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1. A concise overview on historical black carbon in ice cores and remote lake sediments in the northern hemisphere
Poonam Thapa,JianZhong Xu,Bigyan Neupane
Sciences in Cold and Arid Regions    2021, 13 (3): 179-194.   DOI: 10.3724/SP.J.1226.2021.20055.
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Black Carbon (BC), as a driver of environmental change, could significantly impact the snow by accelerating melting and decreasing albedo. Systematic documentation of BC studies is crucial for a better understanding of its spatial and temporal trends. This study reviewed the BC studies in the ice core and remote lake sediments and their sources in the northern hemisphere. The literature surveyed points to around 2.9 to 3.7 times increase of BC in the European Alps and up to a three-fold increase of BC in the Himalayan-Tibetan Plateau (HTP) after the onset of industrialization in Europe and Asia, respectively. BC concentration from Greenland ice core showed seven times increase with an interrupted trend after 1950's. South Asian emissions were dominant in the HTP along with a contribution from the Middle East, whereas Western European and local emissions were responsible for the change in BC concentration in the European Alps. In the Arctic, contributions from North America, Europe and Asia persisted. Similarly, a historical reconstruction of lake sediments records demonstrates the effects of emissions from long-range transport, sediment focusing, local anthropogenic activities, precipitation and total input of flux on the BC concentration.

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2. Discussion on pile axial load test methods and their applicability in cold regions
JiaWei Gao,Ji Chen,Xin Hou,QiHang Mei,YongHeng Liu
Sciences in Cold and Arid Regions    2022, 14 (4): 267-281.   DOI: 10.1016/j.rcar.2022.09.005.
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The measurement of pile axial load is of great significance to determining pile foundation design parameters such as skin friction and end bearing capacity and analyzing load transfer mechanisms. Affected by the temperature and ice content of frozen ground, the interface contact relationship between pile foundation and frozen soil is complicated, making pile axial load measurements more uncertain than that in non-frozen ground. Therefore, it is necessary to gain an in-depth understanding of the current pile axial load test methods. Four methods are systematically reviewed: vibrating wire sensors, strain gauges, sliding micrometers, and optical fiber strain sensors. At the same time, the applicability of the four test methods in frozen soil regions is discussed in detail. The first two methods are mature and commonly used. The sliding micrometer is only suitable for short-term measurement. While the Fiber Bragg grating (FBG) strain gauge meets the monitoring requirements, the Brillouin optical time-domain reflectometer (BOTDR) needs further verification. This paper aims to provide a technical reference for selecting and applying different methods in the pile axial load test for the stability study and bearing capacity assessment of pile foundations in cold regions.

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3. Frost susceptibility of soils―A confusing concept that can misguide geotechnical design in cold regions
DaiChao Sheng
Sciences in Cold and Arid Regions    2021, 13 (2): 87-94.   DOI: 10.3724/SP.J.1226.2021.20051
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Frost susceptibility is a concept widely used in cold region geotechnical design, to quantify the capacity of a soil in generating frost heave and frost damage. The laboratory test used to verify frost susceptibility of a soil is based on the measurement of frost heave generated in the soil under specific conditions. In reality this concept is, however, more related to the soil's potential to thaw weakening than to frost heave. Recent experimental studies show that frost non-susceptible soils like clean sand and clean gavel can also generate much ice segregation and frost heave if the conditions are favourable, hence challenging the usefulness and suitability of soil classification based on frost susceptibility. It is further shown that the concept is not suitable for design scenarios where frost heave itself is a serious hazard, such as in high-speed rail embankments.

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4. Guest Editors Fujun Niu and Jiankun Liu for special Issue International Conference on Permafrost
Sciences in Cold and Arid Regions    2021, 13 (2): 1-1.  
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5. Seasonal variation of airborne fungi of the Tiantishan Grottoes and Western Xia Museum, Wuwei, China
YuLong Duan,FaSi Wu,DongPeng He,RuiHong Xu,HuYuan Feng,Tuo Chen,GuangXiu Liu,WanFu Wang
Sciences in Cold and Arid Regions    2021, 13 (6): 522-532.   DOI: 10.3724/SP.J.1226.2021.20102
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In this study, a systematic survey of cultural airborne fungi was carried out in the occurrence environments of wall paintings that are preserved in the Tiantishan Grottoes and the Western Xia Museum, China. A bio-aerosol sampler was used for sampling in four seasons in 2016. Culture-dependent and -independent methods were taken to acquire airborne fungal concentration and purified strains; by the extraction of genomic DNA, amplification of fungal ITS rRNA gene region, sequencing, and phylogenetic analysis, thereafter the fungal community composition and distribution characteristics of different study sites were clarified. We disclosure the main environmental factors which may be responsible for dynamic changes of airborne fungi at the sampling sites. The concentration of cultural airborne fungi was in a range from 13 to 1,576 CFU/m3, no significant difference between the two sites at the Tiantishan Grottoes, with obvious characteristics of seasonal variation, in winter and spring were higher than in summer and autumn. Also, there was a significant difference in fungal concentration between the inside and outside of the Western Xia Museum, the outside of the museum was far more than the inside of the museum in the four seasons, particularly in the winter. Eight fungal genera were detected, including Cladosporium, Penicillium, Alternaria, and Filobasidium as the dominant groups. The airborne fungal community structures of the Tiantishan Grottoes show a distinct characteristic of seasonal variation and spatial distribution. Relative humidity, temperature and seasonal rainfall influence airborne fungal distribution. Some of the isolated strains have the potential to cause biodeterioration of ancient wall paintings. This study provides supporting information for the pre-warning conservation of cultural relics that are preserved at local sites and inside museums.

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6. Summary of research on frost heave for subgrade in seasonal frozen ground
Shuang Jia,BoWen Tai,ShouChen Qi,Lei Li,Tao Chen
Sciences in Cold and Arid Regions    2021, 13 (3): 195-205.   DOI: 10.3724/SP.J.1226.2021.20092.
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The building of railways on seasonally frozen ground is inevitable as China pursues economic development and the improvement of its citizens' living standards. However, railway construction in seasonally frozen soil areas is often faced with frost heave, leading to uneven subgrades which seriously threaten traffic safety. This article summarizes extant research results on frost heave mechanism, frost heave factors, and anti-frost measures of railway subgrades in seasonally frozen soil areas.

