1962-2014年秦岭主峰太白山地区积雪变化特征及其成因分析

The characteristics and causes of the snow cover variation in the Taibai Mountains during 1962-2014

利用太白气象站1962-2014年地面积雪观测资料,太白、眉县气象站1980-2014年高山积雪观测记录和1988-2010年卫星遥感资料,分析了秦岭主峰太白山西部中山区、西部中高山区和中部中高山区积雪初、终日期、积雪日数和积雪深度等的变化特征,以及西部中山区积雪变化的成因.结果表明:1962-2014年太白山西部中山区积雪初日推迟,终日提前,初终间日数减少,积雪日数显著减少,积雪深度呈现波动变浅的趋势;1980-2014年西部中高山区积雪日数同样呈现波动减少趋势,西部中山区和中高山区年积雪日数减少率分别为3.2 d·(10a)^(-1)和8.9 d·(10a)-1.1980-2014年中部中高山区积雪初、终日期和积雪日数变化趋势不明显.卫星遥感监测资料分析结果显示太白山地区积雪面积呈现波动减少趋势.1962-2014年西部中山区气温升高,降水减少,积雪参数与气候要素相关分析结果表明气温和累积雪深等参数变化关系密切,气温升高是太白山积雪减少的主要原因.1980-2014年太白山地区7月积雪日数很少,关中八景之一的"太白积雪六月(公历7月)天"已很少见到.

The characteristics of snow cover, the number of snow cover days and the snow cover depth in the Taibai Mountains were analyzed by using the snow cover land observation data in Taibai Weather Station from 1962 to 2014 and the observation records of alpine snow cover in Taibai and Meixian Weather Stations from 1980 to 2014, as well as satellite remote sensing data from 1988 to 2010. The results showed that in the western middle mountain zone of the Taibai Mountains the snow cover beginning day had delayed, the snow cover ending day had advanced, the duration from snow cover beginning date to snow cover ending date had reduced, the annual days and depth and area of snow cover had presented a decrease tendency from 1962 through 2014. The same variation had also taken place in the western middle and high mountain zones of the Taibai Mountains from 1980 through 2014, with annual snow cover day decreasing rate of 3.2 d·（10a） ^-1and 8.9 d · （10a）^-1, respectively, in the middle and middle and high zones, The change of snow cover beginning and ending dates and the snow cover days had varied not so obviously from 1980 through 2014, Analyzing the satellite remote sensing monitoring data showed that the snow cover area has decreased in the undulation in the Taibai Mountains. Correlation analysis revealed that there was a close relation between temperature and cumulative snow depth in the western middle mountain zone of the Taibai Mountains from 1962 through 2014. It is clear that the temperature rise is the main reason of precipitation decreasing and the accumulative snow depth decreasing. There were few snow cover days in July in the middle and high mountain zones during 1980 -2014, and one of eight sights in Guanzhong, saying ＂ the snow accumulation in lunar June （July in the Gregorian calendar） on the Taibai Mountains＂ in history, couldn＇t be presented in the mountains,