若尔盖盆地流动沙丘治理前后表层沉积物粒度变化特征  

Characteristics of grain size variation of dunes surface sediments before and after wandering dune control in Zoige Basin, China

作　　者：孟惠聪 胡光印 董治宝 南维鸽 莫皓焜 胡菁菁 Huicong Meng;Guangyin Hu;Zhibao Dong;Weige Nan;Haokun Mo;Jingjing Hu(School of Geography and Tourism,Shaanxi Normal University,Xi'an 710119,China)

机构地区：[1]陕西师范大学地理科学与旅游学院,陕西西安710119

出　　处：《中国沙漠》2024年第3期96-107,共12页Journal of Desert Research

基　　金：国家自然科学基金项目(42071004,42171004);第二次青藏高原综合科学考察研究项目(2019QZKK0403)。

摘　　要：近年来,在若尔盖盆地内部,各县采取设置草方格沙障、种植灌木等措施进行沙漠化治理,众多流动沙丘得到固定。为探讨沙丘治理前后表层沉积物的粒度变化特征,采集了若尔盖盆地西北部黄河左岸沙丘治理前后的沙丘表层样品进行对比分析。结果表明:经治沙措施固定后的沙丘,极细沙、粉沙和黏土成分占比由20.2%增加至29.6%,平均粒径由181.9μm减小至162.0μm,表层沉积物粒度组分变细,分选性变差,偏度由近对称变为极正偏,峰态由中等变为很窄。频率分布曲线出现次峰,概率累积曲线悬移段产生亚组分,总体由两段式变为三段式,悬移组分粒度变细,跃移组分含量占比由99%降低至87%~88%。在麦草方格与固沙植被共同作用下,沙漠化治理成效显著,但沙漠化土地局地环境的改变亦会对治沙效果产生负面影响。因此,需要因地制宜开展治沙工作,并关注治理区域的动态变化,及时做出措施调整。In recent years,various counties in the Zoige Basin have taken measures such as setting checkerboard sand barriers and planting shrubs to control desertification,and many wandering dunes have been fixed.To explore the changes of grain size characteristics of sand dune surface sediments under the influence of sand-fixing vegetation,surface samples were collected before and after sand dune control on the left bank of the Yellow River in Maqu County,Zoige Basin,and the relevant data were compared and analyzed.The results show:(1)After vegetation fixation,the proportion of silt and clay components increased from 1.3%to 9.9%,and the mean particle size decreased from 181.9μm to 162.0μm.The grain size components of surface sediments became finer,the sorting of dunes became worse,the skewness changed from near symmetry to very positive skewness,and the kurtosis changed from medium to very narrow.(2)The frequency distribution curve has a secondary peak,and the probability accumulation curve has a sub-component in the suspension section.The overall change from two-stage to three-stage,the particle size of the suspension component becomes finer,and the proportion of the saltation component content decreases from 99%to 87%-88%.(3)Under the combined action of wheat straw grid and sand-fixing vegetation,the effect of desertification control is remarkable,but the local environment of desertification land will also affect the effect of sand control.Therefore,it is necessary to carry out sand control work according to local conditions,pay attention to the dynamic changes of the control area,and timely take measures to adjust.

关 键 词：沙漠化治理 粒度特征 若尔盖盆地 黄河源区 青藏高原 

分 类 号：P931.3[天文地球—自然地理学]