摘要
小冰期是指15世纪到20世纪早期之间一系列相对寒冷的气候波动阶段,研究小冰期以来的冰川规模变化,对于了解百年尺度上冰川变化及其气候指示意义具有重要意义。利用Google Earth和ArcGIS 10.3研究了念青唐古拉山西段的现代冰川和小冰期冰川,统计了冰川的基本信息和小冰期以来的变化情况,分析了面积、高程、坡度和坡向因素对冰川变化的影响,探讨了平衡线高度变化的气候指示意义。结果表明:念青唐古拉山西段共发育现代冰川847条,总面积约689.71 km2,共识别出小冰期冰川306条,总面积约746.12 km2。小冰期以来冰川面积减少约31%,平衡线高度平均上升约58 m,冰川的面积、坡度和高程对冰川面积变化的解释率为71%,平衡线高度变化与印度季风关系密切。
Background,aim,and scope The Little Ice Age(LIA)is the latest cold climatic event during the Holocene.Delineating glacier change since the LIA is of great importance to understand the character of glacier change and climate change.However,such knowledge is still lacking for some critical regions of the Tibetan Plateau(TP),such as the western Nyainqentanglha Range.This study aims to reconstruct glacier retreat of this mountain and discuss implications for the climate.Materials and methods This paper use Google Earth and ArcGIS 10.3 to reconstruct the extents for 306 LIA glaciers and obtain each glacial area and topographic information.The toe-to-headwall altitude ratio(THAR)method is used to estimate glacial equilibrium line altitudes(ELA)and their changes(ΔELA).The Partial Least Squares(PLS)is used to analyze the influence of glacial area and topographic factors on glacier change since the LIA.We also applied ordinary kriging interpolations toΔELA and mean annual precipitation to investigate their spatial distribution patterns.Results(1)847 modern glacier were identified,and the total area was calculated to be^689.71 km2.306 LIA glaciers boundaries were delineated,covering a total area of^746.12 km2.In the study area,glacier area has lost^31%,and the meanΔELA has risen^58 m since the LIA.(2)PLS regression models suggest that^71%of the glacier area loss could be explained by glacier area,slope and elevation,and only^6%ofΔELA values could be explained by glacial area and topographic factors.(3)The spatial distribution pattern ofΔELA was the same as precipitation,exhibiting a rising trend from east to west.Discussion Area and topography,especially area,can have a significant impact on the area changes.Glaciers with larger area tended to have lost more area since the LIA,and this result may be due to the larger magnitude of glacier mass balance of the lager glaciers.The change of ELA does not show a strong relationship with local factors,suggesting that it may be controlled mainly by climatic factors.The spatial distribution pattern ofΔELA is closely related to the Indian Monsoon.Conclusions Glacial area,slope,and elevation have a remarkable influence on glacial area change.The spatial distribution ofΔLIA shows a pronounced relationship with the Indian Monsoon.Recommendations and perspectives Reconstructing the temperature and precipitation during the LIA in the western Nyainqentanglha Range,even in the southern Tibetan Plateau is helpful to understand the paleoclimate and predict the future climate.
作者
张廉卿
许向科
张骞
易朝路
朱永娇
ZHANG Lianqing;XU Xiangke;ZHANG Qian;YI Chaolu;ZHU Yongjiao(Key Laboratory of Tibetan Environment Changes and Land Surface Processes,Institute of Tibetan Plateau Research,Chinese Academy of Sciences(CAS),Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Geography and Environment,Shandong Normal University,Jinan 250358,China;Capital Normal University,Beijing 100048,China)
出处
《地球环境学报》
CSCD
2019年第6期567-578,共12页
Journal of Earth Environment
基金
国家自然科学基金项目(41771019)。
关键词
小冰期
念青唐古拉山西段
冰川变化
印度季风
Little Ice Age
western Nyainqentanglha Range
Glacier change
Indian Monsoon
作者简介
通信作者:许向科,E-mail:xkxu@itpcas.ac.cn。
