Základní topografická mapa České republiky 1 : 50 000 v ETRS89

The Base Topographic Map of the Czech Republic 1:50 000 in the plane coordinate system of the European Terrestrial Reference System 1989 in the Universal Transverse Mercator projection of meridian zones (ETRS89-TMzn), hereinafter referred to as ZTM 50/ETRS89, is a fundamental national map series. ZTM 50/ETRS89 extends the scale series of the national map series from 1 July 2023 with a variant of ZTM 50 in the plane coordinate system ETRS89-TMzn, as an alternative to ZTM 50 in the national coordinate system S-JTSK. In terms of content, ZTM 50/ETRS89 does not differ from the primary ZTM 50/S-JTSK. ZTM 50/ETRS89 covers the entire territory of the Czech Republic in a continuous map layout; the territory of the Czech Republic is shown on 222 map sheets. The sheet lines of the layout (inner frames) of the ZTM/ETRS89 map sheets form images of meridians and parallels at a specified spacing dependent on the map scale. A ZTM 50/ETRS89 map sheet thus covers an area of 10′ × 20′ (latitude × longitude). The dimensions do not include the accompanying elements shown on the printed version of the map sheet (i.e. the boundary band and frame and non-frame data). The dimensions of the printed map including all frame and non-frame data are 480 mm × 770 mm. ZTM 50/ETRS89 map sheets are identified by a nomenclature of alphanumeric character derived from the designation of the International Map of the World 1:1 000 000 (NM-33 and NM-34 for the Czech Republic), covering 6 degrees of longitude and 4 degrees of latitude. Additional characters specify the position of the map sheet of a given scale within the map sheet of the smaller scale from which it is derived. The map sheets are further supplemented by a map sheet name, which is generally identical to the name of the largest settlement on the given map sheet. If no settlement is found on a map sheet, another unique geographical name (peak, watercourse, land tract) from that map sheet is used. ZTM 50/ETRS89 map sheets are created by dividing a ZTM 100/ETRS89 map sheet into 4 map sheets using 2 rows of 10 minutes of latitude and 2 columns of 20 minutes of longitude, designated consecutively within the ZTM 100/ETRS89 map sheet in rows from the north-west map sheet as A, B, C, D. An example of a map sheet designation is Žďár nad Sázavou NM-33-08-6-B. ZTM 50/ETRS89 contains planimetry, altimetry and descriptions. The planimetry includes settlements and significant economic and cultural objects, roads, hydrography, boundaries of administrative units and cadastre units, boundaries of Protected Landscape Areas, vegetation and land surface. The altimetry includes terrain relief shown by contour lines with a basic contour interval of 10 metres, terrain steps, rock features and points with given elevation including their altitude. The map description consists of standardised geographical nomenclature, names of municipalities and parts of municipalities, names and codes of cadastre units and territorial-technical units, contour line elevations and points with given elevation, names of protected areas. The printed map sheets also contain the ETRS89-TMzn and S-JTSK one-kilometre map grid and the ETRS89 geographical grid, a map frame with frame data (e.g. directional data for selected roads, names of settlements divided between cadastre units, descriptions of neighbouring states, coordinates) and non-frame data (e.g. map legend, imprint data, graphical, numerical and slope diagram, interpolation scale of the ETRS89 geographical grid, graphical representation of the map in the map layout, expression of meridian convergence and magnetic declination, graphical representation of the overview of administrative boundaries, graphical representation of the terrain relief on the map sheet in the form of colour hypsometry, etc.). The map is produced by transforming ZTM 50/S-JTSK data, followed by data verification and the addition of frame and non-frame data. The source data for ZTM 50/S-JTSK are the Fundamental Base of Geographic Data of the Czech Republic (ZABAGED®) and the Database of Geographic Names of the Czech Republic Geonames. Only features occurring within the territory of the Czech Republic are shown. When displaying planimetry in ZTM 50, methods of cartographic generalization are applied to ensure graphical clarity — census choice of map elements and normative choice of map elements (omission of elements based on quantitative and qualitative parameters and further reduction of the number of elements where applicable), geometrical generalization (displacement, simplification of shapes and merging of areas) and reclassification (grouping of multiple categories of elements into a single category).