De or het rijndelta?

The correct Dutch article is:

de rijndelta

How to use rijndelta

the rijndeltade rijndelta
this rijndeltadeze rijndelta
that rijndeltadie rijndelta
our rijndeltaonze rijndelta
your rijndeltajouw rijndelta
every rijndeltaelke rijndelta
which rijndelta?welke rijndelta?
a big rijndelta / the big rijndeltaeen grote rijndelta, de grote rijndelta