|
Zhang, Y., Liu, X., Yuan, S., Song, J., Chen, W., & Dias, D. (2023). A two-dimensional experimental study of active progressive failure of deeply buried Qanat tunnels in sandy ground. Soils and Foundations, 63(3), 101323.
Abstract: As an ancient underground hydraulic engineering facility, the Qanat system has been used to draw groundwater from arid regions. A qanat is a horizontal tunnel with a slight incline that draws groundwater from a higher location and delivers it to lower agricultural land. During long-term water delivery, the qanat tunnel has experienced different degrees of aging and collapse, which may result in the significant ground settlement and even disasters. This paper developed a two-dimensional laboratory system to investigate the influence of progressive failure on the stability of deeply buried qanat tunnels. The developed system is fully instrumented with a particle image velocimetry (PIV) system and earth pressure and displacement monitoring. A special cylindrical membrane tube is designed and connected to an advanced pressure–volume controller to simulate the step-wise failure process of the tunnel. Three model tests were conducted on a dry sand considering the buried qanat tunnels at three different depths. Experimental results clearly show the progressive evolution of soil arching effect in the dry sand associated with the progressive failure of the tunnels. The failure of the Qanat ground starts from the vault and develops upwards, which is closely related to the evolution of stress contour at three consecutive stages. Ground surface settlement and volume loss corresponding to three burial depths were compared. A deeply buried qanat tunnel has a small effect on surface settlement. Earth pressure evolution on the 2D plane shows the load redistribution when the qanat collapses. The maximum arch and the initial point of the limit state correspond to a volume loss of 12.5 % and 50 %, respectively. For the collapse of the deep buried qanat tunnel, ground earth pressure evolution can be divided into a stress-increasing region, stress-decreasing region, and no redistribution region. Furthermore, a multi trap-door model considering soil expansion is proposed to describe the progressive failure behavior and its effects.
|
|
|
Liu, Z., Tan, K., Li, C., Li, Y., Zhang, C., Song, J., et al. (2023). Geochemical and S isotopic studies of pollutant evolution in groundwater after acid in situ leaching in a uranium mine area in Xinjiang. Nuclear Engineering and Technology, 55(4), 1476–1484.
Abstract: Laboratory experiments and point monitoring of reservoir sediments have proven that stable sulfate reduction (SSR) can lower the concentrations of toxic metals and sulfate in acidic groundwater for a long time. Here, we hypothesize that SSR occurred during in situ leaching after uranium mining, which can impact the fate of acid groundwater in an entire region. To test this, we applied a sulfur isotope fractionation method to analyze the mechanism for natural attenuation of contaminated groundwater produced by acid in situ leaching of uranium (Xinjiang, China). The results showed that δ34S increased over time after the cessation of uranium mining, and natural attenuation caused considerable, area-scale immobilization of sulfur corresponding to retention levels of 5.3%–48.3% while simultaneously decreasing the concentration of uranium. Isotopic evidence for SSR in the area, together with evidence for changes of pollutant concentrations, suggest that area-scale SSR is most likely also important at other acid mining sites for uranium, where retention of acid groundwater may be strengthened through natural attenuation. To recapitulate, the sulfur isotope fractionation method constitutes a relatively accurate tool for quantification of spatiotemporal trends for groundwater during migration and transformation resulting from acid in situ leaching of uranium in northern China.
|
|
|
Wang, W., Liang, X., Niu, Q., Wang, Q., Zhuo, J., Su, X., et al. (2023). Reformability evaluation of blasting-enhanced permeability in in situ leaching mining of low-permeability sandstone-type uranium deposits. Nuclear Engineering and Technology, 55(8), 2773–2784.
Abstract: It is essential to evaluate the blasting-enhanced permeability (BEP) feasibility of a low-permeability sandstone-type uranium deposit. In this work, the mineral composition, reservoir physical properties and rock mechanical properties of samples from sandstone-type uranium deposits were first measured. Then, the reformability evaluation method was established by the analytic hierarchy process-entropy weight method (AHP-EWM) and the fuzzy mathematics method. Finally, evaluation results were verified by the split Hopkinson Pressure Bar (SHPB) experiment and permeability test. Results show that medium sandstone, argillaceous sandstone and siltstone exhibit excellent reformability, followed by coarse sandstone and fine sandstone, while the reformability of sandy mudstone is poor and is not able to accept BEP reservoir stimulation. The permeability improvement and the distribution of damage fractures before and after the SHPB experiment confirm the correctness of evaluation results. This research provides a reformability evaluation method for the BEP of the low-permeability sandstone-type uranium deposit, which contributes to the selection of the appropriate regional and stratigraphic horizon of the BEP and the enhanced ISL of the low-permeability sandstone-type uranium deposit.
|
|
|
Zeng, S., Song, J., Sun, B., Wang, F., Ye, W., Shen, Y., et al. (2023). Seepage characteristics of the leaching solution during in situ leaching of uranium. Nuclear Engineering and Technology, 55(2), 566–574.
