呼伦贝尔沙质草原风蚀坑地表风沙流结构特征  

Structure of Drifting Sand Flow over the Surface of Blowouts in the Hulun Buir Sandy Grasslands

作　　者：张惜伟[1] 汪季[2] 海春兴[1] 丁延龙[2] 宝成 ZHANG Xi-wei;WANG Ji;HAI Chun-xing;DING Yan-long;BAO Cheng(Inner Mongolia Normal University,Hohhot 010022,Inner Mongolia,China;Inner Mongolia Agricultural University,Hohhot 010019,Inner Mongolia,China;Forestry Bureau of Old Barag Banner,Bayan Kukuen 021500,Inner Mongolia,China)

机构地区：[1]内蒙古师范大学,内蒙古呼和浩特010022 [2]内蒙古农业大学,内蒙古呼和浩特010019 [3]陈巴尔虎旗林业局,内蒙古巴彦库仁镇021500

出　　处：《干旱区研究》2018年第6期1505-1511,共7页Arid Zone Research

基　　金：国家重点研发计划课题:绿洲;盐碱湖区沙害防治关键技术研究与示范(2016YFC0501003)

摘　　要：在呼伦贝尔沙质草原北部沙带中段风蚀坑集中分布区内,选取不同发育阶段的风蚀坑,通过同步观测风蚀坑地表（0-200 cm）风速及输沙通量,分析并比较风沙流结构特征,为呼伦贝尔沙质草原风蚀坑治理提供理论依据。研究表明：在裸地沙斑、活跃发展、固定阶段及重新活化阶段的风蚀坑,风速廓线基本遵循对数分布规律;而在未风蚀草地、消亡阶段的风蚀坑,气流受下垫面扰动,呈＂S＂形分布。风蚀坑各发育阶段输沙量与高度的最优拟合模型为负指数模型,不同发育阶段风蚀坑内部风沙流输沙量差异较为明显;超过95%的输沙量均在地表0-30 cm高度内,且63. 97%-90. 96%的输沙量集中分布在距地表10 cm高度内。风沙流跃移高度与风速正相关,依次为：活跃发展〉重新活化〉裸地沙斑〉固定阶段〉消亡阶段〉未风蚀草地。通过分析风沙流通量系数,可知在裸地沙斑、活跃发展及重新活化阶段,输沙量有向高层移动的趋势;而在其他阶段,由于植被盖度较高,使得风沙流多集中在近地层。The blowouts at different development stages in the northern sandy zone of the Hulunbuir sandy grasslands were selected to analyze and compare the structure of drifting sand flow based on the simultaneous observation of wind-sand flux over blowout surface（0-200 cm）. The purpose of the study was to provide a theoretical basis for wind erosion control in sandy grasslands. The results showed that the wind profiles were in a logarithmic distribution in the sand patches at their different development stages,while the un-eroded grasslands and the blowouts at their extinction stage were in an ＂S-shaped＂distribution because the air flow was disturbed by the underlying surface. The optimal fitting model for sand flux and height over blowout at each development stage was a negative exponential model,and the difference of sand flux in blowout at different development stages was obvious. More than95% sand flux was distributed within a height of 0-30 cm from the land surface,and 63. 97%-90. 96% sand flux was distributed in 10 cm height. The sand saltation height was positively correlated with wind speed and in an order of active development reactivation stage sand patch fixed stage extinction stage un-eroded grassland.The analyzed results of sand flux coefficient revealed that the high value of sand flux moved upwards over sand patch at the active development and reactivation stages,and the wind-blown sand flux concentrated near ground because of the high vegetation coverage.

关 键 词：风沙流结构 输沙通量 风蚀坑 沙质草原 呼伦贝尔 

分 类 号：S157.1[农业科学—土壤学]