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7. Progress, problems and prospects of palynology in reconstructing environmental change in inland arid areas of Asia
YongTao Zhao,YunFa Miao,Yan Lei,XianYong Cao,MingXing Xiang
Sciences in Cold and Arid Regions    2021, 13 (4): 271-291.   DOI: 10.3724/SP.J.1226.2021.20049.
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Studying the climatic and environmental changes on different time scales in inland arid regions of Asia can greatly improve our understanding of climatic influences for the Qinghai-Tibet Plateau in the context of global change. Pollen, as a remnant of seed plants, is sensitive to environmental factors including precipitation, temperature and altitude, and is a classic proxy in environmental reconstruction. In the last two decades, great progress in the application of palynology to inland areas of Asia has highlighted the role of palynology in paleoclimatic and paleoenvironmental research. The main progress is as follows. (1) On the tectonic time scale of the late Cenozoic, the palaeoclimatological sequence has been established on the basis of pollen percentage, concentration and taxon. Pollen data have revealed a continuous enhancement of drought in the inland arid region of Asia, in contrast to evidence acquired based on other proxies. (2) In the late Quaternary, an increase in herbaceous plants further supports the intensification of drought associated with global cooling. In more detail, the palynological record shows a glacial-interglacial pattern consistent with changes in global ice volume. (3) The Holocene pollen record has been established at a high resolution and across a wide range of inland areas. In general, it presents an arid grassland environment in the early Holocene, followed by the development of woody plants in the mid- to late-Holocene climate optimum. This pattern is related to moisture changes in areas dominated by the westerlies. There are also significant regional differences in the pattern and amplitude of vegetation response to the Holocene environment. (4) Modern pollen studies based on vegetation surveys, meteorological data and statistics show that topsoil palynology can better reflect regional vegetation types (e.g., grassland, meadow, desert). Drier climates yield higher pollen contents of drought-tolerant plants such as Chenopodioideae, Ephedra, and Nitriaria, while contents of Artemisia and Poaceae are greater under humid climates. Besides these achievements, problems remain in palynological research: for example, pollen extraction, identification, interpretation, and quantitative reconstruction. In the future, we encourage strengthened interdisciplinary cooperation to improve experimental methods and innovation. Firstly, we should strengthen palynological classification and improve the skill of identification; secondly, laboratory experiments are needed to better constrain pollen transport dynamics in water and air; thirdly, more rigorous mathematical principles will improve the reliability of reconstructions and deepen the knowledge of plant geography; and finally, new areas and methods in palynology should be explored, for example DNA, UV-B and isotopic analysis. It is expected that palynology will continue to develop, and we hope it will continue to play an important role in the study of past climatic and environmental changes.

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8. Numerical simulation of electroosmosis in unsaturated compacted clay
KangWei Tang,Feng Zhang,DeCheng Feng,GuanFu Wang
Sciences in Cold and Arid Regions    2021, 13 (5): 394-407.   DOI: 10.3724/SP.J.1226.2021.21033.
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The moisture content of a road subgrade in cold regions will increase after freeze-thaw cycles, resulting in subgrade strength and stiffness losses. Electroosmosis is widely used in treating saturated soft soils to decrease the moisture content. The induced moisture migration during electroosmosis in unsaturated soil is much more complex than that of saturated soil because of a series of nonlinear changes in soil properties. This study first uses an exponential function to characterize the relationship between electroosmotic permeability and saturation degree. Then, a one-dimensional model is developed to simulate the electroosmosis-induced moisture migration in unsaturated soil. Simulation results show that electroosmosis reduces the saturation degree of the unsaturated soil, indicating that it can be applied to subgrade dewatering. Key parameters such as soil pore size distribution coefficient, air entry value, and effective voltage significantly affect moisture migration. Electroosmotic properties of unsaturated soils are extremely important to the efficiency of electroosmosis.

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9. Ecophysiological responses to drought stress in Populus euphratica
ChunYan Zhao,JianHua Si,Qi Feng,TengFei Yu,Huan Luo,Jie Qin
Sciences in Cold and Arid Regions    2021, 13 (4): 326-336.   DOI: 10.3724/SP.J.1226.2021.20025.
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Ecophysiological responses to drought stress of Populus euphratica in Alashan Desert Eco-hydrology Experimental Research Station were investigated. Results show that under mild and moderate drought stress, stomatal length, aperture, area and density is likely to decrease in the early days, but afterwards this is likely to recovery with treatment over the passage of treatment time. Under severe drought stress, these properties appear to decline continuously. However, after 45 days of drought-stress treatment, the decline is not as noticeable as before, indicating that Populus euphratica could possibly reduce water evaporation by shutting down the stoma, leading to an improvement in its water use efficiency with better survival under drought stress conditions. The leaf area first decreases, and then increases under mild and moderate drought stress conditions, with the average values under different degree of stress found to be approximately 129.52, 120.08, 116.63 and 107.28 cm2, respectively. Under moderate stress conditions, the leaf water potential appears to show a continuous decline where the average values under different degree of stress are found to be -1.27, -1.85, -4.29 and -4.80 MPa, respectively. In terms of proline content, the results demonstrate that this factor appears to increase significantly under moderate and severe drought stress conditions. Especially under severe drought stress condition, the content is found to be more than 700 μg/g. Ranging over average values of 14.64 and 15.90 nmol/g under moderate and severe drought stress, respectively, Malondialdehyde content is found to increase quite rapidly under moderate and severe drought stress conditions at first, which then appears to decrease gradually with the treatment over time.

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10. Research progress on behaviors and environmental effects of mercury in the cryosphere of the Tibetan Plateau: a critical review
ShiWei Sun,ShiChang Kang,QiangGong Zhang,JunMing Guo,XueJun Sun
Sciences in Cold and Arid Regions    2022, 14 (1): 1-22.   DOI: 10.3724/SP.J.1226.2022.21049.
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The behavior and fates of environmental pollutants within the cryosphere and the associated environmental impacts are of increasing concerns in the context of global warming. The Tibetan Plateau (TP), also known as the "Third Pole", represents one of the most important cryospheric regions in the world. Mercury (Hg) is recognized as a global pollutant. Here, we summarize the current knowledge of Hg concentration levels, pools and spatio-temporal distribution in cryospheric environments (e.g., glacier, permafrost), and its transfer and potential cycle in the TP cryospheric region. Transboundary transport of anthropogenic Hg from the surrounding heavily-polluted regions, such as South and Southeast Asia, provides significant sources of atmospheric Hg depositions onto the TP cryosphere. We concluded that the melting of the cryosphere on the TP represents an increasing source of Hg and brings a risk to the TP environment. In addition, global warming acts as an important catalyst accelerating the release of legacy Hg from the melting cryosphere, adversely impacting ecosystems and biological health. Furthermore, we emphasize on the remaining gaps and proposed issues needed to be addressed in future work, including enhancing our knowledge on some key release pathways and the related environmental effects of Hg in the cryospheric region, integrated observation and consideration of Hg distribution, migration and cycle processes at a key region, and uses of Hg isotopic technical and Hg models to improve the understanding of Hg cycling in the TP cryospheric region.

