Catastrophic floods imminent due to glacier rupture
In the Lötschental valley of Switzerland's Wallis canton, another crisis is looming. A dam of debris, rock, and ice, over a meter high, has obstructed the flow of the Lonza river, causing a rapid accumulation of water behind it. If the dam bursts, a flood wave or a debris flow—similar to an avalanche—could wreak havoc further down the valley, potentially impacting existing structures within the damaged area.
Several homes in two hamlets have been evacuated as a preventative measure, with images from drones revealing that Blatten, a large part of which is covered by a meter-high layer of debris, has largely been spared, save for a few homes still standing but submerged in floodwaters.
The neighboring hamlet of Wiler's Member of Parliament, Beat Rieder, described the situation as a "century's catastrophe" in Swiss television interviews. Houses and essential infrastructure built up over residents' entire lives have been lost, leaving them devastated. The hamlet of Ried, just one kilometer near Blatten, is also affected, with many locals reporting complete destruction of their homes and farms in an instant.
Geologist Flavio Anselmetti of the University of Bern expressed concern over the stability of the dam, voicing concerns that a sudden break could trigger dangerous flood waves or debris flows, potentially threatening the lower valley communities. Currently, the army, rescue teams, and the army cannot proceed with any intervention due to the unstable nature of the debris cone and the risk of further collapses.
The cause of this disaster may be rooted in climate change, according to Jan Beutel, a professor at the University of Innsbruck. Over the past decades, climate change could have contributed to the present strong changes seen in mountainous regions, accelerating glacier melt, enhancing erosion, thawing permafrost, and ensuring more liquid water is available within mountainous layers, all of which ultimately promote mobility and instability driven by gravity. If the dam bursts, an estimated three million cubic meters of rock, debris, and ice could be set loose.
Around 300 residents of Blatten have been displaced, with roughly 90% of the village, including approximately 130 homes and the church, buried beneath a debris layer estimated to be between 50 and 200 meters thick. The basis of the debris cone spans two kilometers and covers around 200 meters in width.
The Swiss mountains are closely monitored, and warnings were issued in mid-May regarding a potential rockslide. However, the sudden need to evacuate the village surfaced just days prior, as fissures in the rock grew rapidly. Though rocks had been crumbling and falling into the valley for days, they didn't reach Blatten. To this point, some residents are still missing.
The Lötschental valley, a popular tourist destination known for its hiking trails, climbing routes, mountain lakes, and winter ski slopes, faces an uncertain future, as the areas faced with this type of disaster require intensive management and planning to mitigate further disasters.
The crisis in the Lötschental valley, aside from presenting an immediate threat to the lower valley communities, also underscores the potential long-term impacts of climate change on the environment and the weather. The unstable dam, caused by rapid glacier melting and permafrost thaw due to climate change, highlights the need for further studies in environmental science, particularly in relation to climate-change and its consequences on geological features.
