1961-2017年青海高原降雪时空变化分析研究

基于1961-2018年青海高原47个台站观测资料，分析了青海高原降雪量、降雪日数的时空演变特征，结果表明：青海高原地区降雪量呈明显的减少趋势，每10年减少3.7 mm，其中1981-1989年、1990-1999年为降雪量偏多期，2000年以来为降雪量偏少期；近57年来青海高原降雪平均日数为11～43 d，青海高原降雪日数及各量级降雪日数总体均无明显趋势性变化，但存在阶段性变化；青海高原降雪量及降雪日数除常年干旱区柴达木盆地均为低值区外，其余地区高海拔地区多于低海拔地区，南部多于北部；青海高原月平均降雪量呈“U”型分布，而月平均降雪日数呈单峰型分布，降雪日数在冬季中末期偏多，春季偏少，其中小雪以上量级降雪日数易发生在秋末冬初，冬末向春季转换的时段内；近57年来青海高原降雪量在2002年前后存在明显的突变现象，其中青南牧区、青海湖地区及东部农业区年降雪量分别在2001年，1996年以及1996年前后存在明显突变现象，柴达木盆地降雪量无明显突变现象；而青海高原降雪日数在2000年前后存在明显突变现象，其中青南牧区1980年、2001年前后存在明显的突变现象，其余3个地区降雪日数无明显突变现象。

Research on the spatiotemporal variation characteristics of snowfall in the Qinghai Plateau from 1961 to 2017

The temporal and spatial variations of snowfall and snowfall days were analyzed based on observations at 47 meteorology stations in Qinghai Plateau from 1961 to 2018 using the methods of running t-test and spatial variable ration. The results indicated that:(1)There was a significant decreasing tendency of snowfall with the rate of 3.7 mm every decade,together with two more snowfall decades in the 1980s and the 1990s,and a less snowfall decade in the 2000s. (2)The mean snowfall days were 11~43 days in the 57 years in the plateau; snowfall days and different levels of snowfall days had no obvious tendency,but had a stage variation. (3)Except for the drought Qaidam Basin,the spatial distributions of snowfall and snowfall days were larger in high altitude area than in low altitude area,and reduced from south to north. (4)Snowfall showed U-shape distribution and snowfall days showed single peak distribution in the research period;snowfall days were more in the late autumn and early winter. (5)There was a remarkable abrupt change of snowfall in 2002 in the plateau,There were obvious abrupt changes in Qingnan pastoral area(2001),Qinghai lake area(1996)and the eastern agricultural area(1996),but no obvious abrupt change in Qaidam Basin;meanwhile,there was a remarkable abrupt change of snowfall days in 2000 in the Qinghai Plateau;Qingnan pastoral area had two abrupt changes in 1980 and 2001,but no obvious change in other regions.