祁连山区风吹雪对积雪质能过程的影响

风吹雪是山区积雪水文过程的重要组成部分. 采用祁连山区冰沟流域2008年积雪期观测数据, 通过对风吹雪实地观测分析、风吹雪的发生概率、风吹雪迁移以及风吹雪升华等分析, 从野外观测、计算模拟两个方面对祁连山区风吹雪质能过程进行了详细探讨. 结果表明: 位于流域海拔较高处(海拔4 146 m)的研究区垭口站, 风吹雪现象较为显著, 因之造成的积雪重新分布极为严重. 垭口站风吹雪频发于冬季及初春融雪未发生时, 积雪在风速作用下迁移量较大; 而进入融雪期之后, 因气温上升、雪面融化以及再冻结, 风吹雪发生概率急剧减小. 风吹雪在积雪升华中占有较大比重, 2008年积雪期, 垭口站风吹雪升华估算值约占积雪升华(包括雪面升华)的41.5%.

Influence of Blowing Snow on Snow Mass and Energy Exchanges in the Qilian Mountainous

Blowing snow is an important part of snow hydrologic processes in mountainous regions. However, the research of it is rare in the Qilian Mountainous, where blowing snow is frequent. Using the observation data in 2008 snow season in Binggou watershed in the Qilian Mountainous, the energy and mass processes of blowing snow are studied in detail by both field observation and model simulation. The results include the analysis of snow observation, the occurrence probability of blowing snow, blowing snow transport and blowing snow sublimation. The results indicate that blowing snow is obvious in high altitude region (4 146 m a.s.l.), and the snow redistribution phenomenon is remarkable. In Yakou Station of the mountains, blowing snow occurs frequently in midwinter and early spring, when there is no melting, and the blowing snow transport is dominated; when snowmelt begins, the occurrence probability of blowing snow decreases rapidly, because of the increasing air temperature, snow melting and refreezing. The blowing snow sublimation accounts for 41.5% of total sublimation in Yakou Station.