THE MORPHOLOGICAL CHARACTERISTICS OF THE KARST POLJE IN THE TERRITORY OF THE REPUBLIC OF ALBANIA.

Karst poljes represent depressions created in territories made up of limestone and dolomite rocks. Generally, in Albania the karst poljes have multiple origin, thus they have a polygenetic character due to the active activity of tectonics faults, river activity and in some cases of the significant influence of glaciation during the Quaternary period. These shapes are of different sizes, the range of hundreds of meters to several kilometers, while the bottom is flat and with small topographic contrasts. Large-scale poljes are considered as a complicated hydrological surface and subterranean system in karst terrains. Poljes that are periodically inundated, especially during the cold and wet periods of the year due to the surface streams mainly appear on the hills of Dumrea, which are characterized by large sizes. The local tectonic faults and fissures appear densely spread out in the limestone rocks, which are very permeable. Usually, the bottom of poljes is covered detritus deposits, which in many cases block the infiltration of underlying limestones. In general, poljes in Albania have been created due to the joining of the dolines and uvalas with each other, or due to the presence of tectonic faults. The highly active dissolution process and corrosive action on limestone rocks has increased the size and emphasized even more the morphological features of the karst poljes. The formation of some of the poljes is conditioned by the presence of synclinal fold structures, with wide and flat axis, over which favorable topographical conditions are created. Shkodra and Great Prespa poljes generally have northwest-southeast diagonal direction due to the formation of graben type structures, which along restrictive blocks are associated with the longitudinal normal tectonic faults. With regards to the criteria concerning the creation of the karst poljes, topographic factors, elements of morphodynamic evolution, current hydrological features and geomorphologic characteristics should be considered. Important factors are the average level of subterranean waters and the detritus deposits accumulated along the bottom of the karst poljes. Usually, the bottom of the poljes is covered with surface deposits of Neogene and the Quaternary periods, such as reddish materials, otherwise called "terra rossa". Periodically inundated poljes, in high mountainous areas, being in close relation to climatic conditions, can be used for breeding livestock, or as pastures. The intensive use of agricultural land for different purposes requires large investments for the rehabilitation of the irrigation system, infrastructure and the development of branches of agricultural economy. Due to the presence of karst processes in poljes, the regionalization according to the scientific criteria of the agricultural crops should be realized. Different trees can be planted along the edges of the poljes which can encourage the development of the forest economy. [ABSTRACT FROM AUTHOR]