塔克拉玛干沙漠北缘荒漠过渡带风沙流结构特征分析

利用多种集沙仪,通过野外实时输沙观测,对塔克拉玛干沙漠北缘荒漠过渡带的地表风沙流特征进行了分析,结果表明：① 100 cm高度范围内,总输沙量的47.3%分布在30 cm高度内,这一比例小于前人的研究结果;输沙量随高度的变化比较符合幂函数分布。② 风沙流输沙的粒径以细砂、极细砂与粉砂为主,各高度层所占比例均达99%以上;风沙流输沙平均粒径随高度增加而减小,沙尘的含量随高度增加呈现“象鼻”状分布。③ 风沙流中贴地层风速廓线受风沙相互作用的影响,不再符合对数分布,更加符合幂函数u=az^b分布。     

塔克拉玛干沙漠腹地人工绿地风沙土的理化性质研究

在极端干旱的塔克拉玛干沙漠腹地 ,利用地下咸水灌溉建立人工绿地后 ,绿地土壤理化性质与流沙相比 ,变化很大。本文通过分析测定 ,结果表明 :绿地土壤细粒含量增加 :比重、容重降低 ,孔隙度 ,饱和含水量增加 ;在 5 0 cm剖面内盐分含量降低 ,但表层高于下层 ,p H增高 ,养分含量增加 ,肥力提高。不同植被类型和利用方式的绿地土壤理化性质有差异     

北非撒哈拉沙漠腹地地理环境特征--与塔克拉玛干沙漠对比

北非撒哈拉是世界第一大沙漠 ,中国的塔克拉玛干沙漠为世界第二大流动沙漠。撒哈拉是非洲语“大荒漠”之意 ,面积 8× 10 6km2 ,囊括了北非的大部分国家和 85 %以上的面积 ,除南部几内亚湾和北部地中海边的小面积地带外 ,其地理座标约处于 10°～ 35°N ,和 17°33’W～ 4 0°E之间。塔克拉玛干沙漠维吾尔语“进去出不来”之意 ,面积约 3.4× 10 5km2 ,约在 37°～ 4 1°N ,78°～ 88°E之间。     

塔克拉玛干沙漠腹地滴灌种植肉苁蓉的试验研究

在塔克拉玛干沙漠腹地的人工梭梭林,利用咸水滴灌技术,对种植肉苁蓉（Cistanche deserticola）的开挖方式、播种方式、接种深度以及稳产技术等进行了试验研究。结果表明：① 提高肉苁蓉种子和寄主根系接触的几率是提高人工接种肉苁蓉效果的有效途径。不同种植方式的肉苁蓉出土率为：沟种>打洞>穴种,撒种>种植带（种植纸）。② 采用开沟、撒种方式种植肉苁蓉,随播种量增加,出土肉苁蓉数量呈增加趋势,但存在一个上限值。在沙地滴灌种植肉苁蓉适宜的播种量为300粒/m。③ 接种深度应控制在寄主根系主要分布层以内,并结合作业方式及作业成本来综合确定,在沙地滴灌接种深度不宜超过60 cm。④ 人工接种肉苁蓉具有一次接种,多年采收的效果,但肉苁蓉出土率年际间差异较大。接种后第2 a至第4 a为主要收获期。采用沟种、撒种技术春季接种肉苁蓉,接种后连续3 a平均出土率可以保持在1株/m以上,肉苁蓉鲜重产量达1 800 kg/hm²,经济效益显著。     

塔克拉玛干沙漠降水入渗和径流补给试验观测

塔克拉玛干沙漠降水不仅直接补给地下水,在粘土平地每年都要产生一定数量的地表径流通过集水网补给地下水,试验观测这两种形式的补给来源,将进一步加深对沙漠腹地下水蓄量分布情况的认识。     

