Event

River networks shape mountain topography, transport water and sediment from continental interiors to the oceans, and serve as conduits for freshwater species. Tectonic and climatic perturbations can drive changes in river network structure that affect all of these functions, but it is difficult to determine the nature and extent of this river network "rewiring" across an entire region. A new technique for mapping the migration directions of drainage divides reveals how the boundaries between neighboring river basins are shifting through time. Using the southern Appalachian Mountains as an example, I demonstrate a surprising result: In contrast to the notion of static drainage patterns in a landscape with declining relief, there is abundant evidence of river network reorganization. I also discuss the possibility that river network reorganization is partly responsible for the pronounced diversity of freshwater species in the region.