塔克拉玛干沙漠腹地降水特征

Characteristics of Precipitation at the Hinterland of the Taklimakan Desert

利用塔克拉玛干沙漠腹地塔中气象站与周边3个气象站2000—2014年的气象观测资料,分析沙漠腹地近15a降水量的年、季、月分布及变化特征,并与同期沙漠周边地区资料进行对比分析。结果表明:塔克拉玛干沙漠腹地近15a年平均降水量为26.0mm,比周边同期平均少37.3%,但降水稳定性高于周边各站;塔克拉玛干沙漠腹地降水的年、季、月分布与沙漠周边各站基本保持一致,夏季降水占总降水量的69.3%,且逐年有所增加,对全年降水量的变化贡献最大;沙漠腹地月降水量分布极不均匀,6月降水量最大,占全年降水的41.6%,2月和3月降水量最少,仅占全年的0.7%,降水最多月是最少月近60倍;水汽压在沙漠腹地相对不稳定,但相对湿度相对较稳定;沙漠腹地最长连续降水日年平均2.9d,最长无降水日数年平均96d,最长连续无降水日数呈逐年上升趋势。

The meteorological data from four meteorological stations in the hinterland of the Taklimakan Des- ert and its surrounding regions were used to examine the annual, seasonal and monthly patterns and possible changes of precipitation with the variation coefficient and relative difference. The mean annual precipitation at the hinterland of the Taklimakan Desert was 26.0 mm, about 37.3 % less than the surrounding areas; The annual, seasonal and monthly distributions of the precipitation at the hinterland of the Taklimakan Desert were rather similar to those of the surrounding areas; Summer precipitation accounted for 69.3% of total rainfall with increase trend. The average monthly precipitation at the hinterland of the Taklimakan Desert was distributed unevenly, the largest was in June and accounted for 41.6 % of annual precipitation, the least were in February and March and accounted for only 0.7 % of annual precipitation, and the former was nearly 60 times than the latter. The vapor pressure at the hinterland of the Taklimakan Desert was relatively unstable, but the relative humidity was relatively stable. The largest annual number of continuous precipitati- on day was 2.9 d at the hinterland of the Taklimakan Desert, and the largest number without precipitation was 96 d. There was an upward trend in the largest number without precipitation.