气候变化背景下新疆地区降水时空变化特征分析

Characteristics of Spatio-temporal Variability of Precipitation in Xinjiang Region under the Background of Climate Change

依据新疆地区1951～2008年月降水资料,运用Morlet小波分析及PCI降水集度等方法分析了新疆地区降水时间及空间的变化规律。结果表明:新疆地区降水存在4a、8a及准12a主周期;年降水由北向南逐渐减少,伊宁、和田形成极大值中心,安德河、吐鲁番形成极小值中心;变异系数由北向南增大,北疆小于0.40,南疆为0.50～0.75。降水年内分配北疆相对均匀,南疆差异较大。北疆年降水呈增加趋势,南疆仅少数地区有减少趋势。未来年降水波动较大,有更趋离散而背离均值的趋势;年内降水分配规律将渐趋稳定,波动呈下降趋势。

Using the Morlet wavelet analysis and rainfall concentration index and climate trend coefficient method,the characteristics of spatio-temporal variability in precipitation are analyzed by the monthly precipitation data from 1951 to 2005 in Xinjiang region. Results indicate that： The main cycles are 4a,8a and 12a approximately. The annual precipitation is decrease from north to south. There are maximum center in Yining and Hetian,forthmore,the minimum center at Andehe and Turfan. Coefficients of variation are increase from north to south,it is smaller than 0. 40 in northern Xinjiang and between 0. 50 and 0. 75 in southern Xinjiang. The annual precipitation will increase in northern,but decrease in southern. In future,the fluctuate of precipitation will increase and far away from the average value. However,the variability will change slowly for the intra-annual distribution of precipitation.