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11. The driving force of water resource stress change based on the STIRPAT model: take Zhangye City as a case study
Xia Tang,XinYuan Wang,Lei Feng
Sciences in Cold and Arid Regions    2021, 13 (4): 337-348.   DOI: 10.3724/SP.J.1226.2021.20093.
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A prominent contradiction between supply and demand of water resources has restricted local development in social and economic aspects of Zhangye City, located in a typical arid region of China. Our study quantified the Water Resource Stress Index (WRSI) from 2003 to 2017 and examined the factors of population, urbanization level, GDP per capita, Engel coefficient, and water consumption per unit of GDP by using the extended stochastic impact by regression on population, affluence and technology (STIRPAT) model to find the key factors that impact WRSI of Zhangye City to relieve the pressure on water resources. The ridge regression method is applied to improve this model to eliminate multicollinearity problems. The WRSI system was developed from the following three aspects: water resources utilization (WR), regional economic development water use (WU), and water environment stress (WE). Results show that the WRSI index has fallen from 0.81 (2003) to 0.17 (2017), with an average annual decreased rate of 9.8%. Moreover, the absolute values of normalized coefficients demonstrate that the Engel coefficient has the largest positive contribution to increase WRSI with an elastic coefficient of 0.2709, followed by water consumption per unit of GDP and population with elastic coefficients of 0.0971 and 0.0387, respectively. In contrast, the urbanization level and GDP per capita can decrease WRSI by -0.2449 and -0.089, respectively. The decline of WRSI was attributed to water-saving society construction which included the improvement of water saving technology and the adjustment of agricultural planting structures. Furthermore, this study demonstrated the feasibility of evaluating the driving forces affecting WRSI by using the STIRPAT model and ridge regression analysis.

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12. Decomposition effects of Lanzhou lily (Lilium davidii var. unicolor) flowers on soil physical and chemical properties and microbial community diversity
Jie Li,YaJun Wang,Yang Qiu,ZhongKui Xie,YuBao Zhang,CuiPing Hua
Sciences in Cold and Arid Regions    2022, 14 (3): 212-222.   DOI: 10.3724/SP.J.1226.2022.21056.
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Timely removal of the flower is a key agricultural measure to ensure the concentrated supply of nutrients for the growth of underground bulbs and to increase the yield of lilies. Removing flowers and returning them to the field is one of the traditional ways of treatment, and field litter is formed at this time. Previous study showed that the decomposition of litter changes the soil properties. In order to study the effects of lily litter decomposition on soil physical and chemical properties and microbial structure, three treatments were set up in reference to the Decomposition Bag Method: control (CK), Lanzhou lily flower treatment (LZF), and Zhongbai No.1 flower treatment (ZBF). The effects of lily decomposition on soil physical and chemical properties and microbial community composition were studied in order to provide a scientific basis and theoretical guidance for the planting process of Lanzhou lily. The results show that the decomposition of lily flowers significantly increased the contents of soil organic matter, soil total nitrogen, soil total phosphorus and soil available potassium, and decreased soil pH. RDA shows that soil available nutrients and pH were the driving factors for the change of the soil microbial community. A short-term change of soil microenvironment caused by the decomposed lily flower is beneficial to growing the Lanzhou lily. However, under the correlation analysis of environmental factors, the long-term effects of returning the Lanzhou lily flower to the field, such as the trend of soil acidification, need to be further studied.

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13. Artificially frozen ground and related engineering technology in Japan
Satoshi Akagawa
Sciences in Cold and Arid Regions    2021, 13 (2): 77-86.   DOI: 10.3724/SP.J.1226.2021.20046
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Since the 1970's, frozen ground has been developing near the Tokyo Bay area around liquefied natural gas (LNG) in-ground storage tanks. For disaster prevention purposes, the tanks are constructed below the ground surface. Since the temperature of the liquid stored in the tanks is -162 °C the soil surrounding the tanks freezes. Since this frozen ground has existed for almost half a century, we have permafrost near Tokyo. The development of artificial frozen ground may cause frost heaving, resulting in frost heave forces that may cause structural damage of adjacent LNG in-ground storage tanks. Therefore, the demand for frozen ground engineering increased and consequently we now have advanced technology in this area. Fortunately, we use this engineering technology and artificial ground freezing for civil engineering, especially in big and crowded cities like Tokyo. This paper provides a summary of the testing apparatus, test methods, and assessment methods for frost heaving.

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14. Litter decomposition in fragile ecosystems: A review
Hao Qu,XueYong Zhao,XiaoAn Zuo,ShaoKun Wang,XuJun Ma,Xia Tang,XinYuan Wang,Eduardo Medina-Roldán
Sciences in Cold and Arid Regions    2022, 14 (3): 151-161.   DOI: 10.3724/SP.J.1226.2022.21061.
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As a linkage between plants and soil, litter decomposition and its effect on nutrient recirculation have an important ecological significance as they contribute to soil structure improvement and the restoration of degraded ecosystems. Fragile ecosystems in arid regions (both hot and cold) are depleted in soil organic matter, and as a result of various factors their circulation of material and energy is slower. Here we discuss how litter decomposition is necessary to maintain the stability of fragile ecosystems. We reviewed research on litter decomposition carried out in arid regions. Our objective in this review is to outline how litter decomposition, and the subsequent buildup of organic matter in soil, is a key process determining the stability of fragile ecosystems. Our review shows that existing studies have focused on the influence of single ecological factors on litter decomposition and nutrient cycling, and highlights how the exploration of interactions among factors determining litter decomposition is still lacking. This interaction is a key aspect, since in the real world, decomposition and nutrient return to soil of litter products is affected by multiple factors. We propose a network setup on a cross-regional scale using standardized methods (e.g., the tea bag method) to understand litter decomposition and nutrient return in fragile ecosystems. Such a unique network could contribute to establish predictive models suitable for litter decomposition and nutrient return in these areas, and thus could provide theoretical and practical support for regional ecological protection and high-quality development.

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15. A nonlinear interface structural damage model between ice crystal and frozen clay soil
Sheng Shi,Feng Zhang,KangWei Tang,DeCheng Feng,XuFeng Lu
Sciences in Cold and Arid Regions    2021, 13 (2): 150-166.   DOI: 10.3724/SP.J.1226.2021.20050
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The shear properties of ice-frozen soil interface are important when studying the constitutive model of frozen soil and slope stability in cold regions. In this research, a series of cryogenic direct shear tests for ice-frozen clay soil interface were conducted. Based on experimental results, a nonlinear interface structural damage model is proposed to describe the shear properties of ice-frozen clay soil interface. Firstly, the cementation and friction structural properties of frozen soil materials were analyzed, and a structural parameter of the ice-frozen clay soil interface is proposed based on the cryogenic direct shear test results. Secondly, a structural coefficient ratio is proposed to describe the structural development degree of ice-frozen clay soil interface under load, which is able to normalize the shear stress of ice-frozen clay soil interface, and the normalized data can be described by the Duncan-Chang model. Finally, the tangent stiffness of ice-frozen clay soil interface is calculated, which can be applied to the mechanics analysis of frozen soil. Also, the shear stress of ice-frozen clay soil interface calculated by the proposed model is compared with test results.

