I am doing a sentiment analysis project about local people's attitudes toward the transportation service in Hong Kong. I used the Twitter API to collect the tweets. However, since my research target is the local people in Hong Kong, tweets posted from, for instance, travelers should be removed. Could anyone give me some hints about how to extract tweets posted from local people given a large volume of Twitter data? My idea now is to construct a dictionary which contains traveling-related words and use these words to filter the tweets. But it may seem not to work
Any hints and insights are welcomed! Thank you!
There are three main ways you can do this.

Language. If the user is Tweeting in Cantonese - or another local language - there is less chance they are a traveller compared to, say, Russian.
User location.  If a user has a location present in their profile, you can see if it is within Hong Kong.
User timezone.  If the user's timezone is the same as HK's timezone, they may be a local.

All of this is very fuzzy.
How to extract tweets posted only from local people?