【摘要】 基于2015—2023年乌东德上游流域IMS遥感积雪产品（水平分辨率为1 km×1 km），结合地形及气象数据，分析乌东德上游流域积雪时空变化特征及气象要素、地形和土地利用对积雪覆盖率（Snow Cover Ratio,SCR）、积雪覆盖频率（Snow Cover Frequency,SCF）的影响。结果表明：乌东德上游流域SCR年平均值16.43%，季节变化明显，冬季最稳定、夏季最不稳定，年均积雪增加、消融日数分别为107 d、176 d,11月—次年4月“降雪部分消融”现象频发，对春季融雪径流贡献较大的区域集中在青海东部和四川北部。气象要素中，气温与SCR的关系最为密切，SCR随温度升高而逐渐减小，日照时数仅对SCR有间接影响，积雪大多发生在日总降水量<1 mm时；地理要素中，海拔高程是积雪时空分布的决定性因素，同海拔高程SCF表现为冬季>春季>秋季>夏季，而坡向和土地利用方式对SCF影响小，雪水当量与SCR的时间变化特征具有较好的一致性。更多还原

【Abstract】 Based on the IMS remote sensing snow products with 1 km resolution from 2015 to 2023, combined with DEM and meteorological data, this study analyzed the spatio-temporal variation characteristics of snow cover in the upper basin of Wudongde hydropower station, and the effects of meteorological elements, terrain and land use on snow cover ratio(SCR) and snow cover frequency(SCF). The results showed that the annual mean SCR in the basin was 16.43%, with obvious seasonal variation.,which was the most stable in winter and the least stable in summer. The annual average snow increase and melt durations were 107 days and 176 days, respectively.The phenomenan of snowfall and partial melting were frequent from November to the following April. The large runoff of spring snowmelt was concentrated in eastern Qinghai and northern Sichuan. Among meteorological elements, the most closely related to SCR was air temperature, which decreased with increasing temperature. The sunshine duration affected SCR indirectly. The snow accumulation process mostly occurred when precipitation was small, mostly when the total daily precipitation was less than 1mm. Among the geographical factors, the elevation was the domainn factor of the spatio-temporal distribution of snow cover, and the SCF of the same elevation followed the order: winter>spring>autumn>summer. However, the topographic slope and land use types had little effect on SCF. The temporal variation characteristics of snow water equivalent showed good consistency with those of SCR.更多还原