Ponorac

A ponorac (plural: ponorci) is a type of intermittent spring or well found in karst regions. These springs are characterized by a periodic flow of water, often linked to rainfall or snowmelt events that exceed the capacity of the underground karst drainage system.

The term "ponorac" originates from the languages of the Balkan region, specifically referring to a type of spring that appears and disappears depending on the water table level. Ponorci are fed by subterranean watercourses within the karst landscape. When the groundwater level rises sufficiently due to precipitation, the ponorac begins to flow, releasing water to the surface. Conversely, during drier periods, the groundwater level drops, and the ponorac ceases to flow, effectively becoming a dry spring.

The specific timing and duration of a ponorac's flow can vary significantly depending on the size of the catchment area, the permeability of the karst rocks, and the amount of precipitation. Understanding the behavior of ponorci is crucial for water resource management in karst areas, as they represent a significant source of freshwater and can also pose a risk of flooding during periods of high flow. They are important features for understanding the hydrogeology of karst environments and are often used as indicators of groundwater levels and flow patterns.