Different regions have different traditions, not only when it comes to naming children but also when it came to choosing surnames.
Someone named Bauke Ferwerda is bound to be Frisian, as the suffix -a can mostly be found in the northern provinces and Bauke is a Frisian first name. Janna Geertruida Meerdink is undoubtely from the eastern part Gelderland. Most people in that area used double first names, and the -ink suffix is typical for farm names in the eastern part of the country.
Read more about finding the origins based on suffixes of names.