Geografie 1962, 67, 143-150
Geographical Median
Statistical series of numbers concerning little territorial unities are divided on the map into two equal groups according to the line which keeps - as much as possible - to such outstanding geographical features as watersheds, orographical borders, etc. This line is called geographical median since its character is predominanty geographical, in contrast to the median expressed by the centrographical method: a) except his position a point posesses no other geographical quality; b) although the geographical median does not show any unambiguous results, it nevertheless suggests more realistic ideas since it delimitates an actual area upon which half of the observed factors really occur. The geographical median is a logical supplement to every statistical map or cartogram as far as it concerns the geographical distribution (not intensity), and as far as it shows to what extent this is balanced. Its main advantage over the centrographical method is the possibility of a world-wide comparison. The author gives the following examples of application (mostly from Czechoslovakia): 1. number of inhabitants according to localities in 1930 and 1955 (fig. 2, line P1, P2); 2. number of inhabitants engaged in industry according to districts in 1930 and 1955 (fig. 1, line I. 1, I. 2); 3. number of inhabitants working in engineering, wood working and food industries (fig. 1, line 1, 2, 3). The occurrence of wood working industry corresponds to the occurrence of forested areas (line 4); 4. extent of the area according to the localities by which the median line keeps as much as possible to the orographic border of the Bohemian Massif (fig. 2, line A). As far as the area and the population is concerned, the author indicates analogical lines also for the Czechoslovak part of the drainage basin of the Odra (Silesia) which extends to both halves of the Czechoslovak territory. The distribution of population as well as industry is much less balanced here than in the remaining parts of the state (fig. 3). The author compares areas delimitated by this in the following three ways: 1. The area on which half of the total population of the state live is compared with the total area of the state. In Czechoslovakia the ratio was 46,9% in 1955, which is a fairly favourable figure. 2. The density of population on a square kilometer was compared in both - western and eastern - halves of the state (106,0: 97,7 = 1,085). The author also compared the density of population in both areas where half of the total population are resident (108,6:95,9 = 1,132). The ratio is called the median density of population. Most probably only in few states the ratio keeps as low as in Czechoslovakia. 3. The author compares half of the state territory with the area on which half of the population live. In 1930 this area was smaller by 19,7% than the half of the state territory, in 1955 only by 6,2%. In this way, the above difference in median areas has been cut down to one third and the density of population in the state has become more balanced.