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16. The influence of the underpassing frozen connecting passage on the deformation of the existing tunnel
JunHao Chen,Jian Zhang,BiJian Chen,Gen Lu
Sciences in Cold and Arid Regions    2022, 14 (4): 223-233.   DOI: 10.1016/j.rcar.2022.09.001.
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Based on the engineering background of the contact channel between Shangyang and Gushan of Fuzhou Metro Line 2 undercrossing the existing tunnel line, the freezing temperature field of the contact channel, the displacement field of the existing tunnel line and the contact channel with different net distances and horizontal angles are analyzed by ANSYS finite element software and field measurement method. The obtained results indicate that during the freezing period, the temperature drops at different measuring holes are almost the same. The temperature near the bottom freezing tube drops faster than that far from the tube. It is found that the bilateral freezing technique improves the formation of the freezing wall in the intersection area. In this case, the intersection time of the cross-section is 7 days faster than that of the adjacent ordinary section. The change curve of the displacement of the surface uplift in different freezing periods with the distance from the center of the channel is "M" shaped. The maximum uplift displacement at 12 m from channel center is 25 mm. The vertical displacement of the measuring point located above the central axis of the connecting channel is large. The farther the point from the central axis, the smaller the corresponding vertical displacement. When the horizontal angle between the existing tunnel and the connecting channel is less than 60°, the existing vertical displacement of the tunnel changes rapidly with the horizontal angle, reaching 0.17 mm/°. Meanwhile, when the net distance is less than 6.1 m, the change rate of the vertical displacement of the tunnel is up to 2.4 mm/m.

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17. Possible controlling factors in the development of seasonal sand wedges on the Ordos Plateau, North China
Hugh M. French,Jef Vandenberghe,HuiJun Jin,RuiXia He
Sciences in Cold and Arid Regions    2021, 13 (2): 167-176.   DOI: 10.3724/SP.J.1226.2021.20095
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Wedge-like structures filled with silty sand penetrate Quaternary fluvial and aeolian sediments and, in places, Tertiary bedrock on the Ordos Plateau, North China. The wedges reflect thermal contraction cracking of either permafrost or seasonal frost during the Late Pleistocene and early Holocene. Wedges of about 1 m in depth form polygonal nets of 2-3 m in diameter (type B). They contrast with wedges of 3-4 m in depth that form polygons of 10-15 m in diameter (type A). This review focuses upon the highly variable size of the inferred polygon nets and discusses the problem of differentiating between seasonally and perennially frozen ground, or between seasonal frost and permafrost.

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18. Laboratory study and predictive modeling for thaw subsidence in deep permafrost
ZhaoHui Joey Yang,Gabriel T. Pierce
Sciences in Cold and Arid Regions    2021, 13 (2): 95-106.   DOI: 10.3724/SP.J.1226.2021.20087
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Oil wells on the North Slope of Alaska pass through deep deposits of permafrost. The heat transferred during their operation causes localized thawing, resulting in ground subsidence adjacent to the well casings. This subsidence has a damaging effect, causing the casings to compress, deform, and potentially fail. This paper presents the results of a laboratory study of the thaw consolidation strain of deep permafrost and its predictive modeling. Tests were performed to determine strains due to thaw and post-thaw loading, as well as soil index properties. Results, together with data from an earlier testing program, were used to produce empirical models for predicting strains and ground subsidence. Four distinct strain cases were analyzed with three models by multiple regression analyses, and the best-fitting model was selected for each case. Models were further compared in a ground subsidence prediction using a shared subsurface profile. Laboratory results indicate that strains due to thaw and post-thaw testing in deep core permafrost are insensitive to depth and are more strongly influenced by stress redistributions and the presence of ice lenses and inclusions. Modeling results show that the most statistically valid and useful models were those constructed using moisture content, porosity, and degree of saturation. The applicability of these models was validated by comparison with results from Finite Element modeling.

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19. Sandstone-concrete interface transition zone (ITZ) damage and debonding micromechanisms under freeze-thaw
YanJun Shen,Huan Zhang,JinYuan Zhang,HongWei Yang,Xu Wang,Jia Pan
Sciences in Cold and Arid Regions    2021, 13 (2): 133-149.   DOI: 10.3724/SP.J.1226.2021.20056
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The sufficient bond between concrete and rock is an important prerequisite to ensure the effect of shotcrete support. However, in cold regions engineering protection system, the bond condition of rock and concrete surface is easily affected by freeze-thaw cycles, resulting in interface damage, debonding and even supporting failure. Understanding the micromechanisms of the damage and debonding of the rock-concrete interface is essential for improving the interface protection. Therefore, the micromorphology, micromechanical properties, and microdebonding evolution of the sandstone-concrete interface transition zone (ITZ) under varying freeze-thaw cycles (0, 5, 10, 15, 20) were studied using scanning electron microscope, stereoscopic microscope, and nano-indentation. Furthermore, the distribution range and evolution process of ITZ affected by freeze-thaw cycles were defined. Major findings of this study are as follows: (1) The microdamage evolution law of the ITZ under increasing freeze-thaw cycles is clarified, and the relationship between the number of cracks in the ITZ and freeze-thaw cycles is established; (2) As the number of freeze-thaw cycles increases, the ITZ's micromechanical strength decreases, and its development width tends to increase; (3) The damage and debonding evolution mechanisms of sandstone-concrete ITZ under freeze-thaw cycles is revealed, and its micromechanical evolution model induced by freeze-thaw cycles is proposed.

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20. Coarse fragment content influences estimates of soil C and N stocks of alpine grassland on the northeastern edge of Qinghai-Tibetan Plateau, China
Yu Qin,ShuHua Yi,JianJun Chen
Sciences in Cold and Arid Regions    2022, 14 (2): 100-108.   DOI: 10.3724/SP.J.1226.2022.21006.
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Soil organic carbon (SOC) and total nitrogen (TN) stocks are usually calculated with samples collected using core samplers. Although the calculation considers the effects of gravel in soil samples, other coarse fragments such as stones or boulders in soil may not be collected due to the restricted diameter of core samplers. This would cause an incorrect estimation of soil bulk density and ultimately SOC and TN stocks. In this study, we compared the relative volume of coarse fragment and bulk density of fine earth determined by large size soil sampler with three core samplers. We also investigated the uncertainties in estimation of SOC and TN stocks caused by this soil sampler procedure in three typical alpine grasslands on the northeast edge of the Qinghai-Tibetan Plateau (QTP), China. Results show that (1) the relative volume and size of coarse fragment collected by large size sampler were significantly (p <0.05) higher and larger than those of core samplers, while bulk density of fine earth, SOC and TN stocks show opposite patterns in all grassland types; (2) SOC and TN stocks determined by core samplers were 17%-45% and 18%-46% higher than larger size sampler for three typical alpine grasslands; and (3) bulk density of fine earth, SOC and TN stocks exponentially decreased with the increasing of coarse fragment content. We concluded that core sampler methods significantly underestimated the volume occupied by coarse fragment but overestimated SOC and TN stocks. Thus, corrections should be made to the results from core samplers using large size samplers on regions with gravel and stone-rich soils in future studies.

