Debris flow modelling and hazard assessment for a glacier area: a case study in Barsem, Tajikistan

Abstract

This study analyses a previous debris fow hazard as a consequence of emerging risks related to climate and regional physical changes. In addition to the increasing food frequencies, there is an increasing risk of mud or debris fow due to increasing temperature and heavy precipitation resulting in glacier melting. One of the most recent dramatic examples of the debris fow incident took place in Barsem, Tajikistan, in 2015. As a result of heavy precipitation and excess temperature, the melting of glaciers caused debris fow which ended up with a catastrophic damage at Barsem Town. In this study, a methodology for modelling debris fow and related hazard is developed by examining the 2015 incident in detail with a commercially available software, Hydrological Engineering Centre-River Analysis System (HEC-RAS). Simulations and hazard assessment of the incident suggest that assessment of debris fow hazard can be implemented similar to food hazard. Moreover, it is seen that debris fow inundation area can be predicted accurately by low-resolution free-source digital elevation models (DEMs), while in the present work they could not predict the debris fow hazard assessment accurately. Sensitivity results also reveal that freesource DEMs with higher resolutions do not necessarily give better predictions than freesource DEMs with lower resolutions.