Roadside landslides are common worldwide. In Japan, 1,310 landslides along national highways 20,000 kilometers in length were reported from April 1990 to December 2004. Surface failure was the most abundant category and constituted 81% of all landslide disasters. The disasters had caused damage to the highways and temporarily suspended road traffic.
Landslides were also very frequent along highways in Hong Kong and large expenditures were incurred on the investigation, design, and implementation of mitigation and preventive measures to reduce loss of lives and damage to properties. Landslides in the mountainous terrain of Hong Kong often occurred during or after heavy rainfall.
In the predominantly mountainous Laos, road networks were also impacted by landslides. These landslides occurred most frequently as shallow slope failures in roadside cuttings. The majority of landslides resulted in partial or complete obstruction of short road segments. These gave rise to several hours of delay to traffic and required expenditures for debris clearance and road repairs. 70% of recorded roadside slope failures had taken place above the road.
Many roadside slopes in Himachal Pradesh, India also suffered from a range of instability and erosion problems. The widening of roads involved massive hill cutting, resulting in yet more unstable slopes.
Landslides were also recurrent in the mountainous Himalayan country of Nepal. Intense seasonal monsoon rains and weak rock and soil cover combined with improper land use practices make the landscapes in Nepal one the most unstable in the world.
Landslides and flash floods triggered by days of heavy rain affected five provinces in the northern part of Thailand in 2006, resulting to hundreds of people killed and thousands of other people stranded. Infrastructures such as bridges and roads were damaged.
With the rapidly increasing concentration of population and development of infrastructure, the loss of life and the damage to property caused by landslides in the Philippines in general and in Baguio in particular have grown significantly over the past decades.
However, despite the high incidence of roadside landslides, there are hardly any databases of roadside landslides available. Data on the extent and volume of landslides affecting roads are difficult to obtain, as there have been very few systematic records or study into the magnitude of the problem.
Landslides were also very frequent along highways in Hong Kong and large expenditures were incurred on the investigation, design, and implementation of mitigation and preventive measures to reduce loss of lives and damage to properties. Landslides in the mountainous terrain of Hong Kong often occurred during or after heavy rainfall.
In the predominantly mountainous Laos, road networks were also impacted by landslides. These landslides occurred most frequently as shallow slope failures in roadside cuttings. The majority of landslides resulted in partial or complete obstruction of short road segments. These gave rise to several hours of delay to traffic and required expenditures for debris clearance and road repairs. 70% of recorded roadside slope failures had taken place above the road.
Many roadside slopes in Himachal Pradesh, India also suffered from a range of instability and erosion problems. The widening of roads involved massive hill cutting, resulting in yet more unstable slopes.
Landslides were also recurrent in the mountainous Himalayan country of Nepal. Intense seasonal monsoon rains and weak rock and soil cover combined with improper land use practices make the landscapes in Nepal one the most unstable in the world.
Landslides and flash floods triggered by days of heavy rain affected five provinces in the northern part of Thailand in 2006, resulting to hundreds of people killed and thousands of other people stranded. Infrastructures such as bridges and roads were damaged.
With the rapidly increasing concentration of population and development of infrastructure, the loss of life and the damage to property caused by landslides in the Philippines in general and in Baguio in particular have grown significantly over the past decades.
However, despite the high incidence of roadside landslides, there are hardly any databases of roadside landslides available. Data on the extent and volume of landslides affecting roads are difficult to obtain, as there have been very few systematic records or study into the magnitude of the problem.
No comments:
Post a Comment