Prague, a city of one million people, is the capital of the Czech Republic. It is renowned for the medieval Charles Bridge, Prague Castle, and its maze-like city center, infused with an antique atmosphere. However, what cannot be seen in the winding streets is the city administration's effort to create uniform digital records of engineering networks and property relations for the entire area quickly and effectively. This task, however, has not been an easy one.

This map combines a detailed technical land-use map with a digital technical map.

Historically, unifying these records has been complicated by numerous factors, not the least of which was that prior to the late 1980s, all records were kept on paper. Then, when the first Unified Digital Map of Prague (UDMP) was created in the early 1990s, the various governments and agencies were expected to revise their own hard-copy maps and forward them to the city administration to be updated in their digital counterparts at intervals. However, as these sketches were waiting to be incorporated into the digital map, the rate of new construction grew, and the number of amendments to the digital map grew, which inevitably slowed down the updating process.

When information technology made a giant step forward, Praque officials sought to ensure up-to-date, consistent, and accurate data for the city's decision making. The result was a new concept of digital mapping, which began to take shape in 2007. Following an intensive program of investigation and comparison, ArcGIS technology was selected by the city for the core of its digital mapping program.

Because Digital Map of Prague (DMP) data is designated as a source for Prague information systems, especially for use in map applications and in relation to external information systems, the city decided to make a change in technology, upgrading from CAD to ArcGIS Desktop where work with data and its visualization is carried out. The geodatabase has become an environment for data structures in new work. For data distribution, the ArcGIS Data Interoperability extension is used. Special tools have been programmed, allowing searching of given areas; the data can be exported to various data formats and filtered by attributes, layers, and location. The tools also support organization of data download, such as comprehensive records of customers and information, price calculations, and the preparation of billing documents. The project was carried out with the cooperation of the NESS Czech, a.s., and T-mapy, s.r.o., companies.

Prague Castle.

The CAD data is transferred into a relational database, and attribute and topological checkups are performed to maintain consistency of the data model and for the creation of derived data layers, which are then processed in the Esri GIS environment. The verified data is regularly shared with the City Development Authority Prague, where detailed quality control is carried out. In case an error is found, the affected part of the data is returned to the supplier for reprocessing. The map's features are accompanied with information about the source from which they came and when they were added to the map. The system also stores the removed features, which allows the map's history to be tracked. Thus, the integrity of the database and the precision of the data model are maintained.

"When transferring data from the old UDMP to the new DMP, we discovered many errors and deficiencies in the topology and data accuracy," explains Jiri Ctyroky, head of the Department of Spatial Information/City Development Authority Prague. "Thanks to the transfer, we were able to remove them."

More Information

For more information, visit www.urm.cz/en/digitalni_mapa_prahy.