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Author (up) Weerahewa, J.; Timsina, J.; Wickramasinghe, C.; Mimasha, S.; Dayananda, D.; Puspakumara, G.
Title Ancient irrigation systems in Asia and Africa: Typologies, degradation and ecosystem services Type Journal Article
Year 2023 Publication Agricultural Systems Abbreviated Journal
Volume 205 Issue Pages 103580
Keywords Agriculture, Climate change, Hydrology, Village tank cascade system, Tank irrigation, Watershed
Abstract CONTEXT Ancient irrigation systems (AISs) have been providing a multitude of ecosystem services to rural farming and urban communities in Asia and Africa, especially in arid and semi-arid climatic areas with low rainfall. Many AISs, however have now been degraded. A systematic analysis of AISs on their typologies, causes of degradation, and their ecosystem services is lacking. OBJECTIVE The objective of this review was to synthesize the knowledge on AISs on their typologies, status and causes of degradation, ecosystem services and functions, and identify gaps in research in Asia and Africa. METHOD A critical review of peer-reviewed journal papers, conference and workshop proceedings, book chapters, grey literature, and country reports was conducted. Qualitative and quantitative information from journal papers were used to conceptualize the typologies and analyze the status and causes of degradation, and ecosystems services and functions provided by the AISs. RESULTS AND CONCLUSION Based on the review, we classified AISs into three groups by source of irrigation water: Rainwater harvesting system (RHS) with small reservoirs, ground water based system, and floodwater based system. The RHSs, which used to receive reliable rainfall and managed by well cohesive social organizations for their maintenance and functioning in past, have now been silting due to extreme rainfall pattern and breakdown of the cohesive organizations in recent decades. In ground water based systems, indiscriminate development of deep tube wells causing siltation of channels has been a major challenge. In floodwater irrigation systems, irregular rainfall in the highlands and the breakage of irrigation structures by destructive floods were the main causes of degradation. Lack of maintenance and increased soil erosion, inadequate skilled manpower, and declining support from the government for repair and maintenance were the main causes of degradation of all AISs. The main ecosystem service provided by all AISs is water for agriculture. In tank- and pond-based systems, fish farming is also practiced. Tank irrigation systems provide various types of provisioning, regulatory, cultural and supporting services, especially in India and Sri Lanka. Ground water based systems provide water for domestic purposes and various cultural services. Floodwater based systems provide water for power generation and wildlife habitat maintenance and help in flood control. SIGNIFICANCE The knowledge generated through the review provide evidence-based information, and help aware governments, private sectors and development agencies for improved policy planning and decision making, and prioritizing the restoration, rehabilitation, and management of various AISs.
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ISSN 0308-521x ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ Weerahewa2023103580 Serial 275
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Author (up) Wilson, G.B.; McNeill, G.W.
Title Noble gas recharge temperatures and the excess air component Type Journal Article
Year 1997 Publication Applied Geochemistry Abbreviated Journal
Volume 12 Issue 6 Pages 747-762
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Abstract The calculation of a groundwater recharge temperature based on the dissolved concentrations of Ne, Ar, Kr and Xe requires a correction for noble gas supersaturation due to excess air entrainment. This entrainment is commonly attributed to the recharge process or to air contamination at the wellhead during sample collection. With the exception of some local studies, most work has concentrated on interpretation of the recharge temperature or quantification of the radiogenic content for palaeoclimatic and dating purposes. The magnitude and source of the excess air is not directly relevant to these studies and so is often ignored. In this work, excess air Ne and other data have been calculated from new and published noble gas data sets for several groundwater systems. For younger groundwaters which have been recharged under one broad climatic regime, the amount of air entrainment increases according to lithology in the order granites, sandstones and limestones respectively. A negative correlation between precipitation and excess air entrainment is identified in at least one aquifer, and some of the mechanisms which may influence the entrainment process are discussed.
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ISSN 0883-2927 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ Wilson1997747 Serial 281
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Author (up) Wolfe, P.
