中国天山西部山区森林积雪消融过程观测分析——以巩乃斯河谷为例  

Ablation process of forest snow in the western Tianshan Mountain,China:a case of Kunes River valley

作　　者：陆恒[1,2] 魏文寿[3] 刘明哲[1,4] 韩茜[3] 洪雯[1,2] 

机构地区：[1]中国科学院新疆生态与地理研究所,新疆乌鲁木齐830011 [2]中国科学院大学,北京100049 [3]中国气象局乌鲁木齐沙漠气象研究所,新疆乌鲁木齐830002 [4]中国科学院天山积雪与雪崩研究站,新疆乌鲁木齐830011

出　　处：《干旱区地理》2015年第5期936-947,共12页Arid Land Geography

基　　金：国家科技支撑计划项目(2012BAC23B01);国家自然科学基金(41271098;41171066)

摘　　要：通过对2013年春季中国科学院天山积雪与雪崩研究站区内阳坡无林地和阴坡不同开阔度森林内积雪深度、融雪速率以及常规气象的观测,分析了融雪期不同开阔度森林积雪的消融过程以及积雪表面能量平衡特征。结果表明：不同开阔度林冠下积雪深度具有相同的变化趋势,森林的林冠开阔度越大,林下积雪深度越大,林下积雪开始消融和完全消融的时间越晚,消融期也越长。森林积雪融雪开始和结束时间比阳坡无林地区晚20-30 d左右。融雪前期林冠开阔度越大,其林下融雪速率越小。融雪后期则森林开阔度越大,森林积雪的融雪速率越大。不同时期由于不同开阔度林冠下雪面能量收支以及雪层深度等物理特性的差异,从而使不同开阔度林冠下森林积雪融雪速率的相对大小,融雪速率最大值出现时间和日变化特征均不相同。晴天森林积雪的消融速率和日变化特征取决于净短波辐射和长波辐射变化特征。降水期间,其融雪速率的变化则主要受降水形式、降水量以及积雪深度等雪层特性的影响。The air temperature,relatively humidity,wind speed,shortwave and longwave radiation beneath forest with different canopy openness were recorded by automatic weather station,the snowmelt rate was measured by snow lysimeter. The energy budget on snow surface was calculated according to these meteorological factors beneath forest. This paper mainly analyzed the characteristics of the snow ablation process,and how the energy budget influence the snow ablation process beneath forest with different canopy openness. The results showed the differences of snow ablation process beneath forest with different canopy openness were decided by the snow equivalent water content and energy budget on snow surface. The snow depth beneath forest with different canopy openness have the same changing tendency. The bigger the canopy openness was,the shallower the snow depth was,the longer the duration of snowmelt period was. The snowmelt rates beneath forest with different canopy openness was increased with time. The beginning and the end time of forest snow melt was 20-30 days later than snow melt on sunny slope. In the early snowmelt period,the larger the canopy openness was,the higher the snowmelt rates was,but the relationships between forest snowmelt rate and canopy openness in late snowmelt period was contrary to that on early snowmelt period. The snowmelt rates beneath different canopy openness have the similar daily variation. The daily variation of snowmelt rate showed the shape of single peak type in the clear day,and the curve was similar to positive skewness distribution. The variation of snowmelt rate in precipitation was mainly affected by the precipitation form,amount of precipitation,snow depth and other physical property of snow. Due to the difference of energy budget and physical property of snow beneath forest with different canopy openness between different snowmelt period,the snowmelt rate and the daily variation of snowmelt rate beneath forest with different canopy openness was different. The forest snowmelt rate

关 键 词：融雪期 森林积雪 积雪深度 融雪速率 能量收支 

分 类 号：P426.635[天文地球—大气科学及气象学]