Analysis of the Application of Windbreak and Sand Fixation Technology in Desert Roads

In order to solve the problems in the construction of desert roads and improve the quality of desert roads in China,this paper discusses the current windbreak and sand fixation technologies in desert areas in China,and puts forward relevant suggestions and corresponding solutions for each problem.This paper is written with hopes of contributing to the development of windbreak and sand fixation technologies in China as well as the development of the economy,society and environment in China's deserts.

Study of Mechanism of the W-OH Sand Fixation

A novel hydrophilic polyurethane (abbreviated as W-OH) was developed and applied as a sustainable sand-fixing material. This paper on the chemical sand fixation mechanism of W-OH discusses the adhesive force between the W-OH solid and sand particles. The solidification mechanism was investigated and the solidifying time was tested. And then the thickness and porosity of the W-OH sand-fixing layer were investigated. By scanning electron microscopy (SEM), the microstructure of the W-OH sand-fixing layer was examined. The hardness and compressive stress of the sand-fixing specimens were studied at W-OH different concentrations. Finally, the resistance to wind erosion of the W-OH sand-fixing layer was investigated by a wind tunnel test. The results demonstrated that the W-OH aqueous solution had an excellent affinity for water on the surface of the sand particles, and the adhesive force between the W-OH solid and sand was primarily hydrogen bonding, covalent bonds and physical absorption, such as Van Der Waals forces. W-OH is a prepolymer of hydrophilic polyurethane containing groups of -NCO that can quickly react with water and other groups containing active H. The W-OH aqueous solution solidified in the range of 2 min to 15 min. The solidifying time decreased with increasing temperature and concentration. Before solidifying it had a good permeability of sand and the formed sand-fixing layer had a thickness of 8 - 35 mm and a porosity of 25% - 8% at a spraying concentration of 2 - 10 L/m2. The hardness index of the sand-fixing layer was in the range of 21 mm to 28 mm and compressive stress was in the range from 0.21 MPa mm to 1.27 MPa, both of which increased linearly with W-OH concentration. Sand treated by over 3% W-OH concentrations showed excellent resistance to wind/sand erosion of more than 25 m/s.

Biological Characteristics of Carex brunnescens for Sand Fixation in the Source Region of the Yellow River

Carex brunnescens, a pioneer plant that has an excellent ability to fix sand in the source region of the Yellow River （Maqu）, plays an important role in maintaining the ecosystem stability of alpine grassland in Maqu. In this study, the biological characteristics （phonological characters, the growth process of overground and underground organs, and the morphological characters of underground organs） of C. brunnescens were studied by a field observation experiment. The results showed that C. brunnescens had the characteristics of turning green earlier than other plants, a long growth period, and two flowering and fruiting cycles. The leaf width, length and number of a single plant, and the density, coverage and leaf density of community increased significantly from the leaf extension period to the fruit mature period and then tended to be stable in the withering period, while the plant height and leaf area of a single plant and the leaf area of community rose significantly at first and then decreased. Underground stems （horizontal and vertical stems） and roots of C. brunnescens could survive in sand at a depth of 0-60 cm. The number of middle roots （0.2-0.5 mm in diameter） was the largest in all soil layers （0-20, 20-40 and 40-60 cm）, and the total length of fine roots （〈0.2 mm） were the maximum in the sand at a depth of 20-40 cm, while the total length of middle roots was the maximum in the sand layer at a depth of 0-20 cm. The length, fresh weight and dry weight of the main root, horizontal and vertical stems was the maximum in the sand layer at a depth of 10-30 cm and was the minimum in the sand layer at a depth of 40-50 cm. It is concluded that C. brunnescens can well adapt to the alpine sand habitat of Maqu, can be used as the constructive species for ecological restoration in the alpine desertified grassland of Maqu, and has good popularization and application prospects.

