蒙古高原交通干线风沙(雪)危害防治技术方案

中蒙俄经济走廊建设是“一带一路”的重要组成部分,将丝绸之路经济带与俄罗斯欧亚大铁路、蒙古国“草原之路”对接联通,对推进区域经济合作发挥着重要作用。区域自然灾害防治是陆路交通干线建设与安全运营的重要关键。中蒙俄经济走廊蒙古高原段在气候变化和人类活动共同作用下,草场退化及风蚀荒漠化问题较为普遍,风沙(雪)害防治则是区域交通干线安全保障的重要课题。结合前人相关的试验理论分析,基于多次大范围实地考察,本文综述了当前蒙古高原交通干线的风沙(雪)害的主要类型及发生机制,预判了路面积沙是未来高等级公路的主要沙害类型;针对现有公路和铁路及未来高等级公路的风沙(雪)危害,结合蒙古高原的生态环境特点,制定了相应防治技术方案和建设性建议,可为蒙古高原段交通干线建设提供科技支撑。

盐旱交叉胁迫对灰胡杨(Populus pruinosa)幼苗生长和生理生化特性的影响

以一年生灰胡杨幼苗为试验材料,利用田间控盐控水的方法,进行干旱和盐胁迫试验,通过测定生长和生理生化指标探讨幼苗在盐旱交叉胁迫下的生长发育及适应规律,旨在阐明干旱及盐交叉胁迫下植物抗旱抗盐机理。研究结果表明:在盐、旱及交叉胁迫下,灰胡杨幼苗抗氧化酶活性、MDA和脯氨酸含量与对照存在显著差异(P<0.05)。(1)在8、11 g/L和15 g/L盐处理下,灰胡杨幼苗相对高生长、相对枝长和冠幅增量均受到抑制,且差异显著(P<0.05),而干旱胁迫和盐旱交互胁迫下差异不显著。(2)在盐胁迫、盐旱交叉胁迫下,随着胁迫程度的加重,抗氧化酶SOD、POD、CAT活性表现出先增加后降低的趋势,三者协调一致;仅干旱胁迫时,抗氧化酶SOD、POD、CAT活性显著增加;(3)在盐、旱及其盐旱交叉胁迫下,脯氨酸含量呈上升趋势,MDA含量则表现出先降低后升高趋势,这与抗氧化酶活性先升高后降低的趋势相对应。因此,抗氧化酶活性对缓解脂膜过氧化的伤害具有一定限度,MDA含量与抗氧化酶活性呈负相关,灰叶胡杨幼苗在盐旱交叉胁迫下表现出一定的耐性。

近20a蒙古国土壤风蚀变化特征及主要影响因素分析

蒙古国风蚀沙漠化严重,成为世界主要的沙尘源地之一,为了深入了解蒙古国全域风蚀时空变化特征,利用蒙古国境内的GLDAS、OLM、MOD13Q1、NASA-SRTM等气象和遥感数据,基于GEE(Google Earth Engine)云计算平台,利用RWEQ模型计算了蒙古国土壤风蚀量和时空变化规律,分析了土壤风蚀的主要影响因素及作用机制。结果表明:(1)自2001-2020年,蒙古国土壤风蚀呈北部低、南部高的空间分布格局;土壤风蚀主要发生在春季,风蚀量占全年的45%;近20 a土壤风蚀量总体上呈显著增加趋势,风蚀模数以0.06 t·hm^(-2)·a^(-1)的速度增长。(2)蒙古国土壤风蚀变化整体上与气候因子及由其引起的植被盖度变化有关,与放牧、耕地开垦等人为活动增强有密切关系。研究结果可为蒙古国风蚀沙漠化防治提供重要的科学参考。

