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不同放牧方式对草场沙退化影响的试验研究 总被引:1,自引:0,他引:1
在我国干旱、半干旱草原区,草场沙退化现象十分严重,而草场沙退化是气候、土壤、植被等自然因素和人为因素共同作用的结果,其中放牧活动是引起草场沙退化的主要因素之一。为了客观地分析和评价不同放牧方式对草场沙退化的影响,在内蒙古自治区包头市达茂旗希拉穆仁荒漠草原进行了为期2 a的放牧、休牧和轮牧试验。试验结果表明:超载放牧不仅使植被盖度、高度和产量大幅度下降,裸地率增加,而且使地表粗糙度变小,风蚀输沙率增大,风蚀作用增强。但合理的放牧方式不但能促进牧草生长发育,保护草地的植物多样性,而且能防止草场进一步沙退化,反而有利于草场的持续利用。 相似文献
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植被盖度对典型草原区地表风沙流结构及风蚀量影响 总被引:6,自引:0,他引:6
选择内蒙古锡林郭勒盟典型草原为研究区域,通过风洞模拟试验开展典型草原植被盖度对土壤风蚀的定量化分析研究,旨在探明不同植被盖度下起动风速、地表风沙流结构及风蚀量影响的规律,从而为该地区制定合理的防风固沙技术提供理论依据。结果表明:起动风速随植被盖度的增加而增大;受植被的影响风沙流结构呈跳跃式分布,近地层的输沙率随植被盖度的增加而减小,最大输沙率的高度层随植被盖度的增加不断上移;不同植被盖度下,风速与总输沙量之间均呈幂函数关系,各风速下总输沙量随着植被盖度的增加而减少。 相似文献
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荒漠草原植物多样性分布格局对微地形尺度环境变化的响应 总被引:1,自引:0,他引:1
采用地统计学方法,以荒漠草原自由放牧草地3种典型"覆沙—侵蚀"微地形地貌为对象,研究不同微地形地貌区域草地植物多样性分布格局对土壤养分、地表枯落物和羊粪量、地表微高程等环境因子的响应。结果表明:微地形坡面面积比例70%,地表微高程变化属中等变异强度(CV1),表层土壤粗沙粒含量为80%,植被盖度为20%时,地表枯落物、土壤全磷和全氮、地表微高程深刻影响着植物多样性空间异质性分布格局。微地形坡面面积比例为50%,地表微高程变化属强度变异(CV1),表层土壤粗沙粒含量为70%,植被盖度40%时,土壤全磷、地表微高程显著影响植物多样性分布格局特征。荒漠草原风蚀作用形成的"覆沙—侵蚀"微地形地貌引起各非生物要素在空间上的重新分配作用,显著影响植物群落多样性的空间异质性特征。不同微地形地貌特征约束条件下,植物多样性分布格局是各非生物要素共同作用的结果,但对不同环境要素的响应程度存在较大差异,这种差异性很可能与放牧干扰强度存在密切相关性。 相似文献
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为阐明准东地区土壤风蚀现状及影响因子,通过实地采样,结合气象、土地利用数据、DEM、遥感影像,从气候因子、地形因子、土壤因子以及植被盖度4个方面进行分析,利用GIS平台结合WEQ经验模型对各因子叠加计算的土壤风蚀状况进行分级,并对各侵蚀等级进行评价分析。结果表明:气候、土壤及植被盖度共同影响该区域的土壤风蚀状况。受各因子的影响,准东地区风蚀分级状况比较明显,侵蚀强度由南向北呈增强趋势,主要表现为重度侵蚀,占研究区面积的43.02%。该区域平均侵蚀模数为4 470.64t/(km2·a),风蚀量达9 969.53万t。为验证模型的准确性,利用137 Cs示踪法推算的风蚀模数与模型值进行对比,结果表明模型计算值与137 Cs示踪法估算值间的平均相对误差7.78%,证明该模型在研究区具有很好的适用性。 相似文献
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植被对土壤风蚀影响的风洞实验研究 总被引:32,自引:3,他引:32
利用风洞模拟实验,系统研究了植被覆盖对土壤风蚀的影响。结果表明,临界侵蚀风速与植被盖度之间、风速与土壤风蚀发生的临界植被盖度之间均为非线性正相关关系;植被盖度与空气动力学粗糙度、摩阻速率之间具有良好的相关性;植被覆盖条件下空气动力学粗糙度和摩阻速率的增大对土壤风蚀具有显著的影响。 相似文献
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[目的] 研究不同放牧强度对荒漠草原植被特征、土壤物理性能及其土壤侵蚀的影响,为荒漠草原水土流失治理和退化及生态系统修复提供科学依据。[方法] 以内蒙古希拉穆仁荒漠草原为研究区,采用原位监测和模拟试验相结合的方法,对重度、中度、轻度和无放牧4种不同放牧强度样地的植被群落、土壤物理性质、土壤侵蚀过程开展了研究。[结果] ①随着放牧强度的增加,群落平均盖度、高度和地上生物量呈降低趋势,物种丰富度指数、多样性指数及均匀度指数整体呈上升趋势。②土壤砂粒含量随放牧强度的增加呈上升趋势,表层土壤(0—10 cm)容重及入渗性能更易受放牧影响。③相同降雨强度下,随放牧强度的增加,土壤的侵蚀产沙量随之增加。土壤初渗速率、Simpson优势度指数和土壤砂粒含量是影响不同放牧强度下土壤侵蚀特征的关键因素。[结论] 放牧显著影响荒漠草原植被群落特征及土壤水文物理性能,因此,建议该区放牧强度控制在中度(2羊单位/hm2)及以下,对于受重度放牧破坏的草原区,围栏封育的同时还可适当进行人工补播或利用微生物改良土壤来提升土壤抗蚀性。 相似文献
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黄泛风沙区耕地土壤风蚀影响因子的通径分析 总被引:3,自引:2,他引:1
[目的]研究黄泛风沙区影响耕地土壤风蚀量的主要因子及其相互作用关系,为土壤风蚀的防治及改善耕作措施提供依据。[方法]通过影响因子的的野外定位观测,及对风蚀数据进行收集整理,在逐步回归分析的前提下,对风蚀量主要影响因子进行通径分析。[结果]风速累计时间、作物盖度、粗糙度是影响耕地土壤风蚀的主要因素;风蚀量的直接影响因素作用大小的排序为风速累计时间粗糙度作物盖度;风蚀量间接影响因素作用大小的排序为粗糙度作物盖度风速累计时间;风蚀量决定系数排序为d_(风速累计时间·风速累计时间)d_(风速累计时间·作物盖度)d_(风速累计时间·粗糙度)d_(作物盖度·粗糙度)d_(作物盖度·作物盖度)d_(粗糙度·粗糙度);风速累计时间与作物盖度主要通过其本身直接影响风蚀量,粗糙度主要通过间接作用减少风蚀量。[结论]可适当地增加作物种植密度,提高粗糙度、作物盖度,减少风蚀危害。 相似文献
