The phrase "is dependent upon" can be replaced with a variety of synonyms to convey the same meaning. Some options include "relies on," "counts on," "is based on," "hinges on," "is determined by," "is influenced by," "is dictated by," "is subject to," "is directed by," and "is conditioned by." Each of these phrases communicates the idea that something is connected to or affected by something else, and that one thing cannot exist or function correctly without the other. Choosing the appropriate synonym depends on the context and tone of the sentence.