1980—2009水文年青藏高原积雪物候时空变化遥感分析

以青藏高原积雪为研究对象,首先对长时间序列逐日雪深被动微波遥感数据进行预处理,获得青藏高原1980—2009水文年逐日雪深数据,然后逐像元计算出每个水文年平均积雪深度、开始日期(SCS)和结束日期(SCE),利用GIS空间分析和地学统计方法系统分析20世纪80年代、90年代和21世纪初青藏高原积雪物候变化特征和异常分布。结果表明：青藏高原积雪深度在20世纪80年代呈递减趋势,20世纪90年代后开始呈现递增趋势。20世纪80年代青藏高原除阿尔金山和昆仑山以外的高海拔山区SCS呈提前趋势,青藏高原高海拔地区SCE呈推迟趋势;20世纪90年代青藏高原高海拔地区的SCS提前趋势减弱,而高原中部腹地SCS出现显著的提前趋势,高原高海拔地区SCE呈提前趋势,高原中部腹地SCE呈推迟趋势;进入21世纪初后帕米尔高原、念青唐古拉山和横断山脉SCS呈推迟趋势,横断山、念青唐古拉、巴颜喀拉山SCE呈提前趋势。总体上,青藏高原积雪物候变化存在明显的空间差异和不同演变规律。

Spatio-temporal changes of snow phenology in the Qinghai-Tibetan Plateau during the hydrological year of 1980-2009

Taking the Qinghai-Tibetan Plateau as the object of study, based on the daily dataset of snow depth from 1980 to 2009, the mean snow depth, snow cover start (SCS) and snow cover end (SCE) dates were calculated for each hydrological year, and the spatial and temporal variations and distribution anomaly of them were analyzed by using the spatial and statistics analysis function of GIS. The results showed that, mean snow depth decreased during the period of 1980-1989, and started to increase from the 1990s. In the 1980s, the SCS showed a significantly advanced trend, which mainly occurred in the high altitude region of the Qinghai-Tibetan Plateau except the Altun Mountains and Kunlun Mountains. The SCE showed a significantly delay, occurred in the high altitude region. In the 1990s, the advanced trend of SCS in the high altitude region showed a slightly delayed trend, but the SCS in the central plateau hinterland showed a significantly advanced trend. The SCE in the high altitude region became weak. And the SCE in the central plateau hinterland showed a delayed trend. In the beginning of the 21st century, the SCS in the Pamir Plateau, Nyainqentanglula Mountains and Transverse Mountains showed a significantly delay trend. The SCE in the Hengduan Mountain, Nianqing Tanggula and Bayan Hara Mountain showed a significantly advanced trend. Generally, the snow phenology showed different spatial patterns and evolution trends in different regions.