Summary
- More than 3,000 glacial lakes have formed in Gilgit-Baltistan and Khyber Pakhtunkhwa. UNDP-backed assessments list 33 to 36 of them as prone to outburst floods.
- In 2026, official warnings ran from March to late August, naming at least nine districts and specific valleys in Nagar and Ghanche.
- Free satellite data can measure how fast individual lakes are growing each year, which helps decide where early-warning equipment and evacuation planning matter most.
The scale of the risk
A glacial lake outburst flood happens when water held back by ice or a loose moraine is released suddenly. As glaciers in the Karakoram and Hindu Kush melt, existing lakes grow and new ones form. UNDP's GLOF-II project, funded by the Green Climate Fund, works on early warning and community preparedness in 24 valleys across Gilgit-Baltistan and Khyber Pakhtunkhwa. A 2019 announcement linked to the project estimated that 7.1 million people are exposed to this risk.
Note on the numbers: the count of hazardous lakes is 33 in UNDP's 2022 project brief and 36 in other UNDP material. A client report would cite one source consistently and explain the difference.
The 2026 alert season
| When | What was reported |
|---|---|
| February | National Emergencies Operation Centre warns of elevated GLOF risk for March to September. |
| March | NDMA issues a GLOF alert for Gilgit-Baltistan and Khyber Pakhtunkhwa as glacial lakes grow with rising temperatures. |
| 2–8 April | PMD alert names Ghizer, Hunza, Nagar, Astore, Ghanche, Diamer, Kharmang, Skardu and Shigar. |
| May | Rain triggers landslides that block the Astore valley road; a further GLOF alert for upper areas. |
| June | Met officials warn of rising GLOF risk during a heatwave expected to last into early July. |
| July | NDMA alert for the Hopar and Hisper valleys in Nagar. Floods damage roads, bridges, power lines, farmland and homes; a suspension bridge over Hushe Nallah in Ghanche is submerged. |
| 21–24 August | GBDMA warns that a westerly system could raise glacial lakes quickly in Diamer, Astore, Ghizer, Skardu and Ghanche. |
The places named in these alerts are plotted on the satellite map in my portfolio.
How I would monitor a lake
For a project team responsible for one or more valleys, the satellite work would be:
- Map open water each late summer, 2016–2026, from Sentinel-2 imagery using the water index NDWI = (Green − NIR) / (Green + NIR), checked by eye against the true-colour image.
- Fill cloudy gaps with Sentinel-1 radar, which sees through cloud, so each year has a usable lake outline.
- Calculate each lake's area per year and flag lakes growing fastest, in absolute and percentage terms.
- Trace the likely flood path downstream using a 30-metre elevation model (Copernicus GLO-30) and mark the villages, roads and bridges along it.
- Deliver a lake-area table, before-and-after maps, GIS layers and a two-page brief in plain language for non-specialists.
All of this runs in Google Earth Engine on free data, so the analysis can be repeated every year at low cost.
What a desk study cannot tell you
- Satellites measure lake area, not depth or volume, so they cannot say how much water would be released.
- Dam stability (ice, moraine) needs field inspection and specialist assessment.
- Flood-path mapping shows where water is likely to go, not exact flood heights or timing.
A brief like this is a starting point for planning, and it should always be combined with local knowledge and the official alerts from NDMA, PMD and GBDMA.
Sources
- UNDP Pakistan — GLOF-II project page
- UNDP — GLOF-II project brief (2022)
- Dawn — GLOF-II agreement with Gilgit-Baltistan (2019)
- ProPakistani — NDMA GLOF warning (March 2026)
- ProPakistani — PMD GLOF alert (April 2026)
- ProPakistani — floods across Gilgit-Baltistan (July 2026)
- Dawn — PMD warns of GLOF risk as rains batter GB
- Daily Pakistan — flood threat update (June 2026)
Need something like this?
Tell me about your project and I will send a fixed quote within two working days.