| Abstract: | 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 multitemporal 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. |