3类典型株型草本植物对沙面风蚀抑制作用的研究

植物自身具有维持生境稳定性的独特功能,而植物株型为主要作用要素之一。研究不同株型草本植物在沙质荒漠地区的地面抗风蚀作用,可以为制定生态恢复措施提供重要的科学参考。通过风洞实验,对3种植物株型(匍匐状、球状、丛状)的草本植物在5种覆盖度(25%、30%、35%、40%和45%)条件下的沙面风蚀率进行了测定,并分析了各株型的风蚀抑制率。结果表明:(1)3种株型草本植物随覆盖度增加,空气动力学粗糙度和对风速的削减均逐步增加。在覆盖度较低时,不同植物株型之间的风蚀抑制率差异较大,球状和匍匐状植物株型固沙能力相对较高,而丛状植物株型固沙能力相对较低;较高风蚀抑制效率植物株型可以达到较低风蚀抑制效率植物株型在较高覆盖度条件下的固沙效果。(2)在覆盖度30%时,匍匐状和球状植物的风蚀抑制效率分别为47.55%、55.70%,分别接近丛状植物覆盖度40%(48.46%)和45%(56.94%)的风蚀抑制效率。(3)3种株型草本植物的风蚀抑制效率均随覆盖度增加而增加,覆盖度越小,三者差异越大,反之覆盖度越大差异越小;3类植物株型的风蚀率匍匐状最低,球状次之,丛状最高;风蚀抑制效率匍匐状最高,球状次之,丛状最低。

蒙古国中部草原地区风蚀沙漠化的风沙活动特征——以乔伊尔市为例

蒙古国是中蒙俄经济走廊的重要区段,但面临严重的荒漠化问题,区域经济社会发展受到严重威胁,而蒙古国中部草原地区是主要的荒漠化新扩展区,正经历强烈的草原风蚀沙漠化过程。以戈壁苏木贝尔省首府乔伊尔市为研究区,利用自建自动气象观测站(2019年5月-2020年7月)、集沙仪观测站(2019年8月-2020年8月)及当地气象站(1990-2018年)数据,对当地风蚀沙漠化的风动力条件、风沙流输沙及其他影响因素等基本特征进行了研究。结果表明:(1)乔伊尔市具有强劲的风动力条件,年输沙势可达735.96 VU,合成输沙势为428.76 VU,合成输沙方向为SSW(195.06°),风向变率指数为0.58,属高风能环境、中等变率双峰风况。(2)临界起沙风速因受土壤水分和植被盖度的共同影响而随季节变化,夏季最高,冬季最低,春季与秋季居中,且相差较小。(3)地表具有强烈的风沙活动,年风沙流输沙通量可达2.135 t·m^(-1)·a^(-1),Owen最大输沙量模型适于该区风沙流模拟。研究结果对于蒙古国中部草原区防沙治沙和生态恢复具有重要参考价值。

咸水滴灌对肉苁蓉寄生体系盐离子分配及品质的影响

为探究咸水滴灌对人工种植肉苁蓉寄生体系盐离子分配和肉苁蓉品质的影响,在塔里木盆地塔克拉玛干沙漠边缘,选择4个灌水矿化度差异较大的样地,采集土壤、梭梭和肉苁蓉样品,分析土壤、寄生体系各部分盐离子含量及肉苁蓉主要药用成分含量,结果表明:(1)在高矿化度咸水滴灌下,接种肉苁蓉的梭梭根部、主茎和同化枝盐离子含量为:同化枝>根>茎,肉苁蓉体内盐离子含量与寄主根系含量相近;(2)肉苁蓉体内总盐、Na^(+)和Cl^(-)含量均随灌水矿化度的增高而增加;肉苁蓉体内K^(+)占总盐分的1/3,具有较强的吸收富集K^(+)的能力,但K^(+)含量并未随灌水盐浓度的变化而表现出显著性差异;(3)肉苁蓉体内主要药用成分苯乙醇苷类物质含量随灌溉水矿化度的升高而增加,盐分胁迫有助于刺激肉苁蓉体内主要药用成分的积累。因此,较高矿化度咸水滴灌可以提高肉苁蓉的品质,但需要注意长期高盐胁迫对寄主梭梭的影响,因而制定合理的灌溉制度是不可或缺的。

