近48a新疆干湿气候时空变化特征

The Spatial-temporal Variation Characteristic of Dry-wet Climate in Recent 48Years in Xinjiang Province,China

根据新疆101个气象台站1961—2008年的逐月气候资料,采用线性回归、Morlet小波、自然正交分解(EOF)、累计距平、t-检验和Kriging空间插值等方法,对近48a反映新疆干湿气候的年降水量、潜在蒸散量和地表干燥度等要素的时空变化特征进行了分析,结果表明:①新疆年降水量在空间分布上表现为山区多于平原和盆(谷)地,北疆多于南疆,西部多于东部的格局;近48a,新疆各地年降水量均为增多趋势,增多倾向率的空间分布为:天山山区>北疆>南疆,全疆平均年降水量以9.123mm/10a的倾向率增多;新疆年降水量空间异常分布主要表现为"全疆一致型"和"南北疆反向变化"两种模态;全疆平均年降水量主要存在3～4a、6～8a、11a和16a的振荡周期,并于1987年发生了突变性的增多。②新疆年潜在蒸散量总体表现为南疆大于北疆、东部大于西部、盆(谷)地大于山区的分布格局;近48a,新疆各地年潜在蒸散量总体为减少趋势,其中南疆为递减倾向率高值区,北疆大部和天山山区为递减倾向率低值区,全疆平均年潜在蒸散量以-23.8mm/10a的倾向率减少;新疆年潜在蒸散量空间异常分布也主要表现为"全疆一致型"和"南北疆反向变化"两种模态;潜在蒸散量主要存在准22a的振荡周期,并于1984年发生了突变性的减小。③受降水量和潜在蒸散量时空变化的共同影响,新疆年干燥度指数总体表现为南疆大于北疆、东部大于西部、盆(谷)地大于山区的分布格局;近48a,新疆各地年干燥度指数均表现为不同程度的减小趋势,其中,吐鲁番、哈密盆地以及塔里木盆地东部地区是干燥度指数减小最明显的区域,全疆平均年干燥度指数以-3.164/10a的倾向率减少;新疆年干燥度指数空间异常分布主要表现为"全疆一致型";干燥度指数主要存在准5a、8a和18a的振荡周期,并于1987年发生了突变性的减小。

Based on the monthly climatic data from 101 meteorological stations in Xinjiang province from 1961 to 2008,the spatial-temporal variation characteristics of the annual precipitation,potential evapotranspiration（ET0） and aridity index are analyzed by using the linear regression,Morlet wavelet,Empirical Orthogonal Function（EOF）,accumulation anomalies,T test and Kriging interpolation methods.The main results are obtained as follows.（1）The spatial distribution of the annual precipitation was varied in Xinjiang： precipitation in mountain area was generally more than that in basin（valley）,in northern more than in southern,and in western more than in eastern;Annual precipitation significantly increased in the recent 48 years with an average rate of 9.123 mm/10a,and the increasing rate was in Tianshan mountain areain north Xinjiangin south Xinjiang;There are two main types of the spatial abnormal distribution of precipitation： ＂consistent in whole Xinjiang＂ and ＂reverse between in northern Xinjiang and in southern Xinjian＂;Change of precipitation in Xinjiang had period of 3—4 a,6—8 a,11 a and 16 a,and the abrupt increasing change happened in 1987.（2）The ET0 in the southern Xinjiang was larger than that in the north,in east larger than in west,in basin（valley） larger than in mountain areas;ET0 significantly decreased from 1961 to 2008 in Xinjiang with a rate of-23.8 mm/10a,but the regional decreasing rate was different,and it was larger in the southern Xinjiang and smaller in the northern Xinjiang and Tianshan mountain areas;There are also two main types of the spatial abnormal distribution of ET0： ＂consistent in whole Xinjiang＂ and ＂reverse between in northern Xinjiang and in southern Xinjian＂;Change of ET0 in Xinjiang had a period of 22 a,and the abrupt decreasing change happened in 1984.（3） Influenced comprehensively by spatial-temporal variation of precipitation and ET0,the spatial distribution of annual aridity index was larger in southern Xinjiang than in north,in east than in west,in basin（valley） than in mountain areas;The aridity index in Xinjiang decreased in recent 48 years with a decreasing rate of-3.164 mm/10a,and the most decreasing rate occurred in the regions of Turpan,Hami and Tlmpd basin,and eastern part of the Tarm basin;The spatial abnormal distribution of aridity index in Xinjiang showed mainly as ＂consistent in whole Xinjiang＂;Change of aridity index in Xinjiang had period of 5 a,8 a,and 18 a,and the abrupt decreasing change happened in 1987.