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

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.

A preliminary study of water use strategy of desert plants in Dunhuang,China

Water is a restrictive factor for plant growth and ecosystem stability in arid and semiarid areas. The dynamics of water availability in soils and water use by plants are consequently critical to ecosystem functions, e.g. maintaining a high resistance to the changing climate. Plant water use strategies, including water-use efficiency （WUE） and the main water source that a plant species utilizes, play an important role in the evaluation of stability and sustainability of a plantation. The water use strategies of desert plants （Tamarix chinensis, Alhagi sparsifolia, Elaeagnus angustifolia, Sophora alopecuroides, Bassia dasyphylla and Nitraria sphaerocarpa） in three different habitats （saline land, sandy land and Gobi） in Dunhuang （located in the typical arid area of northwestern China） were studied. The stable isotope of oxygen was used to determine the main water source and leaf carbon isotope discrimination was used to estimate the long-term WUE of plant species in the summer of 2010. The results suggest that： 1） the studied desert plants took up soil water below the depth of 80 cm; 2） T. chinensis in the three habitats used deeper soil water and T. chinensis in the Gobi site had higher WUE than those in the saline land and the sandy land. The results indicated that desert plants in Dunhuang depended on stable water source and maintained high WUE to survive in water limited environments.

Impacts of water resource planning on regional water consumption pattern: A case study in Dunhuang Oasis, China

Water resources are critical for the existence and development of oases in endorheic basins.Thus,to enable sustainable development,it is fundamentally important to understand how to allocate and use these resources in a reasonable way.We therefore simulated and analyzed changes in water consumption pattern within the Dunhuang Oasis of China under three scenarios using a system dynamic model that corresponds to different water consumption pattern.This was done to assess the impacts of regional water resource planning(comprehensive planning of the rational use of water resource and protection of ecosystem services in the Dunhuang Basin)on water consumption pattern within the Dunhuang Oasis.The first of these,Scenario 1,is a baseline in which the status quo is maintained,while Scenario 2 incorporates the comprehensive effects of agricultural water-saving irrigation measures with an inter-basin water diversion project,and Scenario 3 focuses on ecological rehabilitation.In the baseline Scenario 1,the total water consumption within the Dunhuang Oasis increased progressively while agricultural water consumption remained extremely high and threatened overall ecological security.In contrast,Scenario 2 would decrease agricultural water consumption by almost 5.30×10^7 m^3 following the implementation of water-saving practices.The additional water allocated from an inter-basin water diversion project would play an important role in alleviating ecological strain on the oasis.Finally,in Scenario 3,the total irrigated land must be decreased to 20.6×10^3 hm^2 by 2025 assuming that water supply for ecosystem restoration would be at least 50%of the total consumption.Although water resource planning plays a very important role in alleviating the ecological water crisis within the oasis,it is necessary to consider the suitable scale of oasis with regard to current water consumption pattern.

The impact of Dunhuang railway construction on land desertification

The area that the railway will cross is a region with the main physiognomies of desert and Gobi with a most fragile ecological environment. It is also a region that is highly susceptible to man-made disturbance. The construction of railway will intensify soil erosion along the railway line to a certain degree. The map of soil erosion conditions in the section from Liugou to Dunhuang City in the range of 10 km each side along the line was compiled by using the techniques of remote sensing and geographic information system （GIS）. Based on analysis of the status of desertification and the influence of the railway construction projects, the changes of the types, intensities and the total amount of the soil erosion caused by the construction were predicted.

Digitizing Dunhuang Cultural Heritage:A User Evaluation of Mogao Cave Panorama Digital Library

Purpose： This study is a user evaluation on the usability of the Mogao Cave Panorama Digital Library （DL）, aiming to measure its effectiveness from the users＇ perspective and to propose suggestions for improvement. Design/methodology/approach： Usability tests were conducted based on a framework of evaluation criteria and a set of information seeking tasks designed for the Dunhuang cultural heritage, and interviews were conducted for soliciting in-depth opinions from participants. Findings： The results of the usability tests indicate that the DL was more efficient in supporting simple information seeking tasks than those of higher-complexity levels. Statistical tests reveal that there were correlations among dimensions of usability criteria and user effectiveness measures. Moreover, interview discourses exposed specific usability issues of the DL. Research limitations： This research is based on a relatively small sample size, resulting in a limited representativeness of user diversity. A larger sample size is needed for a systematic cross group comparison. Practical implications： This study evaluated the usability of the Mogao Cave Panorama DL and proposed suggestions for its improvement for better experience. The results also provide a reference to other cultural heritage DLs with panorama functions. Originality/value： This study is one of the first evaluating cultural heritage DLs from the perspective of user experience. It provides methodological references for relevant studies： the evaluation framework, the designed information seeking tasks, and the interview questions can be adopted or adapted in evaluating other visually centric DLs of cultural heritage.

