Technology and procedures for correction of errors and discrepancies of data Workshop on Experiences with Data Management to Improve Land Administration In ECE Countries Sofia, Bulgaria, 23 – 24 April 2009 Jaroslav Bačina Czech Office for Surveying, Mapping and Cadastre

Data quality History of data correction in the Czech Republic Digitalization of cadastral data – not all the applications adhered to standards of recording data Harmonizing of data in local databases with the central database The implementation of a new information system for the cadastre of real estates in 2001 (ISCRE) Data analysis and data corrections Czech Office for Surveying, Mapping and Cadastre

Data quality Data correction is determined by the Cadastral Act No. 344/1992: Cadastral officies shall correct any errors in the register on their own initiative or following a written petition submited by the owner. Errors resulted from the renewal and maintenance of the cadastre, inaccuracies during measurements and in depicting the bounderies in the cadastral maps. Czech Office for Surveying, Mapping and Cadastre

Data quality The errors in records of legal rights, parcel numbers can be corrected according to the deeds submitted to cadastral office for registration. The errors in boundary determination can be corrected according to survey documentation along with a written declaration of the owners of the neighbouring parcels. Other discrepancies of the data are corrected according to adopted standards or the correct data can be taken from some other state registers. Czech Office for Surveying, Mapping and Cadastre

Data quality The Czech Office for Surveying, Mapping and Cadastre has issued: Instruction No. 2055/2001-24 on data quality improvements, Instruction No. 3051/2001-24 on standardizing the name and address data of the owners. The Czech Government has issued the Decree No. 111/2001 on matching and acceptance of the cadastral data and the data of the Population Register. Czech Office for Surveying, Mapping and Cadastre

Data quality A huge data correction process was launched in 2001 to Adjust the data to new data models in ISCRE - the new business rules were not applicable to all historical transactions and records Standardize the data Correct the spelling errors Remove duplication in the records Czech Office for Surveying, Mapping and Cadastre

Data quality Working group for data control Established in 2008 Data analysis Proposals for software updates Guidlines and instructions – methodology Fixing a term for data corrections Czech Office for Surveying, Mapping and Cadastre

Data quality Team of contact persons Discrepances of the same data recorded in several workplaces Data is checked with the deeds 1 contact person for each cadastral workplace 1 workplace is determined as a leading one in each instance Communication by software application or by e-mails Czech Office for Surveying, Mapping and Cadastre

Data quality Sets of error records Created by the Central Database Department Accessible by cadastral workplaces via Internet Data designed in structured fields Updated version of the sets of error records Czech Office for Surveying, Mapping and Cadastre

Data quality Czech Office for Surveying, Mapping and Cadastre

Data quality Database scripts as an automated tool for data correction Created by the Central Database Department Response to control analysis or legislative changes 3 – 4 scripts per year All error data is corrected at the same moment according to rules Czech Office for Surveying, Mapping and Cadastre

Data quality Data error prevention Data standardization Use of code lists Integrity constraints Control digit test Input controls Administrative measures Czech Office for Surveying, Mapping and Cadastre

Thank you for your attention. jaroslav.bacina@cuzk.cz Czech Office for Surveying, Mapping and Cadastre