A robust error estimation method for glacier elevation change using ICESat-2 laser photon and SRTM data
Glaciers are very sensitive to climatic and environmental changes,and are closely linked to changes in water resources and geological disasters.Under the influence of global warming,the melting of glaciers on the Qinghai-Xizang Plateau and its surrounding areas is on the increase.This paper addresses the problem that the large difference in the quality of ICESat-2 laser photon data under different terrain conditions leads to a large error in the glacier elevation change volume estimation when monitoring glacier elevation change using ICESat-2 satellite photon point cloud data,using Qiaqing Glacier,China's largest oceanic glacier on the Qinghai-Xizang Plateau,as an example.Using ICESat-2 laser altimetry data and 30 m resolution SRTM DEM products,we pro-pose a multifunction fitting glacier elevation change estimation error correction model with a robust estimation criterion that reduces the glacier elevation change estimation error caused by terrain slope;then,we estimate the elevation change and mass change of Qiaqing Glacier between 2000 and 2021.The results show that the multi-function correction models proposed in this paper can effectively improve the accuracy of the elevation change monitoring results.Meanwhile,the correction effect of the function model incorporating robust estimation is bet-ter compared with the corresponding traditional least squares estimation results.Subsequently,the effectiveness and feasibility of the error correction model can be demonstrated by cross-validating the correction results with multiple data.The model can effectively improve the accuracy of extracting glacier elevation and mass change information,and it was concluded that the glacier elevation change rate of the study area during the 21-year peri-od was approximately(-0.52±0.56)m·a-1,and the glacier mass change was about-1 277.38 million tonnes.In addition,combined with the meteorological data,the annual and monthly average temperature and precipita-tion data are analyzed,and the overall temperature rise and precipitation fluctuation decline were the main reasons for glacier melting in 21 years.Combined with the data of glacier elevation changes in different seasons,it was also analyzed that spring and winter were the accumulation periods of glaciers,while summer and autumn were the melting periods of glaciers.At the same time,it can be predicted that the glacier will continue to melt in the short term in the future.The situation of continuous degradation and melting of the glaciers is not optimistic.
NETL
NSTL
万方数据