Utilizing sediment grain size characteristics to assess the effectiveness of clay–sand barriers in reducing aeolian erosion in Minqin desert area,China

The clay–sand barriers in Minqin desert area,China,represent a pioneering windbreak and sand fixation project with a venerable history of 60 a.However,studies on evaluating the long-term effectiveness of clay–sand barriers against aeolian erosion,particularly from the perspective of surface sediment grain size,are limited and thus insufficient to ascertain the protective impact of these barriers on regional aeolian activities.This study focused on the surface sediments(topsoil of 0–3 cm depth)of clay–sand barriers in Minqin desert area to explain their erosion resistance from the perspective of surface sediment grain size.In March 2023,six clay–sand barrier sampling plots with clay–sand barriers of different deployment durations(1,5,10,20,40,and 60 a)were selected as experimental plots,and one control sampling plot was set in an adjacent mobile sandy area without sand barriers.Surface sediment samples were collected from the topsoil of each sampling plot in the study area in April 2023 and sediment grain size characteristics were analyzed.Results indicated a predominance of fine and medium sands in the surface sediments of the study area.The deployment of clay–sand barriers cultivated a fine quality in grain size composition of the regional surface sediments,increasing the average contents of very fine sand,silt,and clay by 30.82%,417.38%,and 381.52%,respectively.This trend became markedly pronounced a decade after the deployment of clay–sand barriers.The effectiveness of clay–sand barriers in erosion resistance was manifested through reduced wind velocity,the interception of sand flow,and the promotion of fine surface sediment particles.Coarser particles such as medium,coarse,and very coarse sands predominantly accumulated on the external side of the barriers,while finer particles such as fine and very fine sands concentrated in the upwind(northwest)region of the barriers.By contrast,the contents of finest particles such as silt and clay were higher in the downwind(southeast)region of the sampling plots.For the study area,the deployment of clay–sand barriers remains one of the most cost-effective engineering solutions for aeolian erosion control,with sediment grain size parameters serving as quantitative indicators for the assessment of these barriers in combating desertification.The results of this study provide a theoretical foundation for the construction of windbreak and sand fixation systems and the optimization of artificial sand control projects in arid desert areas.

Comparative Analysis of Wind break and Sand fixation Functions of Several Main Forage Plants in Minqin Desert Area

[Objective] The paper was to study wind-break and sand-fixation functions of forage plants in desert area. [Method]Based on the survey data of four major wind-break and sand-fixation plants( Haloxylon ammondendron,Artemisia arenaria,Nitraria tangutorum and Ephedra przewalskii) in Minqin desert area,the longitudinal section area and the sandpile volume of an individual plant and per unit area were calculated. The wind-break and sand-fixation functions of four major plant communities were comparatively analyzed. [Result] The wind-break functions of an individual plant( cluster) successively were N. tangutorum > H. ammondendron > A. arenaria and E. przewalskii; the sand-fixation functions of an individual plant( cluster) successively were N. tangutorum > E. przewalskii; the wind-break functions per unit area successively were A. arenaria > H. ammondendron > N. tangutorum > E. przewalskii; the sand-fixation functions per unit area were N. tangutorum > E. przewalskii; the wind-break and sand-fixation function per unit area were N. tangutorum > A. arenaria > H. ammondendron >E. przewalskii.[Conclusion]A. arenaria can be selected for only wind-break,and N. tangutorum can be chosen for only sand-fixation. If given consideration to both,N. tangutorum and A. arenaria must be selected.

WINDBREAKS FOR SAND DUNE FIXATION IN JILIN PROVINCE

There are 0.78 million hm2 of sand dune areas in Jilin Province. The effects of two types of windbreaks. shelterbelts and small areas ofartdicial forests, on sand dune fixation were discussed. The temperature, humidity and reduced situation of wind speed in the two types of windbreaks wer systematically studied.

