About 28,000 rivers have disappeared from China’s state maps, an absence seized upon by environmentalists as evidence of the irreversible natural cost of developmental excesses.

More than half of the rivers previously thought to exist in China now appear to be missing, according to the 800,000 surveyors who compiled the first national water census, leaving Beijing fumbling to explain the cause.

Only 22,909 rivers, covering an area of 100 square kilometres were located by surveyors, compared with the more than 50,000 present in the 1990s, a three-year study by the Ministry of Water Resources and the National Bureau of Statistics found.

Officials blame the apparent loss on climate change, arguing that it has caused waterways to vanish, and on mistakes by earlier cartographers. But environmental