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S. H. Mirmousavi 《Eurasian Soil Science》2016,49(8):942-953
About two-thirds of the Iran’s area is located in the arid and semiarid region. Lack of soil moisture and vegetation is poor in most areas can lead to soil erosion caused by wind. So that the annual suffered severe damage to large areas of rich soils. Modeling studies of wind erosion in Iran is very low and incomplete. Therefore, this study aimed to wind erosion modeling, taking into three factors: wind speed, vegetation and soil types have been done. Wind erosion sensitivity was modeled using the key factors of soil sensitivity, vegetation cover and wind erodibility as proxies. These factors were first estimated separately by factor sensitivity maps and later combined by fuzzy logic into a regional-scale wind erosion sensitivity map. Large areas were evaluated by using publicly available datasets of remotely sensed vegetation information, soil maps and meteorological data on wind speed. The resulting estimates were verified by field studies and examining the economic losses from wind erosion as compensated by the state insurance company. The spatial resolution of the resulting sensitivity map is suitable for regional applications, as identifying sensitive areas is the foundation for diverse land development control measures and implementing management activities. 相似文献
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在对黄土高原植被进行分区的基础上,利用地理信息系统技术和景观生态学方法对黄土高原植被区空间数据和土壤侵蚀空间数据进行了空间叠加分析。结果表明,黄土高原被划分为森林植被区、森林草原植被区、温性草原植被区和荒漠半荒漠植被区。在森林植被区,黄土高原土壤侵蚀主要以水蚀为主,轻度以上的侵蚀百分比为41.92%,水蚀土壤侵蚀指数比温性草原植被区和荒漠半荒漠植被区的水蚀土壤侵蚀指数大,为346.90。在森林草原植被区,黄土高原土壤侵蚀主要以水蚀为主,轻度以上的侵蚀百分比为70.45%,水蚀土壤侵蚀指数均比其他植被区的水蚀土壤侵蚀指数大,为449.40,水蚀最为严重。在温性草原植被区,黄土高原土壤侵蚀主要以水-风混合侵蚀为主,风蚀微度-水蚀剧烈的百分比最大,为33.01%,水-风混合侵蚀土壤侵蚀指数均比其他植被区的水-风混合侵蚀土壤侵蚀指数大,为633.45,水-风混合侵蚀最为严重。在荒漠半荒漠植被区,黄土高原土壤侵蚀主要以风蚀为主,轻度以上的侵蚀百分比为99.65%,风蚀土壤侵蚀指数均比其他植被区的风蚀土壤侵蚀指数大,为589.78,风蚀最为严重。黄土高原的土壤侵蚀表现出明显的地带性分异规律。 相似文献
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A. I. KR
PFL G. A. Cecchi N. M. Villasuso R. A. Distel 《Land Degradation \u0026amp; Development》2013,24(4):393-399
Vegetation in many arid and semi‐arid shrublands frequently occurs in patches with high plant cover (shrub patches) interspersed in a low‐cover herbaceous matrix (inter‐shrub areas). We hypothesized that (a) livestock grazing is an important determinant of such spatial patterns of vegetation, and (b) redistribution of soil resources associated with shrub patches helps in the recovery of vegetation in inter‐shrub areas. To test these hypotheses, we (a) used line transects to compare spatial variations in vegetation, soil microtopography, and soil physicochemical properties in grazed areas and areas protected from grazing since 1970, (b) added sediment and seeds to inter‐shrub areas, and (c) measured resource redistribution