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21. 10Be exposure ages of Quaternary Glaciers in Antarctica
WangJing Ni,ZhiGang Zhang,JingXue Guo,XueYuan Tang
Sciences in Cold and Arid Regions    2021, 13 (4): 292-298.   DOI: 10.3724/SP.J.1226.2021.20043.
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In situ terrestrial cosmogenic nuclides (TCN) have been widely applied to date the ages of Quaternary glacial deposits in Antarctica and plays an important role in reconstructing the glacial evolution and climate change. It helps to understand the Antarctic ice sheet's evolution process in Quaternary and shed light on the application of Cosmogenic Nuclide exposure dating technique in glacial geomorphology. In this paper, we retrieved 495 10Be age samples in Antarctica from literature published between 2004 and 2020 and recalculated the TCN ages using version 3.0 online calculator of Cosmic-Ray Produced Nuclide Systematics on Earth (CRONUS-Earth). Several conclusions can be drawn from the results: (1) 75% of the exposure ages are younger than 400 ka, and 91% younger than 1,100 ka. Northern Antarctic Peninsula exposure result is visibly younger than the main glaciers area in East Antarctica due to climate change and geological evaluation since the LGM (Last Glacial Maximum). (2) TCN ages are relevant to the samples' relative positions in the Antarctic continent, but a relationship between their ages and elevations is yet to be determined based on the collected data.

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22. Review and prospect of the effects of freeze-thaw on soil geotechnical properties
Tong Zhang,HaiPeng Li,ChenChen Hu,XinYu Zhen,ZhenHao Xu,Yang Xue
Sciences in Cold and Arid Regions    2021, 13 (5): 349-356.   DOI: 10.3724/SP.J.1226.2021.21019.
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Freeze-thaw hazard is one of the main problems in cold regions engineering and artificial ground freezing engineering. To mitigate freeze-thaw hazards, it is essential to investigate the effects of freeze-thaw on soils engineering properties. This paper summarizes the effects of freeze-thaw on the physical and mechanical properties of soils reported in recent studies. The differences of freeze-thaw conditions between freezing shaft sinking and cold regions engineering are discussed. Based on the technological characteristics of freezing shaft sinking in deep alluvium, we further attempt to identify key research needs regarding the freeze-thaw effects on the engineering properties of deep soils.

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23. Changes in morphology and soil nutrient patterns of nebkhas in arid regions along a precipitation gradient
WeiCheng Luo,WenZhi Zhao,Bing Liu,Heng Ren
Sciences in Cold and Arid Regions    2021, 13 (3): 256-267.   DOI: 10.3724/SP.J.1226.2021.20058.
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Nebkhas, discrete mounds of sand and vegetation, are a common landscape feature critical to the stability of desert ecosystems and supported by limited precipitation. Nebkha morphology and spatial pattern vary in landscapes, but it is unclear how they change along precipitation gradients in arid and semi-arid regions. In this study we determined morphology and soil nutrient patterns of nebkha from different regions of northwestern China. The objective of this study was to understand zonal differences among nebkhas and how morphological characteristics and soil nutrient patterns of nebkha change along a precipitation gradient in northwestern China. Our results shows that mean annual precipitation (MAP) had significant effects on morphological characteristics of nebkhas such as height, area, and volume which significantly decreased with an increase in MAP. MAP had significant positive effects on shrub cover and species richness of nebkha. Soil nutrients such as soil organic matter (SOM), total carbon (TC), total nitrogen (TN), and total phosphorus (TP) in the 0-10 cm layer increased with an increase of MAP, and soil nutrient content within nebkhas was higher than in inter-nebkha areas. We concluded that nebkhas are "fertile islands" with an important role in ecosystem dynamics in study regions. Further, MAP is a key factor which determined zonal differences, morphological, and soil nutrients patterns of nebkhas. However, disturbance, such as animal grazing, and planted sand-stabilizing vegetation accelerated the degeneration of nebkha landscapes. We recommend implementation of protective measures for nebkhas in arid and semi-arid areas of China.

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24. Estimating snow depth or snow water equivalent from space
LiYun Dai,Tao Che
Sciences in Cold and Arid Regions    2022, 14 (2): 79-90.   DOI: 10.3724/SP.J.1226.2022.21046.
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Satellite remote sensing is widely used to estimate snow depth and snow water equivalent (SWE) which are two key parameters in global and regional climatic and hydrological systems. Remote sensing techniques for snow depth mainly include passive microwave remote sensing, Synthetic Aperture Radar (SAR), Interferometric SAR (InSAR) and Lidar. Among them, passive microwave remote sensing is the most efficient way to estimate large scale snow depth due to its long time series data and high temporal frequency. Passive microwave remote sensing was utilized to monitor snow depth starting in 1978 when Nimbus-7 satellite with Scanning Multichannel Microwave Radiometer (SMMR) freely provided multi-frequency passive microwave data. SAR was found to have ability to detecting snow depth in 1980s, but was not used for satellite active microwave remote sensing until 2000. Satellite Lidar was utilized to detect snow depth since the later period of 2000s. The estimation of snow depth from space has experienced significant progress during the last 40 years. However, challenges or uncertainties still exist for snow depth estimation from space. In this study, we review the main space remote sensing techniques of snow depth retrieval. Typical algorithms and their principles are described, and problems or disadvantages of these algorithms are discussed. It was found that snow depth retrieval in mountainous area is a big challenge for satellite remote sensing due to complicated topography. With increasing number of freely available SAR data, future new methods combing passive and active microwave remote sensing are needed for improving the retrieval accuracy of snow depth in mountainous areas.

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25. A full-scale field experiment to study the thermal-deformation process of widening highway embankments in permafrost regions
ShuangJie Wang,Long Jin,Kun Yuan,DongGen Chen,JinPing Li,Yi Song
Sciences in Cold and Arid Regions    2021, 13 (2): 123-132.   DOI: 10.3724/SP.J.1226.2021.20037
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As one of the widely used upgrading way in road engineering, the widening embankment (WE) has suffered evident differential deformation, which is even severer for highway in permafrost regions due to the temperature sensitivity of frozen soil and the heat absorption effect of the asphalt pavement. Given this issue, a full-scale experimental highway of WE was performed along the Qinghai-Tibet Highway (QTH) to investigate the differential deformation features and its developing law. The continuous three years' monitoring data taken from the experimental site, including the ground temperature and the layered deformation of WE and original embankment (OE), were used to analyze the thermal-deformation process. The results indicate that the widening part presented the remarkable thermal disturbance to the existing embankment (EE). The underlying permafrost was in a noteworthy degradation state, embodying the apparent decrease of the permafrost table and the increase of the ground temperature. Correspondingly, the heat disruption induced by widening led to a much higher deformation at the widening side compared to the original embankment, showing a periodic stepwise curve. Specifically, the deformation mainly occurred in the junction of the EE and the widening part, most of which was caused by the thawing consolidation near the original permafrost table. In contrast, the deformation of EE mainly attributed to the compression of the active layer. Furthermore, it was the deformation origination differences that resulted in the differential deformation of WE developed gradually during the monitoring period, the maximum of which reached up to 64 mm.

