area of influence; zone of impact; extent of effect
Refers to the geographical, organizational, or abstract scope within which something has an effect. Common in business, IT, and disaster contexts.
We need to investigate the extent of impact of this system change in advance.
The area affected by the typhoon extended over a wide region.
影響 is the general word for 'influence' or 'effect', while 影響範囲 specifically refers to the scope or area of that influence.
範囲 means 'range' or 'scope' in general; 影響範囲 narrows it to the range of influence or impact.
Compound of 影響 (influence) and 範囲 (range, scope).