近50a来天山博格达峰地区四工河4号冰川表面高程变化特征

基于GIS技术,利用GPS测量数据和1962年地形图分别建立两期DEM,通过对比重点研究了四工河4号冰川1962-2009年冰舌区的表面高程变化特征。结果表明:1962-2009年间,冰舌区平均减薄15±10 m,年均减薄约0.32±0.2 m,冰储量亏损达(14.3±9.5)×10-3km3,折合水当量(12.9±8.6)×10-3km3。不同海拔、坡度区间冰面高程变化差异显著,海拔较低、坡度较缓区域的变化最为强烈。在气候变暖的趋势下,四工河4号冰川发生强烈消融,标志着博格达峰地区的冰川正处于物质严重亏损的状态,直接影响到流域水资源状况。     

2009年喀喇昆仑山叶尔羌河冰川阻塞湖及冰川跃动监测

在气候变化的影响下,喀喇昆仑山叶尔羌河冰川突发洪水近几年频繁发生.2009-05-09,利用中国环境减灾卫星(HJ-1A/1B)影像,对叶尔羌河上游冰川突发洪水的源头进行了动态监测.在克亚吉尔冰川末端发现了冰川阻塞湖,并监测到其不断扩大.2009-08初该处冰川湖突然消失,同期影像显示其消失后,河谷中残留大量冰体,与往年情况差异巨大.结合相关水文记录及历史资料分析认为,极有可能是冰川末端突然前进(跃动)使冰川坝遭到破坏,导致冰川阻塞湖泄水.由此推测克亚吉尔冰川发生了罕见跃动现象,但需要进一步研究验证.     

走进香巴拉

香巴拉,又叫“香格里拉”,是佛教所说佛国净土之意。藏语的含义是“神仙住的地方”,引申为“令人向往的美好地方”。香巴拉的核心禁区在四川稻城亚丁。稻城亚丁这个地处川、滇、藏三省区结合部,横断山脉中南部高山深谷的不知名的地方,在短短的两三年间,便成为众多旅游发烧友心目中的圣地净土,也成了地学工作者进行野外考察的天然博物馆和研究第四纪冰川地貌的重要基地。     

基于MODIS数据的南极洲冰川变化情况遥感调查与分析

南极洲生态环境是世界各国研究的热点。本文利用2003年和2010年两期MODIS数据对南极洲大陆冰川及其冰架进行遥感调查与分析,获得南极洲2003年和2010年两期冰川及冰架类型、面积等信息,并通过监测初步掌握了南极洲冰川变化情况,进一步对其变化原因及其变化趋势进行初步研究和分析。     

Current climate change effects on the ground thermal regime in Central Yakutia

The evolution of ground thermal state has been studied to assess impacts of current climatic warming on permafrost in Central Yakutia. The analysis of long-term data of regional weather stations has revealed one of the highest increasing trends in mean annual air temperature in northern Russia. A forecast of surface air temperature fluctuations has been made by applying a frequency analysis method. Monitoring of ground thermal conditions allows us to identify inter-annual and long-term variability among a wide range of natural conditions. Experimental research has indicated a long-term dynamics of ground thermal state evolution： ground temperatures at the depth of zero annual amplitude and seasonally thawed layer depth. Long-term variability of thaw depth shows near-zero to weak positive trends in small valleys in contrast to weak negative trends on slopes. With significant climatic warming, the thermal state of near-surface layers of permafrost demonstrates steadiness. Anthropogenic impacts on ground thermal regime in various terrain types have been qualitatively evaluated. Clear-cutting, ground cover stripping, and post-fire deforestation in inter-alas type terrains result in a significant increase of temperature and seasonal ground thaw depth, as well as adverse cryogenic processes. The dynamics of mean annual ground temperature in slash and burn sites have been evaluated in reference to stages of successive vegetation recovery.