2000-2012年祁连山中段雪线与气候变化关系

摘要

Based on snow product(MOD10A2),temperature,precipitation data from 2000 to 2012 and DEM da-ta,using spatial analysis technology and statistical method,this paper analyzes snow line variation trend and its re-lationship with climate change in the middle of Qilian Mountains,Nothwest China. The result shows that:1)The average elevation values of snow line fluctuated upward trend from 2000 to 2012 in the middle of Qilian Mountains, and the average decline rate is 42. 3 m/(10 a). The snow line average height value is above 4 600 m and snow line average height value is 4 673 m in recent 10 years. 2)Both the average elevation values of each aspect snow line and average annual increase rate have obviously consistent characteristics in study area,namely the sunny slope >the southern and northern slope > cloudy slope. 3 )The temperature in the warm season and total rainfall in the 6—8 month of 2000—2012 are the important factors to influence the Qilian Mountains snowline changes,the tem-perature in the warm season is the main factor to induce the snowline. If cumulative rainfall remain stable in the 6—8 month,the temperature in the warm season increasing( decreasing)1℃ will result in snow line altitude rising ( falling)58 m in the middle of Qilian Mountains.%利用 MOD10A2积雪产品、气温、降水数据和 DEM 数据，借助于 GIS 空间分析技术和统计方法，分析2000—2012年祁连山中段地区的雪线变化，并探讨温度和降水对雪线变化的影响。研究结果表明：1.2000—2012年祁连山中段雪线平均高程值呈波动上升，平均上升速率为42.3 m/（10 a）；各年的雪线平均高程>4600 m，多年雪线平均高程值为4673 m。2.祁连山中段地区各坡向的雪线平均高程值、年平均上升速率均呈现相一致的特征，即阳坡>半阴半阳坡>阴坡。3.2000—2012年暖季气温和6—8月累计降水量是影响祁连山雪线变化的重要因素，暖季气温升高是引起雪线升高的主导因素。在6—8月累计降水量保持稳定的情况下，暖季气温上升（下降）1℃，祁连山中段雪线高度上升（下降）约58 m。