Discussion of Risk Factors for Triggering of Rockslide Avalanche Dams in Pakistan, Afghanistan, and Tajikistan and Mitigation Strategies

Landslide dams have posed a significant, but subrequent threat to mankind because they usually occur in mountainous areas that are sparsely populated. In tectonically active areas like the Hindu Kush, Pamir, and Himalayan ranges of Pakistan, Afghanistan, and Tajikistan, most landslide dams are triggered by earthquakes, although cumulative precipitation has also triggered deep-seated landslides. Usoi Dam (1911) in Tajikistan is presently the highest landslide dam in the world, and is still filling more than 100 years after it formed. The historic Lake Shewa landslide dam in Afghanistan poses a major threat to thousands of people living downstream. Northern Pakistan is also plagued by landslide dams because it is a region of high seismicity with severe seasonal precipitation cycles (monsoons). The partial breaching of the seismically triggered Hattian Bala landslide dam (formed in 2005) and the Attabad landslide dam (formed in 2010) signify the importance of developing viable mitigation techniques because the emergency spillway excavations may not be sufficient to protect the toes of these dams from erosion