Poljeområder

Poljeområder, often simply referred to as poljes, are extensive flat-floored depressions that are characteristic of karst terrains. They occur where soluble rocks such as limestone, dolomite, or gypsum have been dissolved by underground water, creating large underground voids that collapse and form surface depressions. The term “polje” is derived from the Slovene word meaning “field” and was first used in the early 20th century by geomorphologists studying the Dinaric Karst in the Balkans.

The main physical features of a polje include a broad, flat floor, steep walls formed by faulting or erosion, and a lack of surface water streams because water usually drains underground through sinkholes (ponors) and caves. Because the floor is often covered by thick alluvium or soil, polje areas can support agriculture, forests, or pasture, and in some regions they are valued for their high water tables and fertile soils. Many poljes are seasonal lakes—called shallow seasonal lakes or “polje lakes”—that fill during wet periods and dry up in drought.

Poljeområder can range in size from a few hectares to several hundred square kilometers. Famous examples include the Miroč polje near Sarajevo, the Polje of Bjelovar in Croatia, and the large poljes of the Dinaric Karst stretching across Slovenia, Bosnia, and Croatia. In India, Rajasthan hosts a number of poljes that are important for local water storage.

The study of polje areas is crucial for understanding karst aquifers, managing water resources, and assessing flood risks. They also provide unique ecological niches, supporting specialized plant and animal communities adapted to karst conditions. Understanding the geomorphology, hydrology, and ecology of poljeområder remains an active field of research within geomorphologists, hydrologists, and conservation scientists.