冰川与气候变化相关性分析——以祁连山自然保护区为例

Correlation Analysis between Glaciers and Climate Change—A Case Study of Qilian Mountain Nature Reserve

冰川是淡水资源的一种重要储存形式,近年来冰川面积不断减少,研究冰川面积变化对于干旱区生态保护及可持续发展意义重大。基于Landsat TM、Landsat ETM与Landsat OLI遥感影像数据以及气象观测数据,进行遥感解译与统计分析,运用决策树自动阈值分类方法,同时结合非监督分类方法得到祁连山自然保护区1995—2015年冰川面积变化,参考第2次冰川编目数据对结果进行验证,并运用相关分析法分析与气候变化的相关性。结果表明:①1995—2015年祁连山自然保护区内冰川面积变化有2个不同阶段,1995—2005年缓慢增加,2005—2015年急剧下降,整体呈减少趋势。面积最大时为2005年376.91 km^2,到2015年减少为217.33 km^2。②祁连山自然保护区年均降水量变化与冰川面积变化的相关性强于年均气温变化与冰川面积变化的相关性。降水量与冰川面积之间的相关系数为0.403,气温与冰川面积之间相关系数为-0.327。③祁连山自然保护区内冰川面积变化是降水与气温共同作用的结果,在不同时期,气温与降水分别起主导作用。

The glacier is an important storage form of freshwater resources.In recent years,the area of glaciers has been decreasing.Studying the change of glacial area is of great significance for the ecological protection and sustainable development of arid region.Based on Landsat TM,Landsat ETM and Landsat OLI remote sensing image data and meteorological observation data,remote sensing interpretation and statistical analysis are carried out.The decision tree automatic threshold classification method is used,and the unsupervised classification method is used to get the change of glacier area in Qilian Mountain Nature Reserve from 1995 to 2015.The results are verified by reference to the second glacial catalogue data,and analyzed by correlation aqnalysis method Relevance to climate change.The results showed that:①there were two different stages of glacier area change in Qilian Mountain Nature Reserve from 1995 to 2015,which increased slowly from 1995 to 2005,and declined sharply from^2005 to 2015,showing a decreasing trend as a whole.The maximum area was 376.91 km^2 iN2005 and decreased to 217.33 km^2 by 2015.②The correlation between the annual average precipitation change and the change of glacier area in the Qilian Mountain Nature Reserve was stronger than the correlation between the annual average temperature change and the change of glacier area.The correlation coefficient between precipitation and glacier area was 0.403,and the correlation coefficient between temperature and glacier area was-0.327.③The change of glacier area in Qilian Mountain Nature Reserve is the result of the combination of precipitation and temperature.In different periods,temperature and precipitation played a leading role respectively.