羌塘高原极大陆型冰川厚度分布模拟与冰储量估算

Ice Thickness Simulation and Storage Estimation of the Extreme Glaciers on the Qiangtang Plateau

冰川厚度与储量是未来冰川变化预测、可用淡水资源估计以及潜在海平面上升评估等冰川学研究的前提。基于我国西部31条冰川实测探地雷达厚度数据,对GlabTop2冰厚模型进行参数校正和优化,模拟羌塘高原冰川厚度分布并评估冰川水资源总量,结果表明:(1)GlabTop2模型模拟的冰川平均厚度与实测平均厚度较接近,二者相关性为0.87,均方根误差为18.2 m,模型对冰川厚度的高估和低估分别为9%和-17%,模型模拟冰川中流线基岩地形形状的能力优于剖面基岩形状;(2)2022年羌塘高原冰川储量为(177.6±26.6)km^(3),平均冰川厚度为(88.2±12.3)m,冰储量集中分布在5600~6200 m,为(148.28±22.24)km^(3),占整个羌塘高原冰川总储量的84.4%,其余高程带冰储量分布相对较少。

Ice thickness and storage are prerequisites for glaciological studies that predict future glacier changes,estimate available freshwater resources,and assess potential sea level rise.Based on Ground-Penetrating Radar(GPR)thickness data from 31 glaciers in western China,the parameters of the GlabTop2(Glacier Bed Topography)model were calibrated and optimized.The simulation of ice thickness on the Qiangtang Plateau and the assessment of the total amount of glacier water resources revealed the following results:①The average ice thickness simulated by the GlabTop2 model closely matched the measured average thickness,with a correlation of 0.87 and root-mean-square error of 18.2 m.Overestimation and underestimation of ice thickness by the model were 9%and-17%respectively.The ice thickness distribution along flow was better captured than the distribution across flow;②The GlabTop2 model estimated that the ice storage of glaciers on the Qinghai-Xizang Plateau in 2022 was(177.6±26.6)km^(3),with an average ice thickness of(88.2±12.3)m.The glacier volume was mainly distributed between 5600 and 6200 m,amounting to(148.28±22.24)km^(3),which accounted for 84.4%of the total glacier volume of the Qiangtang Plateau.The glacial volumes in the other elevational bands were relatively small.