Karstic uvala revisited: Toward a redefinition of the term

Uvalas are a particular type of karst closed depression. While other types of closed depression - dolines and poljes - are regularly listed and relatively well defined in overviews of karst surface morphology, uvalas are either excluded or their vague identification is stressed. The leading idea of this paper is to obtain a clearer meaning of the term uvala and prevent its abandonment from karstology and general geomorphology. Within the study, 43 examples of uvalas have been selected. The studied uvalas are located in the Dinaric karst and karst of the Carpatho-Balkanides. All the case examples have been digitally processed in the same way. Creation of high-resolution digital elevation models enabled quantification of morphometric parameters, generation of inclination maps and cross-sections, as well as application of statistical analyses. Formation of the geographical information system of the studied uvalas was done using raster-based and vector-based GIS software packages. In 12 studied uvalas, detailed structural-geological mapping has been carried out, which revealed dominant development of uvalas along regional scale tectonically broken zones. A revised definition of the term uvala is suggested, leaving the opportunity for further discussion.

► Karstic uvala is a particular type of karst surface depression. ► The study includes morphometric analysis and structural-geological mapping. ► Uvalas form by accelerated corrosion with linear or areal focus.► Uvalas mostly develop along tectonically broken zones of regional scale.