Spatio-temporal Variation of Summer Precipitation at Different Altitudes in Xizang During 1981-2023

Li Jihong; Wang Teng; Liu Yi; Liu Shengsheng; Guo Yinan

doi:10.16765/j.cnki.1673-7148.2025.03.002

Abstract：Based on daily precipitation data from 38 meteorological stations across Xizang Autono-mous Region during the summer months(June to August)from 1981 to 2023,the temporal and spatial variations of light and moderate rainfall amount,rainy days and rain intensity at different altitudes in Xi-zang are analyzed.The results show that the summer light and moderate rainfall amount,rain days and rainfall intensity at different altitudes in Xizang show significant interannual and interdecadal changes,and their trends all show a decrease in low-altitude areas but an increase in mid-and high-altitude areas.The climate tendency rates of rainfall amount,rainy days and rainfall intensity for light and moderate rainfall in different altitude regions of Xizang are-1.6-2.2 mm·(decade)-1 and-2.7-6.5 mm·(decade)-1,-0.6-0.7 d·(decade)-1 and-0.1-0.3 d·(decade)-1,-0.5-0.8 mm·(d·1000 years)-1 and-0.1-0.2 mm·(d·decade)-1,respectively.The light and moderate rainfall amount,rainy days and rainfall intensity in Xizang are generally distributed in the pattern of higher in the central and eastern part but lower in the western part,which is positively correlated to altitudes.The meteoro-logical stations having the upward trends are mainly located in the high-altitude areas of central Xizang,while the stations with the downward trends are situated in the low-and mid-altitude areas of the central and eastern Xizang.Among the 38 meteorological stations,the variation trend of light rain is primarily driven by changes in the number of rainy days at 13 stations and by changes in rainfall intensity at 25 sta-tions.For moderate rainfall,the variation trend is mainly influenced by changes in the number of rain days at 6 stations and by rainfall intensity at 32 stations.