风洞模拟“攀援植物-围栏”复合沙障不同疏透度下的防风效果

为探索受风蚀影响围封区域的新型治理技术措施,本研究对不同疏透度(β)“攀援植物-围栏”复合沙障的防风作用进行了风洞模拟试验。分别在6、8和10 m·s^(-1)净风条件下对模型A(网围栏,β:96%~98%)与4种复合沙障[模型B(无叶期,β:59%~64%)、模型C(无叶期,β:50%~55%)、模型D(有叶期,β:40%~45%)、模型E(有叶期,β:30%~35%)]进行试验。结果表明:1)不同类型复合沙障流场结构均呈“减-增-减”的变化趋势,障体背风侧存在风影减速区,网围栏前后流场结构一致,不存在减速区。2)不同风速条件下,无叶期复合沙障(模型B、模型C)在10 m·s^(-1)风速下近地表平均防风效能最低,分别为18.55%与18.38%,有叶期复合沙障(模型D、模型E)则在6 m·s^(-1)风速下最低,分别为44.03%与45.42%,有叶期复合沙障防风效应随风速的增大而增强,无叶期复合沙障则相反。3)综合分析表明,当障体疏透度为59%~64%时便可产生防风效果,复合沙障防风效果优于网围栏,障体有叶期防风效果优于无叶期,可测范围内无叶期复合沙障防护距离为0.6H~15H(H表示障体高度,1H=15 cm),有叶期复合沙障防护距离为0H~15H,复合沙障防风效果与疏透度呈反比。因而,“攀援植物-围栏”复合沙障可以提高围封区域的防风效果,降低风力作用下的地表物质流失。

水葱与香蒲对微咸水中TN、TP、Pb及Cd的去除率研究

2019年4~7月采用模拟人工湿地种植水葱(Scirpus validus Vahl)和香蒲(Typha orientalis Presl),研究水葱与香蒲对微咸水中N、P、Pb和Cd的去除率。通过与进水浓度的比较(去除率1)可知,香蒲湿地、水葱湿地和无植物栽培的CK湿地对N、P和Pb、Cd均有较好的去除。香蒲湿地在第1周期(4月)对Pb和Cd的去除率分别为97.7%和52.7%;水葱湿地在第2周期(5月)对TN和TP的去除率分别为95.3%和85.3%。通过与无栽培植物的CK比较(去除率2)可知,水葱在第1周期(4月)对TN的去除率达66.7%,在第2周期(5月)对TP的去除率达60.7%。香蒲在第1周期(4月)对Pb的去除率达65.0%,对Cd的去除率达52.7%。

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.

Benefits and ecological restoration implications of hanging grass fences in Mongolian desert steppe

Tumbleweeds participate in a common seasonal biological process in temperate grasslands,creating hanging grass fences during the grass-withering season that result in distinct ecological phenomena.In this study,we addressed the urgent need to understand and restore the degraded desert steppe in Central Mongolia,particularly considering the observed vegetation edge effects around hanging grass fences.Using field surveys conducted in 2019 and 2021 in the severely degraded desert steppe of Central Mongolia,we assessed vegetation parameters and soil physical and chemical properties influenced by hanging grass fences and identified the key environmental factors affecting vegetation changes.The results indicate that the edge effects of hanging grass fences led to changes in species distributions,resulting in significant differences in species composition between the desert steppe's interior and edge areas.Vegetation parameters and soil physical and chemical properties exhibited nonlinear responses to the edge effects of hanging grass fences,with changes in vegetation coverage,aboveground biomass,and soil sand content peaking at 26.5,16.5,and 6.5 m on the leeward side of hanging grass fences,respectively.In the absence of sand dune formation,the accumulation of soil organic carbon and available potassium were identified as crucial factors driving species composition and increasing vegetation coverage.Changes in species composition and plant density were primarily influenced by soil sand content,electrical conductivity,and sand accumulation thickness.These findings suggest that hanging grass fences have the potential to alter vegetation habitats,promote vegetation growth,and control soil erosion in the degraded desert steppe of Central Mongolia.Therefore,in the degraded desert steppe,the restoration potential of hanging grass fences during the enclosure process should be fully considered.

