基于3S技术的库布齐沙漠抛物线形沙丘形态变化研究

A Study of Morphological Change of Parabolic Dune in Hobq Desert Based on 3S Technology

以库布齐沙漠南缘典型抛物线形沙丘为研究对象,利用差分GPS实测数据,通过GIS空间插值生成DEM,提取地形因子和形态参数。利用多期高分辨率遥感影像,获取环境本底,同时结合气象数据,对抛物线沙丘形态变化进行分析。结果表明,沙丘平面形态呈U型,丘臂指向W;纵剖面上迎风坡较缓,背风坡较陡,横剖面不对称;沙丘平均移动速度为11.69m/a;沙脊线所夹中轴线走向为WNW—ESE,与盛行风或合成输沙方向一致;油蒿灌丛分布在两翼及其间平坦地,植被盖度年均减少0.95%;在长期合成风的作用下,沙丘向前移动,两丘臂间的油蒿灌丛发生阶段性的自然恢复。

A typical parabolic dune in the south margin of the Hobq Desert was taken as the research object.GIS spatial interpolation was used to generate DEM that was obtained by on-site RTK GPS measurement and the topographical factor and morphological parameter were collected.High resolution images were then used to obtain environmental background information.Form changes of parabolic dune can be analyzed by referring to relevant meteorological data.Results show that the flat form of the dune is U-shaped,with its arm pointing to the west.The windward slope is gentle,while the leeward one is steeper in the long section.However,the cross section is dissymmetrical.The average moving speed is 11.69m/a.The axes of the crest move toward WNW—ESE,in the same direction as the prevailing wind or the resultant sand drift.Artemisia ordosicashrub is distributed on the arms as well as the plain area between them.There is an annual decrease of 0.95% in vegetation coverage.Under long-term resultant wind,the dune moves forwards,while the Artemisia ordosica shrub between the arms recover periodically and spontaneously.