に伴って|にともなって

1. 1As X changes or progresses, Y changes along with it.Ex. 1
2. 2Y occurs, or a measure Y is taken, as an accompaniment to or consequence of a single event X.

A formal expression common in news reports, official announcements, notices, and written explanations of social, economic, or natural changes. In the proportional-change sense, both clauses usually describe large-scale or objective changes. Compared with につれて, it sounds more formal and, unlike につれて, can also describe a single event that brings something else with it, as in notices about relocations or system changes.

• につれてN3「につれて」 covers only sense 1 of 「に伴って」 — both sides changing gradually in tandem — and in that use the two are generally interchangeable; its register is neutral and somewhat more colloquial. It cannot be used for situations caused by one-time events (e.g., 「移転に伴い」), and the second clause cannot be a request.
• に従ってN3The 'as/along with' sense of 「に従って」 is limited to continuous gradual change, where it is interchangeable with 「に伴って」; it cannot be used for one-time events like moving or a change. It also has a separate 'follow rules or instructions' sense, with a neutral register.
• 〜とともにN3In its 'as/along with' sense, 「とともに」 is close to 「に伴って」 and often interchangeable; it can also mean 'together with someone' or 'being both at once,' as in 「教師であるとともに」. When attaching to a verb, it connects directly, with no 「の」 needed.
• に応じてN2「に応じて」 centers on adjusting in line with the amount or situation of the first item, or on responding to a request or invitation; it attaches only to nouns and is neutral in register. 「に伴って」 expresses a change or situation that arises in accompaniment, attaches to both nouns and verbs, and leans written/formal.
• 〜ば〜ほどN2「〜ば〜ほど」 generally requires repeating the same word in both halves (it can take verbs, adjectives, and nouns); its register is neutral and it is common in speech as well. It only expresses the 'the more..., the more...' degree correspondence and cannot express a second situation arising alongside an event.
• 〜に向けてN2「に向けて」 expresses preparing or striving toward a goal, or directing a message at an audience; 「に伴って」 expresses a corresponding situation arising as the first item changes or occurs. The former attaches only to nouns and is neutral in register; sometimes both are possible, but the emphasis differs.

につれて and に従って also express proportional change, but につれて is more neutral and not used for a single triggering event, while に従って can also mean 'in accordance with' rules or instructions. 〜とともに is broader ('together with, at the same time as'), に応じて means adjusting in response to varying conditions, 〜ば〜ほど stresses 'the more…, the more…', and 〜に向けて marks a goal or target rather than an accompanying change.