Ivica Milevski GEOMORPHOLOGIA SLOVACA ET BOHEMICA 2/2011 32 INTRODUCTION Mountains are dominant morphostructural landforms in the chequerboard topography of the Republic of Macedonia. On the relatively small national area (25,713 km 2 ), there are so- me 38 mountain ranges, different in size, sha- pe, geology and mode of formation. According to their altitude, these mountain ranges are di- vided into three groups: high mountain ranges (2,000 – 2,753 m a. s. l. – ibid. thereinafter), with a subgroup of 5 very high ranges (2,500 – 2,753 m); medium-high mountain ranges (1,000 – 2,000 m); and low mountain ranges (below 1,000 m). High mountain ranges are mostly found in the western and central parts; only two of the 13 mountain ranges above 2,000 m are in the eastern Macedonia: the Oso- govo (2,252 m) and the Belasica (2,029 m) (MILEVSKI 2011). Mountain ranges in the western and central parts of Macedonia geotectonically belong to Dinarides and Hellenides and its subunits: Western Macedonian Zone, Pelagonian Massif and Vardar Zone (DUMURDZANOV et al. 2005). For that reason, they have a general N-S to NW-SE strike. In contrast, the ranges in the eastern part of the country are generally E-W aligned because of the predominant N-S exten- sional tectonic regime (DUMURDZANOV et al. 2005). Mountains in the western and central parts are generally composed of marbles (the Jakupica, the Suva Gora), limestones (the Bis- tra, the Jablanica, the Galičica, the Šara), gra- nites (the Pelister) or other very resistant rocks: these mountain ranges usually have narrow, sharp ridges and peaks, and deeply incised val- leys. Mountains in the eastern part of Mace- donia are dominantly composed of more ero- dible crystalline rocks (gneiss, schists) and, consequently, show a more subdued relief, rounded ridges and peaks, and less deeply in- cised valleys. However, both groups of moun- tain ranges were generally shaped during the Neogene-Pleistocene (KOLČ AKOVSKI 2006). Great morphological significance for the high mountain ranges in Macedonia has its Pleistocene glacial phase, especially during the Last Glacial Maximum (LGM) and later Older and Younger Dryas, when numerous mountain glaciers existed (KOLČAKOVSKI 2004, KU- HLEMANN et al. 2009, RIBOLINI et al. 2011). Most of them were cirque glaciers on the Pelister, the Jablanica and the Stogovo Mountains or occupied short and small U-sha- ped valleys downslope on the Šara, the Korab, the Jakupica and the Galičica Mountains (KOLČAKOVSKI and MILEVSKI 2012). The Equilibrium Line Altitude (ELA) was located high (1,900 – 2,100 m), elevating in W-E di- rection (KUHLEMANN et al. 2009), while precipitation was relatively low and decreasing in same (W-E) direction (KOLČAKOVSKI 2004). For that reasons and very weak glacial remnants, it is still doubtful if the high moun- tain ranges on the east, the Osogovo (2,252 m) and the Belasica (2,029 m) were glaciated (MILEVSKI 2008), while the similar problem is with the Suva Gora (2,061 m) on west. From LGM and later glacial phases many landforms have remained: cca 30 cirques generally be- tween 2,000 and 2,400 m of altitude, U-shaped valleys with lengths of up to 2.5 km and mo- MORPHOMETRIC CLASSIFICATION OF HIGH MOUNTAIN RANGES IN THE REPUBLIC OF MACEDONIA IVICA MILEVSKI* Ivica Milevski: Morphometric classification of high mountain ranges in the Republic of Mace- donia. Geomorphologia Slovaca et Bohemica, 2, 2011, 2, 6 figs., 9 tabs., 30 refs. As a result of powerful local and regional geotectonic movements in the past, the landscape in the Re- public of Macedonia is characterized by frequent alternations between mountains and depressions. There are 38 mountain ranges, of which 13 extending above 2,000 m are defined as high, while the highest - Korab – reaches 2,753 m a. s. l. Because of their geomorphological and overall significance, morphometric features of these 13 dominant high mountain ranges are analysed in this work. The data are calculated from a previously prepared 3”SRTM-based DEM model with particular attention to hyp- sometry, slope gradient and aspect, and vertical relief. Based on these variables, a simple supervised classification of the high mountain ranges is made. Key words: morphometry, mountain ranges, supervised classification, 3”SRTM DEM ———————– * Institute of Geography, Faculty of Sciences, Ss. Cyril and Methodius University in Skopje, Gazi Baba bb, 1000 Skopje, Republic of Macedonia, e-mail: ivica@iunona.pmf.ukim.edu.mk