Title The Simplex Method For Quadratic Programming Type Journal Article
Year 1959 Publication Econometrica Abbreviated Journal
Volume 27 Issue Pages 170
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Call Number THL @ christoph.kuells @ Wolfe1959 Serial 285
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Author (up) Xiao, L.; Robinson, M.; O’Connor, M.
Title Woodland’s role in natural flood management: Evidence from catchment studies in Britain and Ireland Type Journal Article
Year 2022 Publication Science of The Total Environment Abbreviated Journal
Volume 813 Issue Pages 151877
Keywords Forest harvesting, Streamflow, Natural flood management, Before-after-control-impact, Evidence-based forest impact
Abstract Despite the attention currently given to the potential environmental benefits of large-scale forest planting, there is a shortage of clear observational evidence regarding the effects on river flows, and what there is has often been contradictory or inconclusive. This paper presents three independently conducted paired-catchment forestry studies covering 66 station-years of flow measurements in the UK and Ireland. In each case coniferous evergreen trees were removed from one catchment with minimal soil disturbance while the adjoining control catchment was left unchanged. Trees were removed from 20% – 90% of the three experimental basins. Following woodland removal there was an increase in dry weather baseflow at all sites. Baseflows increased by about 8% after tree removal from a quarter of the Hore basin and by 41% for the near-total cut at Howan. But the changes were more complex for peak flows. Tree harvesting increased the smallest and most frequent peak storm flows, indicating that afforestation would lead to the suppression of such events. This was however restricted to events well below the mean annual flood, indicating that the impact of forests upon the largest and most damaging floods is likely to be limited. Whilst a forest cover can be effective in mitigating small and frequent stormflows it should never be assumed to provide protection against major flood events.
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ISSN 0048-9697 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ Xiao2022151877 Serial 241
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Author (up) Xie, T.; Lian, B.; Chen, C.; Qian, T.; Liu, X.; Shang, Z.; Li, T.; Wang, R.; Wang, Z.; Zhang, A.; Zhu, J.
Title Leaching behaviour and mechanism of U, 226Ra and 210Pb from uranium tailings at different pH conditions Type Journal Article
Year 2023 Publication Journal of Environmental Radioactivity Abbreviated Journal
Volume 270 Issue Pages 107300
Keywords Leaching experiments, Pb, Ra, U, Uranium tailings
Abstract A large number of radionuclides remain in uranium tailings, and U, 226Ra and 210Pb leach out with water chemistry, causing potential radioactive contamination to the surrounding environment. In this paper, uranium tailings from a uranium tailings pond in southern China were collected at different depths by means of borehole sampling, mixed and homogenised, and analysed for mineral and chemical composition, microscopic morphology, U, 226Ra and 210Pb fugacity, static leaching and dynamic leaching of U, 226Ra and 210Pb in uranium tailings at different pH conditions. The variation of U, 226Ra and 210Pb concentrations in the leachate under different pH conditions with time was obtained, and the leaching mechanism was analysed. The results showed that the uranium tailings were dominated by quartz, plagioclase and other minerals, of which SiO2 and Al2O3 accounted for 65.45% and 13.32% respectively, and U, 226Ra and 210Pb were mainly present in the residue form. The results of the static leaching experiments show that pH mainly influences the leaching of U, 226Ra and 210Pb by changing their chemical forms and the particle properties of the tailings, and that the lower the pH the more favourable the leaching. The results of dynamic leaching experiments during the experimental cycle showed that the leaching concentration and cumulative release of U, 226Ra and 210Pb in the leach solution were greater at lower pH conditions than at higher pH conditions, and the leaching of U, 226Ra and 210Pb at different pH conditions was mainly from the water-soluble and exchangeable states. The present research results are of great significance for the environmental risk management and control of radioactive contamination in existing uranium tailings ponds, and are conducive to ensuring the long-term safety, stability and sustainability of uranium mining sites.
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ISSN 0265-931x ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ xie_leaching_2023 Serial 200
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Author (up) Xu, W.D.; Burns, M.J.; Cherqui, F.; Duchesne, S.; Pelletier, G.; Fletcher, T.D.
