Vulnerabilities

Landslides are unevenly distributed in Bulgaria. More than 920 ones have been recorded up to now in 350 settlements, mostly along the Danube shoreline in North Bulgaria where 10 catastrophic landslides have occurred for the last 30 years. They also occur along the Northern Black Sea coast and in Lower Cretaceous sediments of the Fore-Balkan river banks. Most of the landslides in South Bulgaria are developed in Tertiary basins (Sofia and Pernik valleys, East Maritsa coal basin), in Rila and Rhodope fault zones, on the mountain river valley slopes and on the lava flow peripheries in the Eastern Rhodopes (1).

In Bulgaria, rockfalls occur primarily on steep or vertical mountain slopes which have specific lithological structure and physical properties of the constituent rocks. Most of the dangerous rockfalls are bound up with deeply cut, transverse gorges, troughs and canyons. The declining slope stability and the size of the fragmented rock blocks are associated with rainfall periods,sudden earthquakes and gravitation. Risk areas are especially the marginal escarpments of Northeast Bulgaria’s plateaus (including the Black Sea coast), the East Rhodope Mountains, the high mountain zones of the Rila and Rhodope massif and the Western Stara Planina (1).

Landslides and rockfalls appear when the slope equilibrium is disturbed by the open-pitmines or by excavation and piling of materials needed for the building of roads, railways, hydro-engineering facilities, industrial capacities, etc. (1).

References

The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Bulgaria.

1. Muço et al. (2012)