Use of the spectral clustering to determine coherent precipitation regions in Turkey for the period 1929-2007

摘要

In this study, we suggest the spectral clustering (SC), a hybrid clustering technique based on singular value decomposition (SVD) and K-means for grouping features of precipitation totals of 96 stations in Turkey. Clustering process establishes an exhaustive set of occupied regimes into distinct climatic zones. Results of the SC satisfactorily represent the influences of the synoptic-scale weather systems including such as the mid-latitude and Mediterranean frontal cyclones, and the mid-latitude travelling and eastern Europe high pressures in winter, sub-tropical Azores high pressure and monsoon low in summer. Results of the SC also well display the influences of local-scale atmospheric disturbances, and direct influences of physical geographical features of Turkey (i.e. exposure, topography, orography, land-sea distribution, continentality and the high Anatolian peninsula) on the geographical variability and coherent distribution of the annual precipitation totals over Turkey. Finally, based on the results of the SC method employed to annual precipitation totals of 96 stations in Turkey for the period of 1929-2007, eight clusters of precipitation coherent zones are determined, namely Black Sea, Northwest Turkey, southern Aegean and western Mediterranean, Mediterranean, West Continental Central Anatolia, East Continental Central Anatolia, Continental eastern and south-eastern Anatolia.