排序方式: 共有11条查询结果,搜索用时 15 毫秒
11.
Glacial change in the vicinity of Mt. Qomolangma (Everest), central high Himalayas since 1976 总被引:4,自引:0,他引:4
Glaciers are one of the most important land covers in alpine regions and especially sensitive to global climate change. Remote
sensing has proved to be the best method of investigating the extent of glacial variations in remote mountainous areas. Using
Landsat thematic mapping (TM) and multi-spectral-scanner (MSS) images from Mt. Qomolangma (Everest) National Nature Preserve
(QNNP), central high Himalayas for 1976, 1988 and 2006, we derived glacial extent for these three periods. A combination of
object-oriented image interpretation methods, expert knowledge rules and field surveys were employed. Results showed that
(1) the glacial area in 2006 was 2710.17 ± 0.011 km2 (about 7.41% of the whole study area), and located mainly to the south and between 4700 m to 6800 m above sea level; (2)
from 1976 to 2006, glaciers reduced by 501.91 ± 0.035 km2 and glacial lakes expanded by 36.88 ± 0.035 km2; the rate of glacier retreat was higher in sub-basins on the southern slopes (16.79%) of the Himalayas than on the northern
slopes (14.40%); most glaciers retreated, and mainly occurred at an elevation of 4700–6400 m, and the estimated upper limit
of the retreat zone is between 6600 m and 6700 m; (3) increase in temperature and decrease in precipitation over the study
period are the key factors driving retreat. 相似文献