Landslides Induced by a 7.6 Magnitude Earthquake in the Northern Part of Pakistan on October 8, 2005 and Landslide Risk Reduction Through Implementation of Non-Structural Measures

Abstract

A 7.6 magnitude earthquake struck the northern part of Pakistan on October 8, 2005. Muzaffarabad city, the capital of Azad Jammu and Kashmir, located close to the epicenter, was worst affected by the earthquake. The death toll in the city and its surrounding area rose to more than 70,000. Also, many landslides were induced by the earthquake and the road network was cut, which was detrimental to the rapid recovery of the city from the earthquake damages.In addition to these landslides directly induced by the earthquake, many open cracks were observed on the slopes of the hilly areas surrounding the city and landslide risks had increased in the coming rainy season. Under these circumstances, it was necessary to take drastic measures such as execution of landslide countermeasures and realignment of existing road in the landslide-affected sections. However, these drastic measures required a lot of time and cost and it was unrealistic to treat all landslide-prone slopes in the earthquake-affected areas.The author stayed in Pakistan for more than one year in total after the earthquake as a member of the JICA Study Team, and studied the landslides that occurred during the rainy season in Muzaffarabad city. In the study, the landslide hazard was assessed based on the results of ground mapping and field data obtained from automatic rain gauges and extensometers that were installed before the rainy season. For risk reduction of landslide hazards, the JICA Study Team assisted Muzaffarabad city in establishing early warning systems by organizing the framework for landslide disaster management and installing early warning devices. Furthermore, the team conducted evacuation drills to enhance the early warning system, as well as community-based landslide hazard mitigation activities such as crack filling works of landslides. As a result of the above efforts, there were no serious accidents in the project area despite the occurrence of many small landslides and debris flows near the area. Establishment of early warning and evacuation systems was useful to deduce landslide hazard risks in the situation where drastic measures were difficult to be undertaken due to time and cost restrictions.