The Slano Blato Landslide, or the Salt Mud Slide, is a periodic landslide in Slovenia that is triggered approximately once a century. Although around 8,000 active landslides are present in Slovenia, the Slano Blato Landslide stands out as one of the most serious in terms of the damage it has caused. The landslide is located on the southern edge of the Trnovo Plateau of the Dinaric Alps, below Mount Čaven and Little Mountain next to the Platna mountain pasture. It is moving along Grajšček Creek toward the settlement of Lokavec near Ajdovščina. It is long and wide, covering approximately between the elevations of. Its maximum flow rate was recorded at /day.
Name
The name of the landslide area was recorded as Blatna in 1881. The origin of the designation 'salt' is uncertain. A local folk belief states that the high cleanup cost of the landslide resulted in an exorbitant cost. However, the landslide bore the designation 'salt' before any cleanup efforts were ever made. Other locals state that sheep used to wander down to the area from nearby pastures, where they would lick the mud as a natural salt lick. This basis for the name's origin is supported by the fact that chemical analysis of the water at the landslide has shown it to have a very high mineral content, including sodium sulfate, also known as Glauber's salt.
History and activity
Oral tradition regarding the landslide goes back four centuries, connecting it to the construction of a small church dedicated to Saint Urban on the slope of Mount Čaven above Lokavec and below the landslide. Saint Urban was invoked as a protector against natural disasters, and particularly with regard to a lake that people believed was hidden inside Mount Čaven that threatened to flood the valley. A 1789 source by Belsazar Hacquet mentioned the landslide, describing its debris flow in 1786. It was described again in an 1887 report that discussed the landslide event of 20 October 1885, in which 30 m of the road from Ajdovščina to Gorizia was destroyed. Cleanup efforts and landslide mitigation measures were carried out by Austrian authorities in 1903. In November 2000, heavy rain and warm weather triggered the Slano Blato Landslide, which buried about of grassland and forest. A secondary flow was triggered in September 2001. The landslide stopped moving after this and is currently considered stable. Following these events, an access road was built and of material was removed from the lower part of the landslide and deposited north of the Ajdovščina Airport.