Sand Dunes Fixation in Baiji District, Iraq

This study was carried out at Sand Dunes Stabilization Researches Station in Baiji district (230 km north of Baghdad, Iraq) to evaluate the effects of local soil conditioners manufactured from oil derivatives and plant residuals on sand dunes fixation as the first step for sand dunes stabilization. The results indicate that the fuel oil has the first place in improving wind erosion parameters in the study area, such as increasing mean weight diameter, dry aggregates percentage, the needed time for complete disaggregation by dry sieving, and decreasing the disaggregation rates. Bitumen emulsion occupies the second place, while the plant residuals occupies the third place and has slight effects on the studied parameters. Effects of conditioners on natural vegetation cover are negative in oil derivatives treatments, while positive in plants residuals treatments.

自动巡航草方格固沙机结构设计分析及试验

针对荒漠化治理对草方格固沙机的需求,提出了一种集底盘、开沟机构、草箱机构、插草机构、覆压沙机构、播种及洒水机构、升降机构与一体的多功能草方格固沙机。分析了“T+一”式草方格种植模式的优势,提出了自动巡航草方格固沙机整体结构方案,并对开沟机构、草箱机构、插草机构、覆压沙机构、播种及洒水机构、升降机构等关键组件的功能和结构进行了详细分析。应用三维建模软件建立虚拟机构模型,对推草和插草机构进行了运动仿真分析,并对整机进行了作业性能试验。结果表明:各机构构件间无干涉,构件运动仿真轨迹符合功能要求,杆件尺寸参数设计合理,机器作业效率高,可有效保证草方格铺设的准确性和有效性,满足机械化固沙的要求,具有良好的通用性和适应性。

The effects of human activities on windbreak and sand fixation services in Inner Mongolia grasslands from 2000 to 2020

Windbreak and sand fixation services(SR)provided by grasslands are a joint result of climate change and human activities.Series of grassland protection measurements have been successively implemented on Inner Mongolia grasslands since 2000,but their effects on SR remains unclear.Based on satellite-derived vegetation dynamics and the Revised Wind Erosion Equation(RWEQ)model,this paper developed a method for quantitatively separating the impact of human activities on SR and revealed the contribution of human activities to SR in the Inner Mongolia grasslands from 2000 to 2020.In 2020,the actual sand fixation(SRA)of Inner Mongolia grasslands was 12.50 t·ha^(-1),spatially characterized as lower in the eastern and western parts,which was dominated by the sparse vegetation coverage and the low potential wind erosion respectively,while higher in the central part,due to the grassland vulnerability.The human-driven sand fixation(SRH)of Inner Mongolia grasslands changed from–1.28 t·ha^(-1)to–0.14 t·ha^(-1)from 2000 to 2020,indicating human activities inhibited SR,but the inhibition was gradually weakened.In semidesert and meadow steppes,the SRHchanged from–3.00 t·ha^(-1)to 0.00 t·ha^(-1)and–0.16 t·ha^(-1)to 0.00 t·ha^(-1),respectively,which showed that the effect of human activities changed from inhibition to promotion.However,it should be noted that human activities still inhibited the SR in typical steppes.The results implicated that grassland ecological protection should pay much more attention to reasonable use of vulnerable typical steppes.Future grassland use requires quantitative evaluation on the effects of human activity for precise monitoring and sustainable management.

多时序卫星遥感数据在麦盖提县防风固沙成效分析中的应用

为了守住家园,打造宜人、宜居、宜业、宜游的社会发展环境,多年来,麦盖提县各族群众奋力与沙相争,使黄沙退去,绿色重建。本文利用国产卫星影像作为数据源,提取麦盖提县百万亩防风固沙生态林建设工程历年变化信息,数字重建变化过程,从分布、面积、健康状况等指标方面分析变化特征,对2013年以来防风固沙工程开展遥感监测,通过卫星影像分析和展现防风固沙实际成效,为麦盖提县经济社会发展和生态环境保护提供科学依据。

