Beyond the Melt: Investigating the Frequency and Socio-Economic Impact of Glacial Lake Outburst Floods (GLOFs) in Downstream Communities OF Gilgit Baltistan and Chitral

Abstract

Glacial Lake Outburst Floods (GLOFs) are an increasing hydro-meteorological hazard in the high-altitude areas of northern Pakistan, which is enhanced due to the increased glacial melt under human-induced climate change. This paper examines the spatial-temporal occurrence of GLOFs and assesses the socio-economic impact of GLOFs on down-stream communities in Gilgit-Baltistan (GB) and Chitral District, in the Hindu Kush-Karakoram ranges. The study is based on multi-temporal satellite imagery (Landsat and Sentinel series), historical inventory of the Pakistan Meteorological Department (PMD) and International Centre for Integrated Mountains Development (ICIMOD) highly-resolution digital elevation models, and field-based measurements in 12 high-risk valleys, showing a striking 38% increase in GLOF events over the 35-year period, with intense acceleration since Out of 3,044 glacial lakes identified over GB and neighboring Khyber Pakhtunkhwa, 33 are considered to be potentially dangerous, exposing over 7 million people to increased risk. Socio-economic effects were measured using 450 household surveys, semi-structured interviews with 85 key informants, and a geospatial combination of flood inundation maps and census, agricultural and infrastructure data. Notable disasters, such as the Gupis GLOF in Ghizer in August 2025 (destroying more than 300 houses, the Ghizer River, and displacing hundreds), demonstrate an average direct loss of USD 45 million per major outburst, mainly by destroying irrigated agricultural land (42%), road and bridge networks (31%), hydropower and irrigation systems (18% The indirect impacts (livelihood disruption, temporary migration, food insecurity, and increased poverty) lasted 4-8 years after the event, and they were disproportionately on agrarian households, women and indigenous populations with a low adaptive capacity. Vulnerability mapping identifies hotspots that are a combination of physical exposure and socio-economic marginalization. This analysis places GLOF risk as a deep-rooted socio-economic amplifier in GB and Chitral by moving beyond glaciological drivers to pre-empt human dimensions. Results highlight the necessity of combined, community-based adaptation plans, such as more effective early-warning systems, nature-based response, and transboundary risk-financing framework, to achieve resilience in current cryospheric change.