塔克拉玛干沙漠腹地参考作物蒸散量与蒸发皿蒸发量的对比分析

利用2005-2010年塔克拉玛干沙漠腹地气象资料计算了极端干旱区塔克拉玛干沙漠腹地参考作物蒸散量(ET0),并与气象站蒸发皿蒸发量(Ep)进行了对比分析及影响因素的灰色关联度排序。结果表明:极端干旱区ET0最大值出现于7月,最小值则出现在1月;Ep最大值分别出现在6月,最小值出现在12月。灰色关联分析表明,在年时间尺度上与ET0关系最为紧密的气象因子是Umean,其次是Tmax,而影响Ep气象因子最为紧密的气象因子是Tmax,其次是Umean;在春、夏、秋、冬四个季节尺度上夏季对影响ET0和Ep的气象因子差异最大。ET0与Ep在春、秋、冬三个季节都成极显著关系,而在夏季呈显著线性关系,因此在不同时间尺度上二者可以进行互相替换。     

塔克拉玛干沙漠腹地不同灌溉形式(投入)生物防护林建设效果分析

塔克拉玛干沙漠腹地建立生物防护林 ,在树种选择、种植方式基本确定的基础上 ,应重点考虑以下三点 :1资金投入 ,2灌溉用水量 ,3产生的效果。目前 ,由中国科学院新疆生态与地理研究所承担建成的油田基地路生物防护林 ,分别采用沟灌、滴灌两种灌溉方式 ,本文对两种灌溉方式的资金投入 ,用水量和产生的效果进行比较分析 ,为今后在沙漠公路和油田基地的应用推广 ,提供科学依据。     

塔克拉玛干沙漠腹地复合纵向沙垄间地沙丘空间分形及稳定性

塔克拉玛干沙漠的大地貌格局是高大复合沙垄和宽广垄间地相间分布,而垄间地是研究简单沙丘发育过程的良好试验场地。基于Google Earth影像,以分形理论为基础,对塔克拉玛干沙漠腹地复合纵向沙垄区垄间地上覆沙丘在主导风方向上的分形特征进行了分析,结果表明：① 垄间地沙丘形状指数（面积-周长关系）的标度-频度双对数关系非常显著,分形关系客观存在,并且不受统计时所用标度的影响;② 垄间地各类沙丘的分维值存在差异,其中,饼状沙堆和沙片分维值最大（1.337）,新月形沙丘次之（1.170）,简单线性沙丘最小（1.087）;③ 垄间地沙丘分维值的空间差异较大,在1.187~1.656,其分维数：背风坡脚（1.24）＜垄间地中部（1.40）＜迎风坡脚（1.50）,变异系数为0.106;④ 垄间地沙丘稳定性指数与分维值的空间分布相反,即背风坡脚（0.26）＞垄间地中部（0.16）＞迎风坡脚（0.10）;⑤ 垄间地沙丘分维值空间差异主要与沙丘发育程度有关,其中,风信是动力基础,沙源是物质基础。在流动沙漠,沙丘分形维数可以作为反映其风沙环境特征的定量指标。     

塔克拉玛干沙漠灌草丘的发育特征及环境意义

对灌草丘的发育条件及沉积特征的研究表明，塔克拉玛干沙漠地区的灌草丘形成在绿洲受风沙入浸，由水沉积转为风沙沉积过程中，气候变化对灌草丘的发育未产生重要影响，但流水在其中起了决定性作用。灌草丘开始发育之后，可以依某一速率持续增长，也可能被埋没（主要是风沙流），或被侵蚀夷平，但部分灌草丘在沙漠的发展过程中保存达数千年之久。有限的测年数据及地表景观显示灌草丘发育的阶段性，实际上也是沙漠发展的阶段性。     

Effect of the W-beam central guardrails on wind-blown sand deposition on desert expressways in sandy regions

