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Near-surface wind field characteristics of the desert-oasis transition zone in Dunhuang,China

Journal of Arid Land 2024年第5期16卷 654-667页

作者： PAN Jiapeng zhang kecun AN Zhishan zhang Yu Key Laboratory of Desert and Desertification&Dunhuang Gobi and Desert Ecology and Environment Research Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

The desert-oasis transition zone(DOTZ)serves as a buffer area between the desert and oasis.Understanding its wind field characteristics is of great significance for the prevention and control of aeolian disasters in the oasis.In this study,we used meteorological data during 2013–2019 from the portable meteorological stations at five sites(site A on the edge of the oasis,sites B,C,and D in the DOTZ,and site O in the desert)in Dunhuang,China to analyze the near-surface wind field characteristics and their causes,as well as to reveal the key role of the DOTZ in oasis protection.The results showed that the mean wind speed,frequency of sand-driving wind,and directional variability of wind decreased from west to east within the DOTZ,and wind speed was significantly affected by air temperature.The terrain influenced the prevailing winds in the region,mainly from northeast and southwest.Only some areas adjacent to the oasis were controlled by southeasterly wind.This indicated that the near-surface wind field characteristics of the DOTZ were caused by the combined effects of local terrain and surface hydrothermal difference.At site D,the annual drift potential(DP)was 24.95 vector units(VU),indicating a low wind energy environment,and the resultant drift direction(RDD)showed obvious seasonal differences.Additionally,the DOTZ played an important buffering role between the desert and oasis.Compared with the desert,the mean wind speed in the oasis decreased by 64.98%,and the prevailing wind direction was more concentrated.The results of this study will be useful in interpreting the aeolian activity of the DOTZ in Dunhuang.

关键词： desert-oasis transition zone near-surface wind field hydrothermal difference sand-driving wind aeolian environment Dunhuang

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Wind dynamic environment and wind-sand erosion and deposition processes on different surfaces along the Dunhuang–Golmud railway,China

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Journal of Arid Land 2023年第4期15卷 393-406页

作者： zhang Hongxue zhang kecun AN Zhishan YU Yanping Dunhuang Gobi Desert Research Station Northwest Institute of Eco-Environment and ResourcesChinese Academy ofSciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Gansu Agricultural University Lanzhou 730000China

The Dunhuang–Golmud railway passes through different deserts in arid areas,especially drifting-sand desert and sandy-gravel Gobi.The near-surface wind environment and wind-sand transport process vary due to different external factors,such as topography,vegetation,and regional climate,resulting in evident spatial differences in surface erosion and deposition.Consequently,the measures for preventing wind-sand hazards will differ.However,the mechanism and control theory of sand damage remain poorly understood.In this study,we used meteorological observation,three-dimensional(3D)laser scanning,and grain-size analysis to compare and evaluate the spatial distribution of wind conditions,sand erosion and deposition patterns,and grain composition in the drifting-sand desert and sandy-gravel Gobi along the Dunhuang–Golmud railway in China.Results show that the annual mean wind speed,the frequency of sand-driving wind,and the drift potential of sandy-gravel Gobi are higher than those of drifting-sand desert,indicating a greater wind strength in the sandy-gravel Gobi,which exhibits spatial heterogeneity in wind conditions.The major sediment components in sandy-gravel Gobi are very fine sand,fine sand,and medium sand,and that in drifting-sand desert are very fine sand and fine sand.We found that the sediment in the sandy-gravel Gobi is coarser than that in the drifting-sand desert based on mean grain size and sediment component.The spatial distributions of sand erosion and deposition in the sandy-gravel Gobi and drifting-sand desert are consistent,with sand deposition mainly on the west side of the railway and sand erosion on the east side of the railway.The area of sand deposition in the drifting-sand desert accounts for 75.83%of the total area,with a mean deposition thickness of 0.032 m;while the area of sand deposition in the sandy-gravel Gobi accounts for 65.31%of the total area,with a mean deposition thickness of 0.028 m,indicating greater deposition amounts in the drifting-sand desert due to the presence of more fine se

关键词： surface erosion and deposition wind environment three-dimensional(3D)laser scanner drift potential grain-size characteristic Dunhuang–Golmud railway

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Thermodynamic Effects on Particle Movement:Wind Tunnel Simulation Results

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Chinese Geographical Science 2012年第2期22卷 178-187页

