The Linth plain in eastern Switzerland has lost between 12 and 15 centimetres in recent years as the result of long-term soil drainage, media has reported.
The sinking of the canton Glarus plain – the site of various industries and an important north-south motorway – was noticed by cantonal authorities recently, the Neue Zürcher Zeitung reported on Saturday.
Measurement work in the area consistently discovered discrepancies compared to the measurements in the national altitude register, cantonal authorities communicated at the time.
An expert from the Federal Office of Topography (swisstopo) told the NZZ that the sinkage was part of a long-term trend. “The Linth plain and other areas where major watercourse corrections were made in the 19th and 20th centuries – such as the Jura – are still subsiding today due to soil drainage,” Helena Aström Boss said.
The data have meanwhile been corrected, the NZZ writes, and there have been no border shifts or obvious changes in the landscape for the population.
The Swiss reference point for altitude measurement was fixed in 1902 at a site in Geneva, at 373.6 metres above sea level. A network of over 6,000 points are scattered throughout the country, mostly embedded in rocks and mountains viewed as particularly stable.