摘要
巴丹吉林沙漠与乌兰布和沙漠之间的输沙带由波状高平原带状流沙和山麓带状流沙组成。利用多期高分辨率遥感影像对输沙带新月形沙丘动态开展了监测。选取山麓输沙带、高平原输沙带主体区及其南北两侧4个样区,提取并计算沙丘各参数,分析探讨了沙丘移动、形态和输沙通量的时空变化及其影响因素。结果表明,2003—2020年,沙丘动态因地形、风况和沙丘规模等差异显示不同的时空变化特征。(1)沙丘移动速率为2.09~40.93 m·a^(-1),平均为12.89 m·a^(-1),山麓输沙带沙丘移动快于高平原输沙带沙丘,随合成输沙势的变化,沙丘移动速率在高平原输沙带趋于减小,山麓输沙带趋于增加;(2)沙丘移动方向介于102°~152°,平均为126°,受控于各方向起沙风强弱变化,在高平原输沙带向北偏移,在山麓输沙带向南偏移,但均与合成输沙方向不一致;(3)沙丘移动过程中,迎风坡长度趋于增加、高度趋于降低,主风(W)与次主风(NW)交替作用使南翼伸长;(4)近20年,低矮沙丘出现沙物质损失,相对高大沙丘沙物质收支平衡;(5)考虑输沙带宽度及沙丘密度计算的输沙带输沙通量达117 t·m^(-1)·a^(-1),估计巴丹吉林沙漠每年向乌兰布和沙漠至少贡献55万t沙物质。
The sand belt between the Badain Jaran Desert and Ulan Buh Desert consists of undulating high plains and piedmont banded mobile sands.Using multi-period high-resolution remote sensing images,the monitoring of the barchan dune in the sand belt was carried out.We selected piedmont zone,main body,north and south sides of the high plains as four typical sample areas of the belt.By extracting and calculating the dune parameters,we analyzed and explored the spatio-temporal variations of dune movement,morphology,sand transport fluxes,and their influencing factors.The results showed that the dune movement and morphology in the belt represented different spatio-temporal changes during 2003-2020 due to the differences in topography,wind regime and dune scale.The specific results are as follows:(1)The dune movement rate ranged from 2.09 m·a^(-1)to 40.93 m·a^(-1),with an average of 12.89 m·a^(-1).The down slope-moving dunes in the piedmont sand belt have moved faster than those in the high plains.The dune movement rate tended to decrease in the high plains sand belt,and tended to increase in the piedmont belt,with the change of the resultant drift potential(RDP).(2)The dune movement direction was 102°-152°,with an average of 126°,and controlled by the change of strength of prevailing wind direction.In the high plains sand belt,the belt shifted to the north and to the south in the piedmont,but both are inconsistent with the resultant sand transport direction.(3)In the process of dune movement,the length of the windward slope tended to increase,the height tended to decrease,and the alternating effect of the primary wind(W)and the secondary wind(NW)makes the southern flank elongation.(4)In the past 20 years,the low dunes have a sand material loss,and the relatively tall dunes have a sand material balance.(5)Considering the width and the dune density of the sand belt,the sand flux of the belt was calculated as 117 t·m^(-1)·a^(-1),and it is estimated that the Badain Jaran Desert has contributed at least 5.5×10^(5)t sand to the Ulan Buh Desert every year.
作者
乌友罕
殷婕
武子丰
哈斯额尔敦
Wu Youhan;Yin Jie;Wu Zifeng;Eerdun Hasi(School of Natural Resources,Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China;Institute of Ecological Conservation and Restoration,Chinese Academy of Forestry,Beijing 100091,China)
出处
《中国沙漠》
CSCD
北大核心
2024年第2期78-89,共12页
Journal of Desert Research
基金
第二次青藏高原综合科学考察研究项目(2019QZKK0906)
国家自然科学基金项目(42271005)。