Articles | Volume 17, issue 10
https://doi.org/10.5194/nhess-17-1837-2017
https://doi.org/10.5194/nhess-17-1837-2017
Research article
 | 
24 Oct 2017
Research article |  | 24 Oct 2017

Assessment of evolution and risks of glacier lake outbursts in the Djungarskiy Alatau, Central Asia, using Landsat imagery and glacier bed topography modelling

Vassiliy Kapitsa, Maria Shahgedanova, Horst Machguth, Igor Severskiy, and Akhmetkal Medeu

Abstract. Changes in the abundance and area of mountain lakes in the Djungarskiy (Jetysu) Alatau between 2002 and 2014 were investigated using Landsat imagery. The number of lakes increased by 6.2 % from 599 to 636 with a growth rate of 0.51 % a−1. The combined areas were 16.26 ± 0.85 to 17.35 ± 0.92 km2 respectively and the overall change was within the uncertainty of measurements. Fifty lakes, whose potential outburst can damage existing infrastructure, were identified. The glacier bed topography version 2 (GlabTop2) model was applied to simulate ice thickness and subglacial topography using glacier outlines for 2000 and SRTM DEM (Shuttle Radar Topography Mission digital elevation model) as input data achieving realistic patterns of ice thickness. A total of 513 overdeepenings in the modelled glacier beds, presenting potential sites for the development of lakes, were identified with a combined area of 14.7 km2. Morphometric parameters of the modelled overdeepenings were close to those of the existing lakes. A comparison of locations of the overdeepenings and newly formed lakes in the areas de-glacierized in 2000–2014 showed that 67 % of the lakes developed at the sites of the overdeepenings. The rates of increase in areas of new lakes correlated with areas of modelled overdeepenings. Locations where hazardous lakes may develop in the future were identified. The GlabTop2 approach is shown to be a useful tool in hazard management providing data on the potential evolution of future lakes.

Download
Short summary
Changes in lake count and area in the region of Djungarskiy Alatau were assessed, showing that both increased by 6 % in 2002–2014 due to glacier melt. A total of 50 lakes were identified as potentially dangerous. GlabTop2 was used to simulate location and size of overdeepenings in the subglacier beds which present sites where lakes can develop in the future. The model predicted 67 % of lakes would form in the area de-glacierized in 2002–2014, correctly proving a useful tool in hazard management.
Altmetrics
Final-revised paper
Preprint