The goal of the specialized map is to evaluate spatial differences in the development of the religious structure of Czechia in the 20th and the early 21st centuries and to show the most significant trends in this period. In order to make older quality cartographic documents accessible to a wider readership we used the map of religious denominations from the Atlas of the Czechoslovak Republic (Atlas republiky Československé) published in 1935 to evaluate the inter-war period.
The specialized map contains data from the 1930 census represented by izolines and proportional symbol map created using a combination of territorial and population principles. This method gives a map of squares placed in the centre of continuous territories with populations of 9, 12, 16 thousand and so on that have a similar religious structure.
The map based on data from the most recent census also works with the level of municipalities. Using the izolines method to show the percentage of Roman-Catholics in the population makes it possible to compare changes between 1930 and 2011.
The religious structure of the population is analysed for ORP1 areas which - unlike the map of the 1930 situation (where there are no borders marked between religiously distinct territories) - allows recognition of the religious structure in actual territories.