after a wildfire. Results were consistent with the hypotheses. They indicated greater spatial heterogeneity in vegetation, soil microtopography and soil physicochemical properties in grazed areas than in protected areas, and that addition of sediment and seeds or redistribution of soil resources from shrub patches after a wildfire enhanced re‐establishment of vegetation in degraded inter‐shrub areas. As a synthesis, a conceptual model of degradation and recovery processes in semi‐arid shrublands of Northern Patagonia is presented. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Mohboobeh Tayebi Mohammad H. Tayebi Abdolmajid Sameni 《Archives of Agronomy and Soil Science》2017,63(8):1163-1175
This study employs the Coordination of Information on the Environment (CORINE) model with geographic information system to assess soil erosion risk for restoring and protecting areas within the Bonrod Zangane watershed, western Shiraz, Iran. Actual soil erosion risk was determined by combining two main parameters including potential soil erosion risk and vegetation cover. The potential soil erosion risk was generated by integrating soil erodibility, erosivity and slope parameters. Soil texture, depth and stoniness layers were overlaid to form a soil erodibility map. Modified Fournier index and Bagnouls–Gaussen aridity index were integrated to generate the erosivity layer. The slope classes also were generated from digital elevation model. In order to estimate vegetative land cover, the normalized difference vegetation index (NDVI) was used. The raster-based layers were then integrated to produce erosion risk map. The results showed that 34.7% of the study area has high and only 31.4% of the study area has low soil erosion risk. It is concluded that CORINE model can be used to delineate the soil erosion risk and also to discriminate the potential soil erosion risk areas. 相似文献
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[目的]对晋北沙漠化区土壤风蚀状况及空间差异进行研究,以期为区域土地退化和京津风沙源治理工程的效益评估提供科学依据。[方法]基于耕地和林草地不同地表类型的土壤风蚀模型,逐像元地计算2001—2014年晋北沙漠化地区土壤风蚀状况及空间差异。[结果](1)2001—2014年晋北沙漠化区的平均土壤风蚀模数达到4.67t/(hm~2·a),处于轻度风蚀状态。区域分布上,北部区域风蚀状况明显高于南部。(2)研究区2001,2005,2010和2014年的平均土壤风蚀模数分别为6.83,3.89,4.36和2.55t/(hm~2·a);土壤风蚀总量分别为2.09×10~7 t,1.19×10~7 t,1.31×10~7 t和7.65×106 t。(3)晋北沙漠化地区植被覆盖度提高和风力减弱是区域土壤风蚀强度削弱的主要原因。研究发现风力作用的减弱贡献率约为77.7%,而植被覆盖度的提高的贡献率为22.3%。[结论]晋北土壤风蚀状况空间差异较大,风速减弱是导致区域土壤风蚀削弱的主要原因。晋北沙漠化地区植被覆盖度尚未恢复到良好的状态,生态工程建设还需进一步实施,生态工程实施的成果需加强保护。 相似文献
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Shi Huading Liu Jiyuan Zhuang Dafang Hu Yunfeng 《Land Degradation \u0026amp; Development》2007,18(4):413-422