基于植物防沙工程的沙产业技术进展--以肉苁蓉种植产业为例

沙产业的内涵是在防沙治沙中有效利用沙漠资源,拓展节能绿色农业型产业空间。文章从植物防沙工程中寄生药用植物的模式出发,探讨了肉苁蓉种植产业的技术进展,重点对肉苁蓉产业发展趋势和种植技术的突破进行了简要阐述,并分析和计算了肉苁蓉种植产业的经济效益,最后对肉苁蓉种植技术的推广应用及发展前景进行了展望。

蒙古国植被自然恢复潜力

植被自然恢复能力评估是生态恢复实践的重要内容。基于蒙古国的MODIS EVI植被指数产品、气象数据及土壤数据,依据相似生境原则,构建了植被恢复潜力计算模式,计算得到蒙古国植被恢复潜力值(VRP,可代表在自然条件下区域植被能够恢复到的最佳状况)及植被恢复潜力指数(VRPI,代表植被生长现状与最大潜力之间的差距),并用蒙古国纵贯铁路沿线长期围封区的采样分析数据进行了验证。结果表明:(1)蒙古国整体上具有较高的植被恢复潜力,植被自然恢复潜力值0.6—0.9;(2)受降水、气温、土壤等自然要素组配的空间分异影响,蒙古国植被自然恢复潜力具有较大的空间差异性,其中北部及东部地区为VRP高值区和VRPI低值区,植被轻度退化,且较容易恢复;南部及西部地区为VRP中低值区和VRPI高值区,植被退化程度较重,恢复难度相对较大。

蒙古国植被对干旱响应的敏感性研究

本文分析了蒙古国不同区域、不同土地覆被类型区的植被生长状况对干旱响应的敏感性特征,并探讨了成因。研究表明:(1)2001—2019年,蒙古国虽然发生了3次较为严重的干旱事件,但整体上干旱程度呈轻微降低趋势,SPEI出现轻微上升,总体增速为0.001%/a;植被生长状况出现了好转,植被指数也呈上升趋势,总体增速为0.15%/a。(2)蒙古国大部分区域植被生长受干旱影响较强,各植被指数与干旱指数呈较明显的正相关关系,在NDVI与SPEI-12的相关性分析中,正相关面积占比达76.36%;而在杭爱山脉和肯特山脉以北降水量丰沛的区域和阿尔泰山脉以南荒漠化严重和植被极为稀少区域,植被生长受干旱影响较弱,植被指数与SPEI相关性较小。(3)不同类型植被对干旱响应的敏感性也有差异,其中草地敏感性最强(0.22),而森林敏感性最弱(-0.04)。(4)干旱持续时间长短,对植被生长影响有较大差异,蒙古国大部分区域的植被对延续3个月至半年的干旱最为敏感,而年内以7月份干旱对植被影响最强。(5)植被对干旱响应的敏感性实质是区域水分平衡的植被影响,对同种植被而言多年平均气温越高或降水量越少,植被对干旱响应的敏感性越强,反之则越弱。本文的研究结果对蒙古国因地制宜开展荒漠化防治具有重要参考价值。

种植多枝柽柳的模拟人工湿地对模拟污水中氮、磷、铅和镉的去除率研究

2020年6月30日至9月1日,采用16种模拟污水方案、4级污染水平、5种污染指标的正交实验方法,配制模拟含盐污水,将其作为进水,注入种植多枝柽柳(Tamarix ramosissima)的模拟人工湿地中,每隔16 d监测一次水样中的总溶解性固体、总氮、总磷、铅元素和镉元素的含量,研究种植多枝柽柳的模拟人工湿地对污水中总溶解性固体、总氮、总磷、铅元素和镉元素的去除率及其与总溶解性固体、总氮、总磷、铅元素和镉元素的含量的交互影响;分别于实验开始和实验结束时测量了多枝柽柳的株高和茎粗,分析了导致其变化的影响因素。研究结果表明,种植多枝柽柳的模拟人工湿地对氮中污染和重污染的污水中总氮的去除率相对较大,实验前期模拟人工湿地对污水中总氮的去除效果很好(去除率大于90%),实验后期模拟人工湿地对污水中总氮的去除效果一般(去除率为43.18%和60.70%);在实验的各个阶段,模拟人工湿地对磷中污染和重污染的污水中总磷的去除效果都非常理想,总磷的去除率都大于91%;在实验的前16 d,模拟人工湿地对铅轻污染和中污染的污水中的铅元素的去除率都达到了100%;在实验的后48 d,模拟人工湿地对铅重污染的污水中的铅元素的去除率都大于94%;在实验的前16 d,模拟人工湿地对镉轻污染的污水中的镉元素的去除率都达到了100%;在实验的后48 d,模拟人工湿地对镉重污染的污水中的镉元素的去除率都大于97%;在16种污水方案条件下,多枝柽柳株高增加量为13.40~68.54 cm,茎粗增加量为0.64~3.90 cm;污水中的总溶解性固体含量是总氮、总磷、铅元素和镉元素去除率以及多枝柽柳株高和茎粗变化的最主要影响因素。

