Publications

Mondal, SK; Bharti, R (2023). Spatio-Temporal Variations in the Effective Snow/Glacier Coverage in the Sikkim Himalayas. JOURNAL OF THE INDIAN SOCIETY OF REMOTE SENSING.

Abstract
The sustainability of eco-hydrology of the Eastern Himalaya depends on snow and glacial dynamics. Glaciers, permanent and seasonal snow are the freshwater flow regimes and an indicator of climate variability. Spatio-temporal mapping provides information regarding several aspects such as freshwater storage, mass balance trends, snowline and volume, snow avalanche forecasting, and melt-water run-off predictions. In this article, an attempt has been made to study the spatio-temporal variations in snow coverage of Sikkim using an integrated approach of multivariate statistics and band ratio between 1989 and 2019 at an interval of 2-4 years. Landsat 5/8 and Sentinel 2 datasets have been processed for snow cover products using Principal Component Analysis (PCA), Independent Component Analysis (ICA), and Normalized Difference Snow Index (NDSI) further used as an input to digital AND-gate operator for deriving effective snow cover maps of the Teesta river basin. The intra-annual effective snow cover change has been observed to behave in an inverse correlation with the Extended Reconstructed Sea Surface Temperature (ERSST.v5) in Nino 3.4 region. The snow line altitude (SLA) has been observed to have a twofold periodicity in the last 30 years. The effective snow cover results corroborate well with the field investigation (January 17-28, 2021). The overall mapping accuracy (84.14-85.53%) has been evaluated using MODIS/Terra 8-day L3 500 m composite products (MOD10A2) along with kappa (0.68-0.71) and conditional kappa of snow class (0.74-0.82). In addition, results have been checked for statistical differences using the McNemar test z-scores.

DOI:
10.1007/s12524-022-01643-3

ISSN:
0974-3006