1959-2009年秦岭山地气候变化趋势研究

以秦岭山地39个气象站点1959—2009年近50a来的气温、降水资料为基础,分析研究了秦岭南北坡半个世纪气温与降水的变化趋势及特征。结果表明:(1)近50a来研究区气温总体上呈增加趋势,北坡气温倾向率为0.24℃/10a,南坡为0.15℃/10a;20世纪80年代中期以后,年均温呈极显著的增加趋势,特别是北坡地区气温倾向率高达0.74℃/10a,1993年后秦岭地区气候暖化趋势显著。(2)近50a来除夏季季均气温呈微弱的减少趋势外,研究区春、秋、冬3季均温均呈极显著的上升趋势(p<0.01),尤以冬、春两季平均气温上升更为显著;但1983—2009年27a间秦岭夏季气温呈上升趋势。(3)在50a尺度内秦岭北坡年均降水量在增加,而南坡年均降水量在减少,导致南北降水量差值减少;但近15a来秦岭南北坡年均降水量均有所增加,且北坡降水量增加速度更快(230.4mm/10a),说明秦岭北坡地区气候有暖湿化趋势。

Climatic Change Tendency in Qinling Mountains from 1959 to 2009

The trends and characteristics of temperature and precipitation on north and south slopes of Qinling Mountains were analyzed based on temperature and rainfall data from 1959 to 2009 collected from 39 meteorological sites in Qinling Mountains.Results showed as follows:(1) Temperature presented an increasing trend over the last 50 years.The temperature tendency rate was 0.24 ℃/10 a for the north slope and 0.15 ℃/10 a for the south slope.After the middle of 1980s,the annually averaged temperature appeared an obvious climbing trend and the temperature tendency rate for the north slope,in particular,reached up to 0.74 ℃/10 a.After 1993,Qingling region witnessed an apparent climate warming trend.(2) Over the 50 years,the average temperature in the study area presented a very remarkable rising trend in spring,autumn,and winter,with a slight downward trend in summer(p<0.01).Particularly,the rising trend of the average temperature was more notable in winter and spring.Temperature in summer showed an increasing trend in the 27 years from 1983 to 2009.(3) In the past 50 years,the annually averaged precipitation on the north slope increased,while it decreased on the south slope,which led to the reduction in the precipitation difference between the north slope and the south slope.However,in the last 15 years,both of the average precipitations on the north and south slopes increased slightly,with a faster pace on north slope of Qinling Mountains(230.4 mm/10 a).This indicated that the climate over the north slope of Qinling Mountains possessed a warming and wetting trend.