摘要
利用国家卫星中心提供的1996—2002年冬半年(11月～翌年4月)的旬积雪数据、地面气象站温度和实测积雪数据,以及结合祁连山区DEM数据,研究了同期祁连山区积雪时空分布及其变化特征。结果表明:祁连山区冬半年积雪大多随山脉走向呈带状分布在山脊区,而山谷和南面盆地分布较少;积雪西段最多,东段次之,中段最少。祁连山区不同积雪频率所分布的平均高度的基本趋势为积雪频率越大分布的高度也越高。就不同频率的积雪而言,频率越低所占比例越大,频率越高所占比例越小;总体上祁连山区在1998/1999年冬季积雪达到最小值,在1998/1999年冬季之前呈波动变化,之后呈持续显著增加的趋势,但主要贡献在低频率。对祁连山东、中、西三段而言,东、中两段在1998/1999年冬季前呈减少趋势,1998/1999年冬季后呈增加趋势,东、中两段平均积雪频率变化量很接近;而西段从1996/1997年冬季开始呈缓慢增加的趋势,而且积雪平均出现频率明显要比东、中两段高很多。祁连山东、中、西三段积雪覆盖度随着高度增加而增大,只有中段在1999—2001年随着高度的递增积雪覆盖度增加不明显,变化趋势比较复杂,这可能与中段所受天气系统和地形等的影响比较复杂有关。
Using the dekad snow cover data in the winter half year of 1996-2002 provided by National Satellite Meteorological Center,combined with the temperature and snow data observed by meteorological ground stations and the DEM data of Qilian Mountains,the distribution and variation characteristics of snow cover in Qilian Mountains are studied.The results showed that the snow cover in Qilian Mountains had a band distribution with the mountains orientation in the winter half year,in ridge area with more snow,but in the valley and southen basin less.The characteristic of distribution frequency is that the highest is in west segment,then in east segment and the lowest in middle segment.The basic trend of average distribution height of different frequency snow cover is that the higher the snow cover frequency is,the higher the distributing height is.As far for the snow cover of different frequencies,the lower frequency takes the larger proportion. For mean snow cover frequency,the east and middle segments both is reducing trend reduced before the winter half year of 1998/1999 while increased after it,and the increment of mean snow cover frequency in east and middle segments are quite close,while the west segment increased in the winter half year of 1996/1997,and its mean snow cover frequency is higher than the east and middle segments significantly.The snow cover of three segments all increase as the height increases,only in middle segment of 1999 —2001 didn′t increase with height increasing apparently,it might has relation with the complex effects of weather system and topography in middle segment.
出处
《高原气象》
CSCD
北大核心
2010年第2期366-372,共7页
Plateau Meteorology
基金
国家自然科学基金重点项目"黄土高原陆面过程观测与试验研究"(40830957)资助
关键词
祁连山区
积雪频率
遥感
覆盖度
Qilian Mountains
Snow frequency
Remote sensing
Coverage
