基于站点的中国天山山区积雪要素变化研究

A Study of the Snow Factors Temporal and Spatial Variation in the Tianshan Mountains Based on Weather Stations Data

选取1961—2006年天山山区海拔高于1 000 m的17个气象站的月积雪日数、月最大积雪深度资料,分析天山山区季节性积雪年际变化趋势,探讨17个站点在最大雪深出现月份和海拔之间的相关性以及积雪日数和月最大雪深变化趋势的类型,以及积雪变化的气候归因。结果表明:①按最大雪深出现的月份,天山山区积雪类型可分成4种,分别是1月、2月、3月和双峰。最大雪深出现月份的早晚和海拔高度有着很好的相关性,随着海拔高度的升高,出现的月份也越推后。②积雪日数和最大积雪深度近46年来都呈现略微的增加趋势,几乎所有站点的冬季积雪日数都占全年积雪日数的50%以上,最大雪深出现的年份和月份有很大的差异,90年代之后最大雪深出现的次数明显增多。③根据积雪日数和最大雪深的变化趋势,可将站点的积雪变化类型分为3种:增加和减少同步、积雪日数减少而最大雪深增加、积雪日数增加而最大雪深减少。④分析17个站点月降水量、月平均温度、月空气湿度和全年小于0℃天数的变化趋势,得出天山山区积雪增加的主要原因是冬季降水量和月空气湿度的明显增加。

By using the date of snow cover days and snow depth of 17 weather stations which above 1 000 m above sea lerel during the year of 1961-2006 in Tiashan Mountain,Xinjiang Uighur Autonomous Region,china,the inter-annual temporal and spatial characteristics were analyzed.Based on the time of the most snow depth days appeared,the 17 weather stations were divided into 4 types,and by integrating the change trend of the snow cover days and snow depth,we found three types of change trend.The results showed that： ①There are four snow depth types in Tianshan Mountains.The most snow depth occurs in January,February,March and double maximal values.The month of the most snow depth has a good relationship with the elevation.②Both the snow cover days and maximum snow depth are both increase.Winter snow cover days occupy 50 percents of the whole year and,the maximum snow depth occur frequency became increasing trend in the 90th.③Based on the change trend of snow cover days and maximum snow depth,there are three types of snow change.There are no change trend between snow cover days and elevation,but there are an obviously increasing trend between maximum snow depth and elevation.④Based on the analysis of precipitation,temperature,humidity and the temperature below 0 ℃ days,the main reason of snowcover increase is because of the increasing of winter precipitation and humidity.