Receding coastline?

Question

When you say "receding coastline", which one recedes: the water or the land? How about when it's "receding shoreline", the water or the land? Thanks!

Answer 1

It would appear that "receding coastline" could be either one. The one that is receding is the one the writer is concerned about. However, in the examples I found it was usually the land that was receding.

Here is an example where "receding coastline" means the land is receding.

http://www.ekathimerini.com/4dcgi/news/content.asp?aid=80787

Here is an example where "receding coastline" means the water is receding.

http://books.nap.edu/openbook.php?record_id=6031&page=201
__________

All the examples I found using the term "receding shoreline" referred to the water receding.

Answer 2

Since the noun being modified by the adjective is coastline, and the adjective is receding, it would seem clear.
Coastline gets smaller.