作者： NIU Qinghe QU Jianjun zhang kecun LIU Xianwan Key Laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Dunhuang Gobi and Desert Research Station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Dunhuang 736200 China Gansu Center for Sand Hazard Reduction Engineering and Technology Lanzhou 730000 China

Sand/dust storms are some of the main hazards in arid and semi-arid zones. These storms also influence global environmental changes. By field observations, empirical statistics, and numerical simulations, pioneer researchers on these natural events have concluded the existence of a positive relationship between thermodynamic effects and sand/dust storms. Thermodynamic effects induce an unsteady stratified atmosphere to influence the process of these storms. However, studies on the relationship of thermodynamic effects with particles (i.e., sand and dust) are limited. In this article, wind tunnel with heating was used to simulate the quantitative relationship between thermodynamic effects and particle movement on different surfaces. Compared with the cold state, the threshold wind velocity of particles is found to be significantly decrease under the hot state. The largest decrease percentage exceedes 9% on fine and coarse sand surfaces. The wind velocity also has a three-power function in the sand transport rate under the hot state with increased sand transport. Thermodynamic effects are stronger on loose surfaces and fine particles, but weaker on compacted surfaces and coarse particles.

关键词：热力学效应粒子运动风洞模拟半干旱地区全球环境变化细颗粒物临界风速正相关关系

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Morphological variation of star dune and implications for dune management: a case study at the Crescent Moon Spring scenic spot of Dunhuang, China

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Journal of Arid Land 2019年第3期11卷 357-370页

作者： zhang Weimin TAN Lihai AN Zhishan zhang kecun GAO Yang NIU Qinghe Dunhuang Gobi Desert Research Station Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences

Aerial photographs and 3-D laser scans of a 90-m high star dune at the Crescent Moon Spring scenic spot in Dunhuang,China,are used to investigate the changes in dune morphology on timescales from months to decades.The result revealed that relative-equilibrium airflow strength in three wind directions of northeast,west and south was an important condition for the stability of star dunes with limited migration.Transverse and longitudinal airflows exerted a crucial impact on variation processes of star dune morphology.Controlled by transverse airflows,the easterly winds,the east side was dominated by wind erosion;and strong deposition occurred on the south-south-east arm with a maximum deposition rate of 0.44 m/a in the 46-a monitoring period,causing the east side becoming steep and high.Controlled by longitudinal airflows,the westerly winds,the west-north-west side was mainly eroded and the north arm migrated from west to east with a rate of 0.30 m/a,causing the dune slope becoming gentle and elongate.The local air circulation(southerly winds)exerted a significant impact on the development process of the star dune.Due to the influence of human activities,the south side present surface processes from a concave profile to a convex profile in 46 a,which is a potential threat to the Crescent Moon Spring.The results indicate that rehabilitating the airflow field at most is a crucial strategy to the protection of Crescent Moon Spring from burial.Opening up the passage of easterly,westerly and southerly winds through intermediately cutting the protection forest,demolishing the enclosed wall and changing the pavilion into a porous pattern have been suggested to protect the Crescent Moon Spring from burial.

关键词： star dune morphology variation erosion and deposition time scale Crescent Moon Spring

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Dynamic changes of a typical linear dune in the Tengger Desert

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Journal of Arid Land 2010年第4期2卷 272-278页

作者： zhang, kecun Kai, KenJi Qu, JianJun Ling, YuQuan Niu, QingHe Chinese Acad Sci Dunhuang Gobi & Desert Ecol & Environm Res Stn Cold & Arid Reg Environm & Engn Res Inst Lanzhou 730000 Peoples R China Nagoya Univ Grad Sch Environm Studies Nagoya Aichi 4648601 Japan

The dynamical processes of a typical linear dune including morphological features, dune ridge swing range and crest height were investigated at different monitoring periods in the hinterland of Tengger Desert. The results indicated that the development of linear dune depends on not only the northwesterly prevailing wind, but also the winds from northeast and southwest. The dune ridge swayed along its fundamental strike and took on an eastward movement gradually. The original dune strike was NW70° on August 3, 1994, and then changed to NE15° on April 21, 2001. The dune crest increased by 1.8 m longitudinally, which manifested strong wind-blown sand activities in this region. Wind erosion frequently occured at the bottom of sand dune, while sand accumulation appeared on its mid-upper section. The mean wind erosion depth was 25 cm on the bottom of linear dune and the height difference of the control points on the dune’s ridge was 1.13 m. Although the linear dune swayed laterally, the horizontal displacement of its ridge moved eastward 5.8 m averagely. The swing range of the dune crest line is very distinct, with a maximum value of 13.2 m. The highest site on the K-profile swayed on both sides of the dune ridge and the heights were 19.88 m at the control point K5, 19.61 m at K6 and 19.05 m at K7, respectively. The results indicated that the lateral swing of the linear dune was distinct under the northwesterly wind and it moved toward east gradually.