高矿化度水灌溉条件下梭梭(Haloxylon ammodendron)的光合生理特征

为了探究荒漠优势植物梭梭(Haloxylon ammodendron)对咸水(10、20、30、40、50 g·L-1)灌溉的适应性,测定分析了植株地上部分生长量、叶绿素含量、渗透调节物质含量、抗氧化酶活性、呼吸作用以及叶绿素荧光指标。结果表明:(1)随着灌溉水矿化度的提高(超过20 g·L-1),对地径与新枝有显著抑制作用,50 g·L-1时植株仍能继续生长,表现出很强的耐盐性。(2)渗透调节物质含量与抗氧化酶活性在低浓度处理时升高,但灌水矿化度超过20 g·L-1时表现出下降趋势。(3)限制同化枝净光合速率(Pn)的主要因素随着灌溉时间的增加由非气孔限制逐渐变成气孔限制,同时各组间的差异性减小。(4)同化枝光化学量子效率(ΦPSⅡ)随着灌溉水矿化度提高有明显下降趋势,40、50 g·L-1组与对照组存在显著差异,灌溉60 d后各处理降幅减小。

Comprehensive eco-environmental effects of the shelter-forest ecological engineering along the Tarim Desert Highway

In this work, we report a comprehensive study about the eco-environmental effects of the shelter forest along the Tarim Desert Highway, including the effects on aeolian environment, soil, micro-climate, biodiversity, and groundwater. The results show that: (1) The movement of windblown sand near the ground surface was affected by the shelter forest. The wind speed and sediment transport rate in the shelter forest decreased by 64%―80% and 87.45%―99.02%, respectively. In addition, there were also significant changes in the sand flux structure, the sand grain size, and the deflation and deposition on the ground surface. (2) Compared to the natural mobile sand, the soil bulk density in the forest area decreased while the total salt content, the total porosity, and the water content increased. In addition, the soil fertility was significantly improved in the forest area, and showed the "first rapid, then slow" variation pattern. (3) The shelter forest showed positive effects on the micro-climate. Within the 6 m height above the ground, the air temperature in the shelter forest at different heights was lower than that in the mobile sand, while the air humidity was higher, while, the soil temperature was also lower in the shelter forest than mobile sand. (4) The number of soil microbial species increased significantly with the improvement of habitat in the shelterbelt. However, the population of different species was not distributed evenly across the surveyed area. (5) Currently, no significant effects of groundwater-pumping and forest-irrigation water have been found on the groundwater level and its salinity. The variation amplitude of both groundwater level and salinity was at the level of centimeters and 1g/L, respectively. No obvious variation trend has been observed.

The salt accumulation at the shifting aeolian sandy soil surface with high salinity groundwater drip irrigation in the hinterland of the Taklimakan Desert

The EC analysis and water serial sampling was performed in the Tarim Desert Highway shelterbelt to explore the water and salt dynamics of the shallow aeolian sandy soil ( 0-30cm) under high salinity groundwater drip irrigation. It was found that in one irrigation cycle, the EC of the shallow shifting aeolian sandy soil ( 0-30cm) increased while the water content decreased. The EC of the surface aeolian sandy soil at the wetting front was far greater than that of the wetting area or the outside of the wetting area. During the irrigation cycle, the EC of the wetting front and the wetting area changed at a significant magnitude, whereas the EC of the outside of the wetting area remained largely steady. The horizontal influence distance of drip irrigation on the salt accumulation at the soil surface was about 100 cm, and the vertical influence depth was 5 cm. The three most abundant ions in the accumulated salt at the aeolian sandy soil surface were Na+, Cl- and SO42-. The salt accumulation at the soil surface was influenced by air temperature, wind speed, mineralization of irrigation water, sand burial thickness, soil texture, and litter content.

