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.

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。

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。

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。

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。

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。

沙坡头自然保护区不同固沙技术生态效益监测评价

【目的】为了深入了解设置沙障后不同固沙条件下植被物种组成、多样性的变化规律。【方法】以扎设草方格、尼龙网格、草绳方格固沙的沙地植被恢复技术示范区为研究对象,分析不同固沙模式对土壤风蚀、水分和电导率以及草本植物群落组成的影响,总结不同固沙模式对沙地植被恢复区的土壤风蚀、水分和电导率及植物多样性指数的影响规律。【结果】结果表明,①从总风蚀速率来看,流动沙丘风沙活动最强,为0.15 cm·d^(-1),且以沉积为主;草方格沙丘风沙活动最弱,为0.04 cm·d^(-1);土壤风蚀的总风蚀速率较流动沙丘减小0.11 cm·d^(-1)。沙丘风蚀与沉积的净变化速率在草方格沙丘最小,为-0.04 cm·d^(-1);流动沙丘最为剧烈,为0.15 cm·d^(-1);土壤风蚀的净变化速率较流动沙丘减小0.19 cm·d^(-1)。②流动沙丘和尼龙网格沙丘在不同土层深度的土壤水分和电导率无明显变化(P>0.05);草绳方格沙丘土壤水分含量由大到小依次为表层、深60 cm、深40 cm(P<0.05),不同土层深度电导率差异不显著(P>0.05);草方格沙丘土壤电导率由大到小依次为表层、深60 cm、深40 cm(P<0.05),土层深度对水分含量的影响较小(P>0.05)。③不同固沙模式对多度和物种数无显著影响(P>0.05)。不同固沙模式中,草本植被多样性指数无显著差异(P>0.05),表现较为一致的趋势;草方格沙丘的香浓-威纳指数、均匀度指数、物种数均最高,分别为0.93、0.57和1.80。【结论】综合分析表明,草方格固沙模式下植被恢复效果较好,对土壤水分和电导率影响较小;草绳方格固沙对土壤水分和电导率的影响较大。建议在后续沙地生态修复时,以草方格固沙为主,草绳方格为辅。

荒漠豆科灌丛根际土壤氨氧化和反硝化微生物功能基因丰度及群落多样性特征

为探索宁夏荒漠草原豆科灌丛根际土壤中参与氨氧化和反硝化的微生物功能基因丰度和群落组成对植物类型和生长时期的响应特征,本研究以宁夏白芨滩国家级自然保护区内典型的豆科灌丛群落柠条、沙冬青、猫头刺和毛刺不同生长时期(营养期、盛花期和果实期)的根际土壤为材料,通过功能基因实时荧光定量PCR和高通量测序方法,分析4种灌丛根际土壤中氨氧化和反硝化微生物功能基因丰度、群落结构组成特征及其与土壤因子的相关性。结果表明,功能基因丰度及群落结构因灌丛类型和生长时期不同而存在差异。柠条灌丛根际土壤中各功能基因丰度显著高于其他3种灌丛,且在盛花期达到最高。柠条各生长期根际土壤中氨氧化细菌(ammonia-oxidizing bacteria,AOB)群落多样性高于其他灌丛类型,而毛刺根际氨氧化古菌(ammonia-oxidizing archaea,AOA)和nirK型反硝化菌群落多样性最低。各灌丛根际AOA以未分类类群为绝对优势,占79.34%~98.37%,奇古菌门和泉古菌门分别仅占0.28%~20.37%和0.28%~2.35%;AOB在柠条根际以变形菌门为优势,其他3种植物根际则以未分类类群为优势;nirK和nirS型反硝化菌均以变形菌门为优势门,但nirK型反硝化菌的组成受植物类型和生长时期的影响更显著。功能基因的丰度与土壤全氮、速效钾和pH显著正相关。全钾、速效钾、有机质显著影响氨氧化微生物的群落组成,pH是反硝化微生物群落结构的主要影响因子。

鄂尔多斯黄河流域荒漠生态系统防风固沙的功能价值评估

为定量估算黄河流域荒漠生态系统防风固沙功能价值,以位于鄂尔多斯黄河流域的库布其荒漠生态系统流动沙地、半固定沙地与固定沙地为研究对象,针对其荒漠生态系统防风固沙量开展研究,对库布其荒漠生态系统的防风固沙功能价值进行评估核算。经核算,库布其荒漠生态系统2021年防风固沙量为5.02×10^(8)t,防风固沙服务价值量为753×108元/a,减少农田经济损失价值为16.06×108元/a,减少草地经济损失价值为0.27×10^(8)元/a,土壤营养元素保持价值为38.05×10^(8)元/a,减少泥沙淤积灾害价值为3.01×10^(8)元/a,减少交通运输经济损失价值为7.53×10^(8)元/a。库布其荒漠生态系统具有极大的生态经济价值,其防风固沙功能对于鄂尔多斯黄河流域生态环境保护具有及其重要的作用。

