Recent landform evolution in Bulgaria

Abstract

Morphostructures exert a strong control on the landforms of Bulgaria as in the mountain landscapes planation surfaces prevail. In mountains valley incision is considerable, deep and narrow gorges and cross-section asymmetry of valleys is common. In major valleys two flood and seven upper river terraces have been identified. Regionally, active karst processes are significant in shaping the landscape, especially in the Predbalkan and Rhodope Mountains. Most (59.7%) of the Black Sea coastline is of abrasional type with cliffs, while 28% of its total length is accumulational with beaches, spits, limans, lagoons, and sand dunes. As the equilibrium line altitude (ELA) of glaciers in Bulgaria was the highest in the Carpatho-Balkan area, glacial landforms only developed in the Rila and Pirin Mountains, above 2,400 m, but periglacial features are more common. The southernmost occurrence of loess in Europe is in the Bulgarian Danube Plain. The most severe human interventions into the natural environment are related to mining activities. Improper tillage techniques in agriculture may lead to higher erosion hazard than predictable climate change.