Article
Environmental Sciences
C. Xu, B. Odum, Y. Chen, P. Yao
Summary: The impact of silt content on the flocculation processes and settling and floc properties of clay-silt mixtures was investigated. The results show that increasing silt content reduces floc strength and size, as well as the settling velocities. The study also found that the flux-settling velocities increase with increasing silt content. These findings provide insights into the role of silt in the flocculation process of clay-silt mixtures in natural water environments.
WATER RESOURCES RESEARCH
(2022)
Article
Geochemistry & Geophysics
David C. Nobes
Summary: When studying indigenous sites, respecting the needs and wishes of indigenous people is essential. Noninvasive geophysical imaging techniques show potential for such investigations. Results from a study conducted in the South Island of New Zealand indicate that different types of sites have varying responses to geophysical methods.
Article
Energy & Fuels
Qiongqiong Tang, Yuanbo Chen, Rui Jia, Wei Guo, Weiqiang Chen, Xiaoshuang Li, Huicai Gao, Yu Zhou
Summary: Knowledge of the mechanical properties of natural gas hydrate reservoirs is crucial for the safe and commercial extraction of natural gas hydrate. This study investigated the effects of clay type and content on the failure strength and deformation of clayey silt hydrate sediments. It was found that samples containing illite generally exhibited higher strength and stiffness, while samples containing montmorillonite had higher cohesion. These findings provide valuable insights for the assessment of reservoirs and the design of safe wellbores.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Geosciences, Multidisciplinary
Xiao Bai, Ming'an Shao, Xiaoxu Jia, Chunlei Zhao
Summary: Soil hydraulic parameters are crucial for water flow modeling, biogeochemical processes, and plant growth. This study analyzed the factors strongly correlated with soil hydraulic parameters in the China's Loess Plateau Region (CLPR) and developed models to predict these parameters. The results showed that soil texture, soil depth, mean annual precipitation, slope gradient, slope aspect, and elevation were strongly correlated with soil hydraulic parameters. The established models had higher accuracy compared to the current state-of-the-art in this field. The spatial distribution of soil hydraulic parameters in the CLPR exhibited significant clustering. This research provides empirical evidence for studying soil hydrological processes in the CLPR and other similar regions.
Article
Environmental Sciences
Xuan Du, Can Du, Jesse Radolinski, Qianfeng Wang, Jinshi Jian
Summary: This study developed a new method for estimating soil water retention curve (SWRC) parameters using a Metropolis-Hastings algorithm of the Markov chain Monte Carlo (MH-MCMC) approach. The results show that this MH-MCMC approach is more robust and accurate compared to traditional methods, especially when data for a limited range of matric potential are available.
Article
Engineering, Multidisciplinary
Adil A. M. Elhassan, Mohammed Mnzool, Hichem Smaoui, Abir Jendoubi, Bushra M. E. Elnaim, Maged Faihan Alotaibi
Summary: The impact of clay mineralogy on engineering properties, such as strength and stiffness, of road materials is investigated in this study. It is found that kaolinite is more effective than montmorillonite in reducing clay plasticity, and samples with high kaolinite content exhibit higher strength indicators. Additionally, kaolinitic soil samples have a larger constrained modulus than other samples.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Engineering, Geological
Dhanaji Chavan, G. L. Sivakumar Babu
Summary: This study investigates the effect of thickness and position of layers of saturated silt and sand on the site response of in situ ground. The response of the materials is modeled using a pressure dependent multi yield material model under undrained seismic loading. The results show that the introduction of a 0.5 m thick silt seam at different depths increases the hydraulic gradient, indicating the formation of a water film under sustained high pressure. Liquefaction and spectral accelerations are reduced, and there is no phase difference between the input acceleration record and the acceleration record at the ground surface.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2023)
Article
Engineering, Civil
Tao Li, Xiaowei Tang
Summary: The study shows that low clay and silt contents have an influence on the undrained behavior of sands, affecting filling, bonding, and soil skeleton characteristics of sand particles. The extent of this influence varies depending on the clay and silt contents.
