Comma Before Participal Phrase

Solution 1:

"Creating..." isn't a dependent clause. It's a participle phrase that modifies either the entire preceding clause, the subject-verb in the preceding clause, or a noun that precedes "landforms" in the preceding clause. The base participle phrase is "creating a landscape." You'll notice that's not a clause because there's no subject-verb. Rather, it is the present participle "creating" and its direct object "a landscape," the complete direct object being "a landscape that not only serves..." because "landscape" is adjectivally modified by the restrictive relative clause "that not only serves..."