青藏高原及青藏铁路沿线大风沙尘日数时空特征

Temporal and Spatial Characteristics of Strong Wind and Dust Days in Qinghai-Xizang Plateau and along Qingzang Railway

选取青藏高原66个站的气象实测资料,分析了青藏高原及青藏铁路沿线大风、浮尘、扬沙和沙尘暴日数的时空分布特征。结果表明:青藏高原大风高发区集中在以托托河为中心的高原主体上,有4个沙尘暴和扬沙源区,且冬季发生频率最高,它们的空间分布型随季节变化较小。年代际变化趋势表明,大风日数与扬沙、沙尘暴日数的年代际变化趋势呈反位相关系,高原西部和中部的大风沙尘日数又存在反位相变化特征。中部大风日数呈阶梯型年代际增多,扬沙和沙尘暴日数略呈减少趋势;西部大风日数则呈阶梯型减少,扬沙和沙尘暴日数变化趋势呈现“几”字形分布。

Based on the meteorological observation data of 66 stations in Qinghai-Xizang Plateau(QXP) from 1971 to 2000, the temporal and spatial characteristics of the days with strong wind, floating dust, blowing-sand and sandstorm in QXP and along Qingzang railway were analyzed. Results show that the days of strong wind in QXP mainly occurs in the main body of Plateau centralizing on near to Toutouhe, There are four cores of dust, they occur often in winter, the spatical distribution pattern change with season is not obvoius. The interdecadal variation of strong wind days is out of phase with that of dust weather, particularly remarkable in the central and western parts of the Plateau. In the former region, the days of strong wind increases with time while days of dust weather slightly reduced. In the latter region, the days of strong wind decreases while variation in the days of dust weather is something like the Chinese character“几”with time.