【摘要】 利用1959-2008年间的实测地面气温和降水资料,通过计算气候趋势系数和气候倾向率等统计量分析了西北地区气候的时空变化特征。结果表明,50年来该区气温有明显的上升趋势,年平均气温以0.32℃.(10 a)-1的幅度升高,全年和四季气温都在上升,冬季升温最明显,达0.37℃.(10a)-1,夏季升温幅度最低,约0.24℃.(10 a)-1。20世纪60年代初气温较高,60年代后期气温有所下降,80年代中期显著上升,90年代以后上升更明显。气温升高程度存在区域差异,升温幅度最大的地区在青海西北部、新疆阿尔泰山地区和内蒙古中部;增幅最小的地区为青海海南和甘肃西南部。年降水量变化趋势存在显著的区域差异,西北地区西部和中部降水量呈显著增加趋势,而东部区域降水呈减少趋势。年降水量增加较显著的地区为新疆塔里木盆地南部、阿尔泰山和天山、青海北部和甘肃河西的中东部;年降水量减少区为青海南部、甘肃河东(黄河以东)、宁夏、陕西及内蒙古西部。更多还原

【Abstract】 The spatial-temporal variations of temperature and precipitation in Northwestern China during the period of 1959-2008 were studied,using the observed surface air temperature and precipitation data at 180 stations from 1959 to 2008 and the climate trend coefficient and climate tendency ratio.The results show that:(1) The temperature of the region has markedly ascended in the last 50 years,the warming rate of 0.32 ℃·(10 a)-1 is significantly higher than rest of China and global average rate of warming at the same period.The warming rate of 0.37 ℃·(10 a)-1 in winter is significantly higher than other seasons.(2) In details,the mean temperature ascended in the early of 1960s,but dropped in late of 1960s,whereas it ascended in 1980s again and ascended sharply in 1990s.(3) The variability of precipitation is regionally different.There is significantly increasing trend of precipitation in western and middlle of northwestern China,however declining trend in eastern of northwestern China.(4) The monthly trend of precipitation is different to seasonal precipitation and annual precipitation regionally,however in spring,summer and fall the trends of precipitation are accordant to trend of annual precipitation.更多还原