关键词： linear sand dune dynamic change morphological feature Tengger Desert

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New discoveries on the effects of desertification on the ground temperature of permafrost and its significance to the Qinghai-Tibet Plateau

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Chinese Science Bulletin 2012年第8期57卷 838-842页

作者： XIE ShengBo QU JianJun ZU RuiPing zhang kecun HAN QingJie Key Laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy ofSciencesLanzhou 730000China Dunhuang Gobi and Desert Research Station Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy ofSciencesDunhuang 736200China Gansu Center for Sand Hazard Reduction Engineering and Technology Lanzhou 730000China

The desert and permafrost conditions of the Qinghai-Tibet Plateau are unique.However,the effects of desertification on the ground temperature of permafrost are currently unclear.Recently,understanding this problem has become more urgent because of increasing desertification on the plateau.For this reason,an observational field experiment was undertaken by the authors at Honglianghe on the Qinghai-Tibet Plateau.Thermistor ground temperature probes were used,and synchronized contrasting observations were made in an open area.Observations of the ground temperature of permafrost below sand layers with a range of thicknesses were made from May 2010 to April 2011.The sand layers were found to play a key role in the protection of the underlying permafrost.The ground temperature below a permafrost table overlain by a thick sand layer was lower than that of the average annual temperature for the natural ground surface,and the temperature drop was roughly constant at 0.2°C.During the warmer part of the year (May to September),the maximum temperature drops over the five months were 3.40,3.72,4.85,3.16,and 1.88°C,respectively.The ground temperature near a permafrost table overlain by a thin sand layer was also lower than that of the average annual temperature for the natural ground surface.However,in this case the average of the annual maximum temperature drop was significantly less,0.71°C.The scientific significance of our preliminary conclusions is not only to present an exploration of the interaction between desertification and permafrost,but also to provide new engineering ideas for protecting the permafrost in regions where construction is required on the Qinghai-Tibet Plateau.

关键词：多年冻土地区青藏高原地温观测荒漠化地面温度田间试验热敏电阻最高温度

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基于黏土沙障的复配土壤对土壤水分特征影响对比分析

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水土保持研究 2024年第1期31卷 88-95页

作者：潘加朋张克存安志山张宏雪薛承杰中国科学院西北生态环境资源研究院敦煌戈壁荒漠生态与环境研究站甘肃敦煌736200 中国科学院西北生态环境资源研究院沙漠与沙漠化重点实验室兰州730000 中国科学院大学北京100049

[目的]研究基于黏土沙障的复配土壤在不同复配质量比下对土壤水分特征的影响,旨在揭示其土壤改良效益,为今后黏土沙障的设计提供最佳复配比。[方法]通过试验设计将各样品划分为空白组、对照组与试验组,并分别对三组样品的土壤容重、水... 详细信息

[目的]研究基于黏土沙障的复配土壤在不同复配质量比下对土壤水分特征的影响,旨在揭示其土壤改良效益,为今后黏土沙障的设计提供最佳复配比。[方法]通过试验设计将各样品划分为空白组、对照组与试验组,并分别对三组样品的土壤容重、水分常数及土壤水分特征曲线进行对比分析。[结果](1)试验组样品土壤容重随复配土壤质量比(即复配比)的增加而减小,相较于空白组,当复配比为5∶1时降低至1.45 g/cm^(3),对照组则降低至1.32 g/cm^(3)。(2)试验组样品的土壤饱和含水率在其复配比超过一定阈值时明显增加,当复配比为2∶1时相较于空白组升高了0.97%,同时,其田间持水率与凋萎系数也相较于空白组整体分别升高1.518%,1.543%,对照组两者上升则均超过10%。(3) Gardner模型对三组样品模拟良好,三者土壤含水率均随土壤水势增加而减小,当土壤水势一定时,试验组复配比的增加有效提高了复配土壤的含水率,在土壤水势为0.01~1.5 MPa间不同质量比复配土壤平均增加了1.32%~1.72%。[结论]基于黏土沙障的复配土壤其复配比的增加能有效提升土壤的持水力与保水性,其有效含水量也明显上升,对土壤改良明显。

