The cause of the landslide that destroyed the road in Pamporovo is the accumulation of water in a sunken area above it.
This was shown by the analysis of the geospatial model of the terrain, which was made by specialists from Sofia University. On the other hand, in the Ministry of Regional Development, both ministers are still guessing about the causes. The new minister Ivan Shishkov confirmed the commitment to strengthen the bypass road through Stoykite.
After 40 minutes of flying over the entire affected area with the lidar's scanning eye, the scientists now have a very accurate three-dimensional model of the landslide terrain. And after the vegetation is removed, the relief shines with all its categoricality. And the cause of the landslide is found right above it.
"A careful analysis of the relief shows that here is a platform, so to speak, where a quantity of both rain and snow could have accumulated, which melted with the rise in temperatures", shared Assoc. Prof. Alexander Gikov, geomorphologist, IKI, BAS.
"Here is this leveled section in the upper part, here the relief changes to depressions, in which it is possible to collect water", said Prof. Dr. Steliyan Dimitrov, Center for Geospatial Research and Technologies, Sofia University.
The above-normal rainfall in the region in January and February, the melting of the snow and the retention of water above certainly correspond to what happened now.
"The penetration of this moisture downward reaches a clay horizon, where the sliding occurs. This is a slippery surface, which here in the landslide area has a slope of somewhere around 25 degrees. This is not a small slope," added Gikov.
The exact same site is also above the old landslide next to the new one, which on the map already looks like one whole. And now it seems illogical why they didn't strengthen the remaining 150 meters of the road.
"This is also a landslide slope, but it didn't give way, even though it was in identical conditions. And where the weak spot was, where there was no strengthening, the landslide happened," noted Dimitrov.
However, the services and experts of the Ministry of Construction are still clarifying the reasons.
"Before this, there were no indications that something like this would happen. It happened suddenly. It happened extremely attractively and strikingly," said Nikolay Naydenov, former acting Minister of Regional Development.
"Didn't someone do their job? Everyone who saw the landslide believes that there was something that provoked it on this scale," added Ivan Shishkov, Minister of Regional Development and Public Works:
Modern technologies allow us to clearly see the problem areas, and to take preventive measures. But the landslide at Raykovski Livadi is not even in the field of view of the relevant geoprotection service. And the regional ministry expects the analyses to be ready within days.