2002-2011年新疆积雪时空分布特征研究

Temporal and Spatial Distribution of Snow Cover in Xinjiang from 2002 to 2011

基于2002-2011年的MODIS积雪产品数据, 对新疆积雪的年际变化特征、年内变化特征及空间分布特征进行了分析.结果表明： 年内积雪从10月中旬开始建立, 于1月面积达到最大, 7月面积达到最小.其中, 冬季积雪面积所占比例最大, 夏季最小. 2002-2011年新疆积雪面积总体上呈减少趋势. 其中, 春季和冬季为减少趋势;夏季的积雪由于其基本上都是高海拔的永久性积雪, 故比较稳定, 变化趋势不明显;秋季为上升趋势.新疆积雪空间分布极不均匀, 北疆积雪分布明显多于南疆.山区为积雪覆盖频次的高值区, 盆地为积雪覆盖频次的低值区.永久性积雪在阿尔泰山脉分布较少, 主要分布在天山山脉和昆仑山脉.就永久性积雪面积而言, 分布在海拔5 000~6 000 m的面积最大, 其次是海拔4 000~5 000 m, 再次是海拔6 000~7 000 m.

Based on MODIS snow cover data from 2002 to 2011, the temporal and spatial distribution characteristics of the snow cover in Xinjiang are investigated. It is found that snow deposit starts in mid-October, and snow cover achieves the maximum depth in January and the minimum depth in July. In a year, snow-covered area （SCA） in winter is the largest, and that in summer is the least. The SCA in Xinjiang was decreasing from 2002 to 2011. Seasonally, there was a decreasing trend in spring and winter, no obvious changing trend in summer, and an increasing trend in fall. In summer, only permanent snow cover existed in high altitudes, which was rather stable. Spatially, distribution of SCA was uneven in Xinjiang. The SCA in North Xinjiang is more than that in the South Xinjiang. High frequency regions of snow cover were located in mountains, and low frequency regions in basins. The permanent SCA was the maximum in the Kunlun Mountains, followed by the Tianshan Mountains and was the minimum in the Altay Mountains. Looking along altitude, the permanent SCA was the maximum in the altitude from 5 000 m to 6 000 m, followed by that from 4 000 m to 5 000 m and then from 6 000 m to 7 000 m.