Valorization and Management of Karst Poljes in Southern Croatia - the Example of Jezero Polje

Large karst depressions with fertile soil and permanent streams in their bottoms represent the most valuable and rare fertile areas in the Dinaric karst. Such depressoins, defined in literature as „karst poljes“ , are in contrast with mostly barren, rocky and depopulated hinterland of southern Croatia, and thus represent the largest among the scarce fertile zones in karst. However, the specific hydrographic situation in such depressions has often caused difficulties in terms of floods and draughts, which has required undertaking special measurements for the most optimal valorization and menagement. A typical example is Jezero polje near Vrgorac in southern Croatia, also known as (Jezero – „The Lake“). Although its fertile surfaces have attracted settlers in its vicinity, the periodical flooding of the polje has been a problem which limited agriciltural activities only during the dryer part of the year, when the water would drain away. However, the summer aridity typical for areas with Mediterranean climate such as the area of Vrgorac has additionally shortened the period of the agricultural valorization during the year. Due to the above mentioned conditions, permanent settlements and infrastructure have been situated on the outside rim of the flooded areas of the polje. Such conditions are common to all of the karst poljes in southern Croatia (Imotsko, Rastok, Vrgorsko, Popovo polje), and require special measures, primarily in terms of managing water regimen in order to increase the overall agricultural productivity of the karst poljes.