Many desert expressways are affected by the deposition of the wind-blown sand,which might block the movement of vehicles or cause accidents.W-beam central guardrails,which are used to improve the safety of desert expressways,are thought to influence the deposition of the wind-blown sand,but this has yet not to be studied adequately.To address this issue,we conducted a wind tunnel test to simulate and explore how the W-beam central guardrails affect the airflow,the wind-blown sand flux and the deposition of the wind-blown sand on desert expressways in sandy regions.The subgrade model is 3.5 cm high and 80.0 cm wide,with a bank slope ratio of 1:3.The W-beam central guardrails model is 3.7 cm high,which included a 1.4-cm-high W-beam and a 2.3-cm-high stand column.The wind velocity was measured by using pitot-static tubes placed at nine different heights(1,2,3,5,7,10,15,30 and 50 cm)above the floor of the chamber.The vertical distribution of the wind-blown sand flux in the wind tunnel was measured by using the sand sampler,which was sectioned into 20 intervals.In addition,we measured the wind-blown sand flux in the field at K50 of the Bachu-Shache desert expressway in the Taklimakan Desert on 11 May 2016,by using a customized 78-cm-high gradient sand sampler for the sand flux structure test.Obstruction by the subgrade leads to the formation of two weak wind zones located at the foot of the windward slope and at the leeward slope of the subgrade,and the wind velocity on the leeward side weakens significantly.The W-beam central guardrails decrease the leeward wind velocity,whereas the velocity increases through the bottom gaps and over the top of the W-beam central guardrails.The vertical distribution of the wind-blown sand flux measured by wind tunnel follows neither a power-law nor an exponential function when affected by either the subgrade or the W-beam central guardrails.At 0.0H and 0.5H(where H=3.5 cm,which is the height of the subgrade),the sand transport is less at the 3 cm height from the subgrade surface than at the 1 and 5 cm heights as a result of obstruction by the W-beam central guardrails,and the maximum sand transportation occurs at the 5 cm height affected by the subgrade surface.The average saltation height in the presence of the W-beam central guardrails is greater than the subgrade height.The field test shows that the sand deposits on the overtaking lane leeward of the W-beam central guardrails and that the thickness of the deposited sand is determined by the difference in the sand mass transported between the inlet and outlet points,which is consistent with the position of the minimum wind velocity in the wind tunnel test.The results of this study could help us to understand the hazards of the wind-blown sand onto subgrade with the W-beam central guardrails.     

敦煌月牙泉风沙环境及沙山动态监测

通过对月牙泉景区气象站点资料以及周边沙山高度定点长期监测数据的分析,得出景区内由于受周边高大沙山地形因素影响,景区内形成了两组主导风向下的局地环流,两组环流风向相反,物质搬运方向相反。但随着周边环境的变化,环流产生变化,原有输沙平衡遭到破坏,造成了南山和北山对月牙泉形成夹击之势。从沙山高度变化的监测中,除东山高度有降低趋势外,其余各点均表现为增高趋势,与输沙势分析结果保持一致。通过以上分析,从风流场方面揭示出月牙泉夹击之势的形成原因,剖析出沙害的根源,进而为保护月牙泉提供强有力的科学依据,并为揭示飞沙不落月牙泉现象奠定研究基础。     

Damage by wind-blown sand and its control measures along the Taklimakan Desert Highway in China

Desertification is one of the most serious environmental problems in the world,especially in the arid desert regions.Combating desertification,therefore,is an urgent task on a regional or even global scale.The Taklimakan Desert in China is the second largest mobile desert in the world and has been called the'Dead Sea'due to few organisms can exist in such a harsh environment.The Taklimakan Desert Highway,the longest desert highway(a total length of 446 km)across the mobile desert in the world,was built in the 1990s within the Taklimakan Desert.It has an important strategic significance regarding oil and gas resources exploration and plays a vital role in the socio-economic development of southern Xinjiang,China.However,wind-blow sand seriously damages the smoothness of the desert highway and,in this case,mechanical sand control system(including sand barrier fences and straw checkerboards)was used early in the life of the desert highway to protect the road.Unfortunately,more than 70%of the sand barrier fences and straw checkerboards have lost their functions,and the desert highway has often been buried and frequently blocked since 1999.To solve this problem,a long artificial shelterbelt with the length of 437 km was built along the desert highway since 2000.However,some potential problems still exist for the sustainable development of the desert highway,such as water shortage,strong sandstorms,extreme environmental characteristics and large maintenance costs.The study aims to provide an overview of the damages caused by wind-blown sand and the effects of sand control measures along the Taklimakan Desert Highway.Ultimately,we provide some suggestions for the biological sand control system to ensure the sustainable development of the Taklimakan Desert Highway,such as screening drought-resistant species to reduce the irrigation requirement and ensure the sound development of groundwater,screening halophytes to restore vegetation in the case of soil salinization,and planting cash crops,such as Cistanche,Wolfberry,Apocynum and other cash crops to decrease the high cost of maintenance on highways and shelterbelts.     