Title Real-time controlled rainwater harvesting systems can improve the performance of stormwater networks Type Journal Article
Year 2022 Publication Journal of Hydrology Abbreviated Journal
Volume 614 Issue Pages 128503
Keywords Real-time control, Rainwater harvesting systems, Stormwater control measures, Flood mitigation, Source Control, Climate change
Abstract Real-Time Control (RTC) technology is increasingly applied in Rainwater Harvesting (RWH) systems to optimise their performance related to water supply and flood mitigation. However, most studies to date have focussed on testing the benefits at an individual site scale, leaving the potential benefits for downstream stormwater networks largely untested. In this study, we developed a methodology to predict how at-source RTC RWH systems influence the behaviour of a stormwater network. Simulation was enabled by coupling the drainage model in SWMM with an RTC RWH model coded using the R software. We modelled two different RTC strategies across a range of system settings (e.g. storage size for RWH and proportion of storage to which RTC is applied) under two different climate scenarios—current and future climates. The simulations showed that RTC reduced flooding volume and peak flow of the stormwater network, leading to a potential mitigation of urban flooding risks, while also providing a decentralised supplementary water supply. Implementing RTC in more of RWH storages yielded greater benefits than simply increasing storage capacity, in both current and future climates. More importantly, the RTC systems are capable of more precisely managing the resultant flow regime in reducing the erosion and restoring the pre-development conditions in sensitive receiving waters. Our study suggests that RTC RWH storages distributed throughout a catchment can substantially improve the performance of existing drainage systems, potentially avoiding or deferring expensive network upgrades. Investments in real-time control technology would appear to be more promising than investments in detention volume alone.
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-1694 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ Xu2022128503 Serial 233
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Author (up) Yabusaki, S.B.; Fang, Y.; Long, P.E.; Resch, C.T.; Peacock, A.D.; Komlos, J.; Jaffe, P.R.; Morrison, S.J.; Dayvault, R.D.; White, D.C.; Anderson, R.T.
Title Uranium removal from groundwater via in situ biostimulation: Field-scale modeling of transport and biological processes Type Journal Article
Year 2007 Publication Journal of Contaminant Hydrology Abbreviated Journal
Volume 93 Issue 1 Pages 216-235
Keywords Bioremediation, Biostimulation, Field experiment, Iron, Reactive transport, Sulfate, Uranium
Abstract During 2002 and 2003, bioremediation experiments in the unconfined aquifer of the Old Rifle UMTRA field site in western Colorado provided evidence for the immobilization of hexavalent uranium in groundwater by iron-reducing Geobacter sp. stimulated by acetate amendment. As the bioavailable Fe(III) terminal electron acceptor was depleted in the zone just downgradient of the acetate injection gallery, sulfate-reducing organisms came to dominate the microbial community. In the present study, we use multicomponent reactive transport modeling to analyze data from the 2002 field experiment to identify the dominant transport and biological processes controlling uranium mobility during biostimulation, and determine field-scale parameters for these modeled processes. The coupled process simulation approach was able to establish a quantitative characterization of the principal flow, transport, and reaction processes based on the 2002 field experiment, that could be applied without modification to describe the 2003 field experiment. Insights gained from this analysis include field-scale estimates of the bioavailable Fe(III) mineral threshold for the onset of sulfate reduction, and rates for the Fe(III), U(VI), and sulfate terminal electron accepting processes.
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ISSN 0169-7722 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ yabusaki_uranium_2007 Serial 156
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Author (up) YI, Z.-ji; LIAN, B.; YANG, Y.-qun; ZOU, J.-ling
Title Treatment of simulated wastewater from in situ leaching uranium mining by zerovalent iron and sulfate reducing bacteria Type Journal Article
Year 2009 Publication Transactions of Nonferrous Metals Society of China Abbreviated Journal
Volume 19 Issue Pages 840
Keywords basification, sulfate, sulfate reducing bacteria (SRB), uranium, wastewater, zerovalent iron (ZVI)
Abstract Batch and column experiments were conducted to determine whether zerovalent iron (ZVI) and sulfate reducing bacteria (SRB) can function synergistically and accelerate pollutant removal. Batch experiments suggest that combining ZVI with SRB can enhance the removal of U(?) synergistically. The removal rate of U(?) in the ZVI+SRB combining system is obviously higher than the total rate of ZVI system and SRB system with a difference of 13.4% at t=2 h and 29.9% at t=4 h. Column experiments indicate that the reactor filled with both ZVI and SRB biofilms is of better performance than the SRB bioreactor in wastewater basification, desulfurization and U(?) fixation. The results imply that the ZVI+SRB permeable reactive barrier may be a promising method for treating subsurface uranium contamination.
