金字塔沙丘近地表流场及其对月牙泉影响研究

The Near-surface Airflow Field of Pyramid Dune and Its Influence on The Crescent Moon Spring in Dunhuang,China

对月牙泉景区气象站点资料和积沙量统计分析以及月牙泉北侧金字塔沙丘近地表流场野外观测表明:受地形影响,月牙泉景区和金字塔沙丘各点起沙风玫瑰和输沙势玫瑰在监测期内差别较大。在金字塔沙丘影响下,不同风向下气流发生多次分离和汇集,沙丘近地表气流发生明显变化,携沙气流行进方向发生改变。金字塔沙丘坡面上各点合成输沙势和起沙风与坡面走向呈垂直角度,气流沿坡面爬越沙丘时,动能发生损耗,携沙能力减弱,减少了进入月牙泉的风沙量,减弱了月牙泉的风沙灾害。

In this paper, the author analyzed the data of meteorological instruments and sand deposition in the scenic spot of Crescent Moon Spring, and conducted field observation on the near-surface airflow of the pyramid dune. The results of the study show that the sand-driving wind and the drift potential rose of the sites of meteorological instruments in the scenic spot of Crescent Moon Spring and on the pyramid dune are different because of the influence of the local terrain. Under its influence, the airflow near pyramid dune separates and converges many times. Not only the airflow near pyramid dune exhibits obvious change, but also the direction of the carrying sand flow. Therefore, it will have an great impact on the survival of the Crescent Moon Spring. When the flow climed the dune, the kinetic energy would lose, so the quality of car- rying sand would reduce, It would ruduce the sandstorm disaster of the Crescent Moon Spring. This study would add the research theory about Pyramid dune. Also it would provide the foundation to reveal the phe- nomenon about the sand don＇t fall into the Moon Spring.