乌兰布和沙漠公路“麦草沙障-梭梭”的防护效益

[目的]研究公路防护体系的防风固沙作用为区域公路沙害防治提供科学依据。[方法]以乌兰布和沙漠东北部磴—额线沙漠公路防护体系为研究对象,并对防护体系的输沙量和风速进行了同步观测。[结果](1)风沙流穿过防护体系后各高度风速和总输沙量降低,地表粗糙度增大,防护体系上风向(B点)和下风向(C点)风速由高到低较A点降低分别48.7%,14.4%和3.9%;总输沙率分别较A点降低86.4%和98.3%,地表粗糙度约由0 cm增大到4.92 cm。(2)沙物质粒径的垂直分布表现出中砂含量显著降低,细砂含量显著增加;表层沉积物颗粒粒级变小,频率分布曲线部分波段变窄,分选性变差,颗粒分布均匀且颗粒向着细粒化方向发展,易风蚀颗粒范围在180~200μm。[结论]对于道路防沙工程要有“以阻为主,阻固结合”的建设思想,同时本研究区道路防风固沙体系实践可以为其他区域公路防沙提供重要借鉴经验。

基于GNSS+IMU的草方格固沙机自动巡航控制系统

为了实现草方格固沙机的智能化工作,提出了一种基于GNSS+IMU的草方格固沙机自动巡航控制系统。系统以STM32F407VGT6作为主控芯片,将GNSS(全球导航卫星系统)和IMU(惯性测量单元)的位置、速度和航向角数据通过卡尔曼滤波算法融合,得到最优估计数据;然后,将最优估计数据输入增量式PID算法,以实现草方格固沙机在预定义区域内稳定的导航工作。同时,设计了Android APP终端,实现了用户终端对草方格固沙机的智能监控。研究结果表明:系统导航工作直线航向角偏差RMS不超过0.45,最大偏差不超过1.5°,满足草方格固沙机自动巡航工作的基本需求,体现了草方格固沙机在智能化定位导航方面的可行性与稳定性,可为草方格固沙机实现荒漠化治理提供依据。

基于RWEQ模型的疏勒河流域防风固沙功能价值评估

疏勒河流域地处西北内陆,是“一带一路”的关键节点。近年来随着全球变化与经济社会活动强度增加,导致建设用地快速扩张、土地沙化等问题,影响区域生态与经济社会的可持续发展。疏勒河流域处于北方防沙带中心,开展其防风固沙价值评估对于构建区域生态安全格局和保障流域可持续发展具有重要生态意义。基于修正风蚀方程模型(RWEQ)对2008—2018年疏勒河流域防风固沙功能及其价值进行评估。结果表明:(1)2008—2018年疏勒河流域防风固沙总量为43.927×10^(4)~129.530×10^(4)t·km^(-2),防风固沙量呈上升趋势。(2)2008—2018年疏勒河流域防风固沙价值快速增加,其多年平均价值占比由高到低依次为减少土地损失价值(99.46%)、保持土壤肥力价值(0.47%)、保持土壤有机质价值(0.04%)、减少交通运输经济损失价值(0.03%)。(3)流域防风固沙功能与土地利用密切相关,防风固沙能力较强的区域主要分布在草地、耕地等植被覆盖率较高区域;低值区主要分布在流域土地利用类型为未利用地区域。(4)相较社会因素,自然指标因子对流域防风固沙功能价值影响更大。研究结果可为确定流域生态补偿主客体及补偿标准提供依据。

基于慧鱼创意模型的草方格沙障铺设车设计

针对现有沙障铺设机存在的造价高、自动化程度低、适应性差、沙障铺设效果差等问题,该文基于慧鱼创意模型设计了一款自适应强、工作效率高、自动化程度高的草方格沙障铺设车。完成了铺设车机械系统和控制系统方案设计;实现了自动检测、随动控制、草料运转装置三维可调和秸秆精准等功能;搭建了慧鱼创意模型实物样机;开展了模拟样机草方格沙障铺设试验。实验结果表明,该铺设车完全自适应植入秸秆与巩固秸秆,沙障防风固沙质量稳定性、可靠性强,工程应用预期效果显著。

