基于土壤粒度参数的荒漠草原地表粗粒化过程

发布时间：2018-05-29 22:21

本文选题：粒度参数 + 土壤　；参考：《水土保持研究》2017年06期

【摘要】：草原退化特征已由植被变化为主演变为土壤退化的阶段,其植被覆盖变化可在一定程度上反映退化状况与过程,探明荒漠草原不同退化阶段(覆盖度)地表风蚀状况,对合理利用与保护草地资源意义重大。以希拉穆仁荒漠草原7个覆盖度(裸地,5%,20%,40%,60%,80%和100%)下的表层土壤为研究对象,利用激光衍射技术测量表层0—1cm土壤粒度组成,分析不同覆盖度下的平均粒径、标准偏差、偏度、峰态及分形维数等粒度参数变化情况及颗粒频率分布。结果表明:(1)土壤粒度组成均以沙粒和粉粒为主,黏粒含量较低;偏度可作为有效粒度参数指标。(2)随着盖度降低,平均粒径数值越大,分选性越好,频率曲线由近于对称—正偏—极负偏转变,峰态由尖锐变平缓,分形维数先增加后降低。(3)粒径分布基本呈双峰分布,盖度越小第二波峰滞后越明显,且分布均匀程度越低,易风蚀颗粒范围为144~869μm。
[Abstract]:The characteristics of grassland degradation have changed from vegetation change to soil degradation stage, and the vegetation cover change can reflect the degradation status and process to some extent, and the surface wind erosion status of desert steppe at different degradation stages (coverage) has been proved. It is of great significance for rational utilization and protection of grassland resources. In this paper, the surface soil of Xilamuren desert steppe was studied under 7 coverage (80% and 100%). The particle size composition of surface 0-1cm soil was measured by laser diffraction technique, and the average particle size, standard deviation and deviation under different coverage were analyzed. The change of particle size parameters such as peak state and fractal dimension and particle frequency distribution. The results showed that the grain size composition of the soil was mainly composed of sand and silt, and the clay content was relatively low, and the deviation could be used as the effective granularity parameter. 2) with the decrease of coverage, the larger the average particle size value, the better the sorting property. The frequency curve changes from symmetry to positive bias to extreme negative bias, the peak state changes from sharp to gentle, fractal dimension increases first, then decreases. The particle size distribution is basically bimodal distribution. The smaller the coverage is, the more obvious the second peak lag is, and the lower the distribution uniformity is, the smaller the frequency curve is. The range of wind-prone particles is 144 ~ 869 渭 m.
【作者单位】：内蒙古农业大学沙漠治理学院中央与地方共建风沙物理重点实验室;北京林业大学林学院;鄂尔多斯市水土保持科学研究所;西北农林科技大学水土保持研究所;
【基金】：内蒙古农业大学优秀青年基金(2014XYQ-8) 中科院西部之光“内蒙古中西部沙化草原地表粗粒化过程研究”
【分类号】：S812.2

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