基于分形理论的塔克拉玛干沙漠腹地自然植物根系构型特征分析

采用全根挖掘法挖取塔克拉玛干沙漠腹地3种典型自然植物-塔克拉玛干柽柳(Tamarix taklamakanensis)、塔干沙拐枣(Calligonum roborovskii)、罗布麻(Apocynum venetum)成年植株根系,运用分形理论分析其构型特征。结果表明:(1)塔克拉玛干沙漠腹地3种植物根系均以水平分布为主,根系浅层化特征显著。(2)塔克拉玛干柽柳、塔干沙拐枣和罗布麻根系分形维数分别为1.31±0.05、1.22±0.06、1.14±0.07,分形维数的显著差异表明了3种植物根系分支状况的差异。(3)3种植物根系分支前后横截面积比分别为0.95,1.04和1.06,表明根系具有显著的自相似性和分形特点。(4)根系直径与根长、生物量之间存在很好的相关关系,基径、根系直径等较易测定的指标可以有效地对根长、生物量等构型指标进行预测估计。     

胶质芽孢杆菌Bacillus mucilaginosus的分离及对荒漠沙中棉花种子发芽的影响

对采集的土壤样品中解钾菌进行分离与鉴定,再以荒漠沙为土壤基质,加入含菌量为0、0.16、0.48、0.80、1.20、1.60(×108/CFU·m L-1)的菌液进行发芽试验,研究了解钾菌对棉花种子的发芽率、幼苗的鲜重、芽长和根长、超氧化物歧化酶(SOD)、过氧化物酶(POD)和丙二醛(MDA)含量的影响。结果表明,分离出的解钾菌为胶质芽孢杆菌(Bacillus mucilaginosus)。当沙漠土壤中加入不同含菌量的菌液后:棉花种子发芽时间提前0~24 h,发芽率随着菌含量的增加呈先增大后减少的趋势,当菌含量为0.8×108CFU·m L-1时发芽率最高为70.29%;茎的长度增加0.5~1.2 cm,主根的长度缩短0.20~0.65 cm,但促进了侧根的生长,幼苗的鲜重提高了0.0662~0.1582 g;幼苗中的相关酶和丙二醛含量分别有不同程度的增加和减少。     

内蒙古空中云水资源特征及与降水关系

利用19年的国际卫星云气候计划ISCCP D2资料,分类型对内蒙古地区空中云水资源的时空分布、变化趋势及其与降水的关系进行了分析,并分析了可能影响云量和降水变化的原因。结果表明:内蒙古地区云量总和平均为65.21%,卷云最多,平均达到18.77%。液态层积云、层云、高层云等云量呈现出自西向东依次增多的空间分布特征,同降水量的空间分布特征相一致。降水与液态的云量呈正相关,与冰相的云量呈负相关关系。全球表面增温以及西太平洋副热带高压的变化可能是云量和降水变化的原因。     

Wind regimes and associated sand dune types in the hinterland of the Badain Jaran Desert,China

