【摘要】 复合沙垄是最大的沙丘地貌类型之一 ,表现为简单沙丘类型的垂直叠加和水平连接 ,在沙垄的高大地形影响下 ,沙垄不同部位形成不同的风沙环境特征。以塔克拉玛干沙漠腹地 /复合沙垄为例 ,通过野外实地观测研究其流场和上覆沙丘组合特征。研究结果表明 ,复合沙垄的流场可分为沙垄迎风坡气流加速区、沙垄背风坡气流转向减速区、垄间粗沙平地气流风速风向恢复区和气流风速稳定区。受沙垄流场和地形的控制 ,沙垄上覆新月形沙丘链 ,垄间地分布有简单新月形沙丘、沙堆、沙片、侵蚀地、简单线形沙丘。上覆沙丘分布特征表现为 :垄间地上覆新月形沙丘疏密度较小 ,沙垄迎风坡和沙垄背风坡上覆新月形沙丘疏密度较大 ,而且超过 1,说明沙垄迎背风坡上覆沙丘有叠置现象。沙垄上覆沙丘高度自沙垄迎风坡底部到顶部增高 ,背风坡上覆沙丘高度自沙垄顶部到背风坡底部减小 ,上覆沙丘在自身形态、地形和流场的共同影响下 ,存在相对运动 ,表现为分布进一步集中 ,因此沙垄有增高的趋势。更多还原

【Abstract】 The complex dune chain is one of the main dune types in Taklamakan Desert. According to the field investigation,the height and width of the complex dune chains vary in ranges of 55～95 and 1300～1700m respectively. The meteorological observation shows that the wind direction of the prevailing wind in the hinterland of Taklamakan Desert is NEE. This paper studies the wind field over the complex dune chains and composition and the dynamic features of the dunes overlying on the dune chains in the hinterland of Taklamakan Desert. The results show that the wind field over the complex dune chains can be divided four areas,i.e. the speeding up area on windward slope, speeding down area on leeward slope, speed recovering area and speed stable area. The overlying dunes are characterized by the low density of barchans in the inerdune corridors and high density on the windward slope of the dune chains, which shows that there is a dune superposition on the windward and leeward slopes.更多还原