What does 'alluvium' refer to in geography?

Alluvium refers specifically to sediments that have been transported and deposited by the action of running water, which makes it a crucial component in the study of river systems and their surrounding environments. This material is predominantly found in riverbeds and floodplains, where flowing water carries particles of soil, clay, silt, and other organic or inorganic matter. Over time, these sediments accumulate, enriching the soil and creating fertile areas that are often ideal for agriculture.

The unique properties of alluvium, including its mixture of various-sized particles and nutrient content, contribute significantly to the landscape and ecology of river valleys. Understanding alluvium is essential in geography as it plays a vital role in river morphology, sedimentation processes, and the way rivers shape their environments.