关键词：黏土沙障复配土壤土壤水分特征曲线土壤容重

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A SUPERLINEARLY AND QUADRATICALLY CONVERGENT SQP TYPE FEASIBLE METHOD FOR CONSTRAINED OPTIMIZATION

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Applied Mathematics(A Journal of Chinese Universities) 2000年第3期15卷 319-331页

作者： JianJinbao zhangkecun XueShengjia Dept.ofMath. GuangxiUniv.Nanning530004 SchoolofScience Xi＇anJiaotongUniv.Xi＇an710049 AdministrationInstituteofJinanUniv. Guangzhou510632

A new SQP type feasible method for inequality constrained optimization is presented,it is a combination of a master algorithm and an auxiliary algorithm which is taken only in finite iterations.The directions of the master algorithm are generated by only one quadratic programming, and its step\|size is always one, the directions of the auxiliary algorithm are new “second\|order” feasible descent. Under suitable assumptions,the algorithm is proved to possess global and strong convergence, superlinear and quadratic convergence.

关键词： Constrained optimization SQP feasible method,convergence rate of convergence.

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Pulsatory characteristics of wind velocity in sand flow over typical underlying surfaces

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Science China Earth Sciences 2007年第2期50卷 247-253页

作者： zhang kecun QU JianJun ZU RuiPing FANG HaiYan Key Laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of SciencesLanzhou 730000China

Pulsatory characteristics of wind velocity in sand flow over Gobi and mobile sand surface have been investigated experimentally in the wind tunnel. The primary goal of this paper is to reveal the relation- ship between pulsatory characteristics of instantaneous wind speed in sand flow and the motion state of sand grains. For a given underlying surface, pulsation of wind velocities in sand flow on different heights has a good correlation. As the space distance among different heights increases, fluctuation of instantaneous wind speed presents a decreasing trend and its amplitude is closely related to the mo- tion state of sand grains and their transport. Pulsatory intensity increases with the indicated wind speed, but its relative value does not depend on it, only agrees with height.

关键词： underlying surface sand flow pulsation of wind speed

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Progress on research and mitigation of wind-blown sand risk in Dunhuang Singing Sand Mountain and Crescent Spring Scenic area,China

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寒旱区科学:英文版 2023年第3期15卷 113-121页

作者： BenLi Liu kecun zhang JianJun Qu HaiJiang Li QingHe Niu ZhiShan An YingJun Pang LiHai Tan GenSheng Yang Laboratory of Ecological Safety and Sustainable Development in Arid Lands/Research Station of Gobi Desert Ecology and Environment in Dunhuang Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) GuangzhouGuangdong 51145China Administrative Office of the Dunhuang Singing Sand Mountain and Crescent Spring National Scenic Spot DunhuangGansu 736200China Institute of Desertification Studies Chinese Academy of ForestryBeijing 100091China

The Singing Sand Mountain and Crescent Spring Scenic Spot in Dunhuang,Northwest China is a world-renowned desert attraction that is also an integral component of the Dunhuang UNESCO Global Geopark.This scenic area underwent a 30-year transformation,i.e.,from a severe sand risk with spring water threatened by sand burial due to dune deformation,to restoration of the original sand flow field and mitigation of the sand burial problem.The current paper summarizes the research on the intensive monitoring of the dynamic change of star dunes near the spring,observation of wind and sand flow movement,and then restoring the harmonic vibration of the sand particles(singing sand)that were previously silenced.The existing and prospective impacts of anthropogenic and natural forces on the deformation of the sand dunes are investigated by integrated methods,guiding the implementation of mitigating measures with significant ameliorative effects.Contrast to common sand control practices that aim to reduce wind speed and stop blown sands,our research highlights the importance of maintaining the natural wind flow field in stabilizing surrounding dunes.These mitigation measures consist of removing excessive vegetation and newly constructed buildings to recover the original wind flow field and sand transport activity.Such research and mitigation efforts ensure the scientific protection and restoration of the special desert landform,and contribute to the mutual enhancement of the conservation and exploitation of this desert scenic spot and similar sites.

关键词： Singing Sand Mountain Crescent Spring Wind-blown sand problem Wind flow field Star dune

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