| In the context of global warming,most of the glaciers in western China were in retreat from 2008 to 2018.At the same time,some glaciers with“abnormal”changes also appeared.Glaciers with"abnormal"changes refer to glaciers that are advancing,those that have completely disappeared,and those that have not undergone significant area changes.The emergence of"abnormal changes"glaciers will have an impact on the natural geographical environment and economic and social environment of the western of China.Therefore,it is of very important research significance to study all the"abnormal change"glaciers in western China,analyze their distribution and changes,and the influencing factors of the change"abnormal"glaciers.And these significances are embodied in strengthening the effective management of glacier change disaster risks,and enhancing the adaptability of the western region to respond to glacier disasters.From 2008 to 2018,the total number of advancing glaciers was 143,with a total area of 879.76 km~2.The annual average area change rate of these ranges from 0.08 to8.04%a-1,and the larger the area,the smaller the average area change rate of advancing glaciers.In the western of China,261 glaciers completely disappeared,with an area of12.68 km~2disappeared in China.In terms of accounts,the area of disappeared glaciers is mainly<0.07 km~2,and in terms of area,the maximum area distribution of disappeared glaciers is in the range of 0.0625-0.25 km~2.As for altitude,the disappearing glaciers are mainly distributed between 2700-6200 m,and 40%of the disappearing glaciers are concentrated at altitudes>5700 m.About slope,the distribution of completely disappeared glaciers is concentrated in the range of 5-55°.In the aspect,the area of the disappeared glaciers is concentrated in the true east,northeast and southeast directions.According to statistics on the specific distribution of“abnormal”glaciers in western China,from 2008 to 2018,there were 3,608“stable”glaciers with a total area of 2122.18 km~2.The number and area distribution of"stable"glaciers on 12 mountains are consistent with the overall distribution of glaciers in China.The distribution of"stable"glaciers is mainly in the area of 0.02-0.5 km~2,the area is mainly glaciers>0.5km~2,the"stable"glaciers with a larger debris-covered are>2 km~2.The total value of the average elevation change rate of each"stable"glacier is-0.03 m/a,indicating that glaciers with insignificant changes in area tend to be thinner as a whole.According to the analysis results,there are many factors affecting the rate of change of the advancing glacier area,with precipitation having the largest impact,followed by slope and aspect factors.Among the factors affecting the rate of change of the disappeared glacier area,precipitation has the greatest influence,that is,the change of the disappeared glacier area is mainly affected by climatic conditions.The analysis of the factors affecting the rate of change of the"stable"glacier shows that the dominant factor in the change of its area is the size of the glacier,and the rate of change in elevation is relatively significantly affected by temperature changes. |
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