Analysis on the Changes in Area and Its Influencing Factors of Yamdrok Lake from 1990 to 2024

Danzeng Danda; Basang Luobu; Gesang Danba

doi:10.3969/j.issn.1004-3403.2025.04.007

Abstract：Utilizing Landsat remote sensing imagery and meteorological data from 1990 to 2024,this study calculat-ed the Normalized Difference Water Index(NDWI)through multi-temporal images,combined with the K-means clustering method to calculate the area of Yamdrok Lake.A univariate linear fitting method was employed to ana-lyze its changing trend.Yamdrok Lake experienced significant expansion from 1996 to 2004 due to increased precipi-tation and meltwater input,which exceeded the output.From 2004 to 2014,the lake underwent a marked contraction-attributed to escalated evaporation due to rising temperatures,with no significant changes in meltwater and precipita-tion input,leading to input being less than output.Fourier Transform analysis on the temporal characteristics of the lake area revealed low-frequency characteristics in its changing pattern.On different timescales,the mechanisms in-fluencing changes in the lake area vary with precipitation,temperature and snow cover.In the low-frequency chang-es of more than 15 years(0.03 Hz,0.06 Hz),the lake area showed a weak correlation with precipitation,primarily in-fluenced by rising temperatures and snowmelt,involving changes in evaporation andpromotion or inhibition of snow-melt.Within the 10～15-year period range(0.09 Hz,0.12 Hz),changes in the lake area were co-regulated by precipita-tion and temperature,affecting the balance between lake water input and output.Climate warming is the primary-driver for changes in the lake area on decadal scales.