Abstract: Investigating the seepage characteristics of the leaching solution in the ore-bearing layer during the in situ leaching process can be useful for designing the process parameters for the uranium mining well. We prepared leaching solutions of four different viscosities and conducted experiments using a self-developed multifunctional uranium ore seepage test device. The effects of different viscosities of leaching solutions on the seepage characteristics of uranium-bearing sandstones were examined using seepage mechanics, physicochemical seepage theory, and dissolution erosion mechanism. Results indicated that while the seepage characteristics of various viscosities of leaching solutions were the same in rock samples with similar internal pore architectures, there were regular differences between the saturated and the unsaturated stages. In addition, the time required for the specimen to reach saturation varied with the viscosity of the leaching solution. The higher the viscosity of the solution, the slower the seepage flow from the unsaturated stage to the saturated stage. Furthermore, during the saturation stage, the seepage pressure of a leaching solution with a high viscosity was greater than that of a leaching solution with a low viscosity. However, the permeability coefficient of the high viscosity leaching solution was less than that of a low viscosity leaching solution.
|
|
|
Arya, S., & Kumar, A. (2023). Evaluation of stormwater management approaches and challenges in urban flood control. Urban Climate, 51, 101643.
Abstract: Across the globe, the damage caused by urban floods has increased manifold. The unchecked development has encroached the natural drainage, and the conventional drainage systems are inadequate in handling the augmented hydrological response. To counter this, a variety of approaches with the ability to adjust within the constraints of complex environments by managing surface runoff are being widely investigated and applied worldwide. These can put the flood water to better use, and the ecological balance may get restored. This review discusses recent progress made in the area of Green Infrastructure (GI), modelling tools that help in stormwater management, vulnerability analysis and flood risk assessment. Different ways of handling the problem are summarized through an extensive literature survey. The gaps and barriers that impede the implementation of stormwater management solutions and strategies for further improvement have also been presented. A case study of Gurugram city, India depicting the challenges being faced by urban flooding and the possible solutions through an expert survey is also presented.
|
|
|
Hayes-Rich, E., Levy, J., Hayes-Rich, N., Lightfoot, D., & Gauthier, Y. (2023). Searching for hidden waters: The effectiveness of remote sensing in assessing the distribution and status of a traditional, earthen irrigation system (khettara) in Morocco. Journal of Archaeological Science: Reports, 51, 104175.
Abstract: This paper presents the results of a multi-year, interdisciplinary project that aimed to assess the holistic status of the khettara system in Morocco. The khettara (also known as qanat) is a traditional, earthen water management system. Historically the system was used for settlement in regions without access to reliable surface water. It is both a world and local heritage structure, found in rural and urban regions throughout 46 countries. Recent evaluations of this traditional system have advocated for its preservation and use in arid and semi-arid regions, as modern technologies (pump wells, industrial dams, drip irrigation, etc.) have proven to be unsustainable. This project evaluates remote sensing as a tool for assessing the distribution and status of the khettara in Morocco. The results of this project demonstrate that (1) the khettara system played a large role in the historic settlement of arid and semi-arid regions, and (2) the system continues to be an important part of agriculture and life in many oases across Morocco.
|
|
|
Rusli, S. R., Weerts, A. H., Mustafa, S. M. T., Irawan, D. E., Taufiq, A., & Bense, V. F. (2023). Quantifying aquifer interaction using numerical groundwater flow model evaluated by environmental water tracer data: Application to the data-scarce area of the Bandung groundwater basin, West Java, Indonesia. Journal of Hydrology: Regional Studies, 50, 101585.