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26. Application of geodetector in sensitivity analysis of reference crop evapotranspiration spatial changes in Northwest China
WenJu Cheng,HaiYang Xi,Sindikubwabo Celestin
Sciences in Cold and Arid Regions    2021, 13 (4): 314-325.   DOI: 10.3724/SP.J.1226.2021.20038.
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Reference crop evapotranspiration (ET0) is an important parameter in the research of farmland irrigation management, crop water demand estimation and water balance in scarce data areas, therefore, it is very important to study the factors affecting the spatial variation of ET0. In this paper, the Penman-Monteith formula was used to calculate ET0 which is the dependent variable of elevation (Elev), daily maximum temperature (Tmax), daily minimum temperature (Tmin), daily average temperature (Tmean), wind speed (U2), sunshine duration (SD) and relative humidity (RH). The sensitivity analysis of ET0 was performed using a Geodetector method based on spatial stratified heterogeneity. The applicability of Geodetector in sensitivity analysis of ET0 was verified by comparing it with existing research results. Results show that RH, Tmax, SD, and Tmean are the main factors affecting ET0 in Northwest China, and RH has the best explanatory power for the spatial distribution of ET0. Geodetector has a unique advantage in sensitivity analysis, because it can analyze the synergistic effect of two factors on the change of ET0. The interactive detector of Geodetector revealed that the synergistic effect of RH and Tmean on ET0 is very significant, and can explain 89% of the spatial variation of ET0. This research provides a new method for sensitivity analysis of ET0 changes.

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27. Linkages between soil microbial stability and carbon storage in the active layer under permafrost degradation
ShengYun Chen,MingHui Wu,Yu Zhang,Kai Xue
Sciences in Cold and Arid Regions    2021, 13 (3): 268-270.   DOI: 10.3724/SP.J.1226.2021.21034.
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28. Study on tensile damage characteristics of sandstone under freeze-thaw cycles
Hui Liu,YeHui Yun,Long Jin,JiangHao Lin,Yao Zhang,Yong Luo,JianXi Ren
Sciences in Cold and Arid Regions    2021, 13 (5): 379-393.   DOI: 10.3724/SP.J.1226.2021.20097.
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The meso-structure of sandstone has a significant effect on its mechanical properties under external loads. In this paper, by taking two types of sandstone with different grain sizes as the study objects, the effects of grain size and freeze-thaw cycles on tensile strength and damage mode of sandstone are analyzed using a combination of laboratory tests, theoretical analysis, and numerical calculation. The Brazilian splitting tests are carried out on sandstone samples subjected to freeze-thaw cycles. The results show that: (1) The Brazilian splitting mode of the fine-grained sandstone is dominated by the central fracture, whereas that of the coarse-grained sandstone is controlled by a noncentral fracture. (2) The freeze-thaw cycles aggravate the initial damage of sandstone, and the cumulative freeze-thaw damage has a greater impact on the Brazilian splitting damage mode of the coarse-grained sandstone than on the fine-grained sandstone. (3) The numerical analysis software RFPA2D system can simulate the Brazilian splitting failure process of the two types of sandstone with varying grain sizes under different freeze-thaw cycles. It is shown to be an effective method to reveal the tensile failure process and deterioration mechanism of sandstone under freeze-thaw cycling. (4) The formation mechanisms of the two splitting modes are analyzed according to the energy principle. The energy release of coarse-grained sandstone forms a noncentral splitting mode along the rock sample internal weak structural plane, whereas the fine-grained sandstone sample's energy accumulates in the rock sample center and releases it instantaneously at its center, showing the failure mode of central splitting. In addition, based on damage mechanics theory, the damage evolution equation of sandstone subjected to freeze-thaw cycles under tension is established, and the influence of energy release and dissipation on the sandstone's tensile properties is quantitatively analyzed.

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29. Desertification status mapping in Muttuma Watershed by using Random Forest Model
S. Dharumarajan,Thomas F. A. Bishop
Sciences in Cold and Arid Regions    2022, 14 (1): 32-42.   DOI: 10.3724/SP.J.1226.2022.21003.
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Potential of the Random Forest Model on mapping of different desertification processes was studied in Muttuma watershed of mid-Murrumbidgee river region of New South Wales, Australia. Desertification vulnerability index was developed using climate, terrain, vegetation, soil and land quality indices to identify environmentally sensitive areas for desertification. Random Forest Model (RFM) was used to predict the different desertification processes such as soil erosion, salinization and waterlogging in the watershed and the information needed to train classification algorithms was obtained from satellite imagery interpretation and ground truth data. Climatic factors (evaporation, rainfall, temperature), terrain factors (aspect, slope, slope length, steepness, and wetness index), soil properties (pH, organic carbon, clay and sand content) and vulnerability indices were used as an explanatory variable. Classification accuracy and kappa index were calculated for training and testing datasets. We recorded an overall accuracy rate of 87.7% and 72.1% for training and testing sites, respectively. We found larger discrepancies between overall accuracy rate and kappa index for testing datasets (72.2% and 27.5%, respectively) suggesting that all the classes are not predicted well. The prediction of soil erosion and no desertification process was good and poor for salinization and water-logging process. Overall, the results observed give a new idea of using the knowledge of desertification process in training areas that can be used to predict the desertification processes at unvisited areas.

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30. Cryogenic wedges on the NE Qinghai-Tibet and Ordos Plateaus: Their characteristics, origin and OSL dating
Stuart A. Harris
Sciences in Cold and Arid Regions    2021, 13 (6): 463-473.   DOI: 10.3724/SP.J.1226.2021.20100
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Cryogenic wedges developed due to very cold, rather arid conditions during the maximum of the last cold event when the drying up of the neighboring China Sea resulted in the failure of the East Asian Monsoon. As the climate ameliorated and the Monsoon rains reappeared, ice-wedges developed. Further warming permitted thawing of the ice infillings accompanied by replacement of the ice by sediments partly from the host ground as well as from the surface by wind or sheet wash. In cases of extreme surface water flow on slopes after 10 ka B.P., small baydjarakhs typically c. 50 cm high developed, only to have the resulting hollows infilled by sediments carried by wind and/or sheet wash. These shallow structures form a network on top of many of the cryogenic wedges. This complex history makes dating the ages of the wedges difficult using OSL methodology. Unfortunately, past field work ignored the problem of the angle of the cut face to the direction of the wedge infilling when sampling the contents of the narrow wedges, resulting in potential contamination of the samples with the host sediment. Sampling of the larger deposits should be alright, but the likelihood of contamination makes the interpretation of the resulting OSL dates from the narrow wedges questionable. Primary wedges consisting of primary mineral infillings should still have similar OSL dates with depth for a given wedge, but the distinction between ice-wedge infillings and soil wedges is difficult since both can exhibit older dates of the infillings with depth. The available data suggests that ice-wedges were significantly more common than sediment-filled primary wedges. A protocol to avoid having to obtain large numbers of OSL dates by more careful field sampling and the use of grain size determinations is provided in the Appendix.

