Dams are being built at an alarming rate, either to meet the growing demand for water or to generate electricity. However, this construction has led to concerns about its impact on the environment. A recent study has shed light on the connection between dam building and increased landslide activity.
In March 2019, a landslide devastated Hoseynabad-e Kalpush village in north-central Iran, causing damage to 300 houses and cutting off access to a nearby dam. Local authorities initially attributed the landslide to heavy rainfall and denied any connection to the dam. However, scientists from the German Research Centre for Geosciences have found evidence that suggests otherwise.
The analysis of satellite data from the region revealed that a stable slope where the landslide occurred began to move after the reservoir behind the dam started filling with water in 2013. Over time, the movement progressed from lower portions of the slope towards higher ones as water levels in the reservoir rose. The research, published in Engineering Geology, indicates that filling up the dam caused local water tables to rise, making soil on hillslides more prone to movement. Ultimately, this led to an ancient landslide being activated.
This study serves as a warning to engineers working on dams not only about potential risks associated with reservoir filling but also about their impact on surrounding slopes. By understanding these risks and taking measures to mitigate them, communities and infrastructure can be better protected against potentially devastating consequences of landslides triggered by dam construction.