放牧干扰下荒漠草原植物功能群数量特征与输沙量的关系

[目的]分析放牧干扰下草地群落及功能群数量特征变化与草地土壤风蚀间的关系,阐明草地不同功能群对草地侵蚀过程的影响,为荒漠草原合理放牧利用及保护提供理论依据。[方法]以内蒙古短花针茅荒漠草原为研究对象,采取完全随机试验设计设置对照、中度和重度3个不同的放牧处理,对不同处理下的草地输沙量和功能群特征进行研究。[结果]①随放牧强度增加,各功能群内物种高度、盖度和地上生物量基本呈下降态势。适当放牧能显著提高Simpson优势度指数和Shannon-Wiener多样性指数。②各放牧处理间的草地输沙量差异显著,不同输沙高度处的草地输沙量变化规律均为HG>MG>CK,同一放牧处理下,随输沙高度上升输沙率显著降低。③各功能群高度、盖度与输沙量均存在指数负相关关系,其中多年生禾草和多年生杂类草的高度变化对输沙量的影响更显著。各功能群的地上生物量与输沙量存在负相关指数关系,其中多年生禾草的生物量与输沙量的拟合程度最高。[结论]过度放牧会显著影响功能群特征并降低草地的防风固沙能力,建议放牧强度控制在中度及以下。

不同碳酸钙钙源对CFPK加固风积沙的影响

仿岩溶碳酸氢钙(CFPK)溶液是一种环境友好型固沙材料,碳酸钙钙源对CFPK溶液的制备及其特性有重要影响。为了给CFPK在固沙方面的推广应用提供参考,选择分析纯碳酸钙、生物碳酸钙、轻质碳酸钙、重质碳酸钙4种材料作为制备CFPK溶液的碳酸钙钙源,通过化学试验、力学试验、X射线衍射试验和扫描电镜试验等,分析了不同碳酸钙钙源制备的CFPK溶液的固沙效果。结果表明:1)4种碳酸钙钙源制备的CFPK溶液在反应达到平衡时,电导率和钙离子浓度基本相同,即钙源对碳酸氢钙溶解度影响很小,但是反应速度差别明显,其中重质碳酸钙的反应速率最快、生物碳酸钙的反应速率最慢;2)不同碳酸钙固化沙的表面强度、抗风蚀能力差异明显,重质碳酸钙固化沙表面强度和抗风蚀能力大于其他3种碳酸钙的,生物碳酸钙固化沙表面强度和抗风蚀能力最小;3)4种碳酸钙钙源在固化沙中生成的碳酸钙晶体矿物成分基本相同,主要为方解石,但不同碳酸钙钙源在固化沙中生成的碳酸钙晶体的含量和形态有所不同,分析纯碳酸钙生成的碳酸钙晶体主要为六面体方解石,其他3种碳酸钙生成的碳酸钙晶体以薄片状为主,其中重质碳酸钙生成的碳酸钙晶体尺寸大、高度聚集、致密性高,因此重质碳酸钙作为钙源的固沙效果最好,建议选用重质碳酸钙作为制备CFPK溶液的钙源。

猫头刺盾状移动式固沙障防沙效应风洞模拟试验研究

[目的]猫头刺盾状移动式固沙障是运用仿生学原理,由盾状铁网筛与上方扎制固沙灌木猫头刺(Oxytropis aciphylla)茎叶构成的一种新型固沙障。对猫头刺盾状移动式固沙障的防风固沙效应进行试验,以确定最佳固沙障类型,并揭示其防风固沙机理,为野外工程防沙措施的选择和制定提供理论依据。[方法]通过风洞模拟试验,在6,10,14,18 m/s 4个风速条件下测量了猫头刺盾状移动式固沙障的风速流场,并在10,14,18 m/s 3个风速条件下对该固沙障进行了携沙风吹蚀试验。对照分析了原位自然型与不同类型,不同大小仿生猫头刺盾状移动式固沙障的防风沙效应。[结果](1)气流在经过猫头刺盾状移动式固沙障时速度均会减弱,形成明显的减速区。在6 m/s时,减速沉降区均达到了20 H(H为沙障高度,H=11 cm);随着风速增加,减速沉降区缩小。风速10与14 m/s时,减速沉降区为15 H;且在风速18 m/s时,也能维持15 H的减速沉降区。(2)3种风速梯度下,猫头刺盾状移动式固沙障的平均输沙量是无沙障的13.8%(10 m/s风速),21.1%(14 m/s风速),23.4%(18 m/s风速)。[结论]结构完整,直径更大的猫头刺盾状移动式固沙障具有最好的防风沙效果。该移动式仿生固沙障防风沙效果好,可移动,可组合并可机械化编制,在防治荒漠化、防风固沙领域有广阔的应用前景。

