Prediction on Rapid shrinkage of summer-snow type glaciers

尼泊尔东部的冰川清单是根据地图、航空照片和实地调查编制的。对清查资料的分析表明，东部地区冰川萎缩明显，夏季风影响较强。在尼泊尔东部的昆布冰川和中部的利戎冰川上观测到覆盖着超冰碛的大型冰川。冰川厚度以1 ~ 2 m/年的速度减少；在过去的25年里，这一比率在最近几年一直在上升。对于没有超冰碛的小冰川，尼泊尔东部的AX010冰川和尼泊尔西部的Rikha Samba冰川自20世纪70年代以来一直在监测。人们认为，这些冰川正在加速萎缩，而且萎缩幅度比世界上其他冰川都要大。预测了AX010冰川在21c时消失的可能性。为了重建过去的环境变化，收集了雪/冰芯和树木年轮样本并进行了分析。在不丹喜马拉雅地区，首次与不丹皇家政府就冰川萎缩和冰川湖泊变化进行合作研究。结果表明，不丹的冰川萎缩幅度明显大于尼泊尔，冰湖溃决洪水的危险性在增加。还进行了观测，以建立冰川变化模式，以便进行未来预测。利用冰雷达在昆布冰川和黎陵冰川的厚冰上冰碛带成功地观测了冰川厚度这一冰川动力学的重要参数。通过热平衡测量研究了冰上冰碛对冰川融化的影响；对大型冰川的融化机制有了较好的了解，并将结果用于模拟。此外，在尼泊尔昆布、隐谷和肖龙地区以及不丹获取了自动气象记录，对气候与冰川变化的关系进行了基本分析。

Glacier inventory of east Nepal was compiled from maps, aerophotographs and field research. From analysis of the inventory data, it was clarified that glacier shrinkage was distinct in eastward region, where effect of summer monsoon is stronger. Large glaciers, which are covered with supra-glacial moraine, were observed on Khumbu Glacier in east Nepal and Lirung Glacier in central Nepal. Glacier thickness has been decreasing 1-2 m/year ; the rates have been increasing in recent several years during last 25 years. For small glaciers, which are free from supra-glacial moraine, Glacier AX010 in east Nepal and Rikha Samba Glacier in west Nepal have been monitored since 1970s. It was identified as shrinkage of these glaciers was accelerating and the shrinkage was stronger than other glaciers in the world. Possibility of disappearance of Glacier AX010 in 21c was predicted. To reconstruct the past environmental change, snow/ice cores and tree-ring samples were collected and have been under analyses.In Bhutan Himalayas, the first cooperative study was realized on glacier shrinkage and glacier lakes variations with Royal Government of Bhutan. It was clarified that glacier shrinkage in Bhutan was distincter than that in Nepal, and danger of glacier lake outburst flood was increasing.Observations to develop the model of glacier variation were also carried out for the future prediction. Glacier thickness which is important parameter of glacier dynamics was observed successfully with an ice radar in thick supra-glacial moraine zones on Khumbu Glacier and Lirung Glacier. Effect of the supra-glacial moraine on glacier melt was studied by heat balance measurements ; melting mechanism of large glaciers was well understood and the results have been utilized for the modeling. Moreover, automatic meteorological records were obtained in Khumbu, Hidden Valley and Shorong regions, Nepal and also in Bhutan for the basic analyses on the relation between climate and glacier variations.