Vegetation change detection research of Dunhuang city based on GF-1 data

This study selected the Dunhuang city with the unique landscape pattern, its oasis surround by desert, for studying the vegetation change. Based on two period GaoFen-1 images, combined with field survey data, the dimidiate pixel model and fractional vegetation coverage estimation model were applied to detect the changes of local vegetation coverage from July 2013 to July 2015. Analysis showed that during the study years, the Grain for Green project had a remarkable effect on the changes. The vegetation types of intermediate high and very low grades increased by 0.66 and 6.78 km^2 respectively. The low vegetation coverage decreased by 23.87 km^2. The vegetation coverage types of intermediate grade increased by 88.97 km^2 because of the planted forest, which accounted for 10.84% of the study area. The vegetation coverage types of high grade reduced by 72.47 km^2. This change effectively prevents the spread of desert and lays a good foundation for the ecological construction of Dunhuang city.

Optical Properties and Source Analysis of Aerosols over a Desert Area in Dunhuang,Northwest China

Aerosol observational data for 2012 obtained from Dunhuang Station of CARE-China（Campaign on Atmospheric Aerosol Research Network of China） were analyzed to achieve in-depth knowledge of aerosol optical properties over Dunhuang region. The results showed that the annual average aerosol optical depth（AOD） at 500 nm was 0.32 ± 0.06, and the ？ngstr？m exponent（α） was 0.73 ± 0.27. Aerosol optical properties revealed significant seasonal characteristics. Frequent sandstorms in MAM（March–April–May） resulted in the seasonal maximum AOD, 0.41 ± 0.04, and a relatively smaller αvalue, 0.44 ± 0.04. The tourism seasons, JJA（June–July–August） and SON（September–October–November） coincide with serious emissions of small anthropogenic aerosols. While in DJF（December–January–February）, the composition of the atmosphere was a mixture of dust particles and polluted aerosols released by domestic heating; the average AOD and αwere 0.29 ± 0.02 and 0.66 ± 0.17, respectively. Different air masses exhibited different degrees of influence on the aerosol concentration over Dunhuang in different seasons. During MAM, ranges of AOD（0.11–1.18） and α（0.06–0.82） were the largest under the dust influence of northwest-short-distance air mass in the four trajectories. Urban aerosols transported by northwest-short-distance air mass accounted for a very large proportion in JJA and the mixed aerosols observed in SON were mainly conveyed by air masses from the west. In DJF, the similar ranges of AOD and α under the three air mass demonstrated the analogous diffusion effects on regional pollutants over Dunhuang.

Morphologic changes of simple star dunes during the growth process in Dunhuang,China

Star dune is one typical kind of aeolian geomorphology in global sand seas.It has attracted scholars in various research fields for years because of its unique morphologic features like Egyptian pyramid.The landform pattern of star dune is mainly dominated by factors such as regional wind regime,sand availability,and local topography.Star dunes grow vertically as they accumulate sand brought in from different directions;however,little is known regarding morphologic changes during this process.The stability of star dunes based on quantitative data is another unsolved question due to the limitation in measuring equipment or other factors.And whether the star dune can grow into star sand hills is another scientific problem which needs to be discussed.In this paper,the heightening development process and morphological changes of star dunes were monitored in Mingsha Mountain of Dunhuang with the 3D laser scanner.Results show that the star dunes in Mingsha Mountain were formed by a group of relatively steady winds,which were northwest,northeast and south winds.With the increase of the height of the star dunes,the morphological parameters of the dune,such as the volume and bottom area,did not show regular changes.The surface erosion of both Dune 1 and Dune 2 during the observation period was closely related to the regional wind conditions.During the growth of the star dunes,the overall trend of the dunes was relatively steady and the dune shape maintained its stability although the aspect and slope of the sand dunes changed,indicating that the stability of star dune was not complete and was dynamic.Moreover,the variation range of the dune slope was proportional to the volume change of the dune.

