Water table response to a pumping test in the hinterland core area of the Taklimakan Desert, China

Wei, Y., Fan, J., Xu, X., & Lei, J. (March-April, 2017). Water table response to a pumping test in the hinterland core area of the Taklimakan Desert, China. Water Technology and Sciences (in Spanish), 8(2), 151-158. In this article, hydrogeological parameters were determined by a single well pumping test. Over the course of the study, BETCO was used to eliminate the effects of atmospheric pressure changes on water level based on the regression deconvolution method. The aquifer test was used to analyze data and to calculate hydrogeological parameters. Finally, from the three unconfined aquifer models, though the Boulton model cannot successfully gain well-fitting results, the Theis model with Jacob correction and the Neuman model results obtained hydrogeological parameters by curve-fitting. Additionally, permeability coefficient of the two models is in good agreement with previous research, which can provide a reference for further study in the hinterland of the desert, especially for the construction of hydrological modeling research

Effect of drip irrigation with saline water on the construction of shelterbelts for soil and groundwater protection in the hinterland of the Taklimakan Desert, China

Fan, J., Wei, Y., Xinwen, W., & Yang, X. (March-April, 2017). Effect of drip irrigation with saline water on the construction of shelterbelts for soil and groundwater protection in the hinterland of the Taklimakan Desert, China. Water Technology and Sciences (in Spanish), 8(2), 19-30. In order to perceive the effect of drip irrigation with saline water in the desert hinterland on plant growth of shelterbelts and underground environment (vadose zone and groundwater), by developing water-saving irrigation technology to ensure the scientifically substantiated utilization of water resources, four different irrigation cycle experiments (difference in irrigation period I: 12d; IV: 25d; II & III: 25d in the summer and the respective spring and autumn periods, which were the same: 15d and 20d, respectively) were carried out during the irrigation season in four different regions of well irrigation area. In this paper, regular on-site investigation was adopted to observe soil, water, and salt. Single-factor analysis of variance and least significant difference (LSD) are used to analyze the data acquired by the survey method and for measuring plant growth, complemented with the comparison of groundwater level and chemical index before and after irrigation. The results showed that the reduction of annual irrigation volume from 420 mm to 201.6 mm had almost no effect on plant growth and could save more than 50% of the water as compared to treatment I. Considering the impact on the height-growth of Tamarix, treatment II could be optimized, so that more than 30% of the water could be saved as compared to treatment I. Three days after irrigation, the salt was leached through the soil body into the groundwater. The groundwater level in the shelterbelt area, total dissolved solids (TDS), and total hardness exhibited an upward trend. Six days after irrigation, the high salt concentration region was found at a depth of 0–30 cm

Design and durability analysis of marine concrete

Marine engineering is an important way for a country to go deep blue. In the marine environment, there are many factors that affect the durability of concrete, among which the most harmful one is chloride ion erosion. In order to improve the ability to resist chloride ion permeation, this paper designs, compares and selects the appropriate water cement ratio of marine concrete, with the use of new anticorrosive technologies such as epoxy coating and silane impregnation. The design service life and the chloride ion diffusion coefficient prediction are analysed by establishing models, and this paper verifies whether the engineering design meets the service life requirement

Comprehensive eco-environmental effects of the shelter-forest ecological engineering along the Tarim Desert Highway

In this work, we report a comprehensive study about the eco-environmental effects of the shelter forest along the Tarim Desert Highway, including the effects on aeolian environment, soil, micro-climate, biodiversity, and groundwater. The results show that: (1) The movement of windblown sand near the ground surface was affected by the shelter forest. The wind speed and sediment transport rate in the shelter forest decreased by 64%-80% and 87.45%-99.02%, respectively. In addition, there were also significant changes in the sand flux structure, the sand grain size, and the deflation and deposition on the ground surface. (2) Compared to the natural mobile sand, the soil bulk density in the forest area decreased while the total salt content, the total porosity, and the water content increased. In addition, the soil fertility was significantly improved in the forest area, and showed the "first rapid, then slow" variation pattern. (3) The shelter forest showed positive effects on the micro-climate. Within the 6 m height above the ground, the air temperature in the shelter forest at different heights was lower than that in the mobile sand, while the air humidity was higher, while, the soil temperature was also lower in the shelter forest than mobile sand. (4) The number of soil microbial species increased significantly with the improvement of habitat in the shelterbelt. However, the population of different species was not distributed evenly across the surveyed area. (5) Currently, no significant effects of groundwater-pumping and forest-irrigation water have been found on the groundwater level and its salinity. The variation amplitude of both groundwater level and salinity was at the level of centimeters and 1g/L, respectively. No obvious variation trend has been observed

Effect of the shelterbelt along the Tarim Desert Highway on air temperature and humidity

The temperature and humidity of the shelterbelt micro-climate on both horizontal and vertical scales in the extremely drought area were measured with multiple HOBO temperature and humidity automatic observation equipments in the hinterland of the Taklimakan Desert. The results show that the shelterbelt ecosystem of the desert highway plays typical micro-climate adjustment rolesin stabilizing surface air temperature and increasing air humidity, and so on. Solar radiation significantly affects both temperature and humidity of surface layers, and it has a positive correlation with the temperature but a negative correlation with the air humidity. When it is cloudy, the weather has a great impact on keeping temperature and humidity in the shelterbelt. The shelterbelt also significantly influences the environment, and the micro-climate in the belt has an obvious characteristic of cooling and humidification: compared with the original sand area, the temperature in the shelterbelt is always lower and the humidity is always higher. Moreover, the temperature range at the shelterbelt edge is greater than that in the sand area, but the humidity is always higher. Our conclusion is that the vertical-effect range of temperature of the shelterbelts is 4-10 m, and the humidity range is 6 to 8 m; the horizontal-effect range of temperature is 16 m and the humidity range is about 24 m

