Glaciers in the Yarlung Zangbo River witness severe glacial retreat nowadays,which gives important influence on lake processes in the region.We have studied glacial distribution,glacial mass balance and found large deficit in glacial mass and its impact in the region.Our study also integrated the variation in glacial-fed lakes of the Nam Co and Ranwu Lake,and presented an initial assessment of the impact of glacial mass balance on lakes.The study has shown a significant contribution of glacial melting to recent lake expansion and lake level rising.
YAO TanDongLI ZhiGuoYANG WeiGUO XueJunZHU LiPingKANG ShiChangWU YanHongYU WuSheng
This paper calculated and evaluated the area and ice volume changes of Kangwure Glacier in Mt.Xixiabangma,middle of Himalayas in the past 3 decades,based on the field survey of glacier boundary position by differential GPS and glacier depth by Ground Penetrating Radar(GPR),together with the topographic map and remote sense data.The studied data showed that the Kangwure Glacier has experienced significant mass deficit since the 1970s,with 34.2%of area loss,48.2%ofice volume loss and 7.5 m of average thickness decrease.This result revealed that the ice volume loss of Himalayan glaciers was more serious than expected.Analysis of meteorological data from two weather stations in the region of Mt.Xixiabangma,shows that the air temperature of this region has risen from the middle of the 20th century to the beginning of the 21st century.Significant retreat of Himalayas glacier driven by climatic warming will have a remarkable impact on hydrology and ecosystem.
Little is known about recent variation of temperate glaciers on the Tibetan Plateau,although they are of particular theoretical and practical interests in terms of climate change and water supply.The study of glacier mass balance and terminus variation for six temperate glaciers in the Parlung Zangbo River basin,southeast Tibetan Plateau,shows the facts of the overall negative mass balance and the continued terminus retreat from 2005/2006 to 2007/2008.The mass balances of smaller glaciers were more negative compared to larger glaciers.Referring the trend of glacier mass balance in the Hengduan Mountains,the Himalayas and glacier shrinkage in southeast Tibetan Plateau,the mass loss and recession of temperate glacier in this region are expected if the current climate condition continues.
YANG WeiYAO TanDongXU BaiQingMA LingLongWANG ZhiHuiWAN Ming
Based on the glacier mass balance and meteorological data of air temperature and precipitation on the Qiyi Glacier from June 30 to September 5,2010,we used a degree-day mass balance model to simulate the change of mass balance during this period.Our results indicate that the current value of the mass balance is 856.2 mm w.e.Subjected to the strong influences of air temperature and precipitation,the mass balance process can be divided into three stages:accumulating exiguously → melting intensively → melting exiguously.The variation trends of the mass balance according to the degree-day mass balance model and the observed values are similar and wholly reflect the spatial distribution characteristics of the glacier mass balance,which increases with the increase of altitude.Our experiment on climate sensitivity of the mass balance showed that mass balance was very sensitive to the change of temperature;air temperature is the key factor which influences mass balance;and a slight increase in precipitation will have a negligible effect on mass balance when the air temperature increases continuously.
