Because of the large number and remoteness, satellite data, including microwave data and optical imagery, have commonly been used in alpine glaciers surveys. Using remote sensing and Geographical Information System (G...Because of the large number and remoteness, satellite data, including microwave data and optical imagery, have commonly been used in alpine glaciers surveys. Using remote sensing and Geographical Information System (GIS) techniques the paper presents the results of a multitempora satellite glacier extent mapping and glacier changes by glacier sizes in the Mt. Qomolangma region at the northern slopes of the middle Himalayas over the Tibetan Plateau. Glaciers in this region have both retreated and advanced in the past 35 years, with retreat dominating. The glacier retreat area was 3.23 km2 (or 0.75 km2 yr-1) during 1974 and 1976, 8.68 km2 (or 0.36 km2 yr-1) during 1976 and 1992, 1.44 km2 (or 0.12 km2 yr-1) during 1992-2000. 1.14 km2 (or 0.22 km2 yr-1) during 2000-2003, and 0.52 km2 (or 0.07 km2 yr-1) during 2003-2008, respectively. While supra-glacier lakes on the debris-terminus of the Rongbuk Glacier were enlarged dramatically at the same time, from 0.05 km2 in 1974 increased to 0.71 km2 in 2008, which was more than 13 times larger in the last 35 years. In addition, glacier changes also showed spatial differences, for example, glacier retreat rate was the fastest at glacier termini between 5400 and 5700 m a.s.l than at other elevations. The result also shows that glaciers in the middle Himalayas retreat almost at a same pace with those in the western Himalayas.展开更多
From 8 April to 11 October in 2005,hydrological observation of the Rongbuk Glacier catchment was carried out in the Mt.Qomolangma (Everest) region in the central Himalayas,China.The results demonstrated that due to it...From 8 April to 11 October in 2005,hydrological observation of the Rongbuk Glacier catchment was carried out in the Mt.Qomolangma (Everest) region in the central Himalayas,China.The results demonstrated that due to its large area with glacier lakes at the tongue of the Rongbuk Glacier,a large amount of stream flow was found at night,which indicates the strong storage characteristic of the Rongbuk Glacier catchment.There was a time lag ranging from 8 to 14 hours between daily discharge peaks and maximum melting (maximum temperature).As melting went on the time lag got shorter.A high correlation was found between the hydrological process and daily temperature during the ablation period.The runoff from April to October was about 80% of the total in the observation period.Compared with the discharge data in 1959,the runoff in 2005 was much more,and the runoff in June,July and August increased by 69%,35% and 14%,respectively.The rising of temperature is a major factor causing the increase in runoff.The discharges from precipitation and snow and ice melting are separated.The discharge induced by precipitation accounts for about 20% of the total runoff,while snow and ice melting for about 80%.展开更多
基金supported by the National Natural Science Foundation of China (40601056, 40121101)the Special Funds for Major State Basic Research Project (2009CB723901)+4 种基金the Special Science Foundation on Meteorological Project Research for Public Benefit (GYHY(QX)2007-6-18)the Survey Project on Glacier resources and their changes in China (No.2006FY110200)the Opening Fund projects of State Key Laboratory of Remote Sensing Science in the Institute of Remote Sensing Applicationsthe innovative project of Institute of Tibetan Plateau Research (ITPR),CASthrough a cooperation project between the Climate Change Institute, University of Maine supported by the National Oceanic and Atmospheric Administration (NA04OAR4600179) and the Institute of Tibetan Plateau Research (ITPR), CAS
文摘Because of the large number and remoteness, satellite data, including microwave data and optical imagery, have commonly been used in alpine glaciers surveys. Using remote sensing and Geographical Information System (GIS) techniques the paper presents the results of a multitempora satellite glacier extent mapping and glacier changes by glacier sizes in the Mt. Qomolangma region at the northern slopes of the middle Himalayas over the Tibetan Plateau. Glaciers in this region have both retreated and advanced in the past 35 years, with retreat dominating. The glacier retreat area was 3.23 km2 (or 0.75 km2 yr-1) during 1974 and 1976, 8.68 km2 (or 0.36 km2 yr-1) during 1976 and 1992, 1.44 km2 (or 0.12 km2 yr-1) during 1992-2000. 1.14 km2 (or 0.22 km2 yr-1) during 2000-2003, and 0.52 km2 (or 0.07 km2 yr-1) during 2003-2008, respectively. While supra-glacier lakes on the debris-terminus of the Rongbuk Glacier were enlarged dramatically at the same time, from 0.05 km2 in 1974 increased to 0.71 km2 in 2008, which was more than 13 times larger in the last 35 years. In addition, glacier changes also showed spatial differences, for example, glacier retreat rate was the fastest at glacier termini between 5400 and 5700 m a.s.l than at other elevations. The result also shows that glaciers in the middle Himalayas retreat almost at a same pace with those in the western Himalayas.
基金supported by National Key Project for Basic Research of China (No. 2007CB411503)Chinese COPES project (GYHY200706005)the National Basic Work Program of Chinese MST (Glacier Inventory of China II, Grant No.2006FY110200)
文摘From 8 April to 11 October in 2005,hydrological observation of the Rongbuk Glacier catchment was carried out in the Mt.Qomolangma (Everest) region in the central Himalayas,China.The results demonstrated that due to its large area with glacier lakes at the tongue of the Rongbuk Glacier,a large amount of stream flow was found at night,which indicates the strong storage characteristic of the Rongbuk Glacier catchment.There was a time lag ranging from 8 to 14 hours between daily discharge peaks and maximum melting (maximum temperature).As melting went on the time lag got shorter.A high correlation was found between the hydrological process and daily temperature during the ablation period.The runoff from April to October was about 80% of the total in the observation period.Compared with the discharge data in 1959,the runoff in 2005 was much more,and the runoff in June,July and August increased by 69%,35% and 14%,respectively.The rising of temperature is a major factor causing the increase in runoff.The discharges from precipitation and snow and ice melting are separated.The discharge induced by precipitation accounts for about 20% of the total runoff,while snow and ice melting for about 80%.
