Based on the above results, the following conclusions can be drawn:
(1) The medium-resolution Landsat TM images provided important spatial, spectral, and
temporal information on changes of the Gangotri Glacier from 1990 to 2009. The high-
resolution IKONOS images and the medium-resolution SRTM digital elevation model
provided additional information on glacial geomorphology and flow direction.
(2) From 1990 to 2009, the moraine-covered Gangotri Glacier retreated 345 meters, with a
retreating rate of approximately 18 meters per year. There are no obvious changes in
retreating rates during 1990 - 2001 and 2001 - 2009. We hope these new findings can
provide some insight into the sometimes heated discussions on glacial retreating rates in
the Himalayas, particularly the Gangotri Glacier.
(3) The River Ganges may potentially become a seasonal river as a result of continued
glacier retreating, affecting hundreds of millions of people on the Indian subcontinent.
We thank USGS EROS Data Center for providing Landsat TM images, NASA for providing
SRTM data, and GeoEye Foundation for providing IKONOS images.
Ding, Y., Liu, S., Li, J., and Shangguan, D., 2006. The retreat of glaciers in response to recent
climate warming in western China. Annals of Glaciology, 43: 97-105.
Gupta, R.P., Haritashya, U.K., Singh, P, 2005. Mapping dry/wet snow cover in the Indian
Himalayas using IRS multispectral imagery. Remote Sensing ofEnvironment, 97: 458 -469.
Kargel, J.S., Abrams, M.J, Bishop, M.P., Bush, A., Hamilton, G., Jiskoot, H., Kib, A., Kieffer,
H.H., Lee, E.M., Paul, F., Rau, F., Raup, B., Shroder, J.F., Soltesz, D., Stainforth, D., Stearns, L.,
and Wessels, R., 2005. Multispectral imaging contributions to global land ice measurements
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Ding, Jennifer & Dong, Pinliang. Retreating Glaciers of the Himalayas: A Case Study of Gangotri Glacier Using 1990-2009 Satellite Images. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc84326/. Accessed April 21, 2015.