Spatial-temporal variability of snow cover over the Amur River Basin inferred from MODIS daily snow products in recent decades

• 作者: XiaoLin Lu WanChang Zhang ShuHang Wang Bo Zhang QuanFu Niu JinPing Liu Hao Chen HuiRan Gao
• 来源期刊: 寒旱区科学（英文版）
• 年，卷（期）: 2020,（6）
• 所属期刊栏目: Articles
• 页码范围: 418-429
• 页数: 12页
• 语种: 英文

摘要

MODIS snow products MOD10A1\MYD10A1 provided us a unique chance to investigate snow cover as well as its spa-tial-temporal variability in response to global changes from regional and global perspectives. By means of MODIS snow products MOD10A1\MYD10A1 derived from an extensive area of the Amur River Basin, mainly located in the Northeast part of China, some part in far east area of the former USSR and a minor part in Republic of Mongolia, the reproduced snow datasets after removal of cloud effects covering the whole watershed of the Amur River Basin were generated by us-ing 6 different cloud-effect-removing algorithms. The accuracy of the reproduced snow products was evaluated with the time series of snow depth data observed from 2002 to 2010 within the Chinese part of the basin, and the results suggested that the accuracies for the reproduced monthly mean snow depth datasets derived from 6 different cloud-effect-removing algorithms varied from 82％to 96％, the snow classification accuracies (the harmonic mean of Recall and Precision) was higher than 80％, close to the accuracy of the original snow product under clear sky conditions when snow cover was sta-bly accumulated. By using the reproduced snow product dataset with the best validated cloud-effect-removing algorithm newly proposed, spatial-temporal variability of snow coverage fraction (SCF), the date when snow cover started to accu-mulate (SCS) as well as the date when being melted off (SCM) in the Amur River Basin from 2002 to 2016 were investi-gated. The results indicated that the SCF characterized the significant spatial heterogeneity tended to be higher towards East and North but lower toward West and South over the Amur River Basin. The inter-annual variations of SCF showed an insignificant increase in general with slight fluctuations in majority part of the basin. Both SCS and SCM tended to be slightly linear varied and the inter-annual differences were obvious. In addition, a clear decreasing trend in snow cover is observed in the region. Trend analysis (at 10％ significance level) showed that 71％ of areas between 2,000 and 2,380 m a.s.l. experienced a reduction in duration and coverage of annual snow cover. Moreover, a severe snow cover reduction during recent years with sharp fluctuations was investigated. Overall spatial-temporal variability of Both SCS and SCM tended to coincide with that of SCF over the basin in general.