科学监测新疆叶尔羌河流域山区积雪面积及其变化特征对该区域的气候研究、雪水资源开发利用、环境灾害预报和生态环境保护等方面有重要意义.利用2000—2012年近13a的MOD10A2积雪产品提取研究区域内积雪,结合DEM数据分析研究区内积雪面积的动态变化特征.结果显示:新疆叶尔羌河流域山区的积雪面积的年际变化幅度较大,其中,2005年和2009年积雪面积较大,2007年则为典型少雪年;年内变化差异显著,总体上呈现“M”型的特点,12月和3月处于高位,2月和8月处于低谷.叶尔羌河流域山区积雪覆盖率随着海拔的上升逐渐增大,稳定积雪主要分布在海拔5000m以上的地区;不同坡向的积雪覆盖率差异比较明显,西北坡、东坡、东北坡的积雪覆盖率比北坡、东南坡、西坡、南坡的积雪覆盖率高,西北坡高达52.8%,南坡仅为20%.叶尔羌河流域山区的积雪面积与气温呈负相关,与降水量呈正相关,积雪面积变化对气温因素更为敏感.
To monitor scientifically the snow cover in the mountain region of the Yarkant River basin has impor- tant significance for researching climate, development and utilization of snow meltwater, forecast of natural dis- asters and ecological protection. In combination of DEM data, the dynamic changing features of snow cover were analyzed by snow cover area (SCA)extracted from the snow products of MOD10A2 between 2000 and 2012. The results are as follows: ( 1 ) The annual change of SCA in the mountains was large, with large area in 2005 and 2009 but small area in 2007; the monthly change of SCA in the mountains was significantly different too, high in December and March but low in February and August. (2) The coverage of snow increased gradually with altitude, with a stable snow cover range above the altitude of 5 000 meters; the snow cover ratio changed with slopes; the snow coverage was higher in northwest, east and northeast slopes than that in the north, south- east, west and south slopes, e. g. , on the northwest slope it was 52.8% but on the south slop it was 20% ; (3) The snow coverage, which was sensitive to climatic factors, positively related to air temperature and negatively related to precipitation.