Geocoding Freeform Placenames: An Example of Deciphering the Czech National Immigration Database

• Published in: ISPRS international journal of geo-information Vol. 10; no. 5; p. 335
• Main Authors: Šimbera, Jan, Drbohlav, Dušan, Štych, Přemysl
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.05.2021
• Subjects: Accuracy; Algorithms; Barriers; Country of birth; Czech Republic; Czechia; Datasets; geocoding; Immigrants; Immigration; Information systems; International migration; Migration; Moldova; Noncitizens; Python; spatial data; Transcription; transliteration; Ukraine; Vietnam; Czech Republic; Vietnam; Moldova; Ukraine
• ISSN: 2220-9964; 2220-9964
• DOI: 10.3390/ijgi10050335

The growth of international migration and its societal and political impacts bring a greater need for accurate data to measure, understand and control migration flows. However, in the Czech immigration database, the birthplaces of immigrants are only kept in freeform text fields, a substantial obstacle to their further processing due to numerous errors in transcription and spelling. This study overcomes this obstacle by deploying a custom geocoding engine based on GeoNames, tailored transcription rules and fuzzy matching in order to achieve good accuracy even for noisy data while not depending on third-party services, resulting in lower costs than the comparable approaches. The results are presented on a subnational level for the immigrants coming to Czechia from the USA, Ukraine, Moldova and Vietnam, revealing important spatial patterns that are invisible on the national level.