Implications for predicting river incision rates

Rivers are a familiar feature of Earth's landscape and have a significant impact on human existence, either as a source of water or as a hazard through flooding or triggering of landslides and debris flows.

Because they play a key role in shaping Earth's landscape, it is vital to understand how fluvial systems work. Although considerable research has focused on alluvial rivers that dominate lowland landscapes, much less attention has been paid to rivers that incise bedrock, which typify fluvial channels found in mountainous areas. Whittaker et al. focus on such channels that drain mountains in central Italy, where present-day earthquake activity is contributing to landscape instability. Current landscape models, which can be used to describe how this area might evolve as tectonic activity continues, make important assumptions about how rivers behave. Whittaker et al. challenge these assumptions by showing that rivers dynamically adjust to uplift on active faults and that traditionally used mathematical relations, which link river discharge to channel shape, do not apply in these settings. The results help to clarify the long-term erosion mechanics of bedrock rivers, explain how some rivers manage to cut across active faults, and challenge geomorphologists to improve their landscape evolution models. - Geological Society of America