Worries Arise over Precipitation in the Disaster Zone
Swiss Alps Landslide Threatens Communities and Lonza River
Residents in the Lötschental valley in the Swiss canton of Wallis are on edge as rain showers and warmer temperatures forecast for Sunday potentially exacerbate a massive landslide that engulfed Blatten and partially dammed the Lonza river. The concern is that the unstable landslide could trigger debris flows, endangering communities further down the valley.
State Councillor Stéphane Ganzer told the RTS broadcaster that the current heat is speeding up snowmelt, adding to the threats posed by the looming rain. The colossal landslide, comprising approximately nine million cubic meters of ice and debris, crumbled from the Birsch glacier after recent rockfalls on Wednesday.
The 300 Blatten inhabitants were evacuated prior to the landslide. If water, debris, or ice from the landslide are carried away, an increased risk of damage to lower valley communities may arise. Although the present danger is slim due to the gentle terrain and roomy riverbed of the Lonza, the danger from further rockfalls in the unstable mountain collapse area above Blatten remains.
The Lonza's situation appeared serene at the weekend's outset, as per the crisis team's report. The impounded mountain river's water is flowing through and over the landslide, with roughly equivalent amounts of water flowing into the dammed lake and out of it. Most of the originally spared Blatten houses have been submerged in the resulting reservoir.
If Lonza water carries debris or other materials down the valley, it should be caught in a retention basin in Ferden, around six kilometers downstream from the disaster site. Consequently, the local power plant operator has been instructed to continue releasing water.
Should the retention basin prove insufficient to contain the water volume, the villages of Gampel and Steg at the lower course of the Lonza would be at risk. Imminent flooding would pose particular challenges for the narrow concrete channels through which the Lonza flows just before merging with the Rhone, as measurements reveal. Nevertheless, authorities are continuously monitoring the situation around the clock.
No further evacuations are planned at present, according to the municipalities of Gampel and Steg. Construction machinery is being employed to safeguard the smooth flow of debris and driftwood through the Lonza's riverbed within the village areas, while residents remain prepared as the situation remains critical.
The polluted water from the Lonza, heavy with sand and abrasion from the landslide, cannot be utilized for power generation by the installed turbines at the dam in Ferden. Furthermore, mere hours after the avalanche, unstable rock crashed onto the Birsch glacier, atop which it resides, nearly three kilometers above sea level.
- The current heat and rain forecast are raising concerns in the field of environmental science, as they may accelerate the melting of snow and potentially exacerbate the climate-change induced threats posed by the landslide in the Lötschental valley.
- The colossal landslide in the Swiss Alps, primarily composed of ice and debris, has significantly impacted weather-forecasting, as it has partially dammed the Lonza river, affecting its normal flow.
- As the unstable landslide continues to pose a risk of debris flows, the local authorities are keenly monitoring the weather patterns, particularly the rainfall, to ensure the safety of the communities that lie further down the valley.