The salt accumulation at the shifting aeolian sandy soil surface with high salinity groundwater drip irrigation in the hinterland of the Taklimakan Desert

The EC analysis and water serial sampling was performed in the Tarim Desert Highway shelterbelt to explore the water and salt dynamics of the shallow aeolian sandy soil (0-30cm) under high salinity groundwater drip irrigation. It was found that in one irrigation cycle, the EC of the shallow shifting aeolian sandy soil (0-30cm) increased while the water content decreased. The EC of the surface aeolian sandy soil at the wetting front was far greater than that of the wetting area or the outside of the wetting area. During the irrigation cycle, the EC of the wetting front and the wetting area changed at a significant magnitude, whereas the EC of the outside of the wetting area remained largely steady. The horizontal influence distance of drip irrigation on the salt accumulation at the soil surface was about 100 cm, and the vertical influence depth was 5 cm. The three most abundant ions in the accumulated salt at the aeolian sandy soil surface were Na+, Cl- and SO42-. The salt accumulation at the soil surface was influenced by air temperature, wind speed, mineralization of irrigation water, sand burial thickness, soil texture, and litter content

Topographical changes of ground surface affected by the shelterbelt along the Tarim Desert Highway

To study the effects of sand protection project on modern aeolian landform, the types, distribution, and intensity of topographical changes of the ground surface affected by the shelterbelt along the Tarim Desert Highway were determined by measuring the deflation and deposition of sand surface in the Tazhong area located in the hinterland of the Taklimakan Desert. The results showed that (1) the newly-formed landform in sand protection systems is dominated by aeolian deposition including the small-scale Nabkha Dunes, the medium-scale sheet-like sand deposition and the large-scale ridge-like sand deposition. To some degree, aeolian deflation landform can also be formed in the open space in the shelterbelt. Furthermore, it is difficult for aeolian deflation landform to develop in a large scale in the interdunes. However, aeolian deflation landform can be developed in a large-scale on the windward slope of secondary dunes in longitudinal complex sand ridges; (2) on the windward side of the sand protection systems, both the morphology and strike of dwarf mobile dunes in the interdunes are changed by the sand-obstructing forest belts and the ridge-like sand deposition around it. The windward slope of the ridge-like deposition around the sand-obstructing forest belt forms a stable ground surface. After being damaged by forward-moving dunes in a short period, the ground surface is recovered gradually; (3) on the leeward side of the sand protection systems, aeolian deflations are formed widely. Particularly, the deflation depression is formed in the interdunes. In addition, the dunes in the region with highly topographic relief are cut flat by aeolian deflations; thereafter its relief of topography is reduced. The above analysis indicates that shelterbelts have obvious effects on the windward wind-sand flux in terms of dissipating energy and intercepting sand. With the recovery of wind velocity on the leeward side of the sand protection systems, the wind-sand flux gradually tends to be unsaturated; therefore the sand surface deflation is formed

A critical review on the biomechanical study of cervical interbody fusion cage

Anterior Cervical Discectomy and Fusion (ACDF) is the preferred surgical method for the treatment of severe cervical degenerative disc disease with radiculopathy or myelopathy, of which the objectives are to restore the normal height of intervertebral space and cervical lordosis through the implantation of cervical interbody fusion cage. The biomechanical performance of a cervical interbody fusion cage, which plays a significant role in achieving the goals of ACDF, is influenced by multiple factors. In this paper, various studies focusing on the biomechanical performance of cervical interbody fusion cage are reviewed. Furthermore, the research methods, biomechanical evaluation parameters and data analysis methods of these research are analyzed in order to obtain a comprehensive understanding of the progress and limitations of research in this field. Although great progress has been made to clarify the biomechanical behaviors of cervical interbody fusion cage, there is still controversy regarding the issues such as the relative contribution of multiple factors to the performance of cage, the interactions among these factors, as well as whether the effects of factors change with the process of intervertebral osseointegration and so on. Thus, investigations are still needed to improve the comprehension of cervical interbody fusion cage biomechanically

Spatiotemporal Changes and Driving Force Analysis of Land Sensitivity to Desertification in Xinjiang Based on GEE

Land desertification profoundly affects economic and social development, thus necessitating a collective response. Regional land control planning needs to assess the land sensitivity to desertification across different regions. In this study, we selected 12 factors from soil, vegetation, climate, and terrain aspects to calculate and evaluate Xinjiang’s land sensitivity to desertification, from 2001 to 2020, and analyzed its trends and drivers. The results indicated that the region is highly (22.93%) to extremely sensitive (34.63%) to desertification. Of these, deserts, Gobi lands, oasis–desert transitional zones, and the downstream of rivers are highly and extremely sensitive areas. Mountainous areas, oases, and along rivers are non- and mildly sensitive areas. Over the past two decades, most areas have experienced stability (45.07%) and a slight improvement of desertification (26.18%), while the Junggar Basin and Central Taklamakan Desert have seen slight and severe intensification trends, respectively. Climate-related indicators, such as surface temperature and potential evapotranspiration (PET), were identified as the most important drivers of changes in land sensitivity to desertification. Having an integrated water resource allocation and establishing the long-term monitoring of land sensitivity to desertification would have positive implications for desertification control