EUROPEAN JOURNAL OF ENVIRONMENTAL AND CIVIL ENGINEERING
(2022)
Article
Geosciences, Multidisciplinary
Xiangang Jiang, Qin Huang, Zongliang Zhang, Luis E. Vallejo, Xiaoqing Chen, Wanyu Zhao, Hongyan Deng, Xingrong Liu, Danqing Song, Zhuo Chen
Summary: Clay content has a significant influence on the crack evolution process of clay-sand mixture. When clay content is greater than 50%, the crack development process can be divided into three stages; when clay content is less than 50%, the characteristics of the crack development process are short length, dense crack spacing, no main cracks, and no obvious stages. The addition of clay can increase the tensile strength of the mixture and restrain crack development. The water content of samples decreases nonlinearly with drying time, and the residual water content increases with clay content.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Engineering, Civil
Zhehao Zhu, Jean-Claude Dupla, Jean Canou, Evelyne Foerster
Summary: This paper investigates the impact of non-plastic fines on the sand matrix through a series of undrained triaxial tests. The results indicate that the addition of non-plastic fines enhances the resistance to liquefaction by inducing dilatant behavior and reducing excess pore water pressure. The effect is non-linear in the very loose state but insignificant in the medium-dense state. Additionally, the study reveals a unified line in the p'-q space for the ultimate steady state, with a clockwise rotation observed in the log(p')-e space. The exponential form provides a good fit for silty sand.
EUROPEAN JOURNAL OF ENVIRONMENTAL AND CIVIL ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Darn-Horng Hsiao, Chung-Chieh Lin
Summary: To investigate the effects of plastic fines properties on pore water pressure generation during cyclic loadings, 29 sets of test data from literature and another 21 reconstituted specimens were used. Results showed that clean sands had slow, stagnated, then accelerated pore water pressure ratios until initial liquefaction, while plastic soils with a plastic index greater than 5 had sharp increase in initial stage. Furthermore, cyclic stress ratio of specimens containing plastic fines increased by 1.5-3.0 times more than non-plastic fines. Results were analyzed using a mathematical model, which clarified previous arguments.
APPLIED SCIENCES-BASEL
(2023)
Article
Green & Sustainable Science & Technology
Mingqiang Wang, Pan Chen, Panpan Yi, Tiantian Ma
Summary: Plant sand fixation is an effective and eco-friendly measure for mitigating windblown sand hazards. This study investigated the influence of fines content on the pore size distribution characteristics of aeolian-sand composite soils using low-field nuclear magnetic resonance technology. It was found that the pore size initially increased and then decreased as fines content increased. The distribution curve of pore size changed from a single-peak structure to a double-peak structure and then back to a unimodal structure. The dominant pore size of composite soils also followed a similar trend. This research provides a theoretical basis for selecting suitable materials and designing plant sand fixation measures.
Article
Construction & Building Technology
Liming Yang, Fan Yang, Qian Zhou, Guangbin Zhang
Summary: This study conducted shear strength tests on the silty fine sand and rounded gravel layers in Nanning City and compared them with empirical values. The results showed that the shear strength of the fine sand layer was consistent with the empirical values, while the shear strength of the rounded gravel layer significantly improved compared to the empirical values. It is recommended to determine the shear strength of the rounded gravel layer based on the actual situation.
ADVANCES IN CIVIL ENGINEERING
(2023)
Article
Engineering, Geological
Kangle Zuo, Xiaoqiang Gu, Hangyu Liu, Jing Hu, Guangyun Gao
Summary: In this study, the effects of fines content and host sand gradation on the liquefaction resistance and excess pore water pressure generation of sand-silt mixtures were investigated. The results showed that the effect of fines content on liquefaction resistance depended on relative density, grain size ratio, and sand uniformity coefficient. The relationship between excess pore water pressure ratio and cycle ratio could be well expressed by the Seed model, which was significantly affected by cyclic stress ratio, fines content, and relative density.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2023)
Article
Geochemistry & Geophysics
Shamsollah Ayoubi, Anashia Milikian, Mohammad Reza Mosaddeghi, Mojtaba Zeraatpisheh, Shuai Zhao
Summary: Soil characteristics, especially clay content and clay type, have significant impacts on splash erosion. In this study, splash erosion decreased and shear strength increased with increased clay content.