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31. Climate response and radial growth of Pinus tabulaeformis at different altitudes in Qilian Mountains
Liang Jiao,ChangLiang Qi,RuHong Xue,Ke Chen,XiaoPing Liu
Sciences in Cold and Arid Regions    2021, 13 (6): 496-509.   DOI: 10.3724/SP.J.1226.2021.20080
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In order to test whether the relationship between climate and the radial growth of trees is affected by altitude, altitude variability and time stability of climate-influenced radial growth of a dominant conifer, Chinese pine (Pinus tabulaeformis), in the eastern Qilian Mountains were studied against the background of climate change using dendrochronology. Results show that 1) droughts at the end of the growing season of last year and during the early and middle growing season of the current year were the main limiting factors for the radial growth of Chinese pine at two altitude gradients; this was determined by analyzing the relationship between tree-ring width chronologies and climate factors. 2) The sensitivity of the radial growth of trees to climate change gradually decreased and was affected more by drought stress at a lower altitude. 3) An unstable divergence response was observed in the radial growth at the two altitudes, in response to controlling climatic factors; this observation was based on the moving correlation analysis of growth/climate relationships, and the aggravation of drought stress caused by increasing temperature was the main reason. 4) The growth rate of Chinese pine at the two altitudes increased at first and then decreased, as measured by basal area increment (BAI) modeling. Future temperature rises may have significant effects on mountain forest ecosystems in arid and semi-arid regions. Effective management and protection measures should be taken, according to the response patterns of trees to climate change at different altitude gradients.

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32. Overview of an early warning system for Glacial Lake outburst flood risk mitigation in Dudh-Koshi Basin, Nepal
Sanjaya Gurung,Saroj Dhoj Joshi,Binod Parajuli
Sciences in Cold and Arid Regions    2021, 13 (3): 206-219.   DOI: 10.3724/SP.J.1226.2021.20076.
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Natural disasters inflict severe damage on almost the entire spectrum of social and natural habitats. This ranges from housing and shelter, water, food, health, sanitation to information and communication networks, supply of power and energy, transportation infrastructure, and others. Nepal is a risk prone country for Glacial Lake Outburst Flood (GLOF). GLOFs exist as major challenges as they repeatedly cause a heavy toll of life and property. During such a disaster, major challenges are indeed the protection of life, property and vital life-supporting infrastructure. Any delay or laxity in disaster relief can escalate the magnitude of distress for the victims. Thus, rather than trying to take curative measures, it is better to minimize the impacts of GLOF. These measures subsequently help in reducing the magnitude of death and casualties due to a GLOF event. This reduction of impact is often achieved by optimizing preventive measures. For applying necessary deterrent measures, it is essential to disseminate information about the danger beforehand. Early Warning System (EWS) is an important step for such information dissemination for GLOF disaster management and helps to anticipate the risk of disaster and disseminate information to lives at risk. It is impossible and impractical to reduce all GLOF risks, but it is possible to reduce several impacts of a GLOF through the implementation of the EWS. This paper presents the design and implementation of an EWS for monitoring potential outbursts of a glacier lake in the Dudh-Koshi Basin, Nepal.

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33. Legacy: Hugh French and his Impact on Studies in Periglacial Environments and Permafrost
Jef Vandenberghe
Sciences in Cold and Arid Regions    2021, 13 (2): 177-178.   DOI: 10.3724/SP.J.1226.2021.JefVandenberghe.
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34. Satellite-measured water vapor isotopologues across the Tianshan Mountains, central Asia
ShengJie Wang,Yang Song,MingJun Zhang,Athanassios A. Argiriou,YuDong Shi
Sciences in Cold and Arid Regions    2021, 13 (6): 488-495.   DOI: 10.3724/SP.J.1226.2021.21001
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The satellite-based water vapor stable isotope measurements have been widely used in modern hydrological and atmospheric studies. Their use is important for arid areas where the precipitation events are limited, and below-cloud evaporation is strong. This study presents the spatial and temporal characteristics of water vapor isotopologue across the Tianshan Mountains in arid central Asia using the NASA Aura Tropospheric Emission Spectrometer (TES). The near-surface water vapor stable isotopes are enriched in summer and depleted in winter, consistent with the seasonality of precipitation isotopes. From the surface to 200 hPa, the isotope values in water vapor show a decreasing trend as the atmospheric pressure decreases and elevation rises. The vapor isotope values in the lower atmosphere in the southern basin of the Tianshan Mountains are usually higher than that in the northern basin, and the seasonal difference in vapor isotopes is slightly more significant in the southern basin. In addition, bottom vapor isotopologue in summer shows a depletion trend from west to east, consistent with the rainout effect of the westerly moisture path in central Asia. The isotopic signature provided by the TES is helpful to understand the moisture transport and below-cloud processes influencing stable water isotopes in meteoric water.

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35. Stabilizing subgrades of transport structures by injecting solidifying solutions in cold regions
P. O. Lomov,A. L. Lanis,D. A. Razuvaev,M. G. Kavardakov
Sciences in Cold and Arid Regions    2021, 13 (5): 357-365.   DOI: 10.3724/SP.J.1226.2021.21040.
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Transport structures built throughout the period from 1960 to 1980 in permafrost regions based on the principle of permafrost preservation are subject to deformations. In many cases, the reason is a gradual change in temperature and their subgrade condition within the active zone due to the structures' technogenic impact. Design solutions for the fifty-year-old structures fail to ensure in all cases their reliable operation at the present time. The greatest danger to the reliable operation of railway lines in cold regions is uneven deformations of bridges, which are barrier places. Therefore, the solution to this problem is urgent especially due to the necessity of increase carrying capacity. The purpose of this study is to increase reliability of bridge operation in cold regions through strengthening the subgrade by reinforcement with injection of solidifying solutions. The problem of uneven deformations due to permafrost degradation is considered using the example of a railway bridge located in the northern line of the Krasnoyarsk railway. Deformations of the bridge abutments began immediately after the construction was completed and the bridge was open for traffic-since 1977. Permafrost degradation was developing more actively straight under the abutments due to higher thermal conductivity of the piles concrete. Notably, thawing intensity of frozen soils under the bridge abutments is uneven due to its orientation to the cardinal points. The analysis of archive materials and results of the geodetic survey made it possible to systematize the features of augmenting deformations of each abutment over time. The engineering-geological survey with drilling wells near the abutments ensured determination of soil characteristics, both in the frozen and thawed states. Thermometric wells were arranged to measure temperatures. The analysis and systematization of the data obtained allowed us to develop geotechnical models for each abutment of the bridge. The peculiarity of these models is allowance for changes in the strength and deformation characteristics of the soil calculated layers depending on changes in temperature and the soil condition. Thus, different calculated geological elements with the corresponding strength and deformation characteristics were identified in the soil layers of the same origin. The analysis of the systematized geodetic data allowed us to confirm adequacy of the developed geotechnical models. Studies carried out using geotechnical models made it possible to predict improvement of physical and mechanical characteristics of the subgrade to prevent further growth deformations of the bridge abutments. The method of reinforcement by injection is proposed. Injecting a solution under pressure leads to strengthening of weakened thawed soils and improving their physical and mechanical properties. This research theoretically substantiates and develops the geotechnical models of the reinforced pier footing of bridge abutments by injection of solidifying solutions. The models take into account the reinforcement parameters and elements for the case in question. The influence of reinforcement on the change in physical and mechanical properties of the soil mass is determined.

