The United Nations Development Programme (UNDP) and EvK2CNR, with funding from the Italian Agency for Development Cooperation, launched the "Glaciers and Students" project to map all of Pakistan’s glaciers. This extensive effort resulted in the mapping of 13,032 glaciers, covering an estimated 13,547 km², creating a crucial repository of glacial data.
Building on this foundation, the Preliminary Inventory of Glacial Lakes in Pakistan focuses on supraglacial lakes—water bodies formed on the surface of glaciers previously mapped under the Glaciers and Studentsproject. To ensure methodological consistency, this study uses the same ESA Sentinel-2 satellite imagery (2022) and resolution as the original glacier inventory. This uniformity guarantees a rigorous scientific approach, essential for developing a knowledge base to assess the morphometric factors influencing glacial lake formation in future studies.
This preliminary inventory serves primarily as a methodological framework, establishing protocols for:
Analyzing inter- and intra-annual variability in lake development.
Semi-automated detection and mapping of supraglacial lakes.
Managing and reducing uncertainties associated with lake delineation.
Note: This inventory is considered preliminary as it does not include proglacial lakes (those situated at glacier margins).
The study examined supraglacial lake dynamics between 2020 and 2022, revealing significant fluctuations in lake numbers and extents—not only year-to-year but also month-to-month, due to changing glacier surface conditions.
Crucially, September (the end of the summer melt season before freezing in October) emerged as the most stable period for comparative analysis. For this reason, the inventory relies on September 2022 satellite imagery, and we strongly recommend this timeframe for future remote sensing studies of supraglacial lakes.
The study mapped supraglacial lakes on 142 glaciers across Pakistan, with 99% concentrated in seven northern basins:
Hunza (37%) - Shigar (32%) - Chitral (13%) - Shyok (9%) - Gilgit (5%) - Shaksgam (2%) - Indus (1%)
Key morphological features include:
Mean glacier slope: 21° (considered gentle)
Mean lake elevation: ~3,961 m a.s.l. (ranging from 3,700 to 4,200 m)
Glacier minimum elevation: 3,320 m a.s.l.
Median lake size: 1,895 m²
An error analysis confirmed that the developed methodology achieves an areal uncertainty of approximately ±2%. The total mapped surface area of supraglacial lakes is 5.16 km², comprising 2,722 individual lakes. This project was implemented by EvK2CNR, with scientific support from: Institute of Polar Science, National Research Council of Italy (ISP-CNR) Department of Environmental Science and Policy, University of Milan Department of Chemical and Geological Sciences, University of Cagliari The Karakoram Range in northern Pakistan presents exceptional glacial behavior critical for climate research: The "Karakoram Anomaly" – Unlike global trends, its glaciers remain stable or grow slightly (Bocchiola & Diolaiuti, 2013; Farinotti et al., 2021). Surging Glaciers – Episodes of rapid ice flow (Diolaiuti et al., 2003) often trigger lake formation. GLOF Hotspot – Sudden glacial lake outbursts (Bazai, 2021) threaten millions in Pakistan, exacerbated by: Ice-dammed lakes (90% of GLOFs from 5 key basins). Steep terrain and summer warming (Hewitt et al., 2013). This region’s interplay of stable ice, surges, and floods makes it vital for climate adaptation.Uncertainty Assessment
Collaborating Institutions
Why Study Glacial Lakes? The Karakoram’s Unique Dynamics