Dune dynamics in the southern edge of Dunhuang Oasis and implications for the oasis protection

The survival of Dunhuang Oasis is largely determined by the evolution of sand dunes in the southern edge of the oasis, mainly composed of shield dunes and mega pyramid dunes, which occupy twothirds and one-third of the area, respectively. However, few studies have focused on dynamics of these dunes, especially in terms of quantification. So the theoretical basis of sand-control engineering is relatively limited. Here we present the characteristics of dune dynamics of a shield dune and mega pyramid dune in the southern edge of Dunhuang Oasis during April 2014-April 2016 based on measurement data of a 3-D laser scanner. Results indicate that the volume of the shield dune decreased during the monitoring period of two years, and the gravity centers of the monitored shield dune moved windward, indicating that sand was transported toward the oasis. Conversely, the dune volume of the mega pyramid dune increased and the gravity center presented no prominent movement, indicating that the megapyramid dune was relatively stable and its migration toward the oasis was not notable. Thus, compared with mega pyramid dunes, shield dunes in the southern edge of Dunhuang Oasis are identified as a more significant sand source endangering the protection of the oasis, and sand-control engineering should mainly focus on these shield dunes.

Three source rocks discovered in the Mid-Lower Jurassic,Dunhuang Basin in China

1.Objective Dunhuang Basin is the largest area and the third hydrocarbon resources potential basin among the basins of Hexi Corridor,and also a low exploration degree basin.The source rock position,characteristics and hydrocarbon generating potential of residual Mid-Lower Jurassic are still unknown.The project is to ascertain the source rock development and hydrocarbon generating capacity of Mid-Lower Jurassic,to find out the resource potential,to delineate the resource prospect area and to optimize the favorable areas.It may direct the petroleum exploration in Dunhuang Basin.

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

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 sediment components.However,the sand deposition is more concentrated with a greater thickness on the embankment and track in the sandy-gravel Gobi and is dispersed with a uniform thickness in the drifting-sand desert.The sand deposition on the track of the sandy-gravel Gobi mainly comes from the east side of the railway.The results of this study are helpful in developing the preventive measures and determining appropriate selection and layout measures for sand control.

Investigation on the Degradation of Natural Heritage of Singing Sand Mountain and Crescent Moon Spring at Dunhuang City, China

The main purpose of this study is to put forward a reasonable idea of the general protection for Singing Sand Moun- tain and Crescent Moon Spring, a rare and unique desert wonder, and of sustainable tourism development based on the research on the ecological environment around. Methods of documentation, case study and comparison were employed. Finally, aiming at solving the problems of natural environment and those existing after the exploitation of Singing Sand Mountain and Crescent Moon Spring the author puts forward three measures: the com- prehensive treatment for Crescent Moon Spring (broadening re- sources of water and reducing expenditures, checking the de- creasing depth of Crescent Moon Spring, and improving the geo- graphical environment), the general protection envisions for Singing Sand Mountain and Crescent Moon Spring and establish- ing a dynamic monitoring and early-warning system of regional ecosystem.

Aesthetic evaluation of yardang landforms landscape:the Dunhuang Yardang National Geo-park example

Dunhuang Yardang National Geo-park, situated in the Gansu Province of northwestern China （40°25′36″N-40°33′10″N, 93°00′00″E-93°13′30″E）, was chosen as a research locality of aesthetics evaluation of yardang landforms landscape. The yardang landforms landscape is a composite structural system of patch-corridor-matrix, with four landscape unit elements as dense group, sparse group, single body and remnant. The study of the landscape aesthetics spatial pattern of Dunhuang Yardang National Geo-park shows that yardang dense group, sparse group and single body provide the greatest contribution to the aesthetic value of yardang landforms landscape. Yardang bodies are scarce, unique, irreplaceable, and priceless resources in yardang landforms areas. However, they are easily destroyed under the influence of the natural and artificial factors. Therefore, when the tourism potential of yardang landforms landscape is exploited, the protection should be fully improved.

隋及唐初敦煌艺术对外来影响的吸收与创新

敦煌隋代彩塑受到印度笈多艺术风格的影响,及至唐代,彩塑已形成了中国式的表现手法与风格,既保持了雕塑的写实性,又体现出气韵生动的精神。壁画也同样,隋至唐初的人物造型中,常常出现典型的印度风格晕染法,比起北朝壁画更接近印度绘画的特点,表明当时确有一部分画家擅长画外来风格。但随着唐前期艺术的发展,画家们对外来晕染法不断改造,使之与传统的线描进行了完美的结合。从壁画的装饰图案中,我们也可看到对外来艺术的改造,如隋至唐初流行的联珠纹、石榴纹、葡萄纹等纹样在不断地被吸收改造,最后都融入了形态更为丰富的卷草纹中。

Redrawing Frescoes of Dunhuang Grottoes and Their Application in Costume History Research

This paper explores the relationship between costume history research and the redrawing of frescoes of Dunhnang Grottoes. Redrawing frescoes could provide evidences for costume history research, and the research can correspondingly help the rodrawing. Redrawing frescoes, for the purpose of costume history study, must comply with some specific rules, which are different from those of other studies. The present study also discusses the methods to distinguish, the original fresco colors that have faded or changed after more than one thousand years.

