Analysis on changes in typical glaciers and lakes on the Qinghai-Tibet Plateau based on remote sensing data

ZHANG Xiuzai; XU Dai; YANG Changjun; ZHANG Hao

doi:10.19513/j.cnki.hyqxxb.20250716001

Abstract：As a sensitive area to global climate change,the Qinghai-Tibet Plateau plays an important role in the climate system through the changes in glaciers and lakes.Based on the remote sensing imagery data from 2000 to 2023 and selected typical glaciers and lakes on the Qinghai-Tibet Plateau,the normalized difference snow index(NDSI)and Glacier-Unet method are used to extract the area of glaciers,and the area of lakes is extracted by combining the normalized difference water index(NDWI)and sentinel dual-polarized water index(SDWI).Meanwhile,by using the annual average temperature and annual precipitation data from neighboring weather stations,the principal component analysis is utilized to quantitatively reveal that rising temperatures directly drive glacier retreat by enhancing ablation,while the increased precipitation dominates lake expansion by enhancing lake inflow.The results are shown below.(1)The area of 7 typical glaciers decreases by 20.75 km2 cumulatively,and the retreat rate is decreasing from low latitude to high latitude.Temperature is the main driver of glacier retreat,and there are differences in the timing and magnitude of the response of different glaciers to the rising temperatures,but they all reflect the general trend of enhanced ablation and weakened accumulation in the context of long-term warming.(2)Ten typical lakes show an expansion trend,with the total area increasing by 757.55 km2,and the expansion is mainly concentrated in the endorheic lakes in the central-southern area.There are differences in the timing and magnitude of the response of different lakes to the changes in precipitation,but all of them reflect the general trend of expansion due to enhanced recharge and relatively insufficient evaporation and outflow in the context of long-term increase in precipitation.