Analysis of the Variation Characteristics of Temperature and Precipitation on the Qinghai-Xizang Plateau from 1961 to 2020

基于青藏高原1961~2020年的逐月气温和降水栅格数据，采用气候倾向率法、滑动平均法等方法，系统分析了近60 a来青藏高原气候变化的时空分布特征。结果表明：1) 1961~2023年青藏高原降水总体呈显著增加趋势，速率为5.05 mm/10a，空间上由东南向西北递减，气候倾向率在−23.55~31.47 mm/10a之间，同时降水量在垂直梯度上具有明显的海拔分异性。小波分析揭示降水存在36 a主周期和10~15 a副周期，表现为典型的多尺度波动特征。2) 四季降水量均呈上升趋势，以春季最为显著(2.77 mm/10a)，夏季为主要降水期(占全年58.42%)，冬季最少(仅占3.95%)。季节分配不均，各季降水空间分布与年降水一致，表现为东南高、西北低。3) 年均气温显著上升，速率为0.22℃/10a，空间上东南较高、中西部较低。气候倾向率介于0.01~0.39℃/10a之间，气温随海拔升高明显降低，4500 m区降至−7.6℃，呈现典型的垂直递减特征。小波分析显示气温存在28 a主周期和8~10 a副周期，周期性升温波动明显。4) 四季平均气温均升高，冬季最显著(0.32℃/10a)，升温空间分布异质性明显，东南部升幅高于中西部及西北高海拔区。Based on the monthly temperature and precipitation grid data of the Plateau from 1961 to 2020, the spatio-temporal distribution characteristics of climate change on the Qinghai-Xizang Plateau over the past 60 years were systematically analyzed using methods such as the climate trend rate method and the moving average method. The results show that: 1) From 1961 to 2023, the precipitation on the Qinghai-Xizang Plateau has generally shown a significant increasing trend, with a rate of 5.05 mm/10a. Spatially, it decreases from southeast to northwest, and the climate trend rate ranges from −23.55 to 31.47 mm/10a. Meanwhile, the precipitation shows obvious altitude differentiation in the vertical gradient. Wavelet analysis reveals that the precipitation has a main cycle of 36 years and a secondary cycle of 10 to 15 years, demonstrating typical multi-scale fluctuation characteristics. 2) The precipitation in all four seasons shows an upward trend, with the most significant increase in spring (2.77 mm/10a). Summer is the main precipitation period (accounting for 58.42% of the annual total), while winter has the least precipitation (only 3.95%). The seasonal distribution is uneven, and the spatial distribution of precipitation in each season is consistent with the annual precipitation, showing a pattern of high in the southeast and low in the northwest. 3) The annual average temperature has significantly increased, with a rate of 0.22˚C/10a. Spatially, it is higher in the southeast and lower in the central and western regions and the high-altitude areas in the northwest. The climate trend rate ranges from 0.01 to 0.39˚C/10a. The temperature decreases significantly with increasing altitude. The annual average temperature in the 4500 m area, showing a typical vertical decreasing feature. Wavelet analysis indicates that the temperature has a main cycle of 28 years and a secondary cycle of 8 to 10 years, with obvious periodic warming fluctuations. 4) The average temperature in all four seasons has increased, with the most significant increase in winter (0.32˚C/10a). The spatial distribution of warming is heterogeneous, with a higher increase in the southeast than in the central and western regions and the high-altitude areas in the northwest.