无定河流域防风固沙服务流动模拟

无定河流域包括毛乌素沙漠部分区域,土壤风蚀显著,研究防风固沙服务有利于保持土壤、保护生态环境与维持良好的人地关系。利用RWEQ(Revised Wind Erosion Equation)模型与HYSPLIT(Hybrid Single-Particle Langrangian Integrated Trajectory Model)模型模拟无定河流域2000年、2005年、2010年、2015年以及2018年的土壤风蚀量以及防风固沙服务流的时空变化,并分析受益人口与real GDP。结果表明:(1)2000年至2018年无定河流域风蚀总量与防风固沙量呈“降低-增加-降低”的波动变化整体下降的趋势,在空间分布上,无定河流域西部及西北部沙地土壤风蚀较为剧烈,东部及东南部的旱地土壤风蚀较为缓和;(2)2000年至2018年防风固沙服务流动路径模拟总数分别为494条、504条、537条、482条与437条,整体上呈降低的趋势,受益区主要分布于我国的中部及东部地区以及俄罗斯、韩国等周边国家;(3)2000年至2018年防风固沙服务全国受益人口与受益real GDP均占据总数一定比例;(4)无定河流域防风固沙服务物质流以陕西北部、山西西部地区为中心呈圈层状递减,影响范围扩散到了东亚和东南亚等国家和地区。结果模拟了无定河流域土壤风蚀以及防风固沙服务流,为服务供给区和受益区之间的生态补偿提供科学依据,对植被恢复与防风固沙具有一定的参考作用,可为其他流域的防风固沙服务流动模拟和整个三北地区的防风固沙生态工程的规划、建设、评估提供重要的科学参考。

科尔沁沙地南缘人工固沙林下土壤的酸度特征

【目的】了解科尔沁沙地南缘人工固沙林土壤的酸度特征,明确人工固沙林对土壤生态过程的影响。【方法】选取辽宁章古台国家级自然保护区的四种树种人工固沙林为研究对象,对樟子松、油松、赤松和杨树人工固沙林下不同土层土壤酸度的强度指标和容量指标进行对比研究和统计分析。【结果】不同树种0~10 cm、10~30 cm土层土壤水浸pH值和盐浸pH值的差异分别达到了显著和极显著水平,油松的水浸pH值和盐浸pH值最低,杨树的水浸pH值和盐浸pH值最高。不同树种0~10 cm土壤交换性酸度和交换性H+的差异均达到了极显著水平,水解性总酸度的差异达到了显著水平;除水解性总酸度外,油松土壤的交换性酸度和交换性H+最高,杨树的土壤交换性酸度、交换性H+和水解性总酸度最低。不同树种10~30cm土壤交换性酸度和交换性H+的差异均达到了极显著水平,水解性总酸度的差异达到极显著水平;油松的土壤交换性酸度和交换性H+最高,杨树的土壤交换性酸度和交换性H+最低;赤松的水解性总酸度最高,杨树的水解性总酸度最低。杨树林下的盐浸pH值0~10 cm土层与10~30 cm土层存在极显著差异,其他同一树种不同土层土壤酸度特征的强度指标均无显著差异;在容量指标方面,樟子松、油松0~10 cm土层的交换性总酸度和水解性总酸度均显著或极显著地高于10~30 cm土层;赤松林地0~10 cm土层的水解性总酸度显著高于10~30 cm土层,而交换性总酸度等指标无显著差异;杨树林地0~10 cm土层与10~30 cm土层交换性总酸度存在极显著差异,水解性总酸度无显著差异。【结论】在营造人工固沙林后,由于生态系统植被组成和农业土壤pH值的改变,科尔沁沙地南缘人工固沙林下土壤酸度特征发生了明显变化。

北方风沙区某大型引调水工程水土保持关键技术问题研究

北方风沙区位于欧亚草原东部,在北方生态安全屏障和丝绸之路经济带建设中具有非常重要的战略地位,但同时其生态环境又极其脆弱,区域内沙漠、沙地和戈壁分布集中,降水量稀少、蒸发量大,大风及沙尘暴频发,水土流失及土地荒漠化比较严重,因此控制好北方风沙区人为水土流失就尤为重要。北方风沙区以某供水工程为例,在综合分析工程水土保持设计的复杂程度及技术难点的基础上,明确了水土保持关键技术问题解决方案,为该区域水利工程风沙治理及水土保持措施设计提供了参考。

Effects of soil moisture and soil depth on nitrogen mineralization process under Mongolian pine plantations in Zhanggutai sandy land, P. R. China

The rates of soil N mineralization at soil depths of 0-15, 15-30, 30-45 and 45-0 cm and moisture regimes were measured at three sand-fixation plantations of Pinus sylve.stris var. mongolica by laboratory aerobic incubation method. The results showed that average rates of soil net N-mineralization across soil depth varied from 1.06 to 7.52 mg ~ kg 1.month qat soil depths from 0 to 60 cm. Statistical analyses indicated that the effects of different soil depths, moistures and their interactions on net N-mineralization rates were significant (P<0.05). The net N-mineralization rates significantly decreased with increasing soil depths and at depth 0-15 cm accounted for 60.52% of that at depth of 0-50 cm. There was no difference in soil net N-mineralization rates between half and fully-saturated water treatments, however these rates were substantially higher than that without water treatment (P < 0.05). The factors influencing N mineralization process have to be studied further in these semiarid pine ecosystems.

MICP技术及其在油气田开发过程中的应用进展

微生物诱导碳酸盐沉淀(MICP)技术是利用微生物的新陈代谢活动诱导沉积碳酸盐,从而对松散物质进行胶结的技术,该技术凭借反应速率可控、高渗透性、绿色环保等优点被广泛应用,具有较好的应用前景。笔者系统综述了MICP技术的作用原理、应用菌种、矿化胶结机制,以及MICP技术在油气田开发领域的应用。MICP技术主要通过尿素水解作用、反硝化作用、硫酸盐还原作用或甲烷氧化作用实现,诱导碳酸盐沉淀的微生物主要分为产胞外聚合物菌、产脲酶菌、反硝化菌、硫酸盐还原菌和甲烷氧化菌。MICP技术的矿化作用产生碳酸盐沉淀,可作为桥梁胶结松散物质,形成统一的整体。将MICP技术应用于油气田开发过程中堵塞孔隙及裂缝,可以在预防出砂的同时改善水驱开发效果,提高油气采收率。