Seeking border data which is classified as Coastal and Land?

Question

I am trying to operate regressions over two parameters - (1) Ratio of length of coastal border to land border (2) Average Military Expenditure through 1996-2016 for each country.

For parameter (2) will use the database given by SIPRI(Stockholm Peace Institution) which is available in following link : https://www.sipri.org/databases/milex

However, since I am an quite novice to the field of Geographic informations, so keep losing my times to find the required and proper data for para (1).

For clarification coastal border means measured total length of border where it faces with sea while land border means measured total length of border where it faces with land.

I prefer the csv type of database, but the format would not be big problem and also I am willing to handle and experience some geo-specific data formats too.

Where could I get the border data which is classified as Coastal and Land?

I am basically using Python with NumPy and Matpolib.

Answer 1

I'm not aware of a ready-made dataset that fits your requirements.

An alternative could be Natural Earth. They have borders (total and land): http://www.naturalearthdata.com/downloads/50m-cultural-vectors. Costal will be the difference between total and land.

So while this is certainly possible, some data wrangling will be involved.

Answer 2

The borders in Natural Earth could work as per Underdarks excellent suggestion. However, I think they are based on GSHHS data which is less accurate than OSM's coastlines which are available here. It all depends on the resolution you need.

There is a link on the page to land polygons and water polygons. So you could buffer the coastlines and clip with water polygons to give you areas within a set distance of the coast (depending on your definition of coastal). Doing this globally will be intense depending on your machine but is doable (perhaps run overnight).