Which term refers to something that changes the geography of an area, such as erosion or longshore drift?

The term that best refers to something that changes the geography of an area, such as erosion or longshore drift, is 'Process.' In geographical and environmental contexts, processes are ongoing actions or series of steps that lead to changes in the landscape or environment over time. Erosion and longshore drift are both dynamic processes that continually shape coastlines by transporting and reshaping materials. These changes occur gradually as a result of various natural forces, illustrating how processes can modify geographical features.

While the other terms could loosely relate to geographical changes, they do not capture the continuous and systematic nature of these changes in the way that 'process' does. An 'event' typically refers to a specific, often singular occurrence, while a 'system' refers to a set of interconnected components that work together. 'Phenomenon' generally indicates an observable fact or occurrence but does not specifically imply a transformative action like a process does. Thus, the appropriate term in this context is 'process' due to its definition and implications in geography.