Sensitivity of Glaciers in Part of the Suru Basin, Western Himalaya to Ongoing Climatic Perturbations

Temporal and spatial climate variability acts as the major driving force which induces changes in glacier response. However, variation in the glacier behavior could also be introduced due to the influence of non-climatic factors. Therefore, in order to assess the influence of these climatic and non-climatic factors on the response of 15 major glaciers of the Suru basin, western Himalayas, Jammu and Kashmir, a multiparametric study has been carried out involving estimation of dimensional (area and length changes) parameters, snowline altitude (SLA)/accumulation area ratio (AAR) and non-climatic factors (debris cover and topographic). Satellite data from the Landsat series sensors (MSS/TM/ETM+/OLI) during the period 1977–2016 along with the Shuttle Radar Topographic Mission (SRTM) Global Digital Elevation Model version-3 (GDEM v-3) constitute the primary datasets used. Results indicate towards an overall negative health of the glaciers with 6.25 ± 0.0012% loss in glacier area and increase in the average retreat rate from 16 ± 3.4 (1977) to 23 ± 3.4 m/y (2016). This glacier degeneration was accompanied by a debris cover increase of ~80% and mean snow line altitude (SLA) upshift of 116 ± 17 m over the span of 39 years. The observed glacier changes exhibit strong correlation with long-term temperature variability (average r2 = 0.481 ± 0.06; maximum r2 = 0.925), however, sensitivity to precipitation trends (average r2 = 0.143 ± 0.07) is not found to be significant. Besides, disparity in glacier response can be partly explained by the spatial variability in meteorological parameters, with glaciers of the Ladakh Range (LR) shrinking (area loss: 9%) and accumulating more debris cover (debris increase: 116%) as compared to those in the Greater Himalayan Range (GHR) (6% and 78%, respectively). However, SLA rise was more pronounced in the GHR glaciers (average of 141 ± 97 m). The differential behavior of glaciers in both the ranges can be attributed partly to the impact of the non-climatic factors such as glacier size, length, maximum elevation and mean slope.