Articles | Volume 9, issue 2
The Cryosphere, 9, 505–523, 2015
The Cryosphere, 9, 505–523, 2015

Research article 16 Mar 2015

Research article | 16 Mar 2015

Spatial patterns in glacier characteristics and area changes from 1962 to 2006 in the Kanchenjunga–Sikkim area, eastern Himalaya

A. E. Racoviteanu1, Y. Arnaud1,2, M. W. Williams3, and W. F. Manley4 A. E. Racoviteanu et al.
  • 1Laboratoire de Glaciologie et Géophysique de l'Environnement, 54 rue Molière, Domaine Universitaire, BP 96, 38402 Saint Martin d'Hères CEDEX, France
  • 2Laboratoire d'Étude des Transferts en Hydrologie et Environnement, BP 53, 38401 Saint Martin d'Hères CEDEX, France
  • 3Department of Geography and Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA
  • 4Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA

Abstract. This study investigates spatial patterns in glacier characteristics and area changes at decadal scales in the eastern Himalaya – Nepal (Arun and Tamor basins), India (Teesta basin in Sikkim) and parts of China and Bhutan – based on various satellite imagery: Corona KH4 imagery, Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and Advanced Spaceborne Thermal Emission Radiometer (ASTER), QuickBird (QB) and WorldView-2 (WV2). We compare and contrast glacier surface area changes over the period of 1962–2000/2006 and their dependency on glacier topography (elevation, slope, aspect, percent debris cover) and climate (solar radiation, precipitation) on the eastern side of the topographic barrier (Sikkim) versus the western side (Nepal).

Glacier mapping from 2000 Landsat ASTER yielded 1463 ± 88 km2 total glacierized area, of which 569 ± 34 km2 was located in Sikkim and 488 ± 29 km2 in eastern Nepal. Supraglacial debris covered 11% of the total glacierized area, and supraglacial lakes covered about 5.8% of the debris-covered glacier area alone. Glacier area loss (1962 to 2000) was 0.50 ± 0.2% yr−1, with little difference between Nepal (0.53 ± 0.2% yr−1) and Sikkim (0.44 ± 0.2% yr−1. Glacier area change was controlled mostly by glacier area, elevation, altitudinal range and, to a smaller extent, slope and aspect. In the Kanchenjunga–Sikkim area, we estimated a glacier area loss of 0.23 ± 0.08% yr−1 from 1962 to 2006 based on high-resolution imagery. On a glacier-by-glacier basis, clean glaciers exhibit more area loss on average from 1962 to 2006 (34%) compared to debris-covered glaciers (22%). Glaciers in this region of the Himalaya are shrinking at similar rates to those reported for the last decades in other parts of the Himalaya, but individual glacier rates of change vary across the study area with respect to local topography, percent debris cover or glacier elevations.

Short summary
An overall negative glacier surface area change of 0.5±0.2% yr-1 was observed for the eastern Himalaya since 1962 based on remote sensing data. There were higher rates of area loss for clean glaciers (-34%, or -0.7% yr-1) compared to debris-covered glaciers (-14.3% or -0.3 yr-1) on a glacier-by-glacier basis. Patterns of area change are heterogenous and depend on topographic and climatic factors, glacier altitude (maximum, median, altitudinal range), glacier size, slope and aspect.