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Series Editor Series Title Abbreviated Series Title
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ISSN 1003-6326 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ yi_treatment_2009 Serial 206
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Author (up) Zaeri, A.; Mohammadi, Z.; Rezanezhad, F.
Title Determining the source and mechanism of river salinity: An integrated regional study Type Journal Article
Year 2023 Publication Journal of Hydrology: Regional Studies Abbreviated Journal
Volume 47 Issue Pages 101411
Keywords River salinity, Salinization mechanism, Isotope, Halite brine, River sinuosity
Abstract Study region Zohreh River Basin, Southwest Iran Study focus The salinity of Zohreh River sharply increases in three salinity zones (SZs) along the river named SZ1, SZ2 (the focus of this study), and SZ3. Determining the salinity sources and salinization mechanism using an integrated approach including geological, hydrochemical, isotopic, geophysical, river sinuosity and hydrocarbon analysis are the main objectives of this study. The study focuses on the combination of evidence of regional-scale (i.e., river sinuosity and seismic data) and small-scale (i.e., drilling core analysis). New hydrologic insights for the region Among several known sources of river salinity, it was found that the water quality of the Zohreh River is mainly threatened by the salt-bearing Gachsaran Formation and oil-field brine. It is concluded that halite brine and oil-field brine simultaneously cause the salinization in SZ2, and their contributions were delineated to be 95% and 5%, respectively. The lack of reliable geological evidence to support halite dissolution in surficial layers by circulating waters suggests the possibility of a deep source of halite brine in SZ2. The results revealed that deep halite brine of the salt layers of Gachsaran Formation is mainly responsible for the salinization of SZ2. The mechanism of deep brine penetration to the river through the hidden fault failures detected by the combination of river sinuosity analysis and geophysical data for the first time.
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Series Editor Series Title Abbreviated Series Title
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ISSN 2214-5818 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ Zaeri2023101411 Serial 251
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Author (up) Zeng, S.; Shen, Y.; Sun, B.; Tan, K.; Zhang, S.; Ye, W.
Title Fractal kinetic characteristics of uranium leaching from low permeability uranium-bearing sandstone Type Journal Article
Year 2022 Publication Nuclear Engineering and Technology Abbreviated Journal
Volume 54 Issue 4 Pages 1175-1184
Keywords Fractal characteristics, In-situ leaching, Leaching kinetics, Pore structure, Uranium mine
Abstract The pore structure of uranium-bearing sandstone is one of the critical factors that affect the uranium leaching performance. In this article, uranium-bearing sandstone from the Yili Basin, Xinjiang, China, was taken as the research object. The fractal characteristics of the pore structure of the uranium-bearing sandstone were studied using mercury intrusion experiments and fractal theory, and the fractal dimension of the uranium-bearing sandstone was calculated. In addition, the effect of the fractal characteristics of the pore structure of the uranium-bearing sandstone on the uranium leaching kinetics was studied. Then, the kinetics was analyzed using a shrinking nuclear model, and it was determined that the rate of uranium leaching is mainly controlled by the diffusion reaction, and the dissolution rate constant (K) is linearly related to the pore specific surface fractal dimension (DS) and the pore volume fractal dimension (DV). Eventually, fractal kinetic models for predicting the in-situ leaching kinetics were established using the unreacted shrinking core model, and the linear relationship between the fractal dimension of the sample’s pore structure and the dissolution rate during the leaching was fitted.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1738-5733 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number THL @ christoph.kuells @ zeng_fractal_2022 Serial 193
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