Article
Agronomy
Wenjie Wu, Ze Tao, Guangjie Chen, Tingfang Meng, Yue Li, Hao Feng, Bingcheng Si, Kiril Manevski, Mathias Neumann Andersen, Kadambot H. M. Siddique
Summary: This study measured variations in water use strategies of peach, walnut, and apple trees and found differences in water source utilization and drought stress responses among the three tree species.
AGRICULTURAL AND FOREST METEOROLOGY
(2022)
Article
Agronomy
Ruiqi Ren, Han Fu, Bingcheng Si, Nicholas J. Kinar, Kathy Steppe
Summary: Probe spacing affects sap flow measurement in plants. Most non-destructive methods rely on the assumption of nocturnal zero flow conditions, which is often invalid in natural biological systems. This study presents a novel method for accurate in situ determination of probe spacing, using mathematical models and nonlinear curve fitting during low flow conditions. The proposed method allows real time probe spacing measurements, reducing uncertainties associated with zero flow assumption.
AGRICULTURAL AND FOREST METEOROLOGY
(2022)
Article
Environmental Sciences
Guangjie Chen, Tingfang Meng, Wenjie Wu, Bingcheng Si, Min Li, Boyang Liu, Shufang Wu, Hao Feng, Kadambot H. M. Siddique
Summary: Groundwater recharge decreases due to afforestation with deep-rooted plants, but there are no methods to assess potential recharge under unsteady state conditions. This study developed a new method to quantify groundwater recharge in the unsteady state.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Agronomy
Qian Zhang, Peng Zhang, Yunpeng Deng, Chitao Sun, Xiaoxu Tian, Bingcheng Si, Bo Li, Xiaohong Guo, Fusheng Liu, Zhenhua Zhang
Summary: Aerobic irrigation can enhance the growth and development of tomato roots by regulating auxin, leading to increased crop yield and quality.
Article
Geosciences, Multidisciplinary
Wenjie Wu, Guangjie Chen, Tingfang Meng, Cheng Li, Hao Feng, Bingcheng Si, Kadambot H. M. Siddique
Summary: The comprehensive effects of different vegetation restoration types on soil properties on the Loess Plateau are not clear. Evaluating the soil properties of the main economic and ecological tree species can provide crucial guidance for regional ecological environment restoration. Black locust had greater negative effects on soil properties compared to economic tree species.
Article
Engineering, Civil
Guangjie Chen, Wenjie Wu, Tingfang Meng, Mingyi Wen, Bingcheng Si, Jianqiang He, Min Li, Qinge Dong, Hao Feng, Kadambot H. M. Siddique
Summary: This study investigated the influence of deep-rooted vegetation on the age of soil water and analyzed the proportion of new and old water of transpiration in the unsaturated zone. The results showed that deep-rooted vegetation restrained new pore water velocity and potential groundwater recharge, and mainly used new water for transpiration. These findings provide new insights into the transpiration process and water use of deep-rooted vegetation.
JOURNAL OF HYDROLOGY
(2023)
Article
Environmental Sciences
Guangjie Chen, Tingfang Meng, Wenjie Wu, Ji'na Zhang, Ze Tao, Naijiang Wang, Bingcheng Si, Min Li, Hao Feng, Kadambot H. M. Siddique
Summary: We studied root water uptake responses of three revegetation species (Hippophae rhamnoides, Platycladus orientalis, and Robinia pseudoacacia) in the dry and rainy seasons. The results show that Hippophae rhamnoides and Robinia pseudoacacia mainly extract water from the middle soil layer, while Platycladus orientalis extracts water from the deep soil layer. These findings are helpful in selecting the optimal revegetation species for water use.
