塔克拉玛干地区近四十年来的干湿变化

本文利用塔克玛干，周围山区、及相邻地区的４８个气象站近４０年的降水资料，分析塔克拉玛干地区年与四季干湿变化的阶段与周期，与与周围山区及相邻地区进行相关性分析。

THE WET-DRY CHANGE IN RECENT 40 YEARS IN TAKLIMAKAN AREA

Using the precipitation data in recent 40 years of 48 meteorological stations in Takli makan, around mountains and neighbouring areas, this paper has analyzed the stage and period of the wet-dry changes in annual and four seasons in Taklimakan area, compared the correlation of precipitation change in Taklimakan, in around mountains and in neigh bouring areas, probed the relationship between position of polar vortex and wet - dry change in Taklimakan area and obtain some statistic conclusions, which are as follows:(1) The mean precipitation sequences of annual and four seasons in Taklimakan area have better representativeness to wet-dry changes in the area.(2) The precipitation changes of annual and four seasons in Taklimakan area have dif ferent wet-dry phases and change periods, which almostly have nothing to do with that of four seasons in around mountains, but in autumn the precipitation change between in Taklimakan and in Toyun has better correlation, and which have some correlation with neighbour areas only in spring.(3) Summer precipitation have well directive sense to annual precipitation in Takli makan area, the correlation coefficient is precipitation between summer and annual is 0.901, and the negative correlation between precipitation and temperature in summer is very remarkable.(4) The precentages of the first eigenvetor accouting for total variation of annual and four seasons change in 41 %- 48% in Taklimakan area, and all have spacial distribution features of synchronous change in different areas.(5) There is definite correlation between annual precipitation in Taklimakan area and position of polar vortex, when longitude of polar vortex is partial west in February of cur rent year and its altitute is partial north in September of last year, annual precipitation is above its mean value in the area. In addltion, when position polar vortex is partial west in February, it is beneficial to obtain more summer precipitition in the area.