Abstract

The study on geohazards in the Lạng Sơn area was combined with the geological mapping and mineral survey of the Lạng Sơn Map sheet group at 1:50,000 scale, carried out mainly in the following areas: along the Highways No. 4a and 4b, along interdistrict roads and along the two sides of the Kỳ Cùng River, in residential quarters situated around intercommune and intervillage roads belonging to districts of the two Lạng Sơn and Cao Bằng Provinces. 

 The study results have been helping to recognize the following forms of geohazards: earthquakes, landslide, rock collapse, land fracturing, erosion washing the surface and forming furrows, washout of stream banks, flash flood, tube flood, karstic subsidence and hazards of human origins. The above hazards are being happened and are becoming more and more complicated.

On the basis of study results, some areas having the danger of happening geohazards have been forecasted and delimitated, at the same time, preventive measures have been set forth, aiming to minimize damages caused by these hazards.