropologists, and archeologists in terms of their origin, development, and collapse. However, very rare consideration has been given previously to the role of weather and climate, sanitation, and wastewater technologies in highlighting the lessons of these formerly well-developed ancient metropolitan civilizations. This study presents an existing climate of the archaeological sites, sanitation, and wastewater technologies to recognize the different elements that influenced the evolution of the civilization mystery. In addition, it is recommended that the weather and climate conditions in southwest Asia were the foremost controlling element in resolving the destiny of the Indus and Mehrgarh civilizations. Furthermore, the rural tradition was mostly adapted by the increasing rate of western depressions (winter rains), as well as monsoon precipitation in the region. The factors that affected the climate of both civilizations with the passage of time might be population growth, resource conflicts, technological advancement, industrial revolution, Aryan invasion, deforestation, migration, disasters, and sociocultural advancement. The communities residing in both civilizations had well developed agriculture, sanitation, water management, wells, baths, toilets, dockyards, and waterlogging systems and were the master of the water art.
Two Comprehensive and Practical Methods for Simulating Pan Evaporation under Different Climatic Conditions in Iran
Authors: Dehghanipour Mohammad Hassan , Karami Hojat , Ghazvinian Hamidreza , Kalantari Zahra , Dehghanipour Amir Hossein
Published: October 2021

Evaporation from surface water plays a crucial role in water accounting of basins, water resource management, and irrigation systems management. As such, the simulation of evaporation with high accuracy is very important. In this study, two methods for simulating pan evaporation under different climatic conditions in Iran were developed. In the first method, six experimental relationships (linear, quadratic, and cubic, with two input combinations) were determined for Iran’s six climate types, inspired by a multilayer perceptron neural network (MLP-NN) neuron and optimized with the genetic algorithm. The best relationship of the six was selected for each climate type, and the results were presented in a three-dimensional graph. The best overall relationship obtained in the first method was used as the basic relationship in the second method, and climatic correction coefficients were determined for other climate types using the genetic algorithm optimization model. Finally, the accuracy of the two methods was validated using data from 32 synoptic weather stations throughout Iran. For the first method, error tolerance diagrams and statistical coefficients showed that a quadratic experimental relationship performed best under all climatic conditions. To simplify the method, two graphs were created based on the quadratic relationship for the different climate types, with the axes of the graphs showing relative humidity and temperature, and with pan evaporation, were drawn as contours. For the second method, the quadratic relationship for semi-dry conditions was selected as the basic relationship. The estimated climatic correction coefficients for other climate types lay between 0.8 and 1 for dry, semi-dry, semi-humid, Mediterranean climates, and between 0.4 and 0.6 for humid and very humid climates, indicating that one single relationship cannot be used to simulate pan evaporation for all climatic conditions in Iran. The validation results confirmed the accuracy of the two methods in simulating pan evaporation under different climatic conditions in Iran.
Rainfall Determines Shallow Soil Seepage in a Piedmont Summer Pasture of Alpine Meadow on the Northeastern Qinghai–Tibetan Plateau
Authors: Li Hongqin , Yang Yongsheng , Zhang Fawei , Guo Xiaowei , Li Yikang , Lin Li , Li Yingnian , Cao Guangmin , Zhou Huakun
Published: October 2021

Soil seepage is an important component used for quantifying hydrological processes that remains unclear in high-altitude alpine meadows. Shallow soil seepage was continuously measured using an auto-logged micro-lysimeter (diameter = 30 cm, depth = 30 cm) from July 2018 to June 2019 in a piedmont summer pasture of alpine meadow on the Northeastern Qinghai–Tibetan Plateau. The results showed that all the shallow soil seepage events occurred during the non-frozen period from April to September and that the cumulative amount was 106.8 mm, representing about 1/5 of the annual precipitation. The maximum and minimum monthly soil seepage were 30.7 mm in September and 1.0 mm in April, respectively. The boosted regression trees (BRT) model’s area under the curve averaged 0.92 and revealed that the daily half-hour rainfall frequency, volumetric soil water content, and air temperature played significant roles in the daily soil seepage probability, with the cumulative relative contribution of 68%. The stepwise linear regression analysis showed that the rainfall amount accounted for 59% of the variation in the daily amount of soil seepage. The monthly soil seepage was found to be significantly correlated with the monthly rainfall frequency (r = 0.86, p = 0.005). Our results highlighted that rainfall, including its amount and frequency, was the key determinant of the probability and amount of shallow soil seepage in the piedmont summer pasture of alpine meadows. These findings will be helpful for improving predictions of the water budgets of piedmont alpine meadows.