Abstract: Study Region: Bandung groundwater basin, Indonesia. Study focus: Groundwater abstraction of various magnitudes, pumped out from numerous depths in a multitude of layers of aquifers, stimulates different changes in hydraulic head distribution, including ones under vertical cross-sections. This generates groundwater flow in the vertical direction, where groundwater flows within its storage from the shallow to the underlying confined aquifers. In the Bandung groundwater basin, previous studies have identified such processes, but quantitative evaluations have never been conducted, with data scarcity mainly standing as one of the major challenges. In this study, we utilize the collated (1) environmental water tracer data, including major ion elements (Na+/K+, Ca2+, Mg2+, Cl−, SO42−,HCO3−), stable isotope data (2H and δ18O), and groundwater age determination (14C), in conjunction with (2) groundwater flow modeling to quantify the aquifer interaction, driven mainly by the multi-layer groundwater abstraction in the Bandung groundwater basin, and demonstrate their correspondence. In addition, we also use the model to quantify the impact of multi-layer groundwater abstraction on the spatial distribution of the groundwater level changes. New hydrological insights for the region: In response to the limited calibration data availability, we expand the typical model calibration that makes use of the groundwater level observations, with in-situ measurement and a novel qualitative approach using the collated environmental water tracers (EWT) data for the model evaluation. The analysis in the study area using EWT data and quantitative methods of numerical groundwater flow modeling is found to collaborate with each other. Both methods show agreement in their assessment of (1) the groundwater recharge spatial distribution, (2) the regional groundwater flow direction, (3) the groundwater age estimates, and (4) the identification of aquifer interaction. On average, the downwelling to the deeper aquifer is quantified at 0.110 m/year, which stands out as a significant component compared to other groundwater fluxes in the system. We also determine the unconfined aquifer storage volume decrease, calculated from the change in the groundwater table, resulting in an average declining rate of 51 Mm3/year. This number shows that the upper aquifer storage is dwindling at a rate disproportionate to its groundwater abstraction, hugely influenced by losses to the deeper aquifer. The outflow to the deeper aquifer contributes to 60.3% of the total groundwater storage lost, despite representing only 32.3% of the total groundwater abstraction. This study shows the possibility of quantification of aquifer interaction and groundwater level change dynamics driven by multi-layer groundwater abstraction in a multi-layer hydrogeological setting, even in a data-scarce environment. Applying such methods can assist in deriving basin-scale groundwater policies and management strategies under the changing anthropogenic and climatic factors, thereby ensuring sustainable groundwater management.
|
|
|
Ibrahim, A. S., Zayed, I. S. A., Abdelhaleem, F. S., Afify, M. M., Ahmed, A., & Abd-Elaty, I. (2023). Identifying cost-effective locations of storage dams for rainfall harvesting and flash flood mitigation in arid and semi-arid regions. Journal of Hydrology: Regional Studies, 50, 101526.
Abstract: Study region Wadi Tayyibah is located in south Sinai, Egypt, in a region called Abou Zenima, and it is used to develop this study. Study focus Flash floods tremendously impact many facets of human life due to their destructive consequences and the costs associated with mitigating efforts. This study aims to evaluate the harvesting of Runoff by delineating the watersheds using the Hydrologic Engineering Center-1 (HEC-1) model and ArcGIS software in trying to benefit from it in different ways. All morphometric parameters of the basin were considered, and the risk degree of the different sub-basins was determined. The suitable locations of dams were identified using a Geographical Information System (GIS) using the basin’s morphometric characteristics. New hydrological insights for the region The study proposed a total number of eight dams, including five dams that were recommended for sub-basin (1) and three dams in sub-basin (4), while sub-basins (2) and (3) are not suitable locations to build dams according to the contour map of Wadi Tayyibah. Results indicate that, based on the constructed flash flood hazard maps and the basin’s detailed morphometric characteristics, the best locations of dams are Dam (3) in sub-basin (1) and Dam (7) in sub-basin (4), where the runoff volume reached 3.13 million cubic meters (Mm3) and 5.56 Mm3 for return period 100, respectively. This study is useful for decision-makers and designers for using morphometric parameters and flash flood hazard degree maps to select dam locations. Also, the cost-benefit analysis for using the morphometric parameters is required to be investigated.
|
|
|
Zaeri, A., Mohammadi, Z., & Rezanezhad, F. (2023). Determining the source and mechanism of river salinity: An integrated regional study. Journal of Hydrology: Regional Studies, 47, 101411.
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.
|
|
|
Pham, Q. - N., Nguyen, T. - C., Ta, T. - T., & Tran, T. - L. (2023). Comprehensive approach to sustainable groundwater management in semi-arid Ninh Thuan plain, Vietnam. Groundwater for Sustainable Development, 23, 101031.
Abstract: Vietnam is a country with a long coastline and a high population density residing in the coastal plains. The largest dry area in Vietnam, the coastal plain of Ninh Thuan province, always lacks water in the first dry months of the year (Jan., Feb., Mar., and Apr.). Groundwater is an extremely valuable resource for supplies at this time. Therefore, the objective of this study is to establish a comprehensive approach to sustainable groundwater management in this semi-arid region. This approach is not only mitigating the negative impacts of factors such as climate change, sea level rise, and socio-economic development but also suggesting measures for management of aquifer recharge. A groundwater model for a 3-layer system with variable density flow SEAWAT is built to predict the impacts of climate change and sea level rise without a change in groundwater abstraction. This model helps to understand the trend of salt intrusion and lowering groundwater level in the study area. Afterwards, scenarios with different ground water abstraction and groundwater development such as ground dam, infiltration basin have been set up to meet the demands of socio-economic development in the future. Predicted results will show the impacts of the groundwater systems in the area such as groundwater level change, and saltwater intrusion. Controlled groundwater abstraction and some measures of groundwater development such as infiltration basin, underground dam would allow for an increase of up to 50000m3/day in the year 2050 without negative impacts on the aquifer system.
|
|