Closing of the Fourth Silk Road (Dunhua ng) In ternational Cultural Expo and the Ninth Dunhuang Tour-Silk Road International Tourism Festival

On August 31, the Fourth Silk Road (Dunhuang) International Cultural Expo and the Ninth Dunhuang Tour-Silk Road International Tourism Festival came to a close in Dunhuang. 23 main activities and 30 sub-activities have been held in six categories.

Sichuan Dunhuang Group Co.,Ltd.

The Sichuan Dunhuang Group Co., Ltd. was established in October 1986, with a number of subsidiaries, including the Dunhuang Real Estate Development Company, Chengdu Wenda Handiwork Clothes Company (joint venture), Sichuan Industrial and Commercial Import and Export Co. (Dunhuang), Sichuan (Dujiangyan) Dunhuang Construction and Development Company, Hainan Dunhuang Industrial and Trading Company, FLY Investment Group Co., Ltd. from the USA, Chengdu Dunhuang Embroidery Factory, Dunhuang Printing and Dyeing Factory and Dunhuang Department Store. It is a transprofessional and transregional modern group

跨学科视域与跨文类叙事:《哥伦比亚中国文学史》的敦煌文学书写

自19世纪末,海外汉学家开启了中国文学史的编纂工作,21世纪以来走向成熟和深化。梅维恒主编的《哥伦比亚中国文学史》2001年出版以来,引起了国内外学界的广泛讨论,该书有关敦煌文学书写的问题值得重视。通过阐述选取文献的缘由、撰写的思路以及向文学本位回归的特色,可以提炼出作者书写敦煌文学所采取的研究方法,即跨学科视域和跨文类叙事研究。考察该书的文学史观和文学史方法论,可以为国内的书写实践提供路径参考。中国文学史编纂应该立足中华文化核心价值,参与全球国际对话并构建科学的文学史理论,撰写真正内在于中国文学文化同时又融入世界潮流的文学史著述。

Astrological Talismans and Paper Amulets from Dunhuang: Typology and Function

Over the past three decades,Dunhuang studies have greatly expanded and transformed our knowledge of early and medieval Chinese religions and society.The analysis of documents discovered in the Mogao'Library cave'has led to seminal publications on the history of Buddhism as well as on traditional and parareligious sciences such as divination and medicine.

敦煌戈壁地表反射率光谱的旋翼无人机测量及定标评估

利用敦煌中国遥感卫星辐射校正场的星地同步观测试验,实现对我国在轨气象、海洋、陆地资源、环境减灾、测绘地震、高分、军事等系列卫星光学成像载荷太阳反射波段的绝对辐射定标,是目前的重要手段之一。然而,中国遥感卫星辐射校正场传统的地表反射率光谱星地同步测量方法是基于汽车跑场观测,不仅耗费较大的人力物力、容易造成场地破坏,而且获取的测量数据缺乏区域代表性。鉴于此,自2016年起,在敦煌星地同步观测试验中以旋翼无人机低空同步测量为主,跑场测量为辅,完成从航线设计、航高选择、仪器参数配置、采样策略、航空数据处理的全链路摸底测试。多次飞行试验表明,采用多旋翼无人机低空飞行来代替汽车跑场同步测量,不仅提高了地表反射特性测量的空间一致性和代表性,还提高了地表反射率光谱的测量效率,也对宝贵的中国遥感卫星辐射校正场敦煌戈壁场区地表进行了有效保护,极大的节约了人力物力成本。通过传统跑场测量和航飞测量的地表反射率光谱数据对比分析,发现多次测量数据的均值一致性较好,并且航飞测量的数据标准差更小。利用TERRA MODIS的同步观测来对无人机测量数据开展辐射定标评估,结果表明航飞数据的相对偏差均在5%以内,可以代替跑场数据完成定标,精度满足要求。随着无人机性能的进一步优化和提高,在不久的将来必将得到更加广泛和深入的应用,在外场定标试验领域也将发挥更大更重要的作用。