LAND DEGRADATION & DEVELOPMENT
(2023)
Article
Geosciences, Multidisciplinary
Hongxiu Wang, Han Li, Wei Xiang, Yanwei Lu, Huanhuan Wang, Wei Hu, Bingcheng Si, Scott Jasechko, Jeffrey J. McDonnell
Summary: In this study, a 98 m soil core from the Loess Plateau of China was sampled and the relationship between pore water isotopic values and hydroclimate history was examined. The results showed that the δO-18 and δH-2 values between 14-50 m were anomalously low, corresponding well to the Little Ice Age period from 1420 to 1870. This identification was consistent with other standard proxies in the region and revealed the temporal dynamics of temperature anomalies. The study highlights the potential of stable isotopes of soil water for paleoclimate reconstruction in deep soils.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Engineering, Civil
Dong He, Mingyi Wen, Yanbo Wang, Guangyuan Dub, Congcong Zhang, Hailong He, Jingjing Jin, Min Li, Bingcheng Si
Summary: In this study, the accuracy of three current δH-2 offset correction methods, namely 8.1 parts per thousand Mean-Correc, Line-Correc, and REHYDR, for plant water source identification was evaluated using the CaviTron centrifuge technique. The results suggest that the REHYDR and 8.1 parts per thousand Mean-Correc methods outperformed the Line-Correc method in identifying plant water sources.
JOURNAL OF HYDROLOGY
(2023)
Article
Environmental Sciences
Han Li, Min Li, Changhong Miao, Bingcheng Si, Yanwei Lu
Summary: Accurate estimation of groundwater recharge is essential for assessing its spatial variation at different scales. In this study, field variation in groundwater recharge was evaluated using multiple tracers in the deep vadose zone on the Chinese Loess Plateau. The results showed no significant differences in recharge rates among the sites, and the recharge estimates by different tracers' methods did not differ significantly. However, the chloride mass balance method indicated higher variations in recharge rates compared to the peak depth method. Considering the contribution of immobile water, the peak depth method overestimated groundwater recharge. This study provides valuable insights for accurate estimation of groundwater recharge and its variation in the deep vadose zone.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Zhongen Niu, Honglin He, Pengtao Yu, Stephen Sitch, Ying Zhao, Yanhui Wang, Atul K. Jain, Nicolas Vuichard, Bingcheng Si
Summary: By integrating satellite data and simulation models, this study found that over 90% of the Chinese Loess Plateau has experienced vegetation greening, with human land-use management and environmental change accounting for 54% and 46% of the overall greening trend, respectively. CO2 fertilization and climate change explain 55% and 45% of the greening trend due to environmental change, respectively.
Article
Environmental Sciences
Yanfang Liu, Guocui Wang, Xianna Zhang, Hongchen Li, Bingcheng Si, Wenqian Liu, Zhenhua Zhang
Summary: The characteristics of gas-liquid two-phase flow in a labyrinth channel were studied using particle tracking velocimetry. Bubbly flow was found to be the typical flow pattern, with occasional slug flow. The trajectory of bubbles differed between the mainstream and vortex zones. The study provides important insights into gas-liquid two-phase flow in labyrinth channels used for aerated drip irrigation.
Article
Plant Sciences
Xia Wang, Yanli Fan, Congcong Zhang, Yihong Zhao, Guangyuan Du, Min Li, Bingcheng Si
Summary: This study aimed to identify reliable and easily available drought stress indices for trees and determine the thresholds at which drought activates important physiological responses. It was found that midday xylem water potential (psi(md)) was a better indicator of drought stress than soil water availability (SWA) and predawn xylem water potential (psi(pd)). The study also established five stress levels based on the observed changes in psi(md).
FRONTIERS IN PLANT SCIENCE
(2023)
Article
Agriculture, Multidisciplinary
Huijie Li, Han Li, Qifan Wu, Bingcheng Si, Esteban G. Jobbagy, Jeffrey J. Mcdonnell
Summary: This study reveals the overlooked hydrological costs and over-optimistic expectations of sustained carbon sequestration under afforestation in the Loess Plateau of China. It indicates that water resources are exhausted during the root mining process while carbon fixation only represents a single-pulsed growth.
AGRICULTURE ECOSYSTEMS & ENVIRONMENT
(2023)
Article
Geosciences, Multidisciplinary
Jiming Jin, Lei Wang, Jie Yang, Bingcheng Si, Guo-Yue Niu
Summary: This study aimed to improve runoff simulations in a watershed with complex topography and deep soil, and explored the hydrological processes using the Community Land Model version 5 (CLM5). The results showed that incorporating actual soil depths and river channels into CLM5 significantly improved the accuracy of simulated runoff, and varying the soil evaporation threshold based on soil characteristics further enhanced the simulations. The study provides important insights for investigating hydrological processes in complex terrains with deep soils.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)