中文摘要：

通过对月牙泉景区气象站点资料以及周边沙山高度定点长期监测数据的分析,得出景区内由于受周边高大沙山地形因素影响,景区内形成了两组主导风向下的局地环流,两组环流风向相反,物质搬运方向相反。但随着周边环境的变化,环流产生变化,原有输沙平衡遭到破坏,造成了南山和北山对月牙泉形成夹击之势。从沙山高度变化的监测中,除东山高度有降低趋势外,其余各点均表现为增高趋势,与输沙势分析结果保持一致。通过以上分析,从风流场方面揭示出月牙泉夹击之势的形成原因,剖析出沙害的根源,进而为保护月牙泉提供强有力的科学依据,并为揭示飞沙不落月牙泉现象奠定研究基础。

英文摘要：

Based on the detailed data of wind,sand ripple and long-term dynamic monitoring of sand hill in the scenic spots of Crescent Moon Spring,the author revealed the causes of converging attack from both the northern sand hill and southern sand hill.Under the influence of terrain such as high sand hill in the scenic spots,two different directions of local circulation were formed.The first local circulation was the wind came from the airport in the scenic spots of Crescent Moon Spring.After that,the wind would be affected by northern sand hill,southern sand hill and eastern sand hill in turn.Therefore,the direction of wind was changed.Finally the wind would overflow the scenic spots of Crescent Moon Spring along the western mountain.The other local circulation was the wind came from the western sand hill or the southern sand hill.After that,the wind would be affected by the southern sand hill,northern sand hill and eastern sand hill in turn.Finally the wind would overflow the scenic spots of Crescent Moon Spring through the airport.Compared with the former,the direction of the second local circulation was opposite.Through the analysis of the data of sand hill,the author found that only the height of eastern sand hill was decreasing,while others were increasing.