Accounting has relevance to the study of geography because accounting determines the way in which various economic forces interact. These economic forces, in turn, change the location and spatial interactions of humans.
Geography is usually defined as the study of the spatial perspective, as it questions the influence that location has on human interactions, history and people. A large part of the study of this spatial perspective is the way in which the economy and the trading of money influences the location of humans. This is where accounting comes in, as the money that various people have, the way they spend it and the way that spending can help them in the future are all questions that provide a rich intersection between geographical questions and accounting questions.
These questions address the desirability of studying economics, which is relevant to the spatial perspective of various economic issues. For example, the location of a future company may be determined by what location makes the most economic sense; it wouldn't make economic sense to place a solar power company in a place that rarely gets sun, but it would make economic sense to put a T-shirt factory close to a place in which cotton is farmed.