The temporal and spatial fluctuation of the groundwater level along the Tarim Desert Highway

In this work, a groundwater monitor section along the Tarim Desert Highway was set up, and the groundwater level data were recorded. The temporal and spatial fluctuations of the groundwater level were analyzed based on the groundwater level measurements, hydrologic data, the groundwater/surface water interconversion theory and the groundwater dynamics. The spatial distribution of groundwater is mostly affected by sand dune height and landform variation. The four primary temporal influence factors of groundwater level can be ordered in decreasing significance as: shelterbelt pumping > vertical leakage > river flow change > runoff replenishment. The runoff replenishment has the biggest influence range, and the shelterbelt pumping has the smallest influence range. The groundwater level fluctuates annually in a natural pattern.

中蒙俄经济走廊蒙古国段的风沙流特征

中蒙俄经济走廊穿越蒙古国主要生态类型区,本文对沿线的达尔汗、乔伊尔、赛因山达、扎门乌德4个观测区的风沙流进行研究,研究结果表明:(1)风沙流水平输沙量均随高度增加而降低,两者最优拟合函数随下垫面变化而不同,达尔汗和乔伊尔为指数函数,而赛因山达和扎门乌德为幂函数。(2)各观测区年输沙通量空间分异明显,其中乔伊尔最大,达尔汗其次,扎门乌德再次,赛因山达最小,这与传统认知有较大不同。(3)风沙流输沙通量空间差异与多种因素有关。乔伊尔处于海洋气流影响尾闾区,春季干旱发生频率高,正值风季,风速较大,风蚀强烈;其他地区春季干旱发生频率相对较低,其中达尔汗地处自然条件较好的北部河谷区,但由于农田开垦和过度放牧,风蚀较为强烈,而扎门乌德和赛因山达风季风速相对较小,且放牧强度较低,风蚀较轻。本文的研究结论对蒙古国因地制宜开展风沙灾害防治和荒漠化治理具有重要的参考价值。

Topographical changes of ground surface affected by the shelterbelt along the Tarim Desert Highway

To study the effects of sand protection project on modern aeolian landform, the types, distribution, and intensity of topographical changes of the ground surface affected by the shelterbelt along the Tarim Desert Highway were determined by measuring the deflation and deposition of sand surface in the Tazhong area located in the hinterland of the Taklimakan Desert. The results showed that (1) the newly-formed landform in sand protection systems is dominated by aeolian deposition including the small-scale Nabkha Dunes, the medium-scale sheet-like sand deposition and the large-scale ridge-like sand deposition. To some degree, aeolian deflation landform can also be formed in the open space in the shelterbelt. Furthermore, it is difficult for aeolian deflation landform to develop in a large scale in the interdunes. However, aeolian deflation landform can be developed in a large-scale on the windward slope of secondary dunes in longitudinal complex sand ridges; (2) on the windward side of the sand protection systems, both the morphology and strike of dwarf mobile dunes in the interdunes are changed by the sand-obstructing forest belts and the ridge-like sand deposition around it. The wind- ward slope of the ridge-like deposition around the sand-obstructing forest belt forms a stable ground surface. After being damaged by forward-moving dunes in a short period, the ground surface is re- covered gradually; (3) on the leeward side of the sand protection systems, aeolian deflations are formed widely. Particularly, the deflation depression is formed in the interdunes. In addition, the dunes in the region with highly topographic relief are cut flat by aeolian deflations; thereafter its relief of to- pography is reduced. The above analysis indicates that shelterbelts have obvious effects on the windward wind-sand flux in terms of dissipating energy and intercepting sand. With the recovery of wind velocity on the leeward side of the sand protection systems, the wind-sand flux gradually tends to be unsaturated; therefore the sand surface deflation is formed.