Pakistan’s Alpine Measurements Centre announced the findings on Thursday after an audit found that 31 of its 46 mountain stations had been switched to a lower-capacity logging system during a shortage of memory components. Researchers reviewing recovered data say meltwater surges at several monitored glaciers were up to 2.3 times higher than earlier estimates, a change that could affect flood planning downstream.
The audit examined station settings, surviving data and procurement records from 2022 to 2025. It found that some sensors had been changed from recording every 10 minutes to saving hourly averages, smoothing out short bursts of melt. The centre said the change was made to keep instruments operating when larger memory cards were difficult to obtain.
Missing peaks recovered
Researchers rebuilt the measurement series from backup files at 11 stations and compared them with temperature and stream-flow records. The revised analysis found that rapid melt pulses followed warm nights, when air temperatures stayed above freezing at elevations that usually cool sharply after sunset. At two sites, the short-lived peaks had been nearly erased by the hourly averaging.
Ege Alyanak, a glaciologist who led the reanalysis, said the revised figures do not mean the Indus is suddenly carrying more water every day. They show that brief, powerful surges were hidden inside broader averages. “We were looking at a river smoothed into a lie,” Alyanak said. “The peaks are the warning, not the daily mean.”
We were looking at a river smoothed into a lie. The peaks are the warning, not the daily mean.
Ege Alyanak, glaciologist
The sensor changes followed a procurement deal worth PKR 312 million (about €1 million) with the fictional supplier Mikra Vale Systems, according to the audit’s published summary. The centre said the replacement cards had less storage capacity than specified, but were approved to avoid shutting down stations through the winter. It has suspended new purchases from the supplier while checking equipment at every site.
Rechecking flood forecasts
Jan Zalokar, the centre’s audit director, said the review began after researchers found that several stations reported identical hourly totals despite sharply different weather. Inspectors later found that the logging settings had been altered. Zalokar said no evidence showed that staff had changed scientific results deliberately, but the centre had not required a second technical check before approving the substitutions.
The findings matter because the monitored glaciers feed tributaries of the Indus, which supplies irrigation and drinking water across Pakistan. The new analysis does not predict an immediate flood, and the researchers stressed that meltwater is only one factor in river levels. But it could change how forecasters assess sudden rises during warm spells in the upper valleys.
Martin G. Delattre, a hydrologist advising the centre, said the revised data should be checked against gauges farther downstream before being used to alter public warnings. He called the audit a serious correction, not a reason to discard earlier flood models. The team plans to publish its reworked estimates and station-by-station readings by March 2027.
The centre said it will install higher-capacity storage at the affected stations and publish monthly checks of their logging settings. Researchers are also testing a second, independent recorder at six sites. Until the full review is complete, the centre has told regional forecast offices to treat older glacier-flow summaries as incomplete during short warm spells.
