新疆极端降水事件的时空变化及趋势预测

Temporal-Spatial Variation and Trend Prediction of Extreme Precipitation Events in Xinjiang

基于新疆1960—2011年的日降水量,选取符合条件的50个气象站点数据,采用世界气象组织（WMO）气候委员会（CCI）推荐使用的＂气候变化检测和指标＂体系,从中选取了8个极端降水指数,运用线性趋势法、反距离加权插值法（IDW）、Morlet小波分析法和季节性叠加趋势模型,研究各极端降水指数在时空上的变化特征以及周期和未来变化趋势。结果表明：受气候增暖的影响,新疆降水量增加,极端降水量也呈增加趋势,持续干燥指数下降。因新疆特殊的＂三山夹两盆＂的地形结构,小区域气候变化显著,极端降水量在不同区域分布呈明显差异,总体上除持续干燥指数外,其余指数在北疆大部分站点的变化率较南疆大,天山山区因受海拔高度的影响,降水量大,变差系数也较大。各指数的主周期都集中在22-29 a,可见,极端降水事件的变化周期长。各指数未来26 a的变化趋势与原趋势一致,新疆发生极端降水事件的可能性仍在增加,应加强对极端事件的预防能力,以减少极端气候变化带来的危害。

Based on the daily precipitation data of 50 observational stations in Xinjiang region from 1960 to 2011,we selected 8 indices of extreme precipitation from the ＂Expert Team on Climate Change Detection and Indices＂,which is formulated by WMO,used the linear trend method,the inverse distance weighted interpolation method（ IDW）,Morlet wavelet analysis and superposition trend model to study the spatial and temporal variation,period variation and the trends prediction of extreme precipitation. The results show that： because of the climate warming,the precipitation has increased in Xinjiang region,and the extreme precipitation also increased,consecutive dry index decreased. And because of the special terrain structure of ＂two basins sandwiched among three mountains＂,the climate change of small regions was often significant,the extreme precipitation is of obvious difference in different regions,on the whole,in addition to continuous dry index,the rates of other indices are larger in the northern region than the southern region,due to the impact of altitude,the precipitation and variation coefficient of Tianshan Mountains is large. The main period of each index is concentrated in the 22-29 a,so,the period of extreme precipitation events is longer. The future 26 a trend of each index is consistent with the original trend,the extreme precipitation events may still increase in Xinjing region,and therefore,we should strengthen the ability and reduce the damage caused by extreme precipitation events.