Wind controls the formation and development of sand dunes. Therefore, understanding the wind regimes is necessary in sand dune research. In this study, we combined the wind data from 2017 to 2019 at four meteorological stations (Cherigele and Wuertabulage stations in the lake basins, and Yikeri and Sumujilin stations on the top of sand dunes) in the hinterland of the Badain Jaran Desert in China, with high resolution Google Earth images to analyze the correlation between the wind energy environments and dune morphology. The results of data analysis indicated that both the wind direction and sand drift intensity exhibited notable spatial and temporal variations. The highest level of wind activity was observed in spring. Northwesterly and northeasterly winds were the dominant in the Badain Jaran Desert. At the Cherigele, Wuertabulage, and Yikeri stations, the drift potential (DP) was below 200.00 vector units (VU). The wind energy environments in most areas could be classified as low-energy environments. The resultant drift direction differed at different stations and in different seasons, but the overall direction was mainly the southeast. The resultant drift potential (RDP)/DP ratio was greater than 0.30 in most parts of the study area, suggesting that the wind regimes mainly exhibited unimodal or bimodal characteristics. Differences between the thermodynamic properties and the unique landscape settings of lakes and sand dunes could alter the local circulation and intensify the complexity of the wind regimes. The wind regimes were weaker in the lake basins than on the top of sand dunes. Transverse dunes were the most dominant types of sand dunes in the study area, and the wind regimes at most stations were consistent with sand dune types. Wind was thus the main dynamic factor affecting the formation of sand dunes in the Badain Jaran Desert BJD. The results of this study are important for understanding the relationship between the wind regimes and aeolian landforms of the dune field in the deserts.     

塔克拉玛干沙漠及周围地区地表反射率

本文利用1988年塔克拉玛干沙漠综合科学考察期间在其腹地满西—井获得的地表反射率资料及其周围日射观测站历年反射率平均值资料,分析了沙漠地表反射率的日变化及地表性状、降水等因子对反射率的影响,并讨论了沙漠及周围地区地表反射率的时空分布状况。     

固沙植被土壤水分动态及其对降雨的响应

水分是影响固沙植被生长发育的最重要的限制因素,同时也是沙漠环境中最容易受到影响的生态因子。因此,定位观测研究流动沙地建立固沙植被后土壤水分变化具有重要的现实意义。文中采用Watchdog土壤水分自动监测系统,定位定时记录了7月1日-10月31日期间杨柴固沙林、固定沙丘天然草地和流动沙丘土壤体积含水量数值。结果表明:相同降水量条件下,不同固沙植被土壤重力水湿润深度存在明显差异。5.33mm降雨时流动沙丘水分湿润深度小于20cm,13.97mm降雨时水分湿润深度达40cm,30.3mm降雨时水分湿润深度达80cm,40.3mm降雨时水分湿润深度达120cm。而30.3mm及以下降雨时杨柴固沙林和天然草地植被土壤水的湿润深度小于40cm;40.3mm降雨时杨柴固沙林地水分湿润深度达80cm,天然草地植被水分湿润深度达120cm。植物生长季流动沙地土壤水分状况最好。流动沙丘20cm、40cm、80cm和120cm土层含水量平均值分别为2.15%、2.42%、1.96%和2.94%;而杨柴固沙林和天然草地植被下土壤水分状况明显不良,特别是80cm土层以下土壤水分状况明显恶化。杨柴固沙林生长期20cm、40cm、80cm和120cm土层含水量平均值分别为1.89%、1.67%、0.81%和1.08%;天然草地植被生长期20cm、40cm、80cm和120cm土层含水量平均值分别为2.34%、1.96%、1.02%和1.43%。     

The ecological role of dew in assisting seed germination of the annual desert plant species in a desert environment,northwestern China

It is important to understand the effects of dew events on non-mucilaginous seed germination of annual desert plant species during dry seasons, which is critical to maintaining long-term soil seed banks in a harsh desert environment. We hypothesize that dew deposition also assists in the non-mucilaginous seed germination of annual desert species. A common field dew treatment experiment was conducted in the Linze Inland River Basin Research Station to investigate the effects of dew deposition on the seed germination of four annual species, including Agriophyllum squarrosum, Corispermum mongolicum, Bassia dasyphylla and Halogeton arachnoideus. The results showed that the presence of dew significantly increased seed germination percentages and decreased the nonviable seed percentages of B. dasyphylla and H. arachnoideus, whereas there was no such trend for the seeds of C. mongolicum and A. squarrosum. The ecological effects of dew on the seed germination and viability of the annual desert plants were species specific. Although dew wetting is insufficient to cause seed germination, it may help in priming the seeds.