Prolonged torrential rains, along with human activity, have caused serious landslides (Photo: VietnamPlus) Hanoi (VNA) – Dozens of landslides have occurred across the country since June, with some causing severe consequences and human losses.
Associate Professor, Dr Tran Tan Van, former Director of the Vietnam Institute of Geosciences and Mineral Resources under the Ministry of Natural Resources and Environment (MoNRE), spoke with VietnamPlus about the causes of landslides and measures to prevent and mitigate losses from the natural disaster.
According to the scientist, there are two main factors that caused recent landslides. The first one is prolonged rains which caused the soil and slopes to become unstable. Second, human activity affects the stability of soil and rock masses in sloping areas.
In those recent landslides, prolonged rains in combination with human activity has accelerated soil saturation, directly triggering the landslides.
Mentioning the deadly landslide at Bao Loc pass in the Central Highlands province of Lam Dong that killed three and injured one, Van said human activity without proper research and planning plays an increasing greater role in causing landslides.
The site of a landslide (Photo: VietnamPlus) He stressed that as human activity and land encroachment increases, landslides like the one at Bao Loc Pass which occurred on a durian growing hill, have been increasing in both number and scale.
The scientist said there are many sites across Vietnam that have similar terrains and landforms with the site of the Bao Loc Pass landslide. He stressed the need to consider measures to minimise and prevent such disasters.
Taking note of the fact that most landslides in recent years occurred at sites adjacent to roads, the scientist said this is a grave concern. According to him, the construction of roads across mountains and hills often destroys the natural footslope, raising the risk of landslides. Therefore, it is necessary to invest in construction measures to strengthen the slope to ensure safety, which has to this point been neglected in many cases.
He cited examples in many countries where roads are built in tunnels across mountains, which both protect the natural landscape and avoid risks caused by geological hazards.
With the economic development level at present, Vietnam should go in this direction, Van said.
Many landslides in recent years occur adjacent to the country’s motorways (Photo: VietnamPlus) The expert highlighted signs before a landslide, first of all cracks in the ground, then water or mud leakages at foothills. Trees growing on the slope may tilt.
If the cracks become bigger, longer and deeper, the risk of a landslide also grows more serious. In particular, in sloping areas where human activities like ground leveling and house building destroy the natural foothill, the risk will become serious when prolonged rains saturate the soil.
He advised local administrations to quickly evacuate residents from areas where cracks appear in the ground during or after a period of rains. After that, experts should be sent to the site to monitor the cracks and evaluate the risk, which will serve as scientific grounds for measures to be taken later.
The expert stressed the need to conduct communication activities on the danger of destroying natural slopes to serve human activity, no matter what it is.
In road construction, thorough surveys and calculations are required to reduce the risk of landslide in soil areas adjacent to the motorway./.