Soil wind erosion is the primary process and the main driving force for land desertification and sand‐dust storms in arid and semi‐arid areas of Northern China. While many researchers have studied this issue, this study quantified the various indicators of soil wind erosion, using the GIS technology to extract the spatial data and to construct a RBFN (Radial Basis Function Network) model for Inner Mongolia. By calibrating sample data of the different levels of wind erosion hazard, the model parameters were established, and then the assessment of wind erosion hazard. Results show that in the southern parts of Inner Mongolia wind erosion hazards are very severe, counties in the middle regions of Inner Mongolia vary from moderate to severe, and in eastern are slight. Comparison of the results with other research shows conformity with actual conditions, proving the reasonability and applicability of the RBFN model. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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Samira Zamani 《Archives of Agronomy and Soil Science》2013,59(12):1743-1753
Wind erosion is a serious problem, especially in arid and semi-arid regions. This study was conducted to assess the effects of wind speed as well as soil particle-size distribution on erosion rate (ER) using a wind tunnel. For this purpose, two clay loam soil samples (C2 and C10) in addition to a sandy clay loam (S2) were exposed to different wind velocities of 2, 9 and 18 m s?1. The result showed that erosion rate increased significantly with increasing wind speeds. In addition, a critical diameter of 0.84 mm for soil particles was supported; for larger particles the changes in erosion rate were negligible. Furthermore, soil erodibility (K) was determined, which for S2, C2 and C10 was 57.73, 10.27 and 1.43, respectively. To predict soil erodibility, a power relationship as K = 3.382 MWD?1.732 (R 2 = 0.99) was established. The results indicated with increasing wind speed, the sensitivity of S2 remained constant, whereas C2 and C10 resisted wind speed. The finding of this research indicates the importance of particle-size distribution on wind erosion rate as well as soil erodibility. 相似文献
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基于GIS的榆林市土壤风蚀危险度评价 总被引:3,自引:1,他引:2
土壤风蚀是土地沙漠化过程的重要组成部分和首要环节,对其危险度评价的最终目的在于有效地控制土壤风蚀.选取风力、植被、气温、降水、地形、土壤等因子,在ArcGIS 9.3平台支持下,建立土壤风蚀环境因子数据库,采用层次分析法(AHP)构建土壤风蚀危险度评价模型,对榆林市土壤风蚀危险度进行评价.结果表明:(1)基于GIS技术的土壤风蚀危险度评价可宏观地揭示该区域土壤风蚀危险度空间格局特征.(2)风力、植被、气温、降水、地形、土壤等因素控制着土壤风蚀空间分异格局.(3)榆林市土壤风蚀危险度空间分异格局呈带状分布,表现为危险度从西北向东南逐渐降低. 相似文献
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[目的]揭示毛乌素沙地沙漠化逆转过程对土壤风蚀可蚀性的影响,为该区风蚀防治和生态重建提供科学参考。[方法]选取1986—2021年共8期遥感影像,以ENVI 5.3和ArcGIS 10.7为平台对毛乌素沙地不同时期土地沙漠化进行反演,同时构建研究区2021年沙漠化差值指数(DDI),并按照自然断裂法将毛乌素沙地土地分为非、轻度、中度、重度和极重度5种沙漠化类型代表沙漠化逆转的不同阶段。根据反演结果,应用空间代替时间的方法,对不同沙漠化类型土壤进行样品采集,并对土壤机械组成、土壤有机质含量、土壤结皮、植被因子等土壤风蚀可蚀性影响因子进行测试分析。[结果]毛乌素沙地1986—2021年沙漠化整体呈逆转趋势,沙漠化土地面积由1986年的47 877.81 km2缩减至2021年的45 914.06 km2,以56.11 km2/a的速率逆转。该区土地沙漠化可分为3个时期:1986—2001年为沙漠化发展期,土壤黏粒、粉粒百分含量、有机质含量呈降低趋势,土壤砂粒百分含量、结皮因子和植被因子值呈增加趋势;2001—2011年为沙漠... 相似文献