荒漠-绿洲过渡带风况及输沙势分析--以策勒县为例

Analysis on Wind Regime and Wind Borne Sand Potential in a Desert-oasis Ecotone——A Case Study in Qira County,Xinjiang

以中国科学院新疆策勒荒漠草地生态系统国家野外观测研究站2005-2006年的气象资料为依据,分析了塔克拉玛干沙漠南缘荒漠-绿洲过渡带的风况特征和输沙势变化情况。结果表明：①研究区风向以W风为主,频率占62.43%~76.25%,WNW风次之,频率占17.75%;②该区起沙风主要发生在春夏两季,其频率占全年的11.93%~61.84%,6月出现频率最高,且春夏两季起沙风平均风速较大,最大达7.90 m/s;③在风沙活动期内,研究区风向变率指数（RDP/DP）为0.94,属于单风风况,合成输沙势（RDP）及合成输沙方向（RDD）分别为27.98VU和92.10°（ESE）,属于低风能环境。输沙势的季节变化幅度较大,主要集中在春夏两季。

The Desert-oasis ecotone in southern marginal zone of the Taklimakan Desert is one of the areas with the severest desertification in China. In this study a statistical analysis on wind regime and wind borne sand potential in Qira County located in the southern marginal zone of the Taklimakan Desert was carried out during the period from 2005 to 2006. The results are as follows ： （ 1 ） Wind direction in the study area is dominated by W, its occurring frequency varies in a range of 62.43% - 76. 25% , and then by WNW with an occurring frequency of 17.75% ; （2） Sand-raising wind in the study area occurs mainly in spring and summer, its occurring frequency varies in a range of 11.93% -61.84% , especially in June, the mean sand-raising wind velocity in spring and summet is higher than that in autumn and winter, and its maximum can be up to 7.90 m/s ; （3） During sand drift, the variability index （RDP/DP） of wind direction in this region is as high as 0.95, the wind environment is in a sin- gle-peak form, the resultant sand drift potential （RDP） and resultant sand drift direction （RDD） are 27.98 VU and 92.10°ESE respectively, and these reveal that this region belongs to a low wind-energy environment according to Fryberger＇s （ 1979 ） classification. The seasonal variation extent of sand drift potential is high, especially in spring and summer. It is necessary for the local government to take some measures to conserve the natural vegetation so as to reduce wind velocity and protect environment.