吐鲁番市高昌区不同固沙植物的防风固沙效益

为了解不同防风固沙林对风速、输沙通量和土壤蚀积程度的影响,以期为荒漠化地区植物选择和配置提供技术支持,以吐鲁番市高昌区恰特喀勒乡公相村为实验地,利用气象站、风速仪、集沙仪等监测不同高度下梭梭林、柽柳林以及梭梭-柽柳混交林的风速、地表粗糙度、输沙通量等指标,分析比较不同固沙林的风速廓线、风速增加率、地表蚀积量及风沙堆积物变化规律。结果表明:随着风速的增加,输沙通量逐渐增加,地表粗糙度和蚀积深度呈现降低趋势;不同固沙林不同高度(h)的风速增加率均表现为中层(50 cm<h≤100 cm)最大,低层(10 cm<h≤50 cm)最小,说明固沙植物对低层风速有显著降低作用,增强了中层风速;不同固沙林输沙通量随着高度增加逐渐减小;柽柳林、梭梭-柽柳混交林后出现堆积现象,梭梭林前后为侵蚀现象。梭梭林、柽柳林以及梭梭-柽柳混交林均降低了近地表风速,有效拦截了风沙流,改变了表层风沙堆积物物质组成,梭梭-柽柳混交林防风固沙效果较好。

不同带间距固沙林带间植被与土壤特性变化

在科尔沁沙地敖汉旗沙区,通过评估不同带间距低覆盖度固沙林对土壤及植被的影响,旨在提出更适宜当地条件的带间植被恢复与土壤发育的配置结构模式,为科尔沁沙地人工造林提供科学依据。对3种不同带间距的赤峰杨固沙林带间植被群落多样性、土壤理化性质及其相关性进行了研究。结果表明:不同带间距赤峰杨固沙林带间植被与土壤恢复有明显影响,植被恢复与土壤恢复是相辅相成的。(1)在调查的3种不同带间距的行带式固沙林中,随着带间距的增加,带间植被的物种多样性呈增加趋势,各物种多样性指数的变化趋势比较为:带间距25 m>16 m>10 m>等株距对照样地;(2)土壤含水量、孔隙度及土壤养分(有机碳、碱解氮、速效磷、速效钾)含量比较为:带间距25m>16m>10m>等株距对照样地;土壤容重比较为:带间距25 m<16 m<10 m<等株距对照样地;(3)在不同带间距赤峰杨固沙林中,土壤发育和植被恢复是相互促进的,物种多样性指数与土壤的各项理化性质存在不同程度的显著(P<0.05)或极显著(P<0.01)相关,但与速效钾的相关性不显著。低覆盖度赤峰杨固沙林带间距的大小对带间土壤理化性质、植被恢复有明显的影响,增大带间距,能有效促进土壤发育、促进带间植被生长,25m的带间距,更有利于土壤的发育和带间草本植被生长。

小型草方格沙障机器人结构设计

为了能够高效率、高质量地铺设防风固沙草方格沙障,进行了小型草方格沙障机器人机械结构创新设计。设计了含有凸轮和双曲柄组合调节机构的开沟装置,解决了开沟装置结构复杂、占用空间大的问题。设计了以散草为原料的输草机构,解决了现有草方格铺设机器只能以草帘为原料进行铺设的不足。制作了样机并测试机构运行稳定性。该机器人能够辅助人工在荒漠中进行草方格沙障的铺设作业,减轻工人繁重的体力劳动,具有铺设效率高、通过性好、铺设质量高等优点。