The west-east glacier anomaly over the Hindukush Himalayan Region, a part of third pole, is
well visualised. The Sikkim Himalaya, a part of eastern Himalayas, have different
topography than western part of Himalaya which further provide combined varied
conditions of local topography and climate response on glacier and glacial lakes. The
satellite-based data and limited field-based data have been used to monitor glacier and
glacial lake variability since five decades in Sikkim Hiamalaya. It has been identified by the
researchers that the glacier area loss in Sikkim is much higher ranging from 20 per cent to
30 per cent at different basin level. Among many glaciers, East Rathong, South Lohnak,
Gurudongmar, and Kangchengayo glaciers have showed much faster glacier recession. The development of new glacial lakes adjacent to the receded mother
glaciers and expansion of existed lakes have drawn critical attention. The basin and local
level glacial lake area monitoring research work in Sikkim Himalaya identified varied result,
such as 8 per cent to 35 per cent of lake area expansion based on remote sensing and GIS based data.
Exceptional case of lake area reduction also has been identified in Sikkim Himalaya signifying
lake water breaching event and varied behaviour of supraglacial lake. Some of the enlarging
glacial lakes are South Lohnak lake, Gurudongmar Lake, Khangchung Tsho, Tenbawa
Kangse, etc. Regular monitoring and hazard prevention methods employed over the
South Lohnak Lake has reduced the water level and hence minimised the risk factor.
Further, a synthesis work combined with palaeo-glacier variability, present glacier-glacial
lake responses and future trend modelling is required to understand the complex climate-
glacier-glacial lake interaction at regional level.
