EN
In new version of natural−forest regionalization that was completed in 2010, Poland was divided into 8 natural−forest lands, which, in turn, consisted of 11−35 mezoregions. The objective of the study was to evaluate the delimitation of the defined mezoregions. The correctness of the delimitation was assessed by the means of similarity analysis. The similarity of adjacent mezoregions (within borders of each of the natural−forest lands) was calculated based on three main criteria (geological formations, natural landscapes and vegetation landscapes), which were used for definition of the mezoregions borders. Data on spatial distribution of the above criteria were acquired in digital form and then processed using Geographic Information Systems technology in order to identify and describe each of the mezoregions. The assessment of the similarity was based on the calculation of the partial similarity indices for each of the criteria, and then on the calculation of the overall similarity index for each pair of adjacent mezoregions. Received values of the overall similarity index range from 0.01 to 0.48. The smallest range of the index is in the Sudecka land (0.09−0.28) and the highest is in the Baltic land (0.01−0.41) and in the Carpathian land (0.07−0.48). In order to facilitate analysis of the results, five−level scale of similarity was adopted. All around Poland there are no mezoregions whose degree of similarity to adjacent mezoregions is large or very large. The medium similarity (index value 0.41−0.70) was observed in 1.7% of the analyzed cases, small similarity (index value 0.21−0.40) was observed in 37.7% of the analyzed cases and the lack of similarity (index value 0.00−0.20) in 60.6% of cases. Delimitation of mezoregions was therefore prepared correctly.