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36. Long-term effects of gravel-sand mulch thickness on soil microbes and enzyme activities in semi-arid Loess Plateau, Northwest China
ChengZheng Zhao,YaJun Wang,Yang Qiu,ZhongKui Xie,YuBao Zhang
Sciences in Cold and Arid Regions    2021, 13 (6): 510-521.   DOI: 10.3724/SP.J.1226.2021.21012
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In semi-arid areas of China, gravel and sand mulch is a farming technique with a long history. In this study, a sample survey was conducted on long term gravel sand mulch observational fields in the Northwest Loess Plateau to determine the effects of long term mulch on soil microbial and soil enzyme activities. We found that after long term gravel-sand mulch, compared with bare ground, soil organic matter, alkali nitrogen, conductivity decreased, while pH and soil moisture increased. Urease, saccharase and catalase decreased with increased mulch thickness, while alkaline phosphatase was reversed. The results of Illumina MiSeq sequencing shows that after gravel-sand mulch, the bacterial and fungal community structure was different from bare land, and the diversity was reduced. Compared with bare land, the bacteria Proteobacteria and Acidobacteria abundance increased with increased thickness, and Actinobacteria was opposite. Also, at the fungal genus level, Fusarium abundance was significantly reduced, and Remersonia was significantly increased, compared with bare land. Redundancy analysis (RDA) revealed that soil environmental factors were important drivers of bacterial community changes. Overall, this study revealed some of the reasons for soil degradation after long term gravel-sand mulch. Therefore, it is recommended that the addition of exogenous soil nutrients after long term gravel-sand can help improve soil quality.

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37. Simulating the effect of wind erosion on aeolian desertification process of Horqin sandy land and its significance on material cycle: a wind tunnel study
CaiXia Zhang,JinChang Li
Sciences in Cold and Arid Regions    2022, 14 (1): 43-53.   DOI: 10.3724/SP.J.1226.2022.21021.
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Samples from the Horqin sandy land were exposed to a series of wind velocities, and sink particles were collected at the end of the diffusion section of a wind tunnel. Grain sizes of collected samples show great variation because of the granularity difference of the surface samples. The original samples show lower average content of SiO2 and higher average content of Al2O3, Fe2O3, MgO, CaO, Na2O, and K2O than collected samples. Compared with other dust source areas in China, the Horqin sandy land had higher content of Zr, Ba, SiO2, Al2O3 and K2O. Compared with the average upper continental crust (UCC) composition, surface samples were rich in the content of Y, Zr, Nb, Ba, La, Nd. Geochemistry characteristics of fine grain components of the Horqin sandy land differ from those from other dust source regions, because fine-grained particles in the Horqin sandy land were mostly derived from various local deposits formed in its unique depositional environments influenced by several tectonic activities.

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38. Lessons from construction and health condition evaluation of high-grade highway in permafrost regions
JianHong Fang,QingZhi Wang,KeJin Wang
Sciences in Cold and Arid Regions    2021, 13 (5): 372-378.   DOI: 10.3724/SP.J.1226.2021.21027.
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Located in the eastern margin of the Tibetan Plateau, the Gonghe-Yushu high-grade highway was the first of its kind in plateau permafrost regions. Most of the road sections along the high-grade highway are unstable or extremely unstable warm permafrost with an average annual ground temperature above -1 °C, which is vulnerable to global warming and human engineering activities. This paper describes permafrost characteristics, roadbed design, and operation of the Gonghe-Yushu high-grade highway in detail. It is found that thaw settlement of warm and ice-rich permafrost is the main cause of subgrade subsidence in permafrost sections of this highway due to insufficient permafrost survey and drainage design. It is recommended that the interception and drainage system's design be optimized, and the permafrost upper limit and the variation of ground temperature be further investigated to provide essential data for the treatment of highway distress. It should be emphasized that protecting permafrost soil environment and optimized engineering design are crucial to successful high-grade highway engineering in permafrost regions.

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39. Geographic range size patterns across plants and animals of Xinjiang, China
LiPing Li,ChunYan Zhang,Eimear Nic Lughadha,Tarciso C. C. Leão,Kate Hardwick,YaoMin Zheng,HuaWei Wan,Ming Ma,Nurbay Abudusalih,Hai Ying,Pu Zhen,JiangShan Lai,ZhanFeng Shen,Liu Li,Tuo Wang,YangMing Jiang,HuiHui Zhao,QingJie Liu
Sciences in Cold and Arid Regions    2022, 14 (1): 54-67.   DOI: 10.3724/SP.J.1226.2022.21004.
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Patterns in species geographic range size are relatively well-known for vertebrates, but still poorly known for plants. Contrasts of these patterns between groups have rarely been investigated. With a detailed flora and fauna distribution database of Xinjiang, China, we used regression methods, redundancy analysis and random forests to explore the relationship of environment and body size with the geographic range size of plants, mammals and birds in Xinjiang and contrast these patterns between plants and animals. We found positive correlations between species range size and body size. The range size of plants was more influenced by water variables, while that of mammals and birds was largely influenced by temperature variables. The productivity variable, i.e., Enhanced Vegetation Index (EVI) was far more correlated with range size than climatic variables for both plants and animals, suggesting that vegetation productivity inferred from remote sensing data may be a good predictor of species range size for both plants and animals.

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40. Numerical simulation of vibrational response characteristics of railway subgrades with insulation boards
ZiYu Wang,XianZhang Ling,YingYing Zhao,Feng Zhang,LiHui Tian
Sciences in Cold and Arid Regions    2022, 14 (1): 23-31.   DOI: 10.3724/SP.J.1226.2022.2022.20005.
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This study presents a numerical method based on the surface temperature data and the ground temperature increase in Daqing for predicting temperature field distribution in the Binzhou Railway subgrade and analyzing the temporal and spatial distribution of freeze-thaw status of railway subgrade. The calibrated numerical method is applied to simulate the temperature field distribution and roadbed vibrational response of the railway subgrade with a thermal insulation layer at different seasons. The results show the following: (1) The thermal insulation layer can remarkably increase the soil temperature below it and maximum frost depth in the subgrade. (2) Thermal insulation can effectively reduce the subgrade vibration and protect it from frost damage. (3) Given that the strength requirements are met, the insulation layer should be buried as shallow as possible to effectively reduce the subgrade vibration response. The research findings provide theoretical support for